Merge branch 'libbpf:master' into master

Syncing latest libbpf commits from kernel repository.
Baseline bpf-next commit:   b2531d4bdce19f28364b45aac9132e153b1f23a4
Checkpoint bpf-next commit: ac6a65868a5a45db49d5ee8524df3b701110d844
Baseline bpf commit:        f3f19f939c11925dadd3f4776f99f8c278a7017b
Checkpoint bpf commit:      f3f19f939c11925dadd3f4776f99f8c278a7017b

Andrii Nakryiko (1):
  libbpf: fix memory leak in attach_tp for target-less tracepoint
    program

 src/libbpf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--
2.30.2

.readthedocs.yaml

@@ -10,6 +10,11 @@ sphinx:
   builder: html
   configuration: docs/conf.py
 
+formats:
+  - htmlzip
+  - pdf
+  - epub
+
 # Optionally set the version of Python and requirements required to build your docs
 python:
    version: 3.7

BPF-CHECKPOINT-COMMIT

@@ -1 +1 @@
-fe68195daf34d5dddacd3f93dd3eafc4beca3a0e
+f3f19f939c11925dadd3f4776f99f8c278a7017b

CHECKPOINT-COMMIT

@@ -1 +1 @@
-dc37dc617fabfb1c3a16d49f5d8cc20e9e3608ca
+ac6a65868a5a45db49d5ee8524df3b701110d844

LICENSE.BSD-2-Clause

@@ -7,7 +7,7 @@ Usage-Guide:
     SPDX-License-Identifier: BSD-2-Clause
 License-Text:
 
-Copyright (c) <year> <owner> . All rights reserved.
+Copyright (c) 2015 The Libbpf Authors. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

