netdata_patch_1_4_6: Add patch to run on Debian 10

Bump to latest uraimo/run-on-arch-action@v2.8.1 version, hoping that
fixes the CI.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,3 +0,0 @@
-Thank you for considering a contribution!
-
-Please note that the `libbpf` authoritative source code is developed as part of bpf-next Linux source tree under tools/lib/bpf subdirectory and is periodically synced to Github. As such, all the libbpf changes should be sent to BPF mailing list, please don't open PRs here unless you are changing Github-specific parts of libbpf (e.g., Github-specific Makefile).

.github/actions/build-selftests/action.yml

@@ -12,6 +12,9 @@ inputs:
     description: 'where is vmlinux file'
     required: true
     default: '${{ github.workspace }}/vmlinux'
+  llvm-version:
+    description: 'llvm version'
+    required: true
 
 runs:
   using: "composite"
@@ -28,4 +31,6 @@ runs:
         export REPO_ROOT="${{ github.workspace }}"
         export REPO_PATH="${{ inputs.repo-path }}"
         export VMLINUX_BTF="${{ inputs.vmlinux }}"
+        export LLVM_VERSION="${{ inputs.llvm-version }}"
+
         ${{ github.action_path }}/build_selftests.sh

.github/actions/build-selftests/build_selftests.sh

@@ -10,22 +10,21 @@ foldable start prepare_selftests "Building selftests"
 
 LIBBPF_PATH="${REPO_ROOT}"
 
-llvm_default_version() {
-	echo "16"
-}
-
 llvm_latest_version() {
-	echo "17"
+	echo "19"
 }
 
-LLVM_VERSION=$(llvm_default_version)
 if [[ "${LLVM_VERSION}" == $(llvm_latest_version) ]]; then
 	REPO_DISTRO_SUFFIX=""
 else
 	REPO_DISTRO_SUFFIX="-${LLVM_VERSION}"
 fi
 
-echo "deb https://apt.llvm.org/focal/ llvm-toolchain-focal${REPO_DISTRO_SUFFIX} main" \
+DISTRIB_CODENAME="noble"
+test -f /etc/lsb-release && . /etc/lsb-release
+echo "${DISTRIB_CODENAME}"
+
+echo "deb https://apt.llvm.org/${DISTRIB_CODENAME}/ llvm-toolchain-${DISTRIB_CODENAME}${REPO_DISTRO_SUFFIX} main" \
 	| sudo tee /etc/apt/sources.list.d/llvm.list
 
 PREPARE_SELFTESTS_SCRIPT=${THISDIR}/prepare_selftests-${KERNEL}.sh

.github/actions/vmtest/action.yml

@@ -13,6 +13,10 @@ inputs:
     description: 'pahole rev or master'
     required: true
     default: 'master'
+  llvm-version:
+    description: 'llvm version'
+    required: false
+    default: '17'
 runs:
   using: "composite"
   steps:
@@ -38,6 +42,7 @@ runs:
       with:
         pahole: ${{ inputs.pahole }}
         arch: ${{ inputs.arch }}
+        llvm-version: ${{ inputs.llvm-version }}
     # 1. download CHECKPOINT kernel source
     - name: Get checkpoint commit
       shell: bash
@@ -93,6 +98,7 @@ runs:
       with:
         repo-path: '.kernel'
         kernel: ${{ inputs.kernel }}
+        llvm-version: ${{ inputs.llvm-version }}
     # 4. prepare rootfs
     - name: prepare rootfs
       uses: libbpf/ci/prepare-rootfs@main

.github/workflows/build.yml

@@ -53,7 +53,7 @@ jobs:
 
   ubuntu:
     runs-on: ubuntu-latest
-    name: Ubuntu Focal Build (${{ matrix.arch }})
+    name: Ubuntu Build (${{ matrix.arch }})
     strategy:
       fail-fast: false
       matrix:
@@ -70,12 +70,12 @@ jobs:
       - run: source /tmp/ci_setup && sudo -E $CI_ROOT/managers/ubuntu.sh
         if: matrix.arch == 'x86'
         name: Setup
-      - uses: uraimo/run-on-arch-action@v2.7.1
+      - uses: uraimo/run-on-arch-action@v2.8.1
         name: Build in docker
         if: matrix.arch != 'x86'
         with:
           distro:
-            ubuntu20.04
+            ubuntu22.04
           arch:
             ${{ matrix.arch }}
           setup:

.github/workflows/cifuzz.yml

@@ -33,7 +33,7 @@ jobs:
           dry-run: false
           sanitizer: ${{ matrix.sanitizer }}
       - name: Upload Crash
-        uses: actions/upload-artifact@v1
+        uses: actions/upload-artifact@v4
         if: failure() && steps.build.outcome == 'success'
         with:
           name: ${{ matrix.sanitizer }}-artifacts

.github/workflows/codeql.yml

@@ -17,7 +17,7 @@ permissions:
 jobs:
   analyze:
     name: Analyze
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     concurrency:
       group: ${{ github.workflow }}-${{ matrix.language }}-${{ github.ref }}
       cancel-in-progress: true

.github/workflows/pahole.yml

@@ -1,10 +1,10 @@
 name: pahole-staging
 
 on:
+  workflow_dispatch:
   schedule:
     - cron:  '0 18 * * *'
 
-
 jobs:
   vmtest:
     runs-on: ubuntu-20.04

.github/workflows/test.yml

@@ -13,23 +13,20 @@ concurrency:
 jobs:
   vmtest:
     runs-on: ${{ matrix.runs_on }}
-    name: Kernel ${{ matrix.kernel }} on ${{ matrix.runs_on }} + selftests
+    name: Kernel ${{ matrix.kernel }} on ${{ matrix.arch }} + selftests
     strategy:
       fail-fast: false
       matrix:
         include:
           - kernel: 'LATEST'
-            runs_on: ubuntu-20.04
+            runs_on: ubuntu-24.04
             arch: 'x86_64'
           - kernel: '5.5.0'
-            runs_on: ubuntu-20.04
+            runs_on: ubuntu-24.04
             arch: 'x86_64'
           - kernel: '4.9.0'
-            runs_on: ubuntu-20.04
+            runs_on: ubuntu-24.04
             arch: 'x86_64'
-          - kernel: 'LATEST'
-            runs_on: s390x
-            arch: 's390x'
     steps:
       - uses: actions/checkout@v4
         name: Checkout

.mailmap

@@ -8,10 +8,14 @@ Dan Carpenter <error27@gmail.com> <dan.carpenter@oracle.com>
 Geliang Tang <geliang@kernel.org> <geliang.tang@suse.com>
 Herbert Xu <herbert@gondor.apana.org.au>
 Jakub Kicinski <kuba@kernel.org> <jakub.kicinski@netronome.com>
+Kees Cook <kees@kernel.org> <keescook@chromium.org>
 Leo Yan <leo.yan@linux.dev> <leo.yan@linaro.org>
 Mark Starovoytov <mstarovo@pm.me> <mstarovoitov@marvell.com>
 Maxim Mikityanskiy <maxtram95@gmail.com> <maximmi@mellanox.com>
 Maxim Mikityanskiy <maxtram95@gmail.com> <maximmi@nvidia.com>
+Puranjay Mohan <puranjay@kernel.org> <puranjay12@gmail.com>
 Quentin Monnet <qmo@kernel.org> <quentin@isovalent.com>
 Quentin Monnet <qmo@kernel.org> <quentin.monnet@netronome.com>
+Stanislav Fomichev <sdf@fomichev.me> <sdf@google.com>
+Vadim Fedorenko <vadim.fedorenko@linux.dev> <vadfed@meta.com>
 Vadim Fedorenko <vadim.fedorenko@linux.dev> <vfedorenko@novek.ru>

BPF-CHECKPOINT-COMMIT

@@ -1 +1 @@
-3e9bc0472b910d4115e16e9c2d684c7757cb6c60
+d5fb316e2af1d947f0f6c3666e373a54d9f27c6f

CHECKPOINT-COMMIT

@@ -1 +1 @@
-009367099eb61a4fc2af44d4eb06b6b4de7de6db
+c6fb8030b4baa01c850f99fc6da051b1017edc46

ci/diffs/0001-selftests-bpf-fix-inet_csk_accept-prototype-in-test_.patch

@@ -0,0 +1,32 @@
+From 0daad0a615e687e1247230f3d0c31ae60ba32314 Mon Sep 17 00:00:00 2001
+From: Andrii Nakryiko <andrii@kernel.org>
+Date: Tue, 28 May 2024 15:29:38 -0700
+Subject: [PATCH bpf-next] selftests/bpf: fix inet_csk_accept prototype in
+ test_sk_storage_tracing.c
+
+Recent kernel change ([0]) changed inet_csk_accept() prototype. Adapt
+progs/test_sk_storage_tracing.c to take that into account.
+
+  [0] 92ef0fd55ac8 ("net: change proto and proto_ops accept type")
+
+Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
+---
+ tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c b/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c
+index 02e718f06e0f..40531e56776e 100644
+--- a/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c
++++ b/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c
+@@ -84,7 +84,7 @@ int BPF_PROG(trace_tcp_connect, struct sock *sk)
+ }
+ 
+ SEC("fexit/inet_csk_accept")
+-int BPF_PROG(inet_csk_accept, struct sock *sk, int flags, int *err, bool kern,
++int BPF_PROG(inet_csk_accept, struct sock *sk, struct proto_accept_arg *arg,
+ 	     struct sock *accepted_sk)
+ {
+ 	set_task_info(accepted_sk);
+-- 
+2.43.0
+

ci/diffs/0003-selftests-bpf-Fix-uprobe-consumer-test.patch

@@ -0,0 +1,58 @@
+From affb32e4f056883f285f8535b766293b85752fb4 Mon Sep 17 00:00:00 2001
+From: Jiri Olsa <jolsa@kernel.org>
+Date: Tue, 24 Sep 2024 13:07:30 +0200
+Subject: [PATCH] selftests/bpf: Fix uprobe consumer test
+
+With newly merged code the uprobe behaviour is slightly different
+and affects uprobe consumer test.
+
+We no longer need to check if the uprobe object is still preserved
+after removing last uretprobe, because it stays as long as there's
+pending/installed uretprobe instance.
+
+This allows to run uretprobe consumers registered 'after' uprobe was
+hit even if previous uretprobe got unregistered before being hit.
+
+The uprobe object will be now removed after the last uprobe ref is
+released and in such case it's held by ri->uprobe (return instance)
+which is released after the uretprobe is hit.
+
+Reported-by: Ihor Solodrai <ihor.solodrai@pm.me>
+Signed-off-by: Jiri Olsa <jolsa@kernel.org>
+Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
+Tested-by: Ihor Solodrai <ihor.solodrai@pm.me>
+Closes: https://lore.kernel.org/bpf/w6U8Z9fdhjnkSp2UaFaV1fGqJXvfLEtDKEUyGDkwmoruDJ_AgF_c0FFhrkeKW18OqiP-05s9yDKiT6X-Ns-avN_ABf0dcUkXqbSJN1TQSXo=@pm.me/
+---
+ .../testing/selftests/bpf/prog_tests/uprobe_multi_test.c | 9 +--------
+ 1 file changed, 1 insertion(+), 8 deletions(-)
+
+diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+index 844f6fc8487b..c1ac813ff9ba 100644
+--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
++++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+@@ -869,21 +869,14 @@ static void consumer_test(struct uprobe_multi_consumers *skel,
+ 			fmt = "prog 0/1: uprobe";
+ 		} else {
+ 			/*
+-			 * uprobe return is tricky ;-)
+-			 *
+ 			 * to trigger uretprobe consumer, the uretprobe needs to be installed,
+ 			 * which means one of the 'return' uprobes was alive when probe was hit:
+ 			 *
+ 			 *   idxs: 2/3 uprobe return in 'installed' mask
+-			 *
+-			 * in addition if 'after' state removes everything that was installed in
+-			 * 'before' state, then uprobe kernel object goes away and return uprobe
+-			 * is not installed and we won't hit it even if it's in 'after' state.
+ 			 */
+ 			unsigned long had_uretprobes  = before & 0b1100; /* is uretprobe installed */
+-			unsigned long probe_preserved = before & after;  /* did uprobe go away */
+ 
+-			if (had_uretprobes && probe_preserved && test_bit(idx, after))
++			if (had_uretprobes && test_bit(idx, after))
+ 				val++;
+ 			fmt = "idx 2/3: uretprobe";
+ 		}
+-- 
+2.34.1
+

ci/vmtest/configs/DENYLIST

@@ -12,3 +12,4 @@ xdp_bonding/xdp_bonding_features     # started failing after net merge from 359e
 tc_redirect/tc_redirect_dtime # uapi breakage after net-next commit 885c36e59f46 ("net: Re-use and set mono_delivery_time bit for userspace tstamp packets")
 migrate_reuseport/IPv4 TCP_NEW_SYN_RECV reqsk_timer_handler # flaky, under investigation
 migrate_reuseport/IPv6 TCP_NEW_SYN_RECV reqsk_timer_handler # flaky, under investigation
+verify_pkcs7_sig # keeps failing

ci/vmtest/run_selftests.sh

@@ -67,12 +67,14 @@ local_configs_path=${PROJECT_NAME}/vmtest/configs
 DENYLIST=$(read_lists \
 	"$configs_path/DENYLIST" \
 	"$configs_path/DENYLIST.${ARCH}" \
+	"$local_configs_path/DENYLIST" \
 	"$local_configs_path/DENYLIST-${KERNEL}" \
 	"$local_configs_path/DENYLIST-${KERNEL}.${ARCH}" \
 )
 ALLOWLIST=$(read_lists \
 	"$configs_path/ALLOWLIST" \
 	"$configs_path/ALLOWLIST.${ARCH}" \
+	"$local_configs_path/ALLOWLIST" \
 	"$local_configs_path/ALLOWLIST-${KERNEL}" \
 	"$local_configs_path/ALLOWLIST-${KERNEL}.${ARCH}" \
 )

docs/libbpf_overview.rst

@@ -219,6 +219,14 @@ compilation and skeleton generation. Using Libbpf-rs will make building user
 space part of the BPF application easier. Note that the BPF program themselves
 must still be written in plain C.
 
+libbpf logging
+==============
+
+By default, libbpf logs informational and warning messages to stderr. The
+verbosity of these messages can be controlled by setting the environment
+variable LIBBPF_LOG_LEVEL to either warn, info, or debug. A custom log
+callback can be set using ``libbpf_set_print()``.
+
 Additional Documentation
 ========================
 

docs/program_types.rst

@@ -121,6 +121,8 @@ described in more detail in the footnotes.
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_LWT_XMIT``                |                                        | ``lwt_xmit``                     |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
+| ``BPF_PROG_TYPE_NETFILTER``               |                                        | ``netfilter``                    |           |
++-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_PERF_EVENT``              |                                        | ``perf_event``                   |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE`` |                                        | ``raw_tp.w+`` [#rawtp]_          |           |
@@ -131,11 +133,23 @@ described in more detail in the footnotes.
 +                                           +                                        +----------------------------------+-----------+
 |                                           |                                        | ``raw_tracepoint+``              |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
-| ``BPF_PROG_TYPE_SCHED_ACT``               |                                        | ``action``                       |           |
+| ``BPF_PROG_TYPE_SCHED_ACT``               |                                        | ``action`` [#tc_legacy]_         |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
-| ``BPF_PROG_TYPE_SCHED_CLS``               |                                        | ``classifier``                   |           |
+| ``BPF_PROG_TYPE_SCHED_CLS``               |                                        | ``classifier`` [#tc_legacy]_     |           |
 +                                           +                                        +----------------------------------+-----------+
-|                                           |                                        | ``tc``                           |           |
+|                                           |                                        | ``tc`` [#tc_legacy]_             |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_NETKIT_PRIMARY``                 | ``netkit/primary``               |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_NETKIT_PEER``                    | ``netkit/peer``                  |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_INGRESS``                    | ``tc/ingress``                   |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_EGRESS``                     | ``tc/egress``                    |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_INGRESS``                    | ``tcx/ingress``                  |           |
++                                           +----------------------------------------+----------------------------------+-----------+
+|                                           | ``BPF_TCX_EGRESS``                     | ``tcx/egress``                   |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_SK_LOOKUP``               | ``BPF_SK_LOOKUP``                      | ``sk_lookup``                    |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
@@ -155,7 +169,9 @@ described in more detail in the footnotes.
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_SOCK_OPS``                | ``BPF_CGROUP_SOCK_OPS``                | ``sockops``                      |           |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
-| ``BPF_PROG_TYPE_STRUCT_OPS``              |                                        | ``struct_ops+``                  |           |
+| ``BPF_PROG_TYPE_STRUCT_OPS``              |                                        | ``struct_ops+`` [#struct_ops]_   |           |
++                                           +                                        +----------------------------------+-----------+
+|                                           |                                        | ``struct_ops.s+`` [#struct_ops]_ | Yes       |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
 | ``BPF_PROG_TYPE_SYSCALL``                 |                                        | ``syscall``                      | Yes       |
 +-------------------------------------------+----------------------------------------+----------------------------------+-----------+
@@ -209,5 +225,11 @@ described in more detail in the footnotes.
               ``a-zA-Z0-9_.*?``.
 .. [#lsm] The ``lsm`` attachment format is ``lsm[.s]/<hook>``.
 .. [#rawtp] The ``raw_tp`` attach format is ``raw_tracepoint[.w]/<tracepoint>``.
+.. [#tc_legacy] The ``tc``, ``classifier`` and ``action`` attach types are deprecated, use
+                ``tcx/*`` instead.
+.. [#struct_ops] The ``struct_ops`` attach format supports ``struct_ops[.s]/<name>`` convention,
+                 but ``name`` is ignored and it is recommended to just use plain
+                 ``SEC("struct_ops[.s]")``. The attachments are defined in a struct initializer
+                 that is tagged with ``SEC(".struct_ops[.link]")``.
 .. [#tp] The ``tracepoint`` attach format is ``tracepoint/<category>/<name>``.
 .. [#iter] The ``iter`` attach format is ``iter[.s]/<struct-name>``.

include/uapi/linux/bpf.h

@@ -1121,6 +1121,9 @@ enum bpf_attach_type {
 
 #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
 
+/* Add BPF_LINK_TYPE(type, name) in bpf_types.h to keep bpf_link_type_strs[]
+ * in sync with the definitions below.
+ */
 enum bpf_link_type {
 	BPF_LINK_TYPE_UNSPEC = 0,
 	BPF_LINK_TYPE_RAW_TRACEPOINT = 1,
@@ -1425,6 +1428,8 @@ enum {
 #define BPF_F_TEST_RUN_ON_CPU	(1U << 0)
 /* If set, XDP frames will be transmitted after processing */
 #define BPF_F_TEST_XDP_LIVE_FRAMES	(1U << 1)
+/* If set, apply CHECKSUM_COMPLETE to skb and validate the checksum */
+#define BPF_F_TEST_SKB_CHECKSUM_COMPLETE	(1U << 2)
 