README.md

@@ -73,34 +73,6 @@ $ cd src
 $ PKG_CONFIG_PATH=/build/root/lib64/pkgconfig DESTDIR=/build/root make install
 ```
 
-Distributions
-=============
-
-Distributions packaging libbpf from this mirror:
-  - [Fedora](https://src.fedoraproject.org/rpms/libbpf)
-  - [Gentoo](https://packages.gentoo.org/packages/dev-libs/libbpf)
-  - [Debian](https://packages.debian.org/source/sid/libbpf)
-  - [Arch](https://www.archlinux.org/packages/extra/x86_64/libbpf/)
-  - [Ubuntu](https://packages.ubuntu.com/source/impish/libbpf)
-  - [Alpine](https://pkgs.alpinelinux.org/packages?name=libbpf)
-
-Benefits of packaging from the mirror over packaging from kernel sources:
-  - Consistent versioning across distributions.
-  - No ties to any specific kernel, transparent handling of older kernels.
-    Libbpf is designed to be kernel-agnostic and work across multitude of
-    kernel versions. It has built-in mechanisms to gracefully handle older
-    kernels, that are missing some of the features, by working around or
-    gracefully degrading functionality. Thus libbpf is not tied to a specific
-    kernel version and can/should be packaged and versioned independently.
-  - Continuous integration testing via
-    [TravisCI](https://travis-ci.org/libbpf/libbpf).
-  - Static code analysis via [LGTM](https://lgtm.com/projects/g/libbpf/libbpf)
-    and [Coverity](https://scan.coverity.com/projects/libbpf).
-
-Package dependencies of libbpf, package names may vary across distros:
-  - zlib
-  - libelf
-
 BPF CO-RE (Compile Once – Run Everywhere)
 =========================================
 
@@ -154,6 +126,36 @@ use it:
   converting some more to both contribute to the BPF community and gain some
   more experience with it.
 
+Distributions
+=============
+
+Distributions packaging libbpf from this mirror:
+  - [Fedora](https://src.fedoraproject.org/rpms/libbpf)
+  - [Gentoo](https://packages.gentoo.org/packages/dev-libs/libbpf)
+  - [Debian](https://packages.debian.org/source/sid/libbpf)
+  - [Arch](https://www.archlinux.org/packages/extra/x86_64/libbpf/)
+  - [Ubuntu](https://packages.ubuntu.com/source/impish/libbpf)
+  - [Alpine](https://pkgs.alpinelinux.org/packages?name=libbpf)
+
+Benefits of packaging from the mirror over packaging from kernel sources:
+  - Consistent versioning across distributions.
+  - No ties to any specific kernel, transparent handling of older kernels.
+    Libbpf is designed to be kernel-agnostic and work across multitude of
+    kernel versions. It has built-in mechanisms to gracefully handle older
+    kernels, that are missing some of the features, by working around or
+    gracefully degrading functionality. Thus libbpf is not tied to a specific
+    kernel version and can/should be packaged and versioned independently.
+  - Continuous integration testing via
+    [TravisCI](https://travis-ci.org/libbpf/libbpf).
+  - Static code analysis via [LGTM](https://lgtm.com/projects/g/libbpf/libbpf)
+    and [Coverity](https://scan.coverity.com/projects/libbpf).
+
+Package dependencies of libbpf, package names may vary across distros:
+  - zlib
+  - libelf
+
+[![libbpf distro packaging status](https://repology.org/badge/vertical-allrepos/libbpf.svg)](https://repology.org/project/libbpf/versions)
+
 License
 =======
 

docs/index.rst

@@ -6,14 +6,13 @@ libbpf
 .. toctree::
    :maxdepth: 1
 
+   API Documentation <https://libbpf.readthedocs.io/en/latest/api.html>
    libbpf_naming_convention
    libbpf_build
 
 This is documentation for libbpf, a userspace library for loading and
 interacting with bpf programs.
 
-For API documentation see the `versioned API documentation site <https://libbpf.readthedocs.io/en/latest/api.html>`_.
-
 All general BPF questions, including kernel functionality, libbpf APIs and
 their application, should be sent to bpf@vger.kernel.org mailing list.
 You can `subscribe <http://vger.kernel.org/vger-lists.html#bpf>`_ to the

include/uapi/linux/bpf.h

@@ -997,6 +997,7 @@ enum bpf_attach_type {
 	BPF_SK_REUSEPORT_SELECT,
 	BPF_SK_REUSEPORT_SELECT_OR_MIGRATE,
 	BPF_PERF_EVENT,
+	BPF_TRACE_KPROBE_MULTI,
 	__MAX_BPF_ATTACH_TYPE
 };
 
@@ -1011,6 +1012,8 @@ enum bpf_link_type {
 	BPF_LINK_TYPE_NETNS = 5,
 	BPF_LINK_TYPE_XDP = 6,
 	BPF_LINK_TYPE_PERF_EVENT = 7,
+	BPF_LINK_TYPE_KPROBE_MULTI = 8,
+	BPF_LINK_TYPE_STRUCT_OPS = 9,
 
 	MAX_BPF_LINK_TYPE,
 };
@@ -1118,6 +1121,11 @@ enum bpf_link_type {
  */
 #define BPF_F_XDP_HAS_FRAGS	(1U << 5)
 
+/* link_create.kprobe_multi.flags used in LINK_CREATE command for
+ * BPF_TRACE_KPROBE_MULTI attach type to create return probe.
+ */
+#define BPF_F_KPROBE_MULTI_RETURN	(1U << 0)
+
 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
  * the following extensions:
  *
@@ -1232,6 +1240,8 @@ enum {
 
 /* If set, run the test on the cpu specified by bpf_attr.test.cpu */
 #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)
 
 /* type for BPF_ENABLE_STATS */
 enum bpf_stats_type {
@@ -1393,6 +1403,7 @@ union bpf_attr {
 		__aligned_u64	ctx_out;
 		__u32		flags;
 		__u32		cpu;
+		__u32		batch_size;
 	} test;
 
 	struct { /* anonymous struct used by BPF_*_GET_*_ID */
@@ -1472,6 +1483,22 @@ union bpf_attr {
 				 */
 				__u64		bpf_cookie;
 			} perf_event;
+			struct {
+				__u32		flags;
+				__u32		cnt;
+				__aligned_u64	syms;
+				__aligned_u64	addrs;
+				__aligned_u64	cookies;
+			} kprobe_multi;
+			struct {
+				/* this is overlaid with the target_btf_id above. */
+				__u32		target_btf_id;
+				/* black box user-provided value passed through
+				 * to BPF program at the execution time and
+				 * accessible through bpf_get_attach_cookie() BPF helper
+				 */
+				__u64		cookie;
+			} tracing;
 		};
 	} link_create;
 
@@ -2299,8 +2326,8 @@ union bpf_attr {
  * 	Return
  * 		The return value depends on the result of the test, and can be:
  *
- *		* 0, if current task belongs to the cgroup2.
+ *		* 1, if current task belongs to the cgroup2.
- *		* 1, if current task does not belong to the cgroup2.
+ *		* 0, if current task does not belong to the cgroup2.
  * 		* A negative error code, if an error occurred.
  *
  * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
@@ -2992,8 +3019,8 @@ union bpf_attr {
  *
  * 			# sysctl kernel.perf_event_max_stack=<new value>
  * 	Return
- * 		A non-negative value equal to or less than *size* on success,
+ * 		The non-negative copied *buf* length equal to or less than
- * 		or a negative error in case of failure.
+ * 		*size* on success, or a negative error in case of failure.
  *
  * long bpf_skb_load_bytes_relative(const void *skb, u32 offset, void *to, u32 len, u32 start_header)
  * 	Description
@@ -4299,8 +4326,8 @@ union bpf_attr {
  *
  *			# sysctl kernel.perf_event_max_stack=<new value>
  *	Return
- *		A non-negative value equal to or less than *size* on success,
+ * 		The non-negative copied *buf* length equal to or less than
- *		or a negative error in case of failure.
+ * 		*size* on success, or a negative error in case of failure.
  *
  * long bpf_load_hdr_opt(struct bpf_sock_ops *skops, void *searchby_res, u32 len, u64 flags)
  *	Description
@@ -5086,6 +5113,65 @@ union bpf_attr {
  *	Return
  *		0 on success, or a negative error in case of failure. On error
  *		*dst* buffer is zeroed out.
+ *
+ * long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type)
+ *	Description
+ *		Change the __sk_buff->tstamp_type to *tstamp_type*
+ *		and set *tstamp* to the __sk_buff->tstamp together.
+ *
+ *		If there is no need to change the __sk_buff->tstamp_type,
+ *		the tstamp value can be directly written to __sk_buff->tstamp
+ *		instead.
+ *
+ *		BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
+ *		will be kept during bpf_redirect_*().  A non zero
+ *		*tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
+ *		*tstamp_type*.
+ *
+ *		A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used
+ *		with a zero *tstamp*.
+ *
+ *		Only IPv4 and IPv6 skb->protocol are supported.
+ *
+ *		This function is most useful when it needs to set a
+ *		mono delivery time to __sk_buff->tstamp and then
+ *		bpf_redirect_*() to the egress of an iface.  For example,
+ *		changing the (rcv) timestamp in __sk_buff->tstamp at
+ *		ingress to a mono delivery time and then bpf_redirect_*()
+ *		to sch_fq@phy-dev.
+ *	Return
+ *		0 on success.
+ *		**-EINVAL** for invalid input
+ *		**-EOPNOTSUPP** for unsupported protocol
+ *
+ * long bpf_ima_file_hash(struct file *file, void *dst, u32 size)
+ *	Description
+ *		Returns a calculated IMA hash of the *file*.