 /* type for BPF_ENABLE_STATS */
 enum bpf_stats_type {
@@ -1968,6 +1973,8 @@ union bpf_attr {
  * 		program.
  * 	Return
  * 		The SMP id of the processor running the program.
+ * 	Attributes
+ * 		__bpf_fastcall
  *
  * long bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
  * 	Description
@@ -2849,7 +2856,7 @@ union bpf_attr {
  * 		  **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**,
  * 		  **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**,
  * 		  **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**,
- * 		  **TCP_BPF_RTO_MIN**.
+ *		  **TCP_BPF_RTO_MIN**, **TCP_BPF_SOCK_OPS_CB_FLAGS**.
  * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
  * 		* **IPPROTO_IPV6**, which supports the following *optname*\ s:
  * 		  **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**.
@@ -3099,10 +3106,6 @@ union bpf_attr {
  * 		with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
  * 		option, and in this case it only works on functions tagged with
  * 		**ALLOW_ERROR_INJECTION** in the kernel code.
- *
- * 		Also, the helper is only available for the architectures having
- * 		the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
- * 		x86 architecture is the only one to support this feature.
  * 	Return
  * 		0
  *
@@ -5367,7 +5370,7 @@ union bpf_attr {
  *		Currently, the **flags** must be 0. Currently, nr_loops is
  *		limited to 1 << 23 (~8 million) loops.
  *
- *		long (\*callback_fn)(u32 index, void \*ctx);
+ *		long (\*callback_fn)(u64 index, void \*ctx);
  *
  *		where **index** is the current index in the loop. The index
  *		is zero-indexed.
@@ -5517,11 +5520,12 @@ union bpf_attr {
  *		**-EOPNOTSUPP** if the hash calculation failed or **-EINVAL** if
  *		invalid arguments are passed.
  *
- * void *bpf_kptr_xchg(void *map_value, void *ptr)
+ * void *bpf_kptr_xchg(void *dst, void *ptr)
  *	Description
- *		Exchange kptr at pointer *map_value* with *ptr*, and return the
- *		old value. *ptr* can be NULL, otherwise it must be a referenced
- *		pointer which will be released when this helper is called.
+ *		Exchange kptr at pointer *dst* with *ptr*, and return the old value.
+ *		*dst* can be map value or local kptr. *ptr* can be NULL, otherwise
+ *		it must be a referenced pointer which will be released when this helper
+ *		is called.
  *	Return
  *		The old value of kptr (which can be NULL). The returned pointer
  *		if not NULL, is a reference which must be released using its
@@ -6044,11 +6048,6 @@ enum {
 	BPF_F_MARK_ENFORCE		= (1ULL << 6),
 };
 
-/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
-enum {
-	BPF_F_INGRESS			= (1ULL << 0),
-};
-
 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
 enum {
 	BPF_F_TUNINFO_IPV6		= (1ULL << 0),
@@ -6195,10 +6194,12 @@ enum {
 	BPF_F_BPRM_SECUREEXEC	= (1ULL << 0),
 };
 
-/* Flags for bpf_redirect_map helper */
+/* Flags for bpf_redirect and bpf_redirect_map helpers */
 enum {
-	BPF_F_BROADCAST		= (1ULL << 3),
-	BPF_F_EXCLUDE_INGRESS	= (1ULL << 4),
+	BPF_F_INGRESS		= (1ULL << 0), /* used for skb path */
+	BPF_F_BROADCAST		= (1ULL << 3), /* used for XDP path */
+	BPF_F_EXCLUDE_INGRESS	= (1ULL << 4), /* used for XDP path */
+#define BPF_F_REDIRECT_FLAGS (BPF_F_INGRESS | BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS)
 };
 
 #define __bpf_md_ptr(type, name)	\
@@ -6207,12 +6208,17 @@ union {					\
 	__u64 :64;			\
 } __attribute__((aligned(8)))
 
+/* The enum used in skb->tstamp_type. It specifies the clock type
+ * of the time stored in the skb->tstamp.
+ */
 enum {
-	BPF_SKB_TSTAMP_UNSPEC,
-	BPF_SKB_TSTAMP_DELIVERY_MONO,	/* tstamp has mono delivery time */
-	/* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle,
-	 * the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC
-	 * and try to deduce it by ingress, egress or skb->sk->sk_clockid.
+	BPF_SKB_TSTAMP_UNSPEC = 0,		/* DEPRECATED */
+	BPF_SKB_TSTAMP_DELIVERY_MONO = 1,	/* DEPRECATED */
+	BPF_SKB_CLOCK_REALTIME = 0,
+	BPF_SKB_CLOCK_MONOTONIC = 1,
+	BPF_SKB_CLOCK_TAI = 2,
+	/* For any future BPF_SKB_CLOCK_* that the bpf prog cannot handle,
+	 * the bpf prog can try to deduce it by ingress/egress/skb->sk->sk_clockid.
 	 */
 };
 
@@ -7073,6 +7079,7 @@ enum {
 	TCP_BPF_SYN		= 1005, /* Copy the TCP header */
 	TCP_BPF_SYN_IP		= 1006, /* Copy the IP[46] and TCP header */
 	TCP_BPF_SYN_MAC         = 1007, /* Copy the MAC, IP[46], and TCP header */
+	TCP_BPF_SOCK_OPS_CB_FLAGS = 1008, /* Get or Set TCP sock ops flags */
 };
 
 enum {
@@ -7505,4 +7512,13 @@ struct bpf_iter_num {
 	__u64 __opaque[1];
 } __attribute__((aligned(8)));
 
+/*
+ * Flags to control BPF kfunc behaviour.
+ *     - BPF_F_PAD_ZEROS: Pad destination buffer with zeros. (See the respective
+ *       helper documentation for details.)
+ */
+enum bpf_kfunc_flags {
+	BPF_F_PAD_ZEROS = (1ULL << 0),
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */

include/uapi/linux/fcntl.h

@@ -1,123 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _UAPI_LINUX_FCNTL_H
-#define _UAPI_LINUX_FCNTL_H
-
-#include <asm/fcntl.h>
-#include <linux/openat2.h>
-
-#define F_SETLEASE	(F_LINUX_SPECIFIC_BASE + 0)
-#define F_GETLEASE	(F_LINUX_SPECIFIC_BASE + 1)
-
-/*
- * Cancel a blocking posix lock; internal use only until we expose an
- * asynchronous lock api to userspace:
- */
-#define F_CANCELLK	(F_LINUX_SPECIFIC_BASE + 5)
-
-/* Create a file descriptor with FD_CLOEXEC set. */
-#define F_DUPFD_CLOEXEC	(F_LINUX_SPECIFIC_BASE + 6)
-
-/*
- * Request nofications on a directory.
- * See below for events that may be notified.
- */
-#define F_NOTIFY	(F_LINUX_SPECIFIC_BASE+2)
-
-/*
- * Set and get of pipe page size array
- */
-#define F_SETPIPE_SZ	(F_LINUX_SPECIFIC_BASE + 7)
-#define F_GETPIPE_SZ	(F_LINUX_SPECIFIC_BASE + 8)
-
-/*
- * Set/Get seals
- */
-#define F_ADD_SEALS	(F_LINUX_SPECIFIC_BASE + 9)
-#define F_GET_SEALS	(F_LINUX_SPECIFIC_BASE + 10)
-
-/*
- * Types of seals
- */
-#define F_SEAL_SEAL	0x0001	/* prevent further seals from being set */
-#define F_SEAL_SHRINK	0x0002	/* prevent file from shrinking */
-#define F_SEAL_GROW	0x0004	/* prevent file from growing */
-#define F_SEAL_WRITE	0x0008	/* prevent writes */
-#define F_SEAL_FUTURE_WRITE	0x0010  /* prevent future writes while mapped */
-#define F_SEAL_EXEC	0x0020  /* prevent chmod modifying exec bits */
-/* (1U << 31) is reserved for signed error codes */
-
-/*
- * Set/Get write life time hints. {GET,SET}_RW_HINT operate on the
- * underlying inode, while {GET,SET}_FILE_RW_HINT operate only on
- * the specific file.
- */
-#define F_GET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 11)
-#define F_SET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 12)
-#define F_GET_FILE_RW_HINT	(F_LINUX_SPECIFIC_BASE + 13)
-#define F_SET_FILE_RW_HINT	(F_LINUX_SPECIFIC_BASE + 14)
-
-/*
- * Valid hint values for F_{GET,SET}_RW_HINT. 0 is "not set", or can be
- * used to clear any hints previously set.
- */
-#define RWH_WRITE_LIFE_NOT_SET	0
-#define RWH_WRITE_LIFE_NONE	1
-#define RWH_WRITE_LIFE_SHORT	2
-#define RWH_WRITE_LIFE_MEDIUM	3
-#define RWH_WRITE_LIFE_LONG	4
-#define RWH_WRITE_LIFE_EXTREME	5
-
-/*
- * The originally introduced spelling is remained from the first
- * versions of the patch set that introduced the feature, see commit
- * v4.13-rc1~212^2~51.
- */
-#define RWF_WRITE_LIFE_NOT_SET	RWH_WRITE_LIFE_NOT_SET
-
-/*
- * Types of directory notifications that may be requested.
- */
-#define DN_ACCESS	0x00000001	/* File accessed */
-#define DN_MODIFY	0x00000002	/* File modified */
-#define DN_CREATE	0x00000004	/* File created */
-#define DN_DELETE	0x00000008	/* File removed */
-#define DN_RENAME	0x00000010	/* File renamed */
-#define DN_ATTRIB	0x00000020	/* File changed attibutes */
-#define DN_MULTISHOT	0x80000000	/* Don't remove notifier */
-
-/*
- * The constants AT_REMOVEDIR and AT_EACCESS have the same value.  AT_EACCESS is
- * meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
- * unlinkat.  The two functions do completely different things and therefore,
- * the flags can be allowed to overlap.  For example, passing AT_REMOVEDIR to
- * faccessat would be undefined behavior and thus treating it equivalent to
- * AT_EACCESS is valid undefined behavior.
- */
-#define AT_FDCWD		-100    /* Special value used to indicate
-                                           openat should use the current
-                                           working directory. */
-#define AT_SYMLINK_NOFOLLOW	0x100   /* Do not follow symbolic links.  */
-#define AT_EACCESS		0x200	/* Test access permitted for
-                                           effective IDs, not real IDs.  */
-#define AT_REMOVEDIR		0x200   /* Remove directory instead of
-                                           unlinking file.  */
-#define AT_SYMLINK_FOLLOW	0x400   /* Follow symbolic links.  */
-#define AT_NO_AUTOMOUNT		0x800	/* Suppress terminal automount traversal */
-#define AT_EMPTY_PATH		0x1000	/* Allow empty relative pathname */
-
-#define AT_STATX_SYNC_TYPE	0x6000	/* Type of synchronisation required from statx() */
-#define AT_STATX_SYNC_AS_STAT	0x0000	/* - Do whatever stat() does */
-#define AT_STATX_FORCE_SYNC	0x2000	/* - Force the attributes to be sync'd with the server */
-#define AT_STATX_DONT_SYNC	0x4000	/* - Don't sync attributes with the server */
-
-#define AT_RECURSIVE		0x8000	/* Apply to the entire subtree */
-
-/* Flags for name_to_handle_at(2). We reuse AT_ flag space to save bits... */
-#define AT_HANDLE_FID		AT_REMOVEDIR	/* file handle is needed to
-					compare object identity and may not
-					be usable to open_by_handle_at(2) */
-#if defined(__KERNEL__)
-#define AT_GETATTR_NOSEC	0x80000000
-#endif
-
-#endif /* _UAPI_LINUX_FCNTL_H */

include/uapi/linux/if_xdp.h

@@ -41,6 +41,10 @@
  */
 #define XDP_UMEM_TX_SW_CSUM		(1 << 1)
 
+/* Request to reserve tx_metadata_len bytes of per-chunk metadata.
+ */
+#define XDP_UMEM_TX_METADATA_LEN	(1 << 2)
+
 struct sockaddr_xdp {
 	__u16 sxdp_family;
 	__u16 sxdp_flags;

include/uapi/linux/netdev.h

@@ -93,6 +93,7 @@ enum {
 	NETDEV_A_PAGE_POOL_INFLIGHT,
 	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
 	NETDEV_A_PAGE_POOL_DETACH_TIME,
+	NETDEV_A_PAGE_POOL_DMABUF,
 
 	__NETDEV_A_PAGE_POOL_MAX,
 	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
@@ -131,6 +132,7 @@ enum {
 	NETDEV_A_QUEUE_IFINDEX,
 	NETDEV_A_QUEUE_TYPE,
 	NETDEV_A_QUEUE_NAPI_ID,
+	NETDEV_A_QUEUE_DMABUF,
 
 	__NETDEV_A_QUEUE_MAX,
 	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
@@ -146,11 +148,43 @@ enum {
 	NETDEV_A_QSTATS_TX_PACKETS,
 	NETDEV_A_QSTATS_TX_BYTES,
 	NETDEV_A_QSTATS_RX_ALLOC_FAIL,
+	NETDEV_A_QSTATS_RX_HW_DROPS,
+	NETDEV_A_QSTATS_RX_HW_DROP_OVERRUNS,
+	NETDEV_A_QSTATS_RX_CSUM_COMPLETE,
+	NETDEV_A_QSTATS_RX_CSUM_UNNECESSARY,
+	NETDEV_A_QSTATS_RX_CSUM_NONE,
+	NETDEV_A_QSTATS_RX_CSUM_BAD,
+	NETDEV_A_QSTATS_RX_HW_GRO_PACKETS,
+	NETDEV_A_QSTATS_RX_HW_GRO_BYTES,
+	NETDEV_A_QSTATS_RX_HW_GRO_WIRE_PACKETS,
+	NETDEV_A_QSTATS_RX_HW_GRO_WIRE_BYTES,
+	NETDEV_A_QSTATS_RX_HW_DROP_RATELIMITS,
+	NETDEV_A_QSTATS_TX_HW_DROPS,
+	NETDEV_A_QSTATS_TX_HW_DROP_ERRORS,
+	NETDEV_A_QSTATS_TX_CSUM_NONE,
+	NETDEV_A_QSTATS_TX_NEEDS_CSUM,
+	NETDEV_A_QSTATS_TX_HW_GSO_PACKETS,
+	NETDEV_A_QSTATS_TX_HW_GSO_BYTES,
+	NETDEV_A_QSTATS_TX_HW_GSO_WIRE_PACKETS,
+	NETDEV_A_QSTATS_TX_HW_GSO_WIRE_BYTES,
+	NETDEV_A_QSTATS_TX_HW_DROP_RATELIMITS,
+	NETDEV_A_QSTATS_TX_STOP,
+	NETDEV_A_QSTATS_TX_WAKE,
 
 	__NETDEV_A_QSTATS_MAX,
 	NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)
 };
 
+enum {
+	NETDEV_A_DMABUF_IFINDEX = 1,
+	NETDEV_A_DMABUF_QUEUES,
+	NETDEV_A_DMABUF_FD,
+	NETDEV_A_DMABUF_ID,
+
+	__NETDEV_A_DMABUF_MAX,
+	NETDEV_A_DMABUF_MAX = (__NETDEV_A_DMABUF_MAX - 1)
+};
+
 enum {
 	NETDEV_CMD_DEV_GET = 1,
 	NETDEV_CMD_DEV_ADD_NTF,
@@ -164,6 +198,7 @@ enum {
 	NETDEV_CMD_QUEUE_GET,
 	NETDEV_CMD_NAPI_GET,
 	NETDEV_CMD_QSTATS_GET,
+	NETDEV_CMD_BIND_RX,
 
 	__NETDEV_CMD_MAX,
 	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)

include/uapi/linux/openat2.h

@@ -1,43 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _UAPI_LINUX_OPENAT2_H
-#define _UAPI_LINUX_OPENAT2_H
-
-#include <linux/types.h>
-
-/*
- * Arguments for how openat2(2) should open the target path. If only @flags and
- * @mode are non-zero, then openat2(2) operates very similarly to openat(2).
- *
- * However, unlike openat(2), unknown or invalid bits in @flags result in
- * -EINVAL rather than being silently ignored. @mode must be zero unless one of
- * {O_CREAT, O_TMPFILE} are set.
- *
- * @flags: O_* flags.
- * @mode: O_CREAT/O_TMPFILE file mode.
- * @resolve: RESOLVE_* flags.
- */
-struct open_how {
-	__u64 flags;
-	__u64 mode;
-	__u64 resolve;
-};
-
-/* how->resolve flags for openat2(2). */
-#define RESOLVE_NO_XDEV		0x01 /* Block mount-point crossings
-					(includes bind-mounts). */
-#define RESOLVE_NO_MAGICLINKS	0x02 /* Block traversal through procfs-style
-					"magic-links". */
-#define RESOLVE_NO_SYMLINKS	0x04 /* Block traversal through all symlinks
-					(implies OEXT_NO_MAGICLINKS) */
-#define RESOLVE_BENEATH		0x08 /* Block "lexical" trickery like
-					"..", symlinks, and absolute
-					paths which escape the dirfd. */
-#define RESOLVE_IN_ROOT		0x10 /* Make all jumps to "/" and ".."
-					be scoped inside the dirfd
-					(similar to chroot(2)). */
-#define RESOLVE_CACHED		0x20 /* Only complete if resolution can be
-					completed through cached lookup. May
-					return -EAGAIN if that's not
-					possible. */
-
-#endif /* _UAPI_LINUX_OPENAT2_H */

include/uapi/linux/perf_event.h

@@ -1349,12 +1349,14 @@ union perf_mem_data_src {
 #define PERF_MEM_LVLNUM_L2	0x02 /* L2 */
 #define PERF_MEM_LVLNUM_L3	0x03 /* L3 */
 #define PERF_MEM_LVLNUM_L4	0x04 /* L4 */
-/* 5-0x7 available */
+#define PERF_MEM_LVLNUM_L2_MHB	0x05 /* L2 Miss Handling Buffer */
+#define PERF_MEM_LVLNUM_MSC	0x06 /* Memory-side Cache */
+/* 0x7 available */
 #define PERF_MEM_LVLNUM_UNC	0x08 /* Uncached */
 #define PERF_MEM_LVLNUM_CXL	0x09 /* CXL */
 #define PERF_MEM_LVLNUM_IO	0x0a /* I/O */
 #define PERF_MEM_LVLNUM_ANY_CACHE 0x0b /* Any cache */
-#define PERF_MEM_LVLNUM_LFB	0x0c /* LFB */
+#define PERF_MEM_LVLNUM_LFB	0x0c /* LFB / L1 Miss Handling Buffer */
 #define PERF_MEM_LVLNUM_RAM	0x0d /* RAM */
 #define PERF_MEM_LVLNUM_PMEM	0x0e /* PMEM */
 #define PERF_MEM_LVLNUM_NA	0x0f /* N/A */

src/Makefile

@@ -55,7 +55,7 @@ STATIC_OBJDIR := $(OBJDIR)/staticobjs
 OBJS := bpf.o btf.o libbpf.o libbpf_errno.o netlink.o \
 	nlattr.o str_error.o libbpf_probes.o bpf_prog_linfo.o \
 	btf_dump.o hashmap.o ringbuf.o strset.o linker.o gen_loader.o \
-	relo_core.o usdt.o zip.o elf.o features.o
+	relo_core.o usdt.o zip.o elf.o features.o btf_iter.o btf_relocate.o
 SHARED_OBJS := $(addprefix $(SHARED_OBJDIR)/,$(OBJS))
 STATIC_OBJS := $(addprefix $(STATIC_OBJDIR)/,$(OBJS))
 
@@ -119,13 +119,13 @@ $(OBJDIR)/libbpf.so.$(LIBBPF_VERSION): $(SHARED_OBJS)
 		  -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \
 		  $^ $(ALL_LDFLAGS) -o $@
 