+ *		If the hash is larger than *size*, then only *size*
+ *		bytes will be copied to *dst*
+ *	Return
+ *		The **hash_algo** is returned on success,
+ *		**-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if
+ *		invalid arguments are passed.
+ *
+ * void *bpf_kptr_xchg(void *map_value, 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.
+ *	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
+ *		corresponding release function, or moved into a BPF map before
+ *		program exit.
+ *
+ * void *bpf_map_lookup_percpu_elem(struct bpf_map *map, const void *key, u32 cpu)
+ * 	Description
+ * 		Perform a lookup in *percpu map* for an entry associated to
+ * 		*key* on *cpu*.
+ * 	Return
+ * 		Map value associated to *key* on *cpu*, or **NULL** if no entry
+ * 		was found or *cpu* is invalid.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5280,6 +5366,10 @@ union bpf_attr {
 	FN(xdp_load_bytes),		\
 	FN(xdp_store_bytes),		\
 	FN(copy_from_user_task),	\
+	FN(skb_set_tstamp),		\
+	FN(ima_file_hash),		\
+	FN(kptr_xchg),			\
+	FN(map_lookup_percpu_elem),     \
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -5469,6 +5559,15 @@ union {					\
 	__u64 :64;			\
 } __attribute__((aligned(8)))
 
+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.
+	 */
+};
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
@@ -5509,7 +5608,8 @@ struct __sk_buff {
 	__u32 gso_segs;
 	__bpf_md_ptr(struct bpf_sock *, sk);
 	__u32 gso_size;
-	__u32 :32;		/* Padding, future use. */
+	__u8  tstamp_type;
+	__u32 :24;		/* Padding, future use. */
 	__u64 hwtstamp;
 };
 
@@ -5523,6 +5623,10 @@ struct bpf_tunnel_key {
 	__u8 tunnel_ttl;
 	__u16 tunnel_ext;	/* Padding, future use. */
 	__u32 tunnel_label;
+	union {
+		__u32 local_ipv4;
+		__u32 local_ipv6[4];
+	};
 };
 
 /* user accessible mirror of in-kernel xfrm_state.
@@ -6453,7 +6557,8 @@ struct bpf_sk_lookup {
 	__u32 protocol;		/* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */
 	__u32 remote_ip4;	/* Network byte order */
 	__u32 remote_ip6[4];	/* Network byte order */
-	__u32 remote_port;	/* Network byte order */
+	__be16 remote_port;	/* Network byte order */
+	__u16 :16;		/* Zero padding */
 	__u32 local_ip4;	/* Network byte order */
 	__u32 local_ip6[4];	/* Network byte order */
 	__u32 local_port;	/* Host byte order */

include/uapi/linux/btf.h

@@ -33,8 +33,8 @@ struct btf_type {
 	/* "info" bits arrangement
 	 * bits  0-15: vlen (e.g. # of struct's members)
 	 * bits 16-23: unused
-	 * bits 24-27: kind (e.g. int, ptr, array...etc)
+	 * bits 24-28: kind (e.g. int, ptr, array...etc)
-	 * bits 28-30: unused
+	 * bits 29-30: unused
 	 * bit     31: kind_flag, currently used by
 	 *             struct, union and fwd
 	 */

include/uapi/linux/if_link.h

@@ -860,6 +860,7 @@ enum {
 	IFLA_BOND_PEER_NOTIF_DELAY,
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
+	IFLA_BOND_NS_IP6_TARGET,
 	__IFLA_BOND_MAX,
 };
 

include/uapi/linux/perf_event.h

@@ -251,6 +251,8 @@ enum {
 	PERF_BR_SYSRET		= 8,	/* syscall return */
 	PERF_BR_COND_CALL	= 9,	/* conditional function call */
 	PERF_BR_COND_RET	= 10,	/* conditional function return */
+	PERF_BR_ERET		= 11,	/* exception return */
+	PERF_BR_IRQ		= 12,	/* irq */
 	PERF_BR_MAX,
 };
 
@@ -465,6 +467,8 @@ struct perf_event_attr {
 	/*
 	 * User provided data if sigtrap=1, passed back to user via
 	 * siginfo_t::si_perf_data, e.g. to permit user to identify the event.
+	 * Note, siginfo_t::si_perf_data is long-sized, and sig_data will be
+	 * truncated accordingly on 32 bit architectures.
 	 */
 	__u64	sig_data;
 };

scripts/build-fuzzers.sh

@@ -17,6 +17,24 @@ mkdir -p "$OUT"
 
 export LIB_FUZZING_ENGINE=${LIB_FUZZING_ENGINE:--fsanitize=fuzzer}
 
+# libelf is compiled with _FORTIFY_SOURCE by default and it
+# isn't compatible with MSan. It was borrowed
+# from https://github.com/google/oss-fuzz/pull/7422
+if [[ "$SANITIZER" == memory ]]; then
+    CFLAGS+=" -U_FORTIFY_SOURCE"
+    CXXFLAGS+=" -U_FORTIFY_SOURCE"
+fi
+
+# The alignment check is turned off by default on OSS-Fuzz/CFLite so it should be
+# turned on explicitly there. It was borrowed from
+# https://github.com/google/oss-fuzz/pull/7092
+if [[ "$SANITIZER" == undefined ]]; then
+    additional_ubsan_checks=alignment
+    UBSAN_FLAGS="-fsanitize=$additional_ubsan_checks -fno-sanitize-recover=$additional_ubsan_checks"