-$(OBJDIR)/libbpf.pc: force
+$(OBJDIR)/libbpf.pc: force | $(OBJDIR)
 	$(Q)sed -e "s|@PREFIX@|$(PREFIX)|" \
 		-e "s|@LIBDIR@|$(LIBDIR_PC)|" \
 		-e "s|@VERSION@|$(LIBBPF_VERSION)|" \
 		< libbpf.pc.template > $@
 
-$(STATIC_OBJDIR) $(SHARED_OBJDIR):
+$(OBJDIR) $(STATIC_OBJDIR) $(SHARED_OBJDIR):
 	$(call msg,MKDIR,$@)
 	$(Q)mkdir -p $@
 

src/bpf.c

@@ -105,7 +105,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
  */
 int probe_memcg_account(int token_fd)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd);
+	const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
 	struct bpf_insn insns[] = {
 		BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
 		BPF_EXIT_INSN(),

src/bpf.h

@@ -100,7 +100,7 @@ struct bpf_prog_load_opts {
 	__u32 log_level;
 	__u32 log_size;
 	char *log_buf;
-	/* output: actual total log contents size (including termintaing zero).
+	/* output: actual total log contents size (including terminating zero).
 	 * It could be both larger than original log_size (if log was
 	 * truncated), or smaller (if log buffer wasn't filled completely).
 	 * If kernel doesn't support this feature, log_size is left unchanged.
@@ -129,7 +129,7 @@ struct bpf_btf_load_opts {
 	char *log_buf;
 	__u32 log_level;
 	__u32 log_size;
-	/* output: actual total log contents size (including termintaing zero).
+	/* output: actual total log contents size (including terminating zero).
 	 * It could be both larger than original log_size (if log was
 	 * truncated), or smaller (if log buffer wasn't filled completely).
 	 * If kernel doesn't support this feature, log_size is left unchanged.

src/bpf_gen_internal.h

@@ -34,6 +34,7 @@ struct bpf_gen {
 	void *data_cur;
 	void *insn_start;
 	void *insn_cur;
+	bool swapped_endian;
 	ssize_t cleanup_label;
 	__u32 nr_progs;
 	__u32 nr_maps;

src/bpf_helper_defs.h

@@ -44,6 +44,14 @@ struct bpf_dynptr;
 struct iphdr;
 struct ipv6hdr;
 
+#ifndef __bpf_fastcall
+#if __has_attribute(bpf_fastcall)
+#define __bpf_fastcall __attribute__((bpf_fastcall))
+#else
+#define __bpf_fastcall
+#endif
+#endif
+
 /*
  * bpf_map_lookup_elem
  *
@@ -203,7 +211,7 @@ static __u32 (* const bpf_get_prandom_u32)(void) = (void *) 7;
  * Returns
  * 	The SMP id of the processor running the program.
  */
-static __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;
+static __bpf_fastcall __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;
 
 /*
  * bpf_skb_store_bytes
@@ -1224,7 +1232,7 @@ static long (* const bpf_set_hash)(struct __sk_buff *skb, __u32 hash) = (void *)
  * 	  **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**,
  * 	  **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**,
  * 	  **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**,
- * 	  **TCP_BPF_RTO_MIN**.
+ * 	  **TCP_BPF_RTO_MIN**, **TCP_BPF_SOCK_OPS_CB_FLAGS**.
  * 	* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
  * 	* **IPPROTO_IPV6**, which supports the following *optname*\ s:
  * 	  **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**.
@@ -1511,10 +1519,6 @@ static long (* const bpf_getsockopt)(void *bpf_socket, int level, int optname, v
  * 	option, and in this case it only works on functions tagged with
  * 	**ALLOW_ERROR_INJECTION** in the kernel code.
  *
- * 	Also, the helper is only available for the architectures having
- * 	the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
- * 	x86 architecture is the only one to support this feature.
- *
  * Returns
  * 	0
  */
@@ -4220,7 +4224,7 @@ static long (* const bpf_find_vma)(struct task_struct *task, __u64 addr, void *c
  * 	Currently, the **flags** must be 0. Currently, nr_loops is
  * 	limited to 1 << 23 (~8 million) loops.
  *
- * 	long (\*callback_fn)(u32 index, void \*ctx);
+ * 	long (\*callback_fn)(u64 index, void \*ctx);
  *
  * 	where **index** is the current index in the loop. The index
  * 	is zero-indexed.
@@ -4424,9 +4428,10 @@ static long (* const bpf_ima_file_hash)(struct file *file, void *dst, __u32 size
 /*
  * bpf_kptr_xchg
  *
- * 	Exchange kptr at pointer *map_value* with *ptr*, and return the
- * 	old value. *ptr* can be NULL, otherwise it must be a referenced
- * 	pointer which will be released when this helper is called.
+ * 	Exchange kptr at pointer *dst* with *ptr*, and return the old value.
+ * 	*dst* can be map value or local kptr. *ptr* can be NULL, otherwise
+ * 	it must be a referenced pointer which will be released when this helper
+ * 	is called.
  *
  * Returns
  * 	The old value of kptr (which can be NULL). The returned pointer
@@ -4434,7 +4439,7 @@ static long (* const bpf_ima_file_hash)(struct file *file, void *dst, __u32 size
  * 	corresponding release function, or moved into a BPF map before
  * 	program exit.
  */
-static void *(* const bpf_kptr_xchg)(void *map_value, void *ptr) = (void *) 194;
+static void *(* const bpf_kptr_xchg)(void *dst, void *ptr) = (void *) 194;
 
 /*
  * bpf_map_lookup_percpu_elem

src/bpf_helpers.h

@@ -185,6 +185,7 @@ enum libbpf_tristate {
 #define __kptr_untrusted __attribute__((btf_type_tag("kptr_untrusted")))
 #define __kptr __attribute__((btf_type_tag("kptr")))
 #define __percpu_kptr __attribute__((btf_type_tag("percpu_kptr")))
+#define __uptr __attribute__((btf_type_tag("uptr")))
 
 #if defined (__clang__)
 #define bpf_ksym_exists(sym) ({						\
@@ -341,7 +342,7 @@ extern void bpf_iter_num_destroy(struct bpf_iter_num *it) __weak __ksym;
  * I.e., it looks almost like high-level for each loop in other languages,
  * supports continue/break, and is verifiable by BPF verifier.
  *
- * For iterating integers, the difference betwen bpf_for_each(num, i, N, M)
+ * For iterating integers, the difference between bpf_for_each(num, i, N, M)
  * and bpf_for(i, N, M) is in that bpf_for() provides additional proof to
  * verifier that i is in [N, M) range, and in bpf_for_each() case i is `int
  * *`, not just `int`. So for integers bpf_for() is more convenient.

src/bpf_tracing.h

@@ -163,7 +163,7 @@
 
 struct pt_regs___s390 {
 	unsigned long orig_gpr2;
-};
+} __attribute__((preserve_access_index));
 
 /* s390 provides user_pt_regs instead of struct pt_regs to userspace */
 #define __PT_REGS_CAST(x) ((const user_pt_regs *)(x))
@@ -179,7 +179,7 @@ struct pt_regs___s390 {
 #define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
 #define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
 #define __PT_PARM6_SYSCALL_REG gprs[7]
-#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x)
+#define PT_REGS_PARM1_SYSCALL(x) (((const struct pt_regs___s390 *)(x))->__PT_PARM1_SYSCALL_REG)
 #define PT_REGS_PARM1_CORE_SYSCALL(x) \
 	BPF_CORE_READ((const struct pt_regs___s390 *)(x), __PT_PARM1_SYSCALL_REG)
 
@@ -222,7 +222,7 @@ struct pt_regs___s390 {
 
 struct pt_regs___arm64 {
 	unsigned long orig_x0;
-};
+} __attribute__((preserve_access_index));
 
 /* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */
 #define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x))
@@ -241,7 +241,7 @@ struct pt_regs___arm64 {
 #define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
 #define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
 #define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
-#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x)
+#define PT_REGS_PARM1_SYSCALL(x) (((const struct pt_regs___arm64 *)(x))->__PT_PARM1_SYSCALL_REG)
 #define PT_REGS_PARM1_CORE_SYSCALL(x) \
 	BPF_CORE_READ((const struct pt_regs___arm64 *)(x), __PT_PARM1_SYSCALL_REG)
 
@@ -351,6 +351,10 @@ struct pt_regs___arm64 {
  * https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-cc.adoc#risc-v-calling-conventions
  */
 
+struct pt_regs___riscv {
+	unsigned long orig_a0;
+} __attribute__((preserve_access_index));
+
 /* riscv provides struct user_regs_struct instead of struct pt_regs to userspace */
 #define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
 #define __PT_PARM1_REG a0
@@ -362,12 +366,15 @@ struct pt_regs___arm64 {
 #define __PT_PARM7_REG a6
 #define __PT_PARM8_REG a7
 
-#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
+#define __PT_PARM1_SYSCALL_REG orig_a0
 #define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
 #define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
 #define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
 #define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
 #define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
+#define PT_REGS_PARM1_SYSCALL(x) (((const struct pt_regs___riscv *)(x))->__PT_PARM1_SYSCALL_REG)
+#define PT_REGS_PARM1_CORE_SYSCALL(x) \
+	BPF_CORE_READ((const struct pt_regs___riscv *)(x), __PT_PARM1_SYSCALL_REG)
 
 #define __PT_RET_REG ra
 #define __PT_FP_REG s0
@@ -473,7 +480,7 @@ struct pt_regs;
 #endif
 /*
  * Similarly, syscall-specific conventions might differ between function call
- * conventions within each architecutre. All supported architectures pass
+ * conventions within each architecture. All supported architectures pass
  * either 6 or 7 syscall arguments in registers.
  *
  * See syscall(2) manpage for succinct table with information on each arch.
@@ -515,7 +522,7 @@ struct pt_regs;
 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
 
-#elif defined(bpf_target_sparc)
+#elif defined(bpf_target_sparc) || defined(bpf_target_arm64)
 
 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = PT_REGS_RET(ctx); })
 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
@@ -651,7 +658,7 @@ struct pt_regs;
  * BPF_PROG is a convenience wrapper for generic tp_btf/fentry/fexit and
  * similar kinds of BPF programs, that accept input arguments as a single
  * pointer to untyped u64 array, where each u64 can actually be a typed
- * pointer or integer of different size. Instead of requring user to write
+ * pointer or integer of different size. Instead of requiring user to write
  * manual casts and work with array elements by index, BPF_PROG macro
  * allows user to declare a list of named and typed input arguments in the
  * same syntax as for normal C function. All the casting is hidden and
@@ -801,7 +808,7 @@ struct pt_regs;
  * tp_btf/fentry/fexit BPF programs. It hides the underlying platform-specific
  * low-level way of getting kprobe input arguments from struct pt_regs, and
  * provides a familiar typed and named function arguments syntax and
- * semantics of accessing kprobe input paremeters.
+ * semantics of accessing kprobe input parameters.
  *
  * Original struct pt_regs* context is preserved as 'ctx' argument. This might
  * be necessary when using BPF helpers like bpf_perf_event_output().

src/btf.h

@@ -18,6 +18,7 @@ extern "C" {
 
 #define BTF_ELF_SEC ".BTF"
 #define BTF_EXT_ELF_SEC ".BTF.ext"
+#define BTF_BASE_ELF_SEC ".BTF.base"
 #define MAPS_ELF_SEC ".maps"
 
 struct btf;
@@ -107,6 +108,27 @@ LIBBPF_API struct btf *btf__new_empty(void);
  */
 LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
 
+/**
+ * @brief **btf__distill_base()** creates new versions of the split BTF
+ * *src_btf* and its base BTF. The new base BTF will only contain the types
+ * needed to improve robustness of the split BTF to small changes in base BTF.
+ * When that split BTF is loaded against a (possibly changed) base, this
+ * distilled base BTF will help update references to that (possibly changed)
+ * base BTF.
+ *
+ * Both the new split and its associated new base BTF must be freed by
+ * the caller.
+ *
+ * If successful, 0 is returned and **new_base_btf** and **new_split_btf**
+ * will point at new base/split BTF. Both the new split and its associated
+ * new base BTF must be freed by the caller.
+ *
+ * A negative value is returned on error and the thread-local `errno` variable
+ * is set to the error code as well.
+ */
+LIBBPF_API int btf__distill_base(const struct btf *src_btf, struct btf **new_base_btf,
+				 struct btf **new_split_btf);
+
 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
 LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
@@ -145,6 +167,9 @@ LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size);
 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
 LIBBPF_API const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size);
+LIBBPF_API enum btf_endianness btf_ext__endianness(const struct btf_ext *btf_ext);
+LIBBPF_API int btf_ext__set_endianness(struct btf_ext *btf_ext,
+				       enum btf_endianness endian);
 
 LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
 LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
@@ -231,6 +256,20 @@ struct btf_dedup_opts {
 
 LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts);
 
+/**
+ * @brief **btf__relocate()** will check the split BTF *btf* for references
+ * to base BTF kinds, and verify those references are compatible with
+ * *base_btf*; if they are, *btf* is adjusted such that is re-parented to
+ * *base_btf* and type ids and strings are adjusted to accommodate this.
+ *
+ * If successful, 0 is returned and **btf** now has **base_btf** as its
+ * base.
+ *
+ * A negative value is returned on error and the thread-local `errno` variable
+ * is set to the error code as well.
+ */
+LIBBPF_API int btf__relocate(struct btf *btf, const struct btf *base_btf);
+
 struct btf_dump;
 
 struct btf_dump_opts {
@@ -250,7 +289,7 @@ LIBBPF_API void btf_dump__free(struct btf_dump *d);
 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
 
 struct btf_dump_emit_type_decl_opts {
-	/* size of this struct, for forward/backward compatiblity */
+	/* size of this struct, for forward/backward compatibility */
 	size_t sz;
 	/* optional field name for type declaration, e.g.:
 	 * - struct my_struct <FNAME>

src/btf_dump.c

@@ -304,7 +304,7 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
  * definition, in which case they have to be declared inline as part of field
  * type declaration; or as a top-level anonymous enum, typically used for
  * declaring global constants. It's impossible to distinguish between two
- * without knowning whether given enum type was referenced from other type:
+ * without knowing whether given enum type was referenced from other type:
  * top-level anonymous enum won't be referenced by anything, while embedded
  * one will.
  */
@@ -867,8 +867,8 @@ static void btf_dump_emit_bit_padding(const struct btf_dump *d,
 	} pads[] = {
 		{"long", d->ptr_sz * 8}, {"int", 32}, {"short", 16}, {"char", 8}
 	};
-	int new_off, pad_bits, bits, i;
-	const char *pad_type;
+	int new_off = 0, pad_bits = 0, bits, i;
+	const char *pad_type = NULL;
 
 	if (cur_off >= next_off)
 		return; /* no gap */
@@ -1304,7 +1304,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			 * chain, restore stack, emit warning, and try to
 			 * proceed nevertheless
 			 */
-			pr_warn("not enough memory for decl stack:%d", err);
+			pr_warn("not enough memory for decl stack: %d\n", err);
 			d->decl_stack_cnt = stack_start;
 			return;
 		}
@@ -1559,10 +1559,12 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			 * Clang for BPF target generates func_proto with no
 			 * args as a func_proto with a single void arg (e.g.,
 			 * `int (*f)(void)` vs just `int (*f)()`). We are
-			 * going to pretend there are no args for such case.
+			 * going to emit valid empty args (void) syntax for
+			 * such case. Similarly and conveniently, valid
+			 * no args case can be special-cased here as well.
 			 */
-			if (vlen == 1 && p->type == 0) {
-				btf_dump_printf(d, ")");
+			if (vlen == 0 || (vlen == 1 && p->type == 0)) {
+				btf_dump_printf(d, "void)");
 				return;
 			}
 

src/btf_iter.c

@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (c) 2021 Facebook */
+/* Copyright (c) 2024, Oracle and/or its affiliates. */
+
+#ifdef __KERNEL__
+#include <linux/bpf.h>
+#include <linux/btf.h>
+
+#define btf_var_secinfos(t)	(struct btf_var_secinfo *)btf_type_var_secinfo(t)
+
+#else
+#include "btf.h"
+#include "libbpf_internal.h"
+#endif
+
+int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t,
+			enum btf_field_iter_kind iter_kind)
+{
+	it->p = NULL;
+	it->m_idx = -1;
+	it->off_idx = 0;
+	it->vlen = 0;
+
+	switch (iter_kind) {
+	case BTF_FIELD_ITER_IDS:
+		switch (btf_kind(t)) {
+		case BTF_KIND_UNKN:
+		case BTF_KIND_INT:
+		case BTF_KIND_FLOAT:
+		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
+			it->desc = (struct btf_field_desc) {};
+			break;
+		case BTF_KIND_FWD:
+		case BTF_KIND_CONST:
+		case BTF_KIND_VOLATILE:
+		case BTF_KIND_RESTRICT:
+		case BTF_KIND_PTR:
+		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_FUNC:
+		case BTF_KIND_VAR:
+		case BTF_KIND_DECL_TAG:
+		case BTF_KIND_TYPE_TAG:
+			it->desc = (struct btf_field_desc) { 1, {offsetof(struct btf_type, type)} };
+			break;
+		case BTF_KIND_ARRAY:
+			it->desc = (struct btf_field_desc) {
+				2, {sizeof(struct btf_type) + offsetof(struct btf_array, type),
+				sizeof(struct btf_type) + offsetof(struct btf_array, index_type)}
+			};
+			break;
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+			it->desc = (struct btf_field_desc) {
+				0, {},
+				sizeof(struct btf_member),
+				1, {offsetof(struct btf_member, type)}
+			};
+			break;
+		case BTF_KIND_FUNC_PROTO:
+			it->desc = (struct btf_field_desc) {
+				1, {offsetof(struct btf_type, type)},
+				sizeof(struct btf_param),
+				1, {offsetof(struct btf_param, type)}
+			};
+			break;
+		case BTF_KIND_DATASEC:
+			it->desc = (struct btf_field_desc) {
+				0, {},
+				sizeof(struct btf_var_secinfo),
+				1, {offsetof(struct btf_var_secinfo, type)}
+			};
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case BTF_FIELD_ITER_STRS:
+		switch (btf_kind(t)) {
+		case BTF_KIND_UNKN:
+			it->desc = (struct btf_field_desc) {};
+			break;
+		case BTF_KIND_INT:
+		case BTF_KIND_FLOAT:
+		case BTF_KIND_FWD:
+		case BTF_KIND_ARRAY:
+		case BTF_KIND_CONST:
+		case BTF_KIND_VOLATILE:
+		case BTF_KIND_RESTRICT:
+		case BTF_KIND_PTR:
+		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_FUNC:
+		case BTF_KIND_VAR:
+		case BTF_KIND_DECL_TAG:
+		case BTF_KIND_TYPE_TAG:
+		case BTF_KIND_DATASEC:
+			it->desc = (struct btf_field_desc) {
+				1, {offsetof(struct btf_type, name_off)}
+			};
+			break;
+		case BTF_KIND_ENUM:
+			it->desc = (struct btf_field_desc) {
+				1, {offsetof(struct btf_type, name_off)},
+				sizeof(struct btf_enum),
+				1, {offsetof(struct btf_enum, name_off)}
+			};
+			break;
+		case BTF_KIND_ENUM64:
+			it->desc = (struct btf_field_desc) {
+				1, {offsetof(struct btf_type, name_off)},
+				sizeof(struct btf_enum64),
+				1, {offsetof(struct btf_enum64, name_off)}
+			};
+			break;
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+			it->desc = (struct btf_field_desc) {
+				1, {offsetof(struct btf_type, name_off)},
+				sizeof(struct btf_member),
+				1, {offsetof(struct btf_member, name_off)}
+			};
+			break;
+		case BTF_KIND_FUNC_PROTO:
+			it->desc = (struct btf_field_desc) {
+				1, {offsetof(struct btf_type, name_off)},
+				sizeof(struct btf_param),
+				1, {offsetof(struct btf_param, name_off)}
+			};
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (it->desc.m_sz)
+		it->vlen = btf_vlen(t);
+
+	it->p = t;
+	return 0;
+}
+
+__u32 *btf_field_iter_next(struct btf_field_iter *it)
+{
+	if (!it->p)
+		return NULL;
+
+	if (it->m_idx < 0) {
+		if (it->off_idx < it->desc.t_off_cnt)
+			return it->p + it->desc.t_offs[it->off_idx++];
+		/* move to per-member iteration */
+		it->m_idx = 0;
+		it->p += sizeof(struct btf_type);
+		it->off_idx = 0;
+	}
+
+	/* if type doesn't have members, stop */
+	if (it->desc.m_sz == 0) {
+		it->p = NULL;
+		return NULL;
+	}
+
+	if (it->off_idx >= it->desc.m_off_cnt) {
+		/* exhausted this member's fields, go to the next member */
+		it->m_idx++;
+		it->p += it->desc.m_sz;
+		it->off_idx = 0;
+	}
+
+	if (it->m_idx < it->vlen)
+		return it->p + it->desc.m_offs[it->off_idx++];
+
+	it->p = NULL;
+	return NULL;
+}