+    CFLAGS+=" $UBSAN_FLAGS"
+    CXXFLAGS+=" $UBSAN_FLAGS"
+fi
+
 # Ideally libbelf should be built using release tarballs available
 # at https://sourceware.org/elfutils/ftp/. Unfortunately sometimes they
 # fail to compile (for example, elfutils-0.185 fails to compile with LDFLAGS enabled
@@ -26,7 +44,7 @@ rm -rf elfutils
 git clone git://sourceware.org/git/elfutils.git
 (
 cd elfutils
-git checkout 983e86fd89e8bf02f2d27ba5dce5bf078af4ceda
+git checkout 83251d4091241acddbdcf16f814e3bc6ef3df49a
 git log --oneline -1
 
 # ASan isn't compatible with -Wl,--no-undefined: https://github.com/google/sanitizers/issues/380
@@ -36,6 +54,11 @@ find -name Makefile.am | xargs sed -i 's/,--no-undefined//'
 # https://clang.llvm.org/docs/AddressSanitizer.html#usage
 sed -i 's/^\(ZDEFS_LDFLAGS=\).*/\1/' configure.ac
 
+if [[ "$SANITIZER" == undefined ]]; then
+    # That's basicaly what --enable-sanitize-undefined does to turn off unaligned access
+    # elfutils heavily relies on on i386/x86_64 but without changing compiler flags along the way
+    sed -i 's/\(check_undefined_val\)=[0-9]/\1=1/' configure.ac
+fi
 
 autoreconf -i -f
 if ! ./configure --enable-maintainer-mode --disable-debuginfod --disable-libdebuginfod \

src/Makefile

@@ -8,10 +8,15 @@ else
 	msg = @printf '  %-8s %s%s\n' "$(1)" "$(2)" "$(if $(3), $(3))";
 endif
 
-LIBBPF_VERSION := $(shell \
+LIBBPF_MAJOR_VERSION := 0
-	grep -oE '^LIBBPF_([0-9.]+)' libbpf.map | \
+LIBBPF_MINOR_VERSION := 8
-	sort -rV | head -n1 | cut -d'_' -f2)
+LIBBPF_PATCH_VERSION := 0
-LIBBPF_MAJOR_VERSION := $(firstword $(subst ., ,$(LIBBPF_VERSION)))
+LIBBPF_VERSION := $(LIBBPF_MAJOR_VERSION).$(LIBBPF_MINOR_VERSION).$(LIBBPF_PATCH_VERSION)
+LIBBPF_MAJMIN_VERSION := $(LIBBPF_MAJOR_VERSION).$(LIBBPF_MINOR_VERSION).0
+LIBBPF_MAP_VERSION := $(shell grep -oE '^LIBBPF_([0-9.]+)' libbpf.map | sort -rV | head -n1 | cut -d'_' -f2)
+ifneq ($(LIBBPF_MAJMIN_VERSION), $(LIBBPF_MAP_VERSION))
+$(error Libbpf release ($(LIBBPF_VERSION)) and map ($(LIBBPF_MAP_VERSION)) versions are out of sync!)
+endif
 
 TOPDIR = ..
 
@@ -37,7 +42,7 @@ 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 xsk.o \
 	btf_dump.o hashmap.o ringbuf.o strset.o linker.o gen_loader.o \
-	relo_core.o
+	relo_core.o usdt.o
 SHARED_OBJS := $(addprefix $(SHARED_OBJDIR)/,$(OBJS))
 STATIC_OBJS := $(addprefix $(STATIC_OBJDIR)/,$(OBJS))
 
@@ -51,7 +56,8 @@ endif
 
 HEADERS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \
 	   bpf_helpers.h bpf_helper_defs.h bpf_tracing.h \
-	   bpf_endian.h bpf_core_read.h skel_internal.h libbpf_version.h
+	   bpf_endian.h bpf_core_read.h skel_internal.h libbpf_version.h \
+	   usdt.bpf.h
 UAPI_HEADERS := $(addprefix $(TOPDIR)/include/uapi/linux/,\
 			    bpf.h bpf_common.h btf.h)
 
@@ -99,7 +105,7 @@ $(OBJDIR)/libbpf.so.$(LIBBPF_VERSION): $(SHARED_OBJS)
 		  -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \
 		  $^ $(ALL_LDFLAGS) -o $@
 
-$(OBJDIR)/libbpf.pc:
+$(OBJDIR)/libbpf.pc: force
 	$(Q)sed -e "s|@PREFIX@|$(PREFIX)|" \
 		-e "s|@LIBDIR@|$(LIBDIR_PC)|" \
 		-e "s|@VERSION@|$(LIBBPF_VERSION)|" \
@@ -152,7 +158,7 @@ clean:
 	$(call msg,CLEAN)
 	$(Q)rm -rf *.o *.a *.so *.so.* *.pc $(SHARED_OBJDIR) $(STATIC_OBJDIR)
 
-.PHONY: cscope tags
+.PHONY: cscope tags force
 cscope:
 	$(call msg,CSCOPE)
 	$(Q)ls *.c *.h > cscope.files
@@ -162,3 +168,5 @@ tags:
 	$(call msg,CTAGS)
 	$(Q)rm -f TAGS tags
 	$(Q)ls *.c *.h | xargs $(TAGS_PROG) -a
+
+force:

src/bpf.c

@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <linux/bpf.h>
 #include <linux/filter.h>
+#include <linux/kernel.h>
 #include <limits.h>
 #include <sys/resource.h>
 #include "bpf.h"
@@ -111,7 +112,7 @@ int probe_memcg_account(void)
 		BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
 		BPF_EXIT_INSN(),
 	};
-	size_t insn_cnt = sizeof(insns) / sizeof(insns[0]);
+	size_t insn_cnt = ARRAY_SIZE(insns);
 	union bpf_attr attr;
 	int prog_fd;
 
@@ -638,6 +639,20 @@ int bpf_map_delete_elem(int fd, const void *key)
 	return libbpf_err_errno(ret);
 }
 
+int bpf_map_delete_elem_flags(int fd, const void *key, __u64 flags)
+{
+	union bpf_attr attr;
+	int ret;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.flags = flags;
+
+	ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
+	return libbpf_err_errno(ret);
+}
+
 int bpf_map_get_next_key(int fd, const void *key, void *next_key)
 {
 	union bpf_attr attr;
@@ -816,7 +831,7 @@ int bpf_link_create(int prog_fd, int target_fd,
 {
 	__u32 target_btf_id, iter_info_len;
 	union bpf_attr attr;
-	int fd;
+	int fd, err;
 
 	if (!OPTS_VALID(opts, bpf_link_create_opts))
 		return libbpf_err(-EINVAL);
@@ -853,6 +868,23 @@ int bpf_link_create(int prog_fd, int target_fd,
 		if (!OPTS_ZEROED(opts, perf_event))
 			return libbpf_err(-EINVAL);
 		break;
+	case BPF_TRACE_KPROBE_MULTI:
+		attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0);
+		attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0);
+		attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0));
+		attr.link_create.kprobe_multi.addrs = ptr_to_u64(OPTS_GET(opts, kprobe_multi.addrs, 0));
+		attr.link_create.kprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, kprobe_multi.cookies, 0));
+		if (!OPTS_ZEROED(opts, kprobe_multi))
+			return libbpf_err(-EINVAL);
+		break;
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+	case BPF_MODIFY_RETURN:
+	case BPF_LSM_MAC:
+		attr.link_create.tracing.cookie = OPTS_GET(opts, tracing.cookie, 0);
+		if (!OPTS_ZEROED(opts, tracing))
+			return libbpf_err(-EINVAL);
+		break;
 	default:
 		if (!OPTS_ZEROED(opts, flags))
 			return libbpf_err(-EINVAL);
@@ -860,7 +892,37 @@ int bpf_link_create(int prog_fd, int target_fd,
 	}
 proceed:
 	fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, sizeof(attr));
-	return libbpf_err_errno(fd);
+	if (fd >= 0)
+		return fd;
+	/* we'll get EINVAL if LINK_CREATE doesn't support attaching fentry
+	 * and other similar programs
+	 */
+	err = -errno;
+	if (err != -EINVAL)
+		return libbpf_err(err);
+
+	/* if user used features not supported by
+	 * BPF_RAW_TRACEPOINT_OPEN command, then just give up immediately
+	 */
+	if (attr.link_create.target_fd || attr.link_create.target_btf_id)
+		return libbpf_err(err);
+	if (!OPTS_ZEROED(opts, sz))
+		return libbpf_err(err);
+
+	/* otherwise, for few select kinds of programs that can be
+	 * attached using BPF_RAW_TRACEPOINT_OPEN command, try that as
+	 * a fallback for older kernels
+	 */
+	switch (attach_type) {
+	case BPF_TRACE_RAW_TP:
+	case BPF_LSM_MAC:
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+	case BPF_MODIFY_RETURN:
+		return bpf_raw_tracepoint_open(NULL, prog_fd);
+	default:
+		return libbpf_err(err);
+	}
 }
 
 int bpf_link_detach(int link_fd)
@@ -994,6 +1056,7 @@ int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts)
 
 	memset(&attr, 0, sizeof(attr));
 	attr.test.prog_fd = prog_fd;
+	attr.test.batch_size = OPTS_GET(opts, batch_size, 0);
 	attr.test.cpu = OPTS_GET(opts, cpu, 0);
 	attr.test.flags = OPTS_GET(opts, flags, 0);
 	attr.test.repeat = OPTS_GET(opts, repeat, 0);

src/bpf.h

@@ -244,6 +244,7 @@ LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
 LIBBPF_API int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key,
 						    void *value, __u64 flags);
 LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
+LIBBPF_API int bpf_map_delete_elem_flags(int fd, const void *key, __u64 flags);
 LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
 LIBBPF_API int bpf_map_freeze(int fd);
 
@@ -413,10 +414,20 @@ struct bpf_link_create_opts {
 		struct {
 			__u64 bpf_cookie;
 		} perf_event;
+		struct {
+			__u32 flags;
+			__u32 cnt;
+			const char **syms;
+			const unsigned long *addrs;
+			const __u64 *cookies;
+		} kprobe_multi;
+		struct {
+			__u64 cookie;
+		} tracing;
 	};
 	size_t :0;
 };
-#define bpf_link_create_opts__last_field perf_event
+#define bpf_link_create_opts__last_field kprobe_multi.cookies
 
 LIBBPF_API int bpf_link_create(int prog_fd, int target_fd,
 			       enum bpf_attach_type attach_type,
@@ -512,8 +523,9 @@ struct bpf_test_run_opts {
 	__u32 duration;      /* out: average per repetition in ns */
 	__u32 flags;
 	__u32 cpu;
+	__u32 batch_size;
 };
-#define bpf_test_run_opts__last_field cpu
+#define bpf_test_run_opts__last_field batch_size
 
 LIBBPF_API int bpf_prog_test_run_opts(int prog_fd,
 				      struct bpf_test_run_opts *opts);

src/bpf_core_read.h

@@ -110,21 +110,50 @@ enum bpf_enum_value_kind {
 	val;								      \
 })
 
+#define ___bpf_field_ref1(field)	(field)