src/btf_relocate.c

@@ -0,0 +1,519 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (c) 2024, Oracle and/or its affiliates. */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#ifdef __KERNEL__
+#include <linux/bpf.h>
+#include <linux/bsearch.h>
+#include <linux/btf.h>
+#include <linux/sort.h>
+#include <linux/string.h>
+#include <linux/bpf_verifier.h>
+
+#define btf_type_by_id				(struct btf_type *)btf_type_by_id
+#define btf__type_cnt				btf_nr_types
+#define btf__base_btf				btf_base_btf
+#define btf__name_by_offset			btf_name_by_offset
+#define btf__str_by_offset			btf_str_by_offset
+#define btf_kflag				btf_type_kflag
+
+#define calloc(nmemb, sz)			kvcalloc(nmemb, sz, GFP_KERNEL | __GFP_NOWARN)
+#define free(ptr)				kvfree(ptr)
+#define qsort(base, num, sz, cmp)		sort(base, num, sz, cmp, NULL)
+
+#else
+
+#include "btf.h"
+#include "bpf.h"
+#include "libbpf.h"
+#include "libbpf_internal.h"
+
+#endif /* __KERNEL__ */
+
+struct btf;
+
+struct btf_relocate {
+	struct btf *btf;
+	const struct btf *base_btf;
+	const struct btf *dist_base_btf;
+	unsigned int nr_base_types;
+	unsigned int nr_split_types;
+	unsigned int nr_dist_base_types;
+	int dist_str_len;
+	int base_str_len;
+	__u32 *id_map;
+	__u32 *str_map;
+};
+
+/* Set temporarily in relocation id_map if distilled base struct/union is
+ * embedded in a split BTF struct/union; in such a case, size information must
+ * match between distilled base BTF and base BTF representation of type.
+ */
+#define BTF_IS_EMBEDDED ((__u32)-1)
+
+/* <name, size, id> triple used in sorting/searching distilled base BTF. */
+struct btf_name_info {
+	const char *name;
+	/* set when search requires a size match */
+	bool needs_size: 1;
+	unsigned int size: 31;
+	__u32 id;
+};
+
+static int btf_relocate_rewrite_type_id(struct btf_relocate *r, __u32 i)
+{
+	struct btf_type *t = btf_type_by_id(r->btf, i);
+	struct btf_field_iter it;
+	__u32 *id;
+	int err;
+
+	err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_IDS);
+	if (err)
+		return err;
+
+	while ((id = btf_field_iter_next(&it)))
+		*id = r->id_map[*id];
+	return 0;
+}
+
+/* Simple string comparison used for sorting within BTF, since all distilled
+ * types are named.  If strings match, and size is non-zero for both elements
+ * fall back to using size for ordering.
+ */
+static int cmp_btf_name_size(const void *n1, const void *n2)
+{
+	const struct btf_name_info *ni1 = n1;
+	const struct btf_name_info *ni2 = n2;
+	int name_diff = strcmp(ni1->name, ni2->name);
+
+	if (!name_diff && ni1->needs_size && ni2->needs_size)
+		return ni2->size - ni1->size;
+	return name_diff;
+}
+
+/* Binary search with a small twist; find leftmost element that matches
+ * so that we can then iterate through all exact matches.  So for example
+ * searching { "a", "bb", "bb", "c" }  we would always match on the
+ * leftmost "bb".
+ */
+static struct btf_name_info *search_btf_name_size(struct btf_name_info *key,
+						  struct btf_name_info *vals,
+						  int nelems)
+{
+	struct btf_name_info *ret = NULL;
+	int high = nelems - 1;
+	int low = 0;
+
+	while (low <= high) {
+		int mid = (low + high)/2;
+		struct btf_name_info *val = &vals[mid];
+		int diff = cmp_btf_name_size(key, val);
+
+		if (diff == 0)
+			ret = val;
+		/* even if found, keep searching for leftmost match */
+		if (diff <= 0)
+			high = mid - 1;
+		else
+			low = mid + 1;
+	}
+	return ret;
+}
+
+/* If a member of a split BTF struct/union refers to a base BTF
+ * struct/union, mark that struct/union id temporarily in the id_map
+ * with BTF_IS_EMBEDDED.  Members can be const/restrict/volatile/typedef
+ * reference types, but if a pointer is encountered, the type is no longer
+ * considered embedded.
+ */
+static int btf_mark_embedded_composite_type_ids(struct btf_relocate *r, __u32 i)
+{
+	struct btf_type *t = btf_type_by_id(r->btf, i);
+	struct btf_field_iter it;
+	__u32 *id;
+	int err;
+
+	if (!btf_is_composite(t))
+		return 0;
+
+	err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_IDS);
+	if (err)
+		return err;
+
+	while ((id = btf_field_iter_next(&it))) {
+		__u32 next_id = *id;
+
+		while (next_id) {
+			t = btf_type_by_id(r->btf, next_id);
+			switch (btf_kind(t)) {
+			case BTF_KIND_CONST:
+			case BTF_KIND_RESTRICT:
+			case BTF_KIND_VOLATILE:
+			case BTF_KIND_TYPEDEF:
+			case BTF_KIND_TYPE_TAG:
+				next_id = t->type;
+				break;
+			case BTF_KIND_ARRAY: {
+				struct btf_array *a = btf_array(t);
+
+				next_id = a->type;
+				break;
+			}
+			case BTF_KIND_STRUCT:
+			case BTF_KIND_UNION:
+				if (next_id < r->nr_dist_base_types)
+					r->id_map[next_id] = BTF_IS_EMBEDDED;
+				next_id = 0;
+				break;
+			default:
+				next_id = 0;
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/* Build a map from distilled base BTF ids to base BTF ids. To do so, iterate
+ * through base BTF looking up distilled type (using binary search) equivalents.
+ */
+static int btf_relocate_map_distilled_base(struct btf_relocate *r)
+{
+	struct btf_name_info *info, *info_end;
+	struct btf_type *base_t, *dist_t;
+	__u8 *base_name_cnt = NULL;
+	int err = 0;
+	__u32 id;
+
+	/* generate a sort index array of name/type ids sorted by name for
+	 * distilled base BTF to speed name-based lookups.
+	 */
+	info = calloc(r->nr_dist_base_types, sizeof(*info));
+	if (!info) {
+		err = -ENOMEM;
+		goto done;
+	}
+	info_end = info + r->nr_dist_base_types;
+	for (id = 0; id < r->nr_dist_base_types; id++) {
+		dist_t = btf_type_by_id(r->dist_base_btf, id);
+		info[id].name = btf__name_by_offset(r->dist_base_btf, dist_t->name_off);
+		info[id].id = id;
+		info[id].size = dist_t->size;
+		info[id].needs_size = true;
+	}
+	qsort(info, r->nr_dist_base_types, sizeof(*info), cmp_btf_name_size);
+
+	/* Mark distilled base struct/union members of split BTF structs/unions
+	 * in id_map with BTF_IS_EMBEDDED; this signals that these types
+	 * need to match both name and size, otherwise embedding the base
+	 * struct/union in the split type is invalid.
+	 */
+	for (id = r->nr_dist_base_types; id < r->nr_split_types; id++) {
+		err = btf_mark_embedded_composite_type_ids(r, id);
+		if (err)
+			goto done;
+	}
+
+	/* Collect name counts for composite types in base BTF.  If multiple
+	 * instances of a struct/union of the same name exist, we need to use
+	 * size to determine which to map to since name alone is ambiguous.
+	 */
+	base_name_cnt = calloc(r->base_str_len, sizeof(*base_name_cnt));
+	if (!base_name_cnt) {
+		err = -ENOMEM;
+		goto done;
+	}
+	for (id = 1; id < r->nr_base_types; id++) {
+		base_t = btf_type_by_id(r->base_btf, id);
+		if (!btf_is_composite(base_t) || !base_t->name_off)
+			continue;
+		if (base_name_cnt[base_t->name_off] < 255)
+			base_name_cnt[base_t->name_off]++;
+	}
+
+	/* Now search base BTF for matching distilled base BTF types. */
+	for (id = 1; id < r->nr_base_types; id++) {
+		struct btf_name_info *dist_info, base_info = {};
+		int dist_kind, base_kind;
+
+		base_t = btf_type_by_id(r->base_btf, id);
+		/* distilled base consists of named types only. */
+		if (!base_t->name_off)
+			continue;
+		base_kind = btf_kind(base_t);
+		base_info.id = id;
+		base_info.name = btf__name_by_offset(r->base_btf, base_t->name_off);
+		switch (base_kind) {
+		case BTF_KIND_INT:
+		case BTF_KIND_FLOAT:
+		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
+			/* These types should match both name and size */
+			base_info.needs_size = true;
+			base_info.size = base_t->size;
+			break;
+		case BTF_KIND_FWD:
+			/* No size considerations for fwds. */
+			break;
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+			/* Size only needs to be used for struct/union if there
+			 * are multiple types in base BTF with the same name.
+			 * If there are multiple _distilled_ types with the same
+			 * name (a very unlikely scenario), that doesn't matter
+			 * unless corresponding _base_ types to match them are
+			 * missing.
+			 */
+			base_info.needs_size = base_name_cnt[base_t->name_off] > 1;
+			base_info.size = base_t->size;
+			break;
+		default:
+			continue;
+		}
+		/* iterate over all matching distilled base types */
+		for (dist_info = search_btf_name_size(&base_info, info, r->nr_dist_base_types);
+		     dist_info != NULL && dist_info < info_end &&
+		     cmp_btf_name_size(&base_info, dist_info) == 0;
+		     dist_info++) {
+			if (!dist_info->id || dist_info->id >= r->nr_dist_base_types) {
+				pr_warn("base BTF id [%d] maps to invalid distilled base BTF id [%d]\n",
+					id, dist_info->id);
+				err = -EINVAL;
+				goto done;
+			}
+			dist_t = btf_type_by_id(r->dist_base_btf, dist_info->id);
+			dist_kind = btf_kind(dist_t);
+
+			/* Validate that the found distilled type is compatible.
+			 * Do not error out on mismatch as another match may
+			 * occur for an identically-named type.
+			 */
+			switch (dist_kind) {
+			case BTF_KIND_FWD:
+				switch (base_kind) {
+				case BTF_KIND_FWD:
+					if (btf_kflag(dist_t) != btf_kflag(base_t))
+						continue;
+					break;
+				case BTF_KIND_STRUCT:
+					if (btf_kflag(base_t))
+						continue;
+					break;
+				case BTF_KIND_UNION:
+					if (!btf_kflag(base_t))
+						continue;
+					break;
+				default:
+					continue;
+				}
+				break;
+			case BTF_KIND_INT:
+				if (dist_kind != base_kind ||
+				    btf_int_encoding(base_t) != btf_int_encoding(dist_t))
+					continue;
+				break;
+			case BTF_KIND_FLOAT:
+				if (dist_kind != base_kind)
+					continue;
+				break;
+			case BTF_KIND_ENUM:
+				/* ENUM and ENUM64 are encoded as sized ENUM in
+				 * distilled base BTF.
+				 */
+				if (base_kind != dist_kind && base_kind != BTF_KIND_ENUM64)
+					continue;
+				break;
+			case BTF_KIND_STRUCT:
+			case BTF_KIND_UNION:
+				/* size verification is required for embedded
+				 * struct/unions.
+				 */
+				if (r->id_map[dist_info->id] == BTF_IS_EMBEDDED &&
+				    base_t->size != dist_t->size)
+					continue;
+				break;
+			default:
+				continue;
+			}
+			if (r->id_map[dist_info->id] &&
+			    r->id_map[dist_info->id] != BTF_IS_EMBEDDED) {
+				/* we already have a match; this tells us that
+				 * multiple base types of the same name
+				 * have the same size, since for cases where
+				 * multiple types have the same name we match
+				 * on name and size.  In this case, we have
+				 * no way of determining which to relocate
+				 * to in base BTF, so error out.
+				 */
+				pr_warn("distilled base BTF type '%s' [%u], size %u has multiple candidates of the same size (ids [%u, %u]) in base BTF\n",
+					base_info.name, dist_info->id,
+					base_t->size, id, r->id_map[dist_info->id]);
+				err = -EINVAL;
+				goto done;
+			}
+			/* map id and name */
+			r->id_map[dist_info->id] = id;
+			r->str_map[dist_t->name_off] = base_t->name_off;
+		}
+	}
+	/* ensure all distilled BTF ids now have a mapping... */
+	for (id = 1; id < r->nr_dist_base_types; id++) {
+		const char *name;
+
+		if (r->id_map[id] && r->id_map[id] != BTF_IS_EMBEDDED)
+			continue;
+		dist_t = btf_type_by_id(r->dist_base_btf, id);
+		name = btf__name_by_offset(r->dist_base_btf, dist_t->name_off);
+		pr_warn("distilled base BTF type '%s' [%d] is not mapped to base BTF id\n",
+			name, id);
+		err = -EINVAL;
+		break;
+	}
+done:
+	free(base_name_cnt);
+	free(info);
+	return err;
+}
+
+/* distilled base should only have named int/float/enum/fwd/struct/union types. */
+static int btf_relocate_validate_distilled_base(struct btf_relocate *r)
+{
+	unsigned int i;
+
+	for (i = 1; i < r->nr_dist_base_types; i++) {
+		struct btf_type *t = btf_type_by_id(r->dist_base_btf, i);
+		int kind = btf_kind(t);
+
+		switch (kind) {
+		case BTF_KIND_INT:
+		case BTF_KIND_FLOAT:
+		case BTF_KIND_ENUM:
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+		case BTF_KIND_FWD:
+			if (t->name_off)
+				break;
+			pr_warn("type [%d], kind [%d] is invalid for distilled base BTF; it is anonymous\n",
+				i, kind);
+			return -EINVAL;
+		default:
+			pr_warn("type [%d] in distilled based BTF has unexpected kind [%d]\n",
+				i, kind);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static int btf_relocate_rewrite_strs(struct btf_relocate *r, __u32 i)
+{
+	struct btf_type *t = btf_type_by_id(r->btf, i);
+	struct btf_field_iter it;
+	__u32 *str_off;
+	int off, err;
+
+	err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_STRS);
+	if (err)
+		return err;
+
+	while ((str_off = btf_field_iter_next(&it))) {
+		if (!*str_off)
+			continue;
+		if (*str_off >= r->dist_str_len) {
+			*str_off += r->base_str_len - r->dist_str_len;
+		} else {
+			off = r->str_map[*str_off];
+			if (!off) {
+				pr_warn("string '%s' [offset %u] is not mapped to base BTF\n",
+					btf__str_by_offset(r->btf, off), *str_off);
+				return -ENOENT;
+			}
+			*str_off = off;
+		}
+	}
+	return 0;
+}
+
+/* If successful, output of relocation is updated BTF with base BTF pointing
+ * at base_btf, and type ids, strings adjusted accordingly.
+ */
+int btf_relocate(struct btf *btf, const struct btf *base_btf, __u32 **id_map)
+{
+	unsigned int nr_types = btf__type_cnt(btf);
+	const struct btf_header *dist_base_hdr;
+	const struct btf_header *base_hdr;
+	struct btf_relocate r = {};
+	int err = 0;
+	__u32 id, i;
+
+	r.dist_base_btf = btf__base_btf(btf);
+	if (!base_btf || r.dist_base_btf == base_btf)
+		return -EINVAL;
+
+	r.nr_dist_base_types = btf__type_cnt(r.dist_base_btf);
+	r.nr_base_types = btf__type_cnt(base_btf);
+	r.nr_split_types = nr_types - r.nr_dist_base_types;
+	r.btf = btf;
+	r.base_btf = base_btf;
+
+	r.id_map = calloc(nr_types, sizeof(*r.id_map));
+	r.str_map = calloc(btf_header(r.dist_base_btf)->str_len, sizeof(*r.str_map));
+	dist_base_hdr = btf_header(r.dist_base_btf);
+	base_hdr = btf_header(r.base_btf);
+	r.dist_str_len = dist_base_hdr->str_len;
+	r.base_str_len = base_hdr->str_len;
+	if (!r.id_map || !r.str_map) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	err = btf_relocate_validate_distilled_base(&r);
+	if (err)
+		goto err_out;
+
+	/* Split BTF ids need to be adjusted as base and distilled base
+	 * have different numbers of types, changing the start id of split
+	 * BTF.
+	 */
+	for (id = r.nr_dist_base_types; id < nr_types; id++)
+		r.id_map[id] = id + r.nr_base_types - r.nr_dist_base_types;
+
+	/* Build a map from distilled base ids to actual base BTF ids; it is used
+	 * to update split BTF id references.  Also build a str_map mapping from
+	 * distilled base BTF names to base BTF names.
+	 */
+	err = btf_relocate_map_distilled_base(&r);
+	if (err)
+		goto err_out;
+
+	/* Next, rewrite type ids in split BTF, replacing split ids with updated
+	 * ids based on number of types in base BTF, and base ids with
+	 * relocated ids from base_btf.
+	 */
+	for (i = 0, id = r.nr_dist_base_types; i < r.nr_split_types; i++, id++) {
+		err = btf_relocate_rewrite_type_id(&r, id);
+		if (err)
+			goto err_out;
+	}
+	/* String offsets now need to be updated using the str_map. */
+	for (i = 0; i < r.nr_split_types; i++) {
+		err = btf_relocate_rewrite_strs(&r, i + r.nr_dist_base_types);
+		if (err)
+			goto err_out;
+	}
+	/* Finally reset base BTF to be base_btf */
+	btf_set_base_btf(btf, base_btf);
+
+	if (id_map) {
+		*id_map = r.id_map;
+		r.id_map = NULL;
+	}
+err_out:
+	free(r.id_map);
+	free(r.str_map);
+	return err;
+}

src/elf.c

@@ -28,6 +28,9 @@ int elf_open(const char *binary_path, struct elf_fd *elf_fd)
 	int fd, ret;
 	Elf *elf;
 