+#define ___bpf_field_ref2(type, field)	(((typeof(type) *)0)->field)
+#define ___bpf_field_ref(args...)					    \
+	___bpf_apply(___bpf_field_ref, ___bpf_narg(args))(args)
+
 /*
  * Convenience macro to check that field actually exists in target kernel's.
  * Returns:
  *    1, if matching field is present in target kernel;
  *    0, if no matching field found.
+ *
+ * Supports two forms:
+ *   - field reference through variable access:
+ *     bpf_core_field_exists(p->my_field);
+ *   - field reference through type and field names:
+ *     bpf_core_field_exists(struct my_type, my_field).
  */
-#define bpf_core_field_exists(field)					    \
+#define bpf_core_field_exists(field...)					    \
-	__builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
+	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_EXISTS)
 
 /*
  * Convenience macro to get the byte size of a field. Works for integers,
  * struct/unions, pointers, arrays, and enums.
+ *
+ * Supports two forms:
+ *   - field reference through variable access:
+ *     bpf_core_field_size(p->my_field);
+ *   - field reference through type and field names:
+ *     bpf_core_field_size(struct my_type, my_field).
  */
-#define bpf_core_field_size(field)					    \
+#define bpf_core_field_size(field...)					    \
-	__builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE)
+	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_SIZE)
+
+/*
+ * Convenience macro to get field's byte offset.
+ *
+ * Supports two forms:
+ *   - field reference through variable access:
+ *     bpf_core_field_offset(p->my_field);
+ *   - field reference through type and field names:
+ *     bpf_core_field_offset(struct my_type, my_field).
+ */
+#define bpf_core_field_offset(field...)					    \
+	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_OFFSET)
 
 /*
  * Convenience macro to get BTF type ID of a specified type, using a local BTF

src/bpf_helper_defs.h

@@ -961,8 +961,8 @@ static long (*bpf_probe_write_user)(void *dst, const void *src, __u32 len) = (vo
  * Returns
  * 	The return value depends on the result of the test, and can be:
  *
- * 	* 0, if current task belongs to the cgroup2.
+ * 	* 1, if current task belongs to the cgroup2.
- * 	* 1, if current task does not belong to the cgroup2.
+ * 	* 0, if current task does not belong to the cgroup2.
  * 	* A negative error code, if an error occurred.
  */
 static long (*bpf_current_task_under_cgroup)(void *map, __u32 index) = (void *) 37;
@@ -1752,8 +1752,8 @@ static long (*bpf_skb_get_xfrm_state)(struct __sk_buff *skb, __u32 index, struct
  * 		# sysctl kernel.perf_event_max_stack=<new value>
  *
  * Returns
- * 	A non-negative value equal to or less than *size* on success,
+ * 	The non-negative copied *buf* length equal to or less than
- * 	or a negative error in case of failure.
+ * 	*size* on success, or a negative error in case of failure.
  */
 static long (*bpf_get_stack)(void *ctx, void *buf, __u32 size, __u64 flags) = (void *) 67;
 
@@ -3305,8 +3305,8 @@ static struct udp6_sock *(*bpf_skc_to_udp6_sock)(void *sk) = (void *) 140;
  * 		# sysctl kernel.perf_event_max_stack=<new value>
  *
  * Returns
- * 	A non-negative value equal to or less than *size* on success,
+ * 	The non-negative copied *buf* length equal to or less than
- * 	or a negative error in case of failure.
+ * 	*size* on success, or a negative error in case of failure.
  */
 static long (*bpf_get_task_stack)(struct task_struct *task, void *buf, __u32 size, __u64 flags) = (void *) 141;
 
@@ -4295,4 +4295,79 @@ static long (*bpf_xdp_store_bytes)(struct xdp_md *xdp_md, __u32 offset, void *bu
  */
 static long (*bpf_copy_from_user_task)(void *dst, __u32 size, const void *user_ptr, struct task_struct *tsk, __u64 flags) = (void *) 191;
 
+/*
+ * bpf_skb_set_tstamp
+ *
+ * 	Change the __sk_buff->tstamp_type to *tstamp_type*
+ * 	and set *tstamp* to the __sk_buff->tstamp together.
+ *
+ * 	If there is no need to change the __sk_buff->tstamp_type,
+ * 	the tstamp value can be directly written to __sk_buff->tstamp
+ * 	instead.
+ *
+ * 	BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
+ * 	will be kept during bpf_redirect_*().  A non zero
+ * 	*tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
+ * 	*tstamp_type*.
+ *