+	elf_fd->elf = NULL;
+	elf_fd->fd = -1;
+
 	if (elf_version(EV_CURRENT) == EV_NONE) {
 		pr_warn("elf: failed to init libelf for %s\n", binary_path);
 		return -LIBBPF_ERRNO__LIBELF;

src/features.c

@@ -22,7 +22,7 @@ int probe_fd(int fd)
 
 static int probe_kern_prog_name(int token_fd)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, prog_name);
+	const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
 	struct bpf_insn insns[] = {
 		BPF_MOV64_IMM(BPF_REG_0, 0),
 		BPF_EXIT_INSN(),
@@ -392,11 +392,41 @@ static int probe_uprobe_multi_link(int token_fd)
 	link_fd = bpf_link_create(prog_fd, -1, BPF_TRACE_UPROBE_MULTI, &link_opts);
 	err = -errno; /* close() can clobber errno */
 
+	if (link_fd >= 0 || err != -EBADF) {
+		if (link_fd >= 0)
+			close(link_fd);
+		close(prog_fd);
+		return 0;
+	}
+
+	/* Initial multi-uprobe support in kernel didn't handle PID filtering
+	 * correctly (it was doing thread filtering, not process filtering).
+	 * So now we'll detect if PID filtering logic was fixed, and, if not,
+	 * we'll pretend multi-uprobes are not supported, if not.
+	 * Multi-uprobes are used in USDT attachment logic, and we need to be
+	 * conservative here, because multi-uprobe selection happens early at
+	 * load time, while the use of PID filtering is known late at
+	 * attachment time, at which point it's too late to undo multi-uprobe
+	 * selection.
+	 *
+	 * Creating uprobe with pid == -1 for (invalid) '/' binary will fail
+	 * early with -EINVAL on kernels with fixed PID filtering logic;
+	 * otherwise -ESRCH would be returned if passed correct binary path
+	 * (but we'll just get -BADF, of course).
+	 */
+	link_opts.uprobe_multi.pid = -1; /* invalid PID */
+	link_opts.uprobe_multi.path = "/"; /* invalid path */
+	link_opts.uprobe_multi.offsets = &offset;
+	link_opts.uprobe_multi.cnt = 1;
+
+	link_fd = bpf_link_create(prog_fd, -1, BPF_TRACE_UPROBE_MULTI, &link_opts);
+	err = -errno; /* close() can clobber errno */
+
 	if (link_fd >= 0)
 		close(link_fd);
 	close(prog_fd);
 
-	return link_fd < 0 && err == -EBADF;
+	return link_fd < 0 && err == -EINVAL;
 }
 
 static int probe_kern_bpf_cookie(int token_fd)

src/gen_loader.c

@@ -401,6 +401,15 @@ int bpf_gen__finish(struct bpf_gen *gen, int nr_progs, int nr_maps)
 		opts->insns_sz = gen->insn_cur - gen->insn_start;
 		opts->data = gen->data_start;
 		opts->data_sz = gen->data_cur - gen->data_start;
+
+		/* use target endianness for embedded loader */
+		if (gen->swapped_endian) {
+			struct bpf_insn *insn = (struct bpf_insn *)opts->insns;
+			int insn_cnt = opts->insns_sz / sizeof(struct bpf_insn);
+
+			for (i = 0; i < insn_cnt; i++)
+				bpf_insn_bswap(insn++);
+		}
 	}
 	return gen->error;
 }
@@ -414,6 +423,28 @@ void bpf_gen__free(struct bpf_gen *gen)
 	free(gen);
 }
 
+/*
+ * Fields of bpf_attr are set to values in native byte-order before being
+ * written to the target-bound data blob, and may need endian conversion.
+ * This macro allows providing the correct value in situ more simply than
+ * writing a separate converter for *all fields* of *all records* included
+ * in union bpf_attr. Note that sizeof(rval) should match the assignment
+ * target to avoid runtime problems.
+ */
+#define tgt_endian(rval) ({					\
+	typeof(rval) _val = (rval);				\
+	if (gen->swapped_endian) {				\
+		switch (sizeof(_val)) {				\
+		case 1: break;					\
+		case 2: _val = bswap_16(_val); break;		\
+		case 4: _val = bswap_32(_val); break;		\
+		case 8: _val = bswap_64(_val); break;		\
+		default: pr_warn("unsupported bswap size!\n");	\
+		}						\
+	}							\
+	_val;							\
+})
+
 void bpf_gen__load_btf(struct bpf_gen *gen, const void *btf_raw_data,
 		       __u32 btf_raw_size)
 {
@@ -422,11 +453,12 @@ void bpf_gen__load_btf(struct bpf_gen *gen, const void *btf_raw_data,
 	union bpf_attr attr;
 
 	memset(&attr, 0, attr_size);
-	pr_debug("gen: load_btf: size %d\n", btf_raw_size);
 	btf_data = add_data(gen, btf_raw_data, btf_raw_size);
 
-	attr.btf_size = btf_raw_size;
+	attr.btf_size = tgt_endian(btf_raw_size);
 	btf_load_attr = add_data(gen, &attr, attr_size);
+	pr_debug("gen: load_btf: off %d size %d, attr: off %d size %d\n",
+		 btf_data, btf_raw_size, btf_load_attr, attr_size);
 
 	/* populate union bpf_attr with user provided log details */
 	move_ctx2blob(gen, attr_field(btf_load_attr, btf_log_level), 4,
@@ -457,28 +489,29 @@ void bpf_gen__map_create(struct bpf_gen *gen,
 	union bpf_attr attr;
 
 	memset(&attr, 0, attr_size);
-	attr.map_type = map_type;
-	attr.key_size = key_size;
-	attr.value_size = value_size;
-	attr.map_flags = map_attr->map_flags;
-	attr.map_extra = map_attr->map_extra;
+	attr.map_type = tgt_endian(map_type);
+	attr.key_size = tgt_endian(key_size);
+	attr.value_size = tgt_endian(value_size);
+	attr.map_flags = tgt_endian(map_attr->map_flags);
+	attr.map_extra = tgt_endian(map_attr->map_extra);
 	if (map_name)
 		libbpf_strlcpy(attr.map_name, map_name, sizeof(attr.map_name));
-	attr.numa_node = map_attr->numa_node;
-	attr.map_ifindex = map_attr->map_ifindex;
-	attr.max_entries = max_entries;
-	attr.btf_key_type_id = map_attr->btf_key_type_id;
-	attr.btf_value_type_id = map_attr->btf_value_type_id;
-
-	pr_debug("gen: map_create: %s idx %d type %d value_type_id %d\n",
-		 attr.map_name, map_idx, map_type, attr.btf_value_type_id);
+	attr.numa_node = tgt_endian(map_attr->numa_node);
+	attr.map_ifindex = tgt_endian(map_attr->map_ifindex);
+	attr.max_entries = tgt_endian(max_entries);
+	attr.btf_key_type_id = tgt_endian(map_attr->btf_key_type_id);
+	attr.btf_value_type_id = tgt_endian(map_attr->btf_value_type_id);
 
 	map_create_attr = add_data(gen, &attr, attr_size);
-	if (attr.btf_value_type_id)
+	pr_debug("gen: map_create: %s idx %d type %d value_type_id %d, attr: off %d size %d\n",
+		 map_name, map_idx, map_type, map_attr->btf_value_type_id,
+		 map_create_attr, attr_size);
+
+	if (map_attr->btf_value_type_id)
 		/* populate union bpf_attr with btf_fd saved in the stack earlier */
 		move_stack2blob(gen, attr_field(map_create_attr, btf_fd), 4,
 				stack_off(btf_fd));
-	switch (attr.map_type) {
+	switch (map_type) {
 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
 	case BPF_MAP_TYPE_HASH_OF_MAPS:
 		move_stack2blob(gen, attr_field(map_create_attr, inner_map_fd), 4,
@@ -498,8 +531,8 @@ void bpf_gen__map_create(struct bpf_gen *gen,
 	/* emit MAP_CREATE command */
 	emit_sys_bpf(gen, BPF_MAP_CREATE, map_create_attr, attr_size);
 	debug_ret(gen, "map_create %s idx %d type %d value_size %d value_btf_id %d",
-		  attr.map_name, map_idx, map_type, value_size,
-		  attr.btf_value_type_id);
+		  map_name, map_idx, map_type, value_size,
+		  map_attr->btf_value_type_id);
 	emit_check_err(gen);
 	/* remember map_fd in the stack, if successful */
 	if (map_idx < 0) {
@@ -784,12 +817,12 @@ log:
 	emit_ksym_relo_log(gen, relo, kdesc->ref);
 }
 
-static __u32 src_reg_mask(void)
+static __u32 src_reg_mask(struct bpf_gen *gen)
 {
-#if defined(__LITTLE_ENDIAN_BITFIELD)
-	return 0x0f; /* src_reg,dst_reg,... */
-#elif defined(__BIG_ENDIAN_BITFIELD)
-	return 0xf0; /* dst_reg,src_reg,... */
+#if defined(__LITTLE_ENDIAN_BITFIELD) /* src_reg,dst_reg,... */
+	return gen->swapped_endian ? 0xf0 : 0x0f;
+#elif defined(__BIG_ENDIAN_BITFIELD) /* dst_reg,src_reg,... */
+	return gen->swapped_endian ? 0x0f : 0xf0;
 #else
 #error "Unsupported bit endianness, cannot proceed"
 #endif
@@ -840,7 +873,7 @@ static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo,
 	emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, 3));
 clear_src_reg:
 	/* clear bpf_object__relocate_data's src_reg assignment, otherwise we get a verifier failure */
-	reg_mask = src_reg_mask();
+	reg_mask = src_reg_mask(gen);
 	emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code)));
 	emit(gen, BPF_ALU32_IMM(BPF_AND, BPF_REG_9, reg_mask));
 	emit(gen, BPF_STX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, offsetofend(struct bpf_insn, code)));
@@ -931,48 +964,94 @@ static void cleanup_relos(struct bpf_gen *gen, int insns)
 	cleanup_core_relo(gen);
 }
 
+/* Convert func, line, and core relo info blobs to target endianness */
+static void info_blob_bswap(struct bpf_gen *gen, int func_info, int line_info,
+			    int core_relos, struct bpf_prog_load_opts *load_attr)
+{
+	struct bpf_func_info *fi = gen->data_start + func_info;
+	struct bpf_line_info *li = gen->data_start + line_info;
+	struct bpf_core_relo *cr = gen->data_start + core_relos;
+	int i;
+
+	for (i = 0; i < load_attr->func_info_cnt; i++)
+		bpf_func_info_bswap(fi++);
+
+	for (i = 0; i < load_attr->line_info_cnt; i++)
+		bpf_line_info_bswap(li++);
+
+	for (i = 0; i < gen->core_relo_cnt; i++)
+		bpf_core_relo_bswap(cr++);
+}
+
 void bpf_gen__prog_load(struct bpf_gen *gen,
 			enum bpf_prog_type prog_type, const char *prog_name,
 			const char *license, struct bpf_insn *insns, size_t insn_cnt,
 			struct bpf_prog_load_opts *load_attr, int prog_idx)
 {
+	int func_info_tot_sz = load_attr->func_info_cnt *
+			       load_attr->func_info_rec_size;
+	int line_info_tot_sz = load_attr->line_info_cnt *
+			       load_attr->line_info_rec_size;
+	int core_relo_tot_sz = gen->core_relo_cnt *
+			       sizeof(struct bpf_core_relo);
 	int prog_load_attr, license_off, insns_off, func_info, line_info, core_relos;
 	int attr_size = offsetofend(union bpf_attr, core_relo_rec_size);
 	union bpf_attr attr;
 
 	memset(&attr, 0, attr_size);
-	pr_debug("gen: prog_load: type %d insns_cnt %zd progi_idx %d\n",
-		 prog_type, insn_cnt, prog_idx);
 	/* add license string to blob of bytes */
 	license_off = add_data(gen, license, strlen(license) + 1);
 	/* add insns to blob of bytes */
 	insns_off = add_data(gen, insns, insn_cnt * sizeof(struct bpf_insn));
+	pr_debug("gen: prog_load: prog_idx %d type %d insn off %d insns_cnt %zd license off %d\n",
+		 prog_idx, prog_type, insns_off, insn_cnt, license_off);
 
-	attr.prog_type = prog_type;
-	attr.expected_attach_type = load_attr->expected_attach_type;
-	attr.attach_btf_id = load_attr->attach_btf_id;
-	attr.prog_ifindex = load_attr->prog_ifindex;
+	/* convert blob insns to target endianness */
+	if (gen->swapped_endian) {
+		struct bpf_insn *insn = gen->data_start + insns_off;
+		int i;
+
+		for (i = 0; i < insn_cnt; i++, insn++)
+			bpf_insn_bswap(insn);
+	}
+
+	attr.prog_type = tgt_endian(prog_type);
+	attr.expected_attach_type = tgt_endian(load_attr->expected_attach_type);
+	attr.attach_btf_id = tgt_endian(load_attr->attach_btf_id);
+	attr.prog_ifindex = tgt_endian(load_attr->prog_ifindex);
 	attr.kern_version = 0;
-	attr.insn_cnt = (__u32)insn_cnt;
-	attr.prog_flags = load_attr->prog_flags;
+	attr.insn_cnt = tgt_endian((__u32)insn_cnt);
+	attr.prog_flags = tgt_endian(load_attr->prog_flags);
 
-	attr.func_info_rec_size = load_attr->func_info_rec_size;
-	attr.func_info_cnt = load_attr->func_info_cnt;
-	func_info = add_data(gen, load_attr->func_info,
-			     attr.func_info_cnt * attr.func_info_rec_size);
+	attr.func_info_rec_size = tgt_endian(load_attr->func_info_rec_size);
+	attr.func_info_cnt = tgt_endian(load_attr->func_info_cnt);
+	func_info = add_data(gen, load_attr->func_info, func_info_tot_sz);
+	pr_debug("gen: prog_load: func_info: off %d cnt %d rec size %d\n",
+		 func_info, load_attr->func_info_cnt,
+		 load_attr->func_info_rec_size);
 
-	attr.line_info_rec_size = load_attr->line_info_rec_size;
-	attr.line_info_cnt = load_attr->line_info_cnt;
-	line_info = add_data(gen, load_attr->line_info,
-			     attr.line_info_cnt * attr.line_info_rec_size);
+	attr.line_info_rec_size = tgt_endian(load_attr->line_info_rec_size);
+	attr.line_info_cnt = tgt_endian(load_attr->line_info_cnt);
+	line_info = add_data(gen, load_attr->line_info, line_info_tot_sz);
+	pr_debug("gen: prog_load: line_info: off %d cnt %d rec size %d\n",
+		 line_info, load_attr->line_info_cnt,
+		 load_attr->line_info_rec_size);
 
-	attr.core_relo_rec_size = sizeof(struct bpf_core_relo);
-	attr.core_relo_cnt = gen->core_relo_cnt;
-	core_relos = add_data(gen, gen->core_relos,
-			     attr.core_relo_cnt * attr.core_relo_rec_size);
+	attr.core_relo_rec_size = tgt_endian((__u32)sizeof(struct bpf_core_relo));
+	attr.core_relo_cnt = tgt_endian(gen->core_relo_cnt);
+	core_relos = add_data(gen, gen->core_relos, core_relo_tot_sz);
+	pr_debug("gen: prog_load: core_relos: off %d cnt %d rec size %zd\n",
+		 core_relos, gen->core_relo_cnt,
+		 sizeof(struct bpf_core_relo));
+
+	/* convert all info blobs to target endianness */
+	if (gen->swapped_endian)
+		info_blob_bswap(gen, func_info, line_info, core_relos, load_attr);
 
 	libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name));
 	prog_load_attr = add_data(gen, &attr, attr_size);
+	pr_debug("gen: prog_load: attr: off %d size %d\n",
+		 prog_load_attr, attr_size);
 
 	/* populate union bpf_attr with a pointer to license */
 	emit_rel_store(gen, attr_field(prog_load_attr, license), license_off);
@@ -1040,7 +1119,6 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue,
 	int zero = 0;
 
 	memset(&attr, 0, attr_size);
-	pr_debug("gen: map_update_elem: idx %d\n", map_idx);
 
 	value = add_data(gen, pvalue, value_size);
 	key = add_data(gen, &zero, sizeof(zero));
@@ -1068,6 +1146,8 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue,
 	emit(gen, BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel));
 
 	map_update_attr = add_data(gen, &attr, attr_size);
+	pr_debug("gen: map_update_elem: idx %d, value: off %d size %d, attr: off %d size %d\n",
+		 map_idx, value, value_size, map_update_attr, attr_size);
 	move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4,
 		       blob_fd_array_off(gen, map_idx));
 	emit_rel_store(gen, attr_field(map_update_attr, key), key);
@@ -1084,14 +1164,16 @@ void bpf_gen__populate_outer_map(struct bpf_gen *gen, int outer_map_idx, int slo
 	int attr_size = offsetofend(union bpf_attr, flags);
 	int map_update_attr, key;
 	union bpf_attr attr;
+	int tgt_slot;
 
 	memset(&attr, 0, attr_size);
-	pr_debug("gen: populate_outer_map: outer %d key %d inner %d\n",
-		 outer_map_idx, slot, inner_map_idx);
 
-	key = add_data(gen, &slot, sizeof(slot));
+	tgt_slot = tgt_endian(slot);
+	key = add_data(gen, &tgt_slot, sizeof(tgt_slot));
 
 	map_update_attr = add_data(gen, &attr, attr_size);
+	pr_debug("gen: populate_outer_map: outer %d key %d inner %d, attr: off %d size %d\n",
+		 outer_map_idx, slot, inner_map_idx, map_update_attr, attr_size);
 	move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4,
 		       blob_fd_array_off(gen, outer_map_idx));
 	emit_rel_store(gen, attr_field(map_update_attr, key), key);
@@ -1112,8 +1194,9 @@ void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx)
 	union bpf_attr attr;
 
 	memset(&attr, 0, attr_size);
-	pr_debug("gen: map_freeze: idx %d\n", map_idx);
 	map_freeze_attr = add_data(gen, &attr, attr_size);
+	pr_debug("gen: map_freeze: idx %d, attr: off %d size %d\n",
+		 map_idx, map_freeze_attr, attr_size);
 	move_blob2blob(gen, attr_field(map_freeze_attr, map_fd), 4,
 		       blob_fd_array_off(gen, map_idx));
 	/* emit MAP_FREEZE command */

src/hashmap.h

@@ -166,8 +166,8 @@ bool hashmap_find(const struct hashmap *map, long key, long *value);
  * @bkt: integer used as a bucket loop cursor
  */
 #define hashmap__for_each_entry(map, cur, bkt)				    \
-	for (bkt = 0; bkt < map->cap; bkt++)				    \
-		for (cur = map->buckets[bkt]; cur; cur = cur->next)
+	for (bkt = 0; bkt < (map)->cap; bkt++)				    \
+		for (cur = (map)->buckets[bkt]; cur; cur = cur->next)
 
 /*
  * hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe
@@ -178,8 +178,8 @@ bool hashmap_find(const struct hashmap *map, long key, long *value);
  * @bkt: integer used as a bucket loop cursor
  */
 #define hashmap__for_each_entry_safe(map, cur, tmp, bkt)		    \
-	for (bkt = 0; bkt < map->cap; bkt++)				    \
-		for (cur = map->buckets[bkt];				    \
+	for (bkt = 0; bkt < (map)->cap; bkt++)				    \
+		for (cur = (map)->buckets[bkt];				    \
 		     cur && ({tmp = cur->next; true; });		    \
 		     cur = tmp)
 
@@ -190,19 +190,19 @@ bool hashmap_find(const struct hashmap *map, long key, long *value);
  * @key: key to iterate entries for
  */
 #define hashmap__for_each_key_entry(map, cur, _key)			    \
-	for (cur = map->buckets						    \
-		     ? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
+	for (cur = (map)->buckets					    \
+		     ? (map)->buckets[hash_bits((map)->hash_fn((_key), (map)->ctx), (map)->cap_bits)] \
 		     : NULL;						    \
 	     cur;							    \
 	     cur = cur->next)						    \
-		if (map->equal_fn(cur->key, (_key), map->ctx))
+		if ((map)->equal_fn(cur->key, (_key), (map)->ctx))
 
 #define hashmap__for_each_key_entry_safe(map, cur, tmp, _key)		    \
-	for (cur = map->buckets						    \
-		     ? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
+	for (cur = (map)->buckets					    \
+		     ? (map)->buckets[hash_bits((map)->hash_fn((_key), (map)->ctx), (map)->cap_bits)] \
 		     : NULL;						    \
 	     cur && ({ tmp = cur->next; true; });			    \
 	     cur = tmp)							    \
-		if (map->equal_fn(cur->key, (_key), map->ctx))
+		if ((map)->equal_fn(cur->key, (_key), (map)->ctx))
 
 #endif /* __LIBBPF_HASHMAP_H */

src/libbpf.c

@@ -229,7 +229,30 @@ static const char * const prog_type_name[] = {
 static int __base_pr(enum libbpf_print_level level, const char *format,
 		     va_list args)
 {
-	if (level == LIBBPF_DEBUG)
+	const char *env_var = "LIBBPF_LOG_LEVEL";
+	static enum libbpf_print_level min_level = LIBBPF_INFO;
+	static bool initialized;
+
+	if (!initialized) {
+		char *verbosity;
+
+		initialized = true;
+		verbosity = getenv(env_var);
+		if (verbosity) {
+			if (strcasecmp(verbosity, "warn") == 0)
+				min_level = LIBBPF_WARN;
+			else if (strcasecmp(verbosity, "debug") == 0)
+				min_level = LIBBPF_DEBUG;
+			else if (strcasecmp(verbosity, "info") == 0)
+				min_level = LIBBPF_INFO;
+			else
+				fprintf(stderr, "libbpf: unrecognized '%s' envvar value: '%s', should be one of 'warn', 'debug', or 'info'.\n",
+					env_var, verbosity);
+		}
+	}
+
+	/* if too verbose, skip logging  */
+	if (level > min_level)
 		return 0;
 
 	return vfprintf(stderr, format, args);
@@ -473,8 +496,6 @@ struct bpf_program {
 };
 
 struct bpf_struct_ops {
-	const char *tname;
-	const struct btf_type *type;
 	struct bpf_program **progs;
 	__u32 *kern_func_off;
 	/* e.g. struct tcp_congestion_ops in bpf_prog's btf format */
@@ -549,6 +570,7 @@ struct bpf_map {
 	bool pinned;
 	bool reused;
 	bool autocreate;
+	bool autoattach;
 	__u64 map_extra;
 };
 
@@ -672,6 +694,8 @@ struct bpf_object {
 	/* Information when doing ELF related work. Only valid if efile.elf is not NULL */
 	struct elf_state efile;
 
+	unsigned char byteorder;
+
 	struct btf *btf;
 	struct btf_ext *btf_ext;
 
@@ -918,6 +942,20 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 	return 0;
 }
 
+static void bpf_object_bswap_progs(struct bpf_object *obj)
+{
+	struct bpf_program *prog = obj->programs;
+	struct bpf_insn *insn;
+	int p, i;
+
+	for (p = 0; p < obj->nr_programs; p++, prog++) {
+		insn = prog->insns;
+		for (i = 0; i < prog->insns_cnt; i++, insn++)
+			bpf_insn_bswap(insn);
+	}
+	pr_debug("converted %zu BPF programs to native byte order\n", obj->nr_programs);
+}
+
 static const struct btf_member *
 find_member_by_offset(const struct btf_type *t, __u32 bit_offset)
 {
@@ -964,7 +1002,7 @@ find_struct_ops_kern_types(struct bpf_object *obj, const char *tname_raw,
 {
 	const struct btf_type *kern_type, *kern_vtype;
 	const struct btf_member *kern_data_member;
-	struct btf *btf;
+	struct btf *btf = NULL;
 	__s32 kern_vtype_id, kern_type_id;
 	char tname[256];
 	__u32 i;
@@ -1059,11 +1097,14 @@ static int bpf_object_adjust_struct_ops_autoload(struct bpf_object *obj)
 			continue;
 
 		for (j = 0; j < obj->nr_maps; ++j) {
+			const struct btf_type *type;
+
 			map = &obj->maps[j];
 			if (!bpf_map__is_struct_ops(map))
 				continue;
 
-			vlen = btf_vlen(map->st_ops->type);
+			type = btf__type_by_id(obj->btf, map->st_ops->type_id);
+			vlen = btf_vlen(type);
 			for (k = 0; k < vlen; ++k) {
 				slot_prog = map->st_ops->progs[k];
 				if (prog != slot_prog)
@@ -1091,14 +1132,14 @@ static int bpf_map__init_kern_struct_ops(struct bpf_map *map)
 	const struct btf *btf = obj->btf;
 	struct bpf_struct_ops *st_ops;
 	const struct btf *kern_btf;
-	struct module_btf *mod_btf;
+	struct module_btf *mod_btf = NULL;
 	void *data, *kern_data;
 	const char *tname;
 	int err;
 
 	st_ops = map->st_ops;
-	type = st_ops->type;
-	tname = st_ops->tname;
+	type = btf__type_by_id(btf, st_ops->type_id);
+	tname = btf__name_by_offset(btf, type->name_off);
 	err = find_struct_ops_kern_types(obj, tname, &mod_btf,
 					 &kern_type, &kern_type_id,
 					 &kern_vtype, &kern_vtype_id,
@@ -1377,6 +1418,7 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
 		map->def.value_size = type->size;
 		map->def.max_entries = 1;
 		map->def.map_flags = strcmp(sec_name, STRUCT_OPS_LINK_SEC) == 0 ? BPF_F_LINK : 0;
+		map->autoattach = true;
 
 		map->st_ops = calloc(1, sizeof(*map->st_ops));
 		if (!map->st_ops)
@@ -1398,8 +1440,6 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
 		memcpy(st_ops->data,
 		       data->d_buf + vsi->offset,
 		       type->size);
-		st_ops->tname = tname;
-		st_ops->type = type;
 		st_ops->type_id = type_id;
 
 		pr_debug("struct_ops init: struct %s(type_id=%u) %s found at offset %u\n",
@@ -1482,6 +1522,7 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 
 	elf_end(obj->efile.elf);
 	obj->efile.elf = NULL;
+	obj->efile.ehdr = NULL;
 	obj->efile.symbols = NULL;
 	obj->efile.arena_data = NULL;
 
@@ -1547,6 +1588,16 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 		goto errout;
 	}
 
+	/* Validate ELF object endianness... */
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB &&
+	    ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
+		err = -LIBBPF_ERRNO__ENDIAN;
+		pr_warn("elf: '%s' has unknown byte order\n", obj->path);
+		goto errout;
+	}
+	/* and save after bpf_object_open() frees ELF data */
+	obj->byteorder = ehdr->e_ident[EI_DATA];
+
 	if (elf_getshdrstrndx(elf, &obj->efile.shstrndx)) {
 		pr_warn("elf: failed to get section names section index for %s: %s\n",
 			obj->path, elf_errmsg(-1));
@@ -1575,19 +1626,15 @@ errout:
 	return err;
 }
 
-static int bpf_object__check_endianness(struct bpf_object *obj)
+static bool is_native_endianness(struct bpf_object *obj)
 {
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
-		return 0;
+	return obj->byteorder == ELFDATA2LSB;
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
-		return 0;
+	return obj->byteorder == ELFDATA2MSB;
 #else
 # error "Unrecognized __BYTE_ORDER__"
 #endif
-	pr_warn("elf: endianness mismatch in %s.\n", obj->path);
-	return -LIBBPF_ERRNO__ENDIAN;
 }
 
 static int
@@ -1824,7 +1871,7 @@ static char *internal_map_name(struct bpf_object *obj, const char *real_name)
 	snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
 		 sfx_len, real_name);
 
-	/* sanitise map name to characters allowed by kernel */
+	/* sanities map name to characters allowed by kernel */
 	for (p = map_name; *p && p < map_name + sizeof(map_name); p++)
 		if (!isalnum(*p) && *p != '_' && *p != '.')
 			*p = '_';
@@ -3557,11 +3604,12 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 report:
 	if (err) {
 		btf_mandatory = kernel_needs_btf(obj);
-		pr_warn("Error loading .BTF into kernel: %d. %s\n", err,
-			btf_mandatory ? "BTF is mandatory, can't proceed."
-				      : "BTF is optional, ignoring.");
-		if (!btf_mandatory)
+		if (btf_mandatory) {
+			pr_warn("Error loading .BTF into kernel: %d. BTF is mandatory, can't proceed.\n", err);
+		} else {
+			pr_info("Error loading .BTF into kernel: %d. BTF is optional, ignoring.\n", err);
 			err = 0;
+		}
 	}
 	return err;
 }
@@ -3929,6 +3977,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 		return -LIBBPF_ERRNO__FORMAT;
 	}
 
+	/* change BPF program insns to native endianness for introspection */
+	if (!is_native_endianness(obj))
+		bpf_object_bswap_progs(obj);
+
 	/* sort BPF programs by section name and in-section instruction offset
 	 * for faster search
 	 */
@@ -3961,7 +4013,7 @@ static bool sym_is_subprog(const Elf64_Sym *sym, int text_shndx)
 		return true;
 
 	/* global function */
-	return bind == STB_GLOBAL && type == STT_FUNC;
+	return (bind == STB_GLOBAL || bind == STB_WEAK) && type == STT_FUNC;
 }
 
 static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
@@ -4365,7 +4417,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
 
 static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog)
 {
-	return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1;
+	return prog->sec_idx == obj->efile.text_shndx;
 }
 
 struct bpf_program *
@@ -4796,6 +4848,20 @@ int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate)
 	return 0;
 }
 
+int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach)
+{
+	if (!bpf_map__is_struct_ops(map))
+		return libbpf_err(-EINVAL);
+
+	map->autoattach = autoattach;
+	return 0;
+}
+
+bool bpf_map__autoattach(const struct bpf_map *map)
+{
+	return map->autoattach;
+}
+
 int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 {
 	struct bpf_map_info info;
@@ -5056,6 +5122,7 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
 	enum libbpf_map_type map_type = map->libbpf_type;
 	char *cp, errmsg[STRERR_BUFSIZE];
 	int err, zero = 0;
+	size_t mmap_sz;
 
 	if (obj->gen_loader) {
 		bpf_gen__map_update_elem(obj->gen_loader, map - obj->maps,
@@ -5069,8 +5136,8 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
 	if (err) {
 		err = -errno;
 		cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
-		pr_warn("Error setting initial map(%s) contents: %s\n",
-			map->name, cp);
+		pr_warn("map '%s': failed to set initial contents: %s\n",
+			bpf_map__name(map), cp);
 		return err;
 	}
 
@@ -5080,11 +5147,43 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
 		if (err) {
 			err = -errno;
 			cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
-			pr_warn("Error freezing map(%s) as read-only: %s\n",
-				map->name, cp);
+			pr_warn("map '%s': failed to freeze as read-only: %s\n",
+				bpf_map__name(map), cp);
 			return err;
 		}
 	}
+
+	/* Remap anonymous mmap()-ed "map initialization image" as
+	 * a BPF map-backed mmap()-ed memory, but preserving the same
+	 * memory address. This will cause kernel to change process'
+	 * page table to point to a different piece of kernel memory,
+	 * but from userspace point of view memory address (and its
+	 * contents, being identical at this point) will stay the
+	 * same. This mapping will be released by bpf_object__close()
+	 * as per normal clean up procedure.
+	 */
+	mmap_sz = bpf_map_mmap_sz(map);
+	if (map->def.map_flags & BPF_F_MMAPABLE) {
+		void *mmaped;
+		int prot;
+
+		if (map->def.map_flags & BPF_F_RDONLY_PROG)
+			prot = PROT_READ;
+		else
+			prot = PROT_READ | PROT_WRITE;
+		mmaped = mmap(map->mmaped, mmap_sz, prot, MAP_SHARED | MAP_FIXED, map->fd, 0);
+		if (mmaped == MAP_FAILED) {
+			err = -errno;
+			pr_warn("map '%s': failed to re-mmap() contents: %d\n",
+				bpf_map__name(map), err);
+			return err;
+		}
+		map->mmaped = mmaped;
+	} else if (map->mmaped) {
+		munmap(map->mmaped, mmap_sz);
+		map->mmaped = NULL;
+	}
+
 	return 0;
 }
 
@@ -5401,8 +5500,7 @@ retry:
 				err = bpf_object__populate_internal_map(obj, map);
 				if (err < 0)
 					goto err_out;
-			}
-			if (map->def.type == BPF_MAP_TYPE_ARENA) {
+			} else if (map->def.type == BPF_MAP_TYPE_ARENA) {
 				map->mmaped = mmap((void *)(long)map->map_extra,
 						   bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE,
 						   map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED,
@@ -7314,8 +7412,14 @@ static int libbpf_prepare_prog_load(struct bpf_program *prog,
 		opts->prog_flags |= BPF_F_XDP_HAS_FRAGS;
 
 	/* special check for usdt to use uprobe_multi link */
-	if ((def & SEC_USDT) && kernel_supports(prog->obj, FEAT_UPROBE_MULTI_LINK))
+	if ((def & SEC_USDT) && kernel_supports(prog->obj, FEAT_UPROBE_MULTI_LINK)) {
+		/* for BPF_TRACE_UPROBE_MULTI, user might want to query expected_attach_type
+		 * in prog, and expected_attach_type we set in kernel is from opts, so we
+		 * update both.
+		 */
 		prog->expected_attach_type = BPF_TRACE_UPROBE_MULTI;
+		opts->expected_attach_type = BPF_TRACE_UPROBE_MULTI;
+	}
 
 	if ((def & SEC_ATTACH_BTF) && !prog->attach_btf_id) {
 		int btf_obj_fd = 0, btf_type_id = 0, err;
@@ -7405,6 +7509,7 @@ static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog
 	load_attr.attach_btf_id = prog->attach_btf_id;
 	load_attr.kern_version = kern_version;
 	load_attr.prog_ifindex = prog->prog_ifindex;
+	load_attr.expected_attach_type = prog->expected_attach_type;
 
 	/* specify func_info/line_info only if kernel supports them */
 	if (obj->btf && btf__fd(obj->btf) >= 0 && kernel_supports(obj, FEAT_BTF_FUNC)) {
@@ -7436,9 +7541,6 @@ static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog
 		insns_cnt = prog->insns_cnt;
 	}
 
-	/* allow prog_prepare_load_fn to change expected_attach_type */
-	load_attr.expected_attach_type = prog->expected_attach_type;
-
 	if (obj->gen_loader) {
 		bpf_gen__prog_load(obj->gen_loader, prog->type, prog->name,
 				   license, insns, insns_cnt, &load_attr,
@@ -7867,16 +7969,19 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
 }
 
 static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf, size_t obj_buf_sz,
+					  const char *obj_name,
 					  const struct bpf_object_open_opts *opts)
 {
-	const char *obj_name, *kconfig, *btf_tmp_path, *token_path;
+	const char *kconfig, *btf_tmp_path, *token_path;
 	struct bpf_object *obj;
-	char tmp_name[64];
 	int err;
 	char *log_buf;
 	size_t log_size;
 	__u32 log_level;
 
+	if (obj_buf && !obj_name)
+		return ERR_PTR(-EINVAL);
+
 	if (elf_version(EV_CURRENT) == EV_NONE) {
 		pr_warn("failed to init libelf for %s\n",
 			path ? : "(mem buf)");
@@ -7886,16 +7991,12 @@ static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf,
 	if (!OPTS_VALID(opts, bpf_object_open_opts))
 		return ERR_PTR(-EINVAL);
 
-	obj_name = OPTS_GET(opts, object_name, NULL);
+	obj_name = OPTS_GET(opts, object_name, NULL) ?: obj_name;
 	if (obj_buf) {
-		if (!obj_name) {
-			snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
-				 (unsigned long)obj_buf,
-				 (unsigned long)obj_buf_sz);
-			obj_name = tmp_name;
-		}
 		path = obj_name;
 		pr_debug("loading object '%s' from buffer\n", obj_name);
+	} else {
+		pr_debug("loading object from %s\n", path);
 	}
 
 	log_buf = OPTS_GET(opts, kernel_log_buf, NULL);
@@ -7955,7 +8056,6 @@ static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf,
 	}
 
 	err = bpf_object__elf_init(obj);
-	err = err ? : bpf_object__check_endianness(obj);
 	err = err ? : bpf_object__elf_collect(obj);
 	err = err ? : bpf_object__collect_externs(obj);
 	err = err ? : bpf_object_fixup_btf(obj);
@@ -7979,9 +8079,7 @@ bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts)
 	if (!path)
 		return libbpf_err_ptr(-EINVAL);
 
-	pr_debug("loading %s\n", path);
-
-	return libbpf_ptr(bpf_object_open(path, NULL, 0, opts));
+	return libbpf_ptr(bpf_object_open(path, NULL, 0, NULL, opts));
 }
 
 struct bpf_object *bpf_object__open(const char *path)
@@ -7993,10 +8091,15 @@ struct bpf_object *
 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
 		     const struct bpf_object_open_opts *opts)
 {
+	char tmp_name[64];
+
 	if (!obj_buf || obj_buf_sz == 0)
 		return libbpf_err_ptr(-EINVAL);
 
-	return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, opts));
+	/* create a (quite useless) default "name" for this memory buffer object */
+	snprintf(tmp_name, sizeof(tmp_name), "%lx-%zx", (unsigned long)obj_buf, obj_buf_sz);
+
+	return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, tmp_name, opts));
 }
 
 static int bpf_object_unload(struct bpf_object *obj)
@@ -8406,11 +8509,13 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
 
 static void bpf_map_prepare_vdata(const struct bpf_map *map)
 {
+	const struct btf_type *type;
 	struct bpf_struct_ops *st_ops;
 	__u32 i;
 
 	st_ops = map->st_ops;
-	for (i = 0; i < btf_vlen(st_ops->type); i++) {
+	type = btf__type_by_id(map->obj->btf, st_ops->type_id);
+	for (i = 0; i < btf_vlen(type); i++) {
 		struct bpf_program *prog = st_ops->progs[i];
 		void *kern_data;
 		int prog_fd;
@@ -8456,8 +8561,15 @@ static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const ch
 		return libbpf_err(-EINVAL);
 	}
 