+ * 	A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used
+ * 	with a zero *tstamp*.
+ *
+ * 	Only IPv4 and IPv6 skb->protocol are supported.
+ *
+ * 	This function is most useful when it needs to set a
+ * 	mono delivery time to __sk_buff->tstamp and then
+ * 	bpf_redirect_*() to the egress of an iface.  For example,
+ * 	changing the (rcv) timestamp in __sk_buff->tstamp at
+ * 	ingress to a mono delivery time and then bpf_redirect_*()
+ * 	to sch_fq@phy-dev.
+ *
+ * Returns
+ * 	0 on success.
+ * 	**-EINVAL** for invalid input
+ * 	**-EOPNOTSUPP** for unsupported protocol
+ */
+static long (*bpf_skb_set_tstamp)(struct __sk_buff *skb, __u64 tstamp, __u32 tstamp_type) = (void *) 192;
+
+/*
+ * bpf_ima_file_hash
+ *
+ * 	Returns a calculated IMA hash of the *file*.
+ * 	If the hash is larger than *size*, then only *size*
+ * 	bytes will be copied to *dst*
+ *
+ * Returns
+ * 	The **hash_algo** is returned on success,
+ * 	**-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if
+ * 	invalid arguments are passed.
+ */
+static long (*bpf_ima_file_hash)(struct file *file, void *dst, __u32 size) = (void *) 193;
+
+/*
+ * 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.
+ *
+ * Returns
+ * 	The old value of kptr (which can be NULL). The returned pointer
+ * 	if not NULL, is a reference which must be released using its
+ * 	corresponding release function, or moved into a BPF map before
+ * 	program exit.
+ */
+static void *(*bpf_kptr_xchg)(void *map_value, void *ptr) = (void *) 194;
+
+/*
+ * bpf_map_lookup_percpu_elem
+ *
+ * 	Perform a lookup in *percpu map* for an entry associated to
+ * 	*key* on *cpu*.
+ *
+ * Returns
+ * 	Map value associated to *key* on *cpu*, or **NULL** if no entry
+ * 	was found or *cpu* is invalid.
+ */
+static void *(*bpf_map_lookup_percpu_elem)(void *map, const void *key, __u32 cpu) = (void *) 195;
+
 

src/bpf_helpers.h

@@ -75,6 +75,30 @@
 	})
 #endif
 
+/*
+ * Compiler (optimization) barrier.
+ */
+#ifndef barrier
+#define barrier() asm volatile("" ::: "memory")
+#endif
+
+/* Variable-specific compiler (optimization) barrier. It's a no-op which makes
+ * compiler believe that there is some black box modification of a given
+ * variable and thus prevents compiler from making extra assumption about its
+ * value and potential simplifications and optimizations on this variable.
+ *
+ * E.g., compiler might often delay or even omit 32-bit to 64-bit casting of
+ * a variable, making some code patterns unverifiable. Putting barrier_var()
+ * in place will ensure that cast is performed before the barrier_var()
+ * invocation, because compiler has to pessimistically assume that embedded
+ * asm section might perform some extra operations on that variable.
+ *
+ * This is a variable-specific variant of more global barrier().
+ */
+#ifndef barrier_var
+#define barrier_var(var) asm volatile("" : "=r"(var) : "0"(var))
+#endif
+
 /*
  * Helper macro to throw a compilation error if __bpf_unreachable() gets
  * built into the resulting code. This works given BPF back end does not
@@ -149,6 +173,8 @@ enum libbpf_tristate {
 
 #define __kconfig __attribute__((section(".kconfig")))
 #define __ksym __attribute__((section(".ksyms")))
+#define __kptr __attribute__((btf_type_tag("kptr")))
+#define __kptr_ref __attribute__((btf_type_tag("kptr_ref")))
 
 #ifndef ___bpf_concat
 #define ___bpf_concat(a, b) a ## b

src/bpf_tracing.h

@@ -27,6 +27,9 @@
 #elif defined(__TARGET_ARCH_riscv)
 	#define bpf_target_riscv
 	#define bpf_target_defined
+#elif defined(__TARGET_ARCH_arc)
+	#define bpf_target_arc
+	#define bpf_target_defined
 #else
 
 /* Fall back to what the compiler says */
@@ -54,6 +57,9 @@
 #elif defined(__riscv) && __riscv_xlen == 64
 	#define bpf_target_riscv
 	#define bpf_target_defined
+#elif defined(__arc__)
+	#define bpf_target_arc
+	#define bpf_target_defined
 #endif /* no compiler target */
 
 #endif
@@ -233,6 +239,23 @@ struct pt_regs___arm64 {
 /* riscv does not select ARCH_HAS_SYSCALL_WRAPPER. */
 #define PT_REGS_SYSCALL_REGS(ctx) ctx
 
+#elif defined(bpf_target_arc)
+
+/* arc provides struct user_pt_regs instead of struct pt_regs to userspace */
+#define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
+#define __PT_PARM1_REG scratch.r0
+#define __PT_PARM