-	if (obj->gen_loader)
+	/* Disallow kernel loading programs of non-native endianness but
+	 * permit cross-endian creation of "light skeleton".
+	 */
+	if (obj->gen_loader) {
 		bpf_gen__init(obj->gen_loader, extra_log_level, obj->nr_programs, obj->nr_maps);
+	} else if (!is_native_endianness(obj)) {
+		pr_warn("object '%s': loading non-native endianness is unsupported\n", obj->name);
+		return libbpf_err(-LIBBPF_ERRNO__ENDIAN);
+	}
 
 	err = bpf_object_prepare_token(obj);
 	err = err ? : bpf_object__probe_loading(obj);
@@ -9017,6 +9129,11 @@ unsigned int bpf_object__kversion(const struct bpf_object *obj)
 	return obj ? obj->kern_version : 0;
 }
 
+int bpf_object__token_fd(const struct bpf_object *obj)
+{
+	return obj->token_fd ?: -1;
+}
+
 struct btf *bpf_object__btf(const struct bpf_object *obj)
 {
 	return obj ? obj->btf : NULL;
@@ -9049,6 +9166,7 @@ int bpf_object__gen_loader(struct bpf_object *obj, struct gen_loader_opts *opts)
 	if (!gen)
 		return -ENOMEM;
 	gen->opts = opts;
+	gen->swapped_endian = !is_native_endianness(obj);
 	obj->gen_loader = gen;
 	return 0;
 }
@@ -9673,6 +9791,7 @@ static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
 static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
 					    Elf64_Shdr *shdr, Elf_Data *data)
 {
+	const struct btf_type *type;
 	const struct btf_member *member;
 	struct bpf_struct_ops *st_ops;
 	struct bpf_program *prog;
@@ -9732,13 +9851,14 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
 		}
 		insn_idx = sym->st_value / BPF_INSN_SZ;
 
-		member = find_member_by_offset(st_ops->type, moff * 8);
+		type = btf__type_by_id(btf, st_ops->type_id);
+		member = find_member_by_offset(type, moff * 8);
 		if (!member) {
 			pr_warn("struct_ops reloc %s: cannot find member at moff %u\n",
 				map->name, moff);
 			return -EINVAL;
 		}
-		member_idx = member - btf_members(st_ops->type);
+		member_idx = member - btf_members(type);
 		name = btf__name_by_offset(btf, member->name_off);
 
 		if (!resolve_func_ptr(btf, member->type, NULL)) {
@@ -10336,7 +10456,7 @@ __bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
 struct bpf_map *
 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
 {
-	if (prev == NULL)
+	if (prev == NULL && obj != NULL)
 		return obj->maps;
 
 	return __bpf_map__iter(prev, obj, 1);
@@ -10345,7 +10465,7 @@ bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
 struct bpf_map *
 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *next)
 {
-	if (next == NULL) {
+	if (next == NULL && obj != NULL) {
 		if (!obj->nr_maps)
 			return NULL;
 		return obj->maps + obj->nr_maps - 1;
@@ -11644,7 +11764,7 @@ static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru
 		ret = 0;
 		break;
 	case 3:
-		opts.retprobe = strcmp(probe_type, "uretprobe.multi") == 0;
+		opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
 		*link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts);
 		ret = libbpf_get_error(*link);
 		break;
@@ -12711,7 +12831,7 @@ struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,
 	}
 
 	if (prog->type != BPF_PROG_TYPE_EXT) {
-		pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace",
+		pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace\n",
 			prog->name);
 		return libbpf_err_ptr(-EINVAL);
 	}
@@ -12877,8 +12997,10 @@ struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map)
 	__u32 zero = 0;
 	int err, fd;
 
-	if (!bpf_map__is_struct_ops(map))
+	if (!bpf_map__is_struct_ops(map)) {
+		pr_warn("map '%s': can't attach non-struct_ops map\n", map->name);
 		return libbpf_err_ptr(-EINVAL);
+	}
 
 	if (map->fd < 0) {
 		pr_warn("map '%s': can't attach BPF map without FD (was it created?)\n", map->name);
@@ -13671,14 +13793,15 @@ int libbpf_num_possible_cpus(void)
 
 static int populate_skeleton_maps(const struct bpf_object *obj,
 				  struct bpf_map_skeleton *maps,
-				  size_t map_cnt)
+				  size_t map_cnt, size_t map_skel_sz)
 {
 	int i;
 
 	for (i = 0; i < map_cnt; i++) {
-		struct bpf_map **map = maps[i].map;
-		const char *name = maps[i].name;
-		void **mmaped = maps[i].mmaped;
+		struct bpf_map_skeleton *map_skel = (void *)maps + i * map_skel_sz;
+		struct bpf_map **map = map_skel->map;
+		const char *name = map_skel->name;
+		void **mmaped = map_skel->mmaped;
 
 		*map = bpf_object__find_map_by_name(obj, name);
 		if (!*map) {
@@ -13695,13 +13818,14 @@ static int populate_skeleton_maps(const struct bpf_object *obj,
 
 static int populate_skeleton_progs(const struct bpf_object *obj,
 				   struct bpf_prog_skeleton *progs,
-				   size_t prog_cnt)
+				   size_t prog_cnt, size_t prog_skel_sz)
 {
 	int i;
 
 	for (i = 0; i < prog_cnt; i++) {
-		struct bpf_program **prog = progs[i].prog;
-		const char *name = progs[i].name;
+		struct bpf_prog_skeleton *prog_skel = (void *)progs + i * prog_skel_sz;
+		struct bpf_program **prog = prog_skel->prog;
+		const char *name = prog_skel->name;
 
 		*prog = bpf_object__find_program_by_name(obj, name);
 		if (!*prog) {
@@ -13715,40 +13839,24 @@ static int populate_skeleton_progs(const struct bpf_object *obj,
 int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
 			      const struct bpf_object_open_opts *opts)
 {
-	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, skel_opts,
-		.object_name = s->name,
-	);
 	struct bpf_object *obj;
 	int err;
 
-	/* Attempt to preserve opts->object_name, unless overriden by user
-	 * explicitly. Overwriting object name for skeletons is discouraged,
-	 * as it breaks global data maps, because they contain object name
-	 * prefix as their own map name prefix. When skeleton is generated,
-	 * bpftool is making an assumption that this name will stay the same.
-	 */
-	if (opts) {
-		memcpy(&skel_opts, opts, sizeof(*opts));
-		if (!opts->object_name)
-			skel_opts.object_name = s->name;
-	}
-
-	obj = bpf_object__open_mem(s->data, s->data_sz, &skel_opts);
-	err = libbpf_get_error(obj);
-	if (err) {
-		pr_warn("failed to initialize skeleton BPF object '%s': %d\n",
-			s->name, err);
+	obj = bpf_object_open(NULL, s->data, s->data_sz, s->name, opts);
+	if (IS_ERR(obj)) {
+		err = PTR_ERR(obj);
+		pr_warn("failed to initialize skeleton BPF object '%s': %d\n", s->name, err);
 		return libbpf_err(err);
 	}
 
 	*s->obj = obj;
-	err = populate_skeleton_maps(obj, s->maps, s->map_cnt);
+	err = populate_skeleton_maps(obj, s->maps, s->map_cnt, s->map_skel_sz);
 	if (err) {
 		pr_warn("failed to populate skeleton maps for '%s': %d\n", s->name, err);
 		return libbpf_err(err);
 	}
 
-	err = populate_skeleton_progs(obj, s->progs, s->prog_cnt);
+	err = populate_skeleton_progs(obj, s->progs, s->prog_cnt, s->prog_skel_sz);
 	if (err) {
 		pr_warn("failed to populate skeleton progs for '%s': %d\n", s->name, err);
 		return libbpf_err(err);
@@ -13778,26 +13886,26 @@ int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s)
 		return libbpf_err(-errno);
 	}
 
-	err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt);
+	err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt, s->map_skel_sz);
 	if (err) {
 		pr_warn("failed to populate subskeleton maps: %d\n", err);
 		return libbpf_err(err);
 	}
 
-	err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt);
+	err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt, s->prog_skel_sz);
 	if (err) {
 		pr_warn("failed to populate subskeleton maps: %d\n", err);
 		return libbpf_err(err);
 	}
 
 	for (var_idx = 0; var_idx < s->var_cnt; var_idx++) {
-		var_skel = &s->vars[var_idx];
+		var_skel = (void *)s->vars + var_idx * s->var_skel_sz;
 		map = *var_skel->map;
 		map_type_id = bpf_map__btf_value_type_id(map);
 		map_type = btf__type_by_id(btf, map_type_id);
 
 		if (!btf_is_datasec(map_type)) {
-			pr_warn("type for map '%1$s' is not a datasec: %2$s",
+			pr_warn("type for map '%1$s' is not a datasec: %2$s\n",
 				bpf_map__name(map),
 				__btf_kind_str(btf_kind(map_type)));
 			return libbpf_err(-EINVAL);
@@ -13838,47 +13946,13 @@ int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
 	}
 
 	for (i = 0; i < s->map_cnt; i++) {
-		struct bpf_map *map = *s->maps[i].map;
-		size_t mmap_sz = bpf_map_mmap_sz(map);
-		int prot, map_fd = map->fd;
-		void **mmaped = s->maps[i].mmaped;
+		struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
+		struct bpf_map *map = *map_skel->map;
 
-		if (!mmaped)
+		if (!map_skel->mmaped)
 			continue;
 
-		if (!(map->def.map_flags & BPF_F_MMAPABLE)) {
-			*mmaped = NULL;
-			continue;
-		}
-
-		if (map->def.type == BPF_MAP_TYPE_ARENA) {
-			*mmaped = map->mmaped;
-			continue;
-		}
-
-		if (map->def.map_flags & BPF_F_RDONLY_PROG)
-			prot = PROT_READ;
-		else
-			prot = PROT_READ | PROT_WRITE;
-
-		/* Remap anonymous mmap()-ed "map initialization image" as
-		 * a BPF map-backed mmap()-ed memory, but preserving the same
-		 * memory address. This will cause kernel to change process'
-		 * page table to point to a different piece of kernel memory,
-		 * but from userspace point of view memory address (and its
-		 * contents, being identical at this point) will stay the
-		 * same. This mapping will be released by bpf_object__close()
-		 * as per normal clean up procedure, so we don't need to worry
-		 * about it from skeleton's clean up perspective.
-		 */
-		*mmaped = mmap(map->mmaped, mmap_sz, prot, MAP_SHARED | MAP_FIXED, map_fd, 0);
-		if (*mmaped == MAP_FAILED) {
-			err = -errno;
-			*mmaped = NULL;
-			pr_warn("failed to re-mmap() map '%s': %d\n",
-				 bpf_map__name(map), err);
-			return libbpf_err(err);
-		}
+		*map_skel->mmaped = map->mmaped;
 	}
 
 	return 0;
@@ -13889,8 +13963,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
 	int i, err;
 
 	for (i = 0; i < s->prog_cnt; i++) {
-		struct bpf_program *prog = *s->progs[i].prog;
-		struct bpf_link **link = s->progs[i].link;
+		struct bpf_prog_skeleton *prog_skel = (void *)s->progs + i * s->prog_skel_sz;
+		struct bpf_program *prog = *prog_skel->prog;
+		struct bpf_link **link = prog_skel->link;
 
 		if (!prog->autoload || !prog->autoattach)
 			continue;
@@ -13922,6 +13997,38 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
 		 */
 	}
 
+
+	for (i = 0; i < s->map_cnt; i++) {
+		struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
+		struct bpf_map *map = *map_skel->map;
+		struct bpf_link **link;
+
+		if (!map->autocreate || !map->autoattach)
+			continue;
+
+		/* only struct_ops maps can be attached */
+		if (!bpf_map__is_struct_ops(map))
+			continue;
+
+		/* skeleton is created with earlier version of bpftool, notify user */
+		if (s->map_skel_sz < offsetofend(struct bpf_map_skeleton, link)) {
+			pr_warn("map '%s': BPF skeleton version is old, skipping map auto-attachment...\n",
+				bpf_map__name(map));
+			continue;
+		}
+
+		link = map_skel->link;
+		if (*link)
+			continue;
+
+		*link = bpf_map__attach_struct_ops(map);
+		if (!*link) {
+			err = -errno;
+			pr_warn("map '%s': failed to auto-attach: %d\n", bpf_map__name(map), err);
+			return libbpf_err(err);
+		}
+	}
+
 	return 0;
 }
 
@@ -13930,11 +14037,25 @@ void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
 	int i;
 
 	for (i = 0; i < s->prog_cnt; i++) {
-		struct bpf_link **link = s->progs[i].link;
+		struct bpf_prog_skeleton *prog_skel = (void *)s->progs + i * s->prog_skel_sz;
+		struct bpf_link **link = prog_skel->link;
 
 		bpf_link__destroy(*link);
 		*link = NULL;
 	}
+
+	if (s->map_skel_sz < sizeof(struct bpf_map_skeleton))
+		return;
+
+	for (i = 0; i < s->map_cnt; i++) {
+		struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
+		struct bpf_link **link = map_skel->link;
+
+		if (link) {
+			bpf_link__destroy(*link);
+			*link = NULL;
+		}
+	}
 }
 
 void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
@@ -13942,8 +14063,7 @@ void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
 	if (!s)
 		return;
 
-	if (s->progs)
-		bpf_object__detach_skeleton(s);
+	bpf_object__detach_skeleton(s);
 	if (s->obj)
 		bpf_object__close(*s->obj);
 	free(s->maps);

src/libbpf.h

@@ -98,7 +98,10 @@ typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
 
 /**
  * @brief **libbpf_set_print()** sets user-provided log callback function to
- * be used for libbpf warnings and informational messages.
+ * be used for libbpf warnings and informational messages. If the user callback
+ * is not set, messages are logged to stderr by default. The verbosity of these
+ * messages can be controlled by setting the environment variable
+ * LIBBPF_LOG_LEVEL to either warn, info, or debug.
  * @param fn The log print function. If NULL, libbpf won't print anything.
  * @return Pointer to old print function.
  *
@@ -149,7 +152,7 @@ struct bpf_object_open_opts {
 	 * log_buf and log_level settings.
 	 *
 	 * If specified, this log buffer will be passed for:
-	 *   - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden
+	 *   - each BPF progral load (BPF_PROG_LOAD) attempt, unless overridden
 	 *     with bpf_program__set_log() on per-program level, to get
 	 *     BPF verifier log output.
 	 *   - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get
@@ -291,6 +294,14 @@ LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
 
+/**
+ * @brief **bpf_object__token_fd** is an accessor for BPF token FD associated
+ * with BPF object.
+ * @param obj Pointer to a valid BPF object
+ * @return BPF token FD or -1, if it wasn't set
+ */
+LIBBPF_API int bpf_object__token_fd(const struct bpf_object *obj);
+
 struct btf;
 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
@@ -452,7 +463,7 @@ LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 /**
  * @brief **bpf_program__attach()** is a generic function for attaching
  * a BPF program based on auto-detection of program type, attach type,
- * and extra paremeters, where applicable.
+ * and extra parameters, where applicable.
  *
  * @param prog BPF program to attach
  * @return Reference to the newly created BPF link; or NULL is returned on error,
@@ -676,7 +687,7 @@ struct bpf_uprobe_opts {
 /**
  * @brief **bpf_program__attach_uprobe()** attaches a BPF program
  * to the userspace function which is found by binary path and
- * offset. You can optionally specify a particular proccess to attach
+ * offset. You can optionally specify a particular process to attach
  * to. You can also optionally attach the program to the function
  * exit instead of entry.
  *
@@ -975,6 +986,23 @@ bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
 
+/**
+ * @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach
+ * map during BPF skeleton attach phase.
+ * @param map the BPF map instance
+ * @param autoattach whether to attach map during BPF skeleton attach phase
+ * @return 0 on success; negative error code, otherwise
+ */
+LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach);
+
+/**
+ * @brief **bpf_map__autoattach()** returns whether BPF map is configured to
+ * auto-attach during BPF skeleton attach phase.
+ * @param map the BPF map instance
+ * @return true if map is set to auto-attach during skeleton attach phase; false, otherwise
+ */
+LIBBPF_API bool bpf_map__autoattach(const struct bpf_map *map);
+
 /**
  * @brief **bpf_map__fd()** gets the file descriptor of the passed
  * BPF map
@@ -1573,11 +1601,11 @@ LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_i
  * memory region of the ring buffer.
  * This ring buffer can be used to implement a custom events consumer.
  * The ring buffer starts with the *struct perf_event_mmap_page*, which
- * holds the ring buffer managment fields, when accessing the header
+ * holds the ring buffer management fields, when accessing the header
  * structure it's important to be SMP aware.
  * You can refer to *perf_event_read_simple* for a simple example.
  * @param pb the perf buffer structure
- * @param buf_idx the buffer index to retreive
+ * @param buf_idx the buffer index to retrieve
  * @param buf (out) gets the base pointer of the mmap()'ed memory
  * @param buf_size (out) gets the size of the mmap()'ed region
  * @return 0 on success, negative error code for failure
@@ -1669,6 +1697,7 @@ struct bpf_map_skeleton {
 	const char *name;
 	struct bpf_map **map;
 	void **mmaped;
+	struct bpf_link **link;
 };
 
 struct bpf_prog_skeleton {

src/libbpf.map

@@ -419,6 +419,13 @@ LIBBPF_1.4.0 {
 
 LIBBPF_1.5.0 {
 	global:
+		btf__distill_base;
+		btf__relocate;
+		btf_ext__endianness;
+		btf_ext__set_endianness;
+		bpf_map__autoattach;
+		bpf_map__set_autoattach;
+		bpf_object__token_fd;
 		bpf_program__attach_sockmap;
 		ring__consume_n;
 		ring_buffer__consume_n;

src/libbpf_internal.h

@@ -10,6 +10,7 @@
 #define __LIBBPF_LIBBPF_INTERNAL_H
 
 #include <stdlib.h>
+#include <byteswap.h>
 #include <limits.h>
 #include <errno.h>
 #include <linux/err.h>
@@ -234,6 +235,9 @@ struct btf_type;
 struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id);
 const char *btf_kind_str(const struct btf_type *t);
 const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
+const struct btf_header *btf_header(const struct btf *btf);
+void btf_set_base_btf(struct btf *btf, const struct btf *base_btf);
+int btf_relocate(struct btf *btf, const struct btf *base_btf, __u32 **id_map);
 
 static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t)
 {
@@ -445,11 +449,11 @@ struct btf_ext_info {
  *
  * The func_info subsection layout:
  *   record size for struct bpf_func_info in the func_info subsection
- *   struct btf_sec_func_info for section #1
+ *   struct btf_ext_info_sec for section #1
  *   a list of bpf_func_info records for section #1
  *     where struct bpf_func_info mimics one in include/uapi/linux/bpf.h
  *     but may not be identical
- *   struct btf_sec_func_info for section #2
+ *   struct btf_ext_info_sec for section #2
  *   a list of bpf_func_info records for section #2
  *   ......
  *
@@ -481,6 +485,8 @@ struct btf_ext {
 		struct btf_ext_header *hdr;
 		void *data;
 	};
+	void *data_swapped;
+	bool swapped_endian;
 	struct btf_ext_info func_info;
 	struct btf_ext_info line_info;
 	struct btf_ext_info core_relo_info;
@@ -508,11 +514,59 @@ struct bpf_line_info_min {
 	__u32	line_col;
 };
 
+/* Functions to byte-swap info records */
+
+typedef void (*info_rec_bswap_fn)(void *);
+
+static inline void bpf_func_info_bswap(struct bpf_func_info *i)
+{
+	i->insn_off = bswap_32(i->insn_off);
+	i->type_id = bswap_32(i->type_id);
+}
+
+static inline void bpf_line_info_bswap(struct bpf_line_info *i)
+{
+	i->insn_off = bswap_32(i->insn_off);
+	i->file_name_off = bswap_32(i->file_name_off);
+	i->line_off = bswap_32(i->line_off);
+	i->line_col = bswap_32(i->line_col);
+}
+
+static inline void bpf_core_relo_bswap(struct bpf_core_relo *i)
+{
+	i->insn_off = bswap_32(i->insn_off);
+	i->type_id = bswap_32(i->type_id);
+	i->access_str_off = bswap_32(i->access_str_off);
+	i->kind = bswap_32(i->kind);
+}
+
+enum btf_field_iter_kind {
+	BTF_FIELD_ITER_IDS,
+	BTF_FIELD_ITER_STRS,
+};
+
+struct btf_field_desc {
+	/* once-per-type offsets */
+	int t_off_cnt, t_offs[2];
+	/* member struct size, or zero, if no members */
+	int m_sz;
+	/* repeated per-member offsets */
+	int m_off_cnt, m_offs[1];
+};
+
+struct btf_field_iter {
+	struct btf_field_desc desc;
+	void *p;
+	int m_idx;
+	int off_idx;
+	int vlen;
+};
+
+int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t, enum btf_field_iter_kind iter_kind);
+__u32 *btf_field_iter_next(struct btf_field_iter *it);
 
 typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx);
 typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx);
-int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx);
-int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx);
 int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx);
 int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx);
 __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name,
@@ -563,6 +617,16 @@ static inline bool is_ldimm64_insn(struct bpf_insn *insn)
 	return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
 }
 
+static inline void bpf_insn_bswap(struct bpf_insn *insn)
+{
+	__u8 tmp_reg = insn->dst_reg;
+
+	insn->dst_reg = insn->src_reg;
+	insn->src_reg = tmp_reg;
+	insn->off = bswap_16(insn->off);
+	insn->imm = bswap_32(insn->imm);
+}
+
 /* Unconditionally dup FD, ensuring it doesn't use [0, 2] range.
  * Original FD is not closed or altered in any other way.
  * Preserves original FD value, if it's invalid (negative).
@@ -597,13 +661,9 @@ static inline int ensure_good_fd(int fd)
 	return fd;
 }
 
-static inline int sys_dup2(int oldfd, int newfd)
+static inline int sys_dup3(int oldfd, int newfd, int flags)
 {
-#ifdef __NR_dup2
-	return syscall(__NR_dup2, oldfd, newfd);
-#else
-	return syscall(__NR_dup3, oldfd, newfd, 0);
-#endif
+	return syscall(__NR_dup3, oldfd, newfd, flags);
 }
 
 /* Point *fixed_fd* to the same file that *tmp_fd* points to.
@@ -614,7 +674,7 @@ static inline int reuse_fd(int fixed_fd, int tmp_fd)
 {
 	int err;
 
-	err = sys_dup2(tmp_fd, fixed_fd);
+	err = sys_dup3(tmp_fd, fixed_fd, O_CLOEXEC);
 	err = err < 0 ? -errno : 0;
 	close(tmp_fd); /* clean up temporary FD */
 	return err;

src/libbpf_legacy.h

@@ -76,7 +76,7 @@ enum libbpf_strict_mode {
 	 * first BPF program or map creation operation. This is done only if
 	 * kernel is too old to support memcg-based memory accounting for BPF
 	 * subsystem. By default, RLIMIT_MEMLOCK limit is set to RLIM_INFINITY,
-	 * but it can be overriden with libbpf_set_memlock_rlim() API.
+	 * but it can be overridden with libbpf_set_memlock_rlim() API.
 	 * Note that libbpf_set_memlock_rlim() needs to be called before
 	 * the very first bpf_prog_load(), bpf_map_create() or bpf_object__load()
 	 * operation.
@@ -97,7 +97,7 @@ LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode);
  * @brief **libbpf_get_error()** extracts the error code from the passed
  * pointer
  * @param ptr pointer returned from libbpf API function
- * @return error code; or 0 if no error occured
+ * @return error code; or 0 if no error occurred
  *
  * Note, as of libbpf 1.0 this function is not necessary and not recommended
  * to be used. Libbpf doesn't return error code embedded into the pointer

src/libbpf_probes.c

@@ -97,6 +97,9 @@ __u32 get_kernel_version(void)
 	if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
 		return 0;
 
+	if (major == 4 && minor == 19 && patch > 255)
+		return KERNEL_VERSION(major, minor, 255);
+
 	return KERNEL_VERSION(major, minor, patch);
 }
 

src/linker.c

@@ -135,6 +135,7 @@ struct bpf_linker {
 	int fd;
 	Elf *elf;
 	Elf64_Ehdr *elf_hdr;
+	bool swapped_endian;
 
 	/* Output sections metadata */
 	struct dst_sec *secs;
@@ -324,13 +325,8 @@ static int init_output_elf(struct bpf_linker *linker, const char *file)
 
 	linker->elf_hdr->e_machine = EM_BPF;
 	linker->elf_hdr->e_type = ET_REL;
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-	linker->elf_hdr->e_ident[EI_DATA] = ELFDATA2LSB;
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-	linker->elf_hdr->e_ident[EI_DATA] = ELFDATA2MSB;
-#else
-#error "Unknown __BYTE_ORDER__"
-#endif
+	/* Set unknown ELF endianness, assign later from input files */
+	linker->elf_hdr->e_ident[EI_DATA] = ELFDATANONE;
 
 	/* STRTAB */
 	/* initialize strset with an empty string to conform to ELF */
@@ -396,6 +392,8 @@ static int init_output_elf(struct bpf_linker *linker, const char *file)
 		pr_warn_elf("failed to create SYMTAB data");
 		return -EINVAL;
 	}
+	/* Ensure libelf translates byte-order of symbol records */
+	sec->data->d_type = ELF_T_SYM;
 
 	str_off = strset__add_str(linker->strtab_strs, sec->sec_name);
 	if (str_off < 0)
@@ -539,19 +537,21 @@ static int linker_load_obj_file(struct bpf_linker *linker, const char *filename,
 				const struct bpf_linker_file_opts *opts,
 				struct src_obj *obj)
 {
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-	const int host_endianness = ELFDATA2LSB;
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-	const int host_endianness = ELFDATA2MSB;
-#else
-#error "Unknown __BYTE_ORDER__"
-#endif
 	int err = 0;
 	Elf_Scn *scn;
 	Elf_Data *data;
 	Elf64_Ehdr *ehdr;
 	Elf64_Shdr *shdr;
 	struct src_sec *sec;
+	unsigned char obj_byteorder;
+	unsigned char link_byteorder = linker->elf_hdr->e_ident[EI_DATA];
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	const unsigned char host_byteorder = ELFDATA2LSB;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	const unsigned char host_byteorder = ELFDATA2MSB;
+#else
+#error "Unknown __BYTE_ORDER__"
+#endif
 
 	pr_debug("linker: adding object file '%s'...\n", filename);
 
@@ -577,11 +577,25 @@ static int linker_load_obj_file(struct bpf_linker *linker, const char *filename,
 		pr_warn_elf("failed to get ELF header for %s", filename);
 		return err;
 	}
-	if (ehdr->e_ident[EI_DATA] != host_endianness) {
+
+	/* Linker output endianness set by first input object */
+	obj_byteorder = ehdr->e_ident[EI_DATA];
+	if (obj_byteorder != ELFDATA2LSB && obj_byteorder != ELFDATA2MSB) {
 		err = -EOPNOTSUPP;
-		pr_warn_elf("unsupported byte order of ELF file %s", filename);
+		pr_warn("unknown byte order of ELF file %s\n", filename);
 		return err;
 	}
+	if (link_byteorder == ELFDATANONE) {
+		linker->elf_hdr->e_ident[EI_DATA] = obj_byteorder;
+		linker->swapped_endian = obj_byteorder != host_byteorder;
+		pr_debug("linker: set %s-endian output byte order\n",
+			 obj_byteorder == ELFDATA2MSB ? "big" : "little");
+	} else if (link_byteorder != obj_byteorder) {
+		err = -EOPNOTSUPP;
+		pr_warn("byte order mismatch with ELF file %s\n", filename);
+		return err;
+	}
+
 	if (ehdr->e_type != ET_REL
 	    || ehdr->e_machine != EM_BPF
 	    || ehdr->e_ident[EI_CLASS] != ELFCLASS64) {
@@ -957,19 +971,33 @@ static int check_btf_str_off(__u32 *str_off, void *ctx)
 static int linker_sanity_check_btf(struct src_obj *obj)
 {
 	struct btf_type *t;
-	int i, n, err = 0;
+	int i, n, err;
 
 	if (!obj->btf)
 		return 0;
 
 	n = btf__type_cnt(obj->btf);
 	for (i = 1; i < n; i++) {
+		struct btf_field_iter it;
+		__u32 *type_id, *str_off;
+
 		t = btf_type_by_id(obj->btf, i);
 
-		err = err ?: btf_type_visit_type_ids(t, check_btf_type_id, obj->btf);
-		err = err ?: btf_type_visit_str_offs(t, check_btf_str_off, obj->btf);
+		err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_IDS);
 		if (err)
 			return err;
+		while ((type_id = btf_field_iter_next(&it))) {
+			if (*type_id >= n)
+				return -EINVAL;
+		}
+
+		err = btf_field_iter_init(&it, t, BTF_FIELD_ITER_STRS);
+		if (err)
+			return err;
+		while ((str_off = btf_field_iter_next(&it))) {
+			if (!btf__str_by_offset(obj->btf, *str_off))
+				return -EINVAL;
+		}
 	}
 
 	return 0;
@@ -1095,6 +1123,24 @@ static bool sec_content_is_same(struct dst_sec *dst_sec, struct src_sec *src_sec
 	return true;
 }
 
+static bool is_exec_sec(struct dst_sec *sec)
+{
+	if (!sec || sec->ephemeral)
+		return false;
+	return (sec->shdr->sh_type == SHT_PROGBITS) &&
+	       (sec->shdr->sh_flags & SHF_EXECINSTR);
+}
+
+static void exec_sec_bswap(void *raw_data, int size)
+{
+	const int insn_cnt = size / sizeof(struct bpf_insn);
+	struct bpf_insn *insn = raw_data;
+	int i;
+
+	for (i = 0; i < insn_cnt; i++, insn++)
+		bpf_insn_bswap(insn);
+}
+
 static int extend_sec(struct bpf_linker *linker, struct dst_sec *dst, struct src_sec *src)
 {
 	void *tmp;
@@ -1154,6 +1200,10 @@ static int extend_sec(struct bpf_linker *linker, struct dst_sec *dst, struct src
 		memset(dst->raw_data + dst->sec_sz, 0, dst_align_sz - dst->sec_sz);
 		/* now copy src data at a properly aligned offset */
 		memcpy(dst->raw_data + dst_align_sz, src->data->d_buf, src->shdr->sh_size);
+
+		/* convert added bpf insns to native byte-order */
+		if (linker->swapped_endian && is_exec_sec(dst))
+			exec_sec_bswap(dst->raw_data + dst_align_sz, src->shdr->sh_size);
 	}
 
 	dst->sec_sz = dst_final_sz;
@@ -1399,7 +1449,7 @@ recur:
 		return true;
 	case BTF_KIND_PTR:
 		/* just validate overall shape of the referenced type, so no
-		 * contents comparison for struct/union, and allowd fwd vs
+		 * contents comparison for struct/union, and allowed fwd vs
 		 * struct/union
 		 */
 		exact = false;
@@ -1948,7 +1998,7 @@ static int linker_append_elf_sym(struct bpf_linker *linker, struct src_obj *obj,
 
 		/* If existing symbol is a strong resolved symbol, bail out,
 		 * because we lost resolution battle have nothing to
-		 * contribute. We already checked abover that there is no
+		 * contribute. We already checked above that there is no
 		 * strong-strong conflict. We also already tightened binding
 		 * and visibility, so nothing else to contribute at that point.
 		 */
@@ -2213,10 +2263,17 @@ static int linker_fixup_btf(struct src_obj *obj)
 		vi = btf_var_secinfos(t);
 		for (j = 0, m = btf_vlen(t); j < m; j++, vi++) {
 			const struct btf_type *vt = btf__type_by_id(obj->btf, vi->type);
-			const char *var_name = btf__str_by_offset(obj->btf, vt->name_off);
-			int var_linkage = btf_var(vt)->linkage;
+			const char *var_name;
+			int var_linkage;
 			Elf64_Sym *sym;
 
+			/* could be a variable or function */
+			if (!btf_is_var(vt))
+				continue;
+
+			var_name = btf__str_by_offset(obj->btf, vt->name_off);
+			var_linkage = btf_var(vt)->linkage;
+
 			/* no need to patch up static or extern vars */
 			if (var_linkage != BTF_VAR_GLOBAL_ALLOCATED)
 				continue;
@@ -2234,26 +2291,10 @@ static int linker_fixup_btf(struct src_obj *obj)
 	return 0;
 }
 
-static int remap_type_id(__u32 *type_id, void *ctx)
-{
-	int *id_map = ctx;
-	int new_id = id_map[*type_id];
-
-	/* Error out if the type wasn't remapped. Ignore VOID which stays VOID. */
-	if (new_id == 0 && *type_id != 0) {
-		pr_warn("failed to find new ID mapping for original BTF type ID %u\n", *type_id);
-		return -EINVAL;
-	}
-
-	*type_id = id_map[*type_id];
-
-	return 0;
-}
-
 static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
 {
 	const struct btf_type *t;
-	int i, j, n, start_id, id;
+	int i, j, n, start_id, id, err;
 	const char *name;
 
 	if (!obj->btf)
@@ -2324,9 +2365,25 @@ static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
 	n = btf__type_cnt(linker->btf);
 	for (i = start_id; i < n; i++) {
 		struct btf_type *dst_t = btf_type_by_id(linker->btf, i);
+		struct btf_field_iter it;
+		__u32 *type_id;
 
-		if (btf_type_visit_type_ids(dst_t, remap_type_id, obj->btf_type_map))
-			return -EINVAL;
+		err = btf_field_iter_init(&it, dst_t, BTF_FIELD_ITER_IDS);
+		if (err)
+			return err;
+
+		while ((type_id = btf_field_iter_next(&it))) {
+			int new_id = obj->btf_type_map[*type_id];
+
+			/* Error out if the type wasn't remapped. Ignore VOID which stays VOID. */
+			if (new_id == 0 && *type_id != 0) {
+				pr_warn("failed to find new ID mapping for original BTF type ID %u\n",
+					*type_id);
+				return -EINVAL;
+			}
+
+			*type_id = obj->btf_type_map[*type_id];
+		}
 	}
 
 	/* Rewrite VAR/FUNC underlying types (i.e., FUNC's FUNC_PROTO and VAR's
@@ -2394,6 +2451,10 @@ static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
 			if (glob_sym && glob_sym->var_idx >= 0) {
 				__s64 sz;
 
+				/* FUNCs don't have size, nothing to update */
+				if (btf_is_func(t))
+					continue;
+
 				dst_var = &dst_sec->sec_vars[glob_sym->var_idx];
 				/* Because underlying BTF type might have
 				 * changed, so might its size have changed, so
@@ -2607,6 +2668,10 @@ int bpf_linker__finalize(struct bpf_linker *linker)
 		if (!sec->scn)
 			continue;
 
+		/* restore sections with bpf insns to target byte-order */
+		if (linker->swapped_endian && is_exec_sec(sec))
+			exec_sec_bswap(sec->raw_data, sec->sec_sz);
+
 		sec->data->d_buf = sec->raw_data;
 	}
 
@@ -2675,6 +2740,7 @@ static int emit_elf_data_sec(struct bpf_linker *linker, const char *sec_name,
 
 static int finalize_btf(struct bpf_linker *linker)
 {
+	enum btf_endianness link_endianness;
 	LIBBPF_OPTS(btf_dedup_opts, opts);
 	struct btf *btf = linker->btf;
 	const void *raw_data;
@@ -2719,6 +2785,13 @@ static int finalize_btf(struct bpf_linker *linker)
 		return err;
 	}
 
+	/* Set .BTF and .BTF.ext output byte order */
+	link_endianness = linker->elf_hdr->e_ident[EI_DATA] == ELFDATA2MSB ?
+			  BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN;
+	btf__set_endianness(linker->btf, link_endianness);
+	if (linker->btf_ext)
+		btf_ext__set_endianness(linker->btf_ext, link_endianness);
+
 	/* Emit .BTF section */
 	raw_data = btf__raw_data(linker->btf, &raw_sz);
 	if (!raw_data)

src/relo_core.c

@@ -1339,7 +1339,7 @@ int bpf_core_calc_relo_insn(const char *prog_name,
 					  cands->cands[i].id, cand_spec);
 		if (err < 0) {
 			bpf_core_format_spec(spec_buf, sizeof(spec_buf), cand_spec);
-			pr_warn("prog '%s': relo #%d: error matching candidate #%d %s: %d\n ",
+			pr_warn("prog '%s': relo #%d: error matching candidate #%d %s: %d\n",
 				prog_name, relo_idx, i, spec_buf, err);
 			return err;
 		}

src/skel_internal.h

@@ -107,7 +107,7 @@ static inline void skel_free(const void *p)
  * The loader program will perform probe_read_kernel() from maps.rodata.initial_value.
  * skel_finalize_map_data() sets skel->rodata to point to actual value in a bpf map and
  * does maps.rodata.initial_value = ~0ULL to signal skel_free_map_data() that kvfree
- * is not nessary.
+ * is not necessary.
  *
  * For user space:
  * skel_prep_map_data() mmaps anon memory into skel->rodata that can be accessed directly.
@@ -351,10 +351,11 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 	attr.test.ctx_size_in = opts->ctx->sz;
 	err = skel_sys_bpf(BPF_PROG_RUN, &attr, test_run_attr_sz);
 	if (err < 0 || (int)attr.test.retval < 0) {
-		opts->errstr = "failed to execute loader prog";
 		if (err < 0) {
+			opts->errstr = "failed to execute loader prog";
 			set_err;
 		} else {
+			opts->errstr = "error returned by loader prog";
 			err = (int)attr.test.retval;
 #ifndef __KERNEL__
 			errno = -err;

src/usdt.bpf.h

@@ -39,7 +39,7 @@ enum __bpf_usdt_arg_type {
 struct __bpf_usdt_arg_spec {
 	/* u64 scalar interpreted depending on arg_type, see below */
 	__u64 val_off;
-	/* arg location case, see bpf_udst_arg() for details */
+	/* arg location case, see bpf_usdt_arg() for details */
 	enum __bpf_usdt_arg_type arg_type;
 	/* offset of referenced register within struct pt_regs */
 	short reg_off;

src/zip.c

@@ -223,7 +223,7 @@ struct zip_archive *zip_archive_open(const char *path)
 	if (!archive) {
 		munmap(data, size);
 		return ERR_PTR(-ENOMEM);
-	};
+	}
 
 	archive->data = data;
 	archive->size = size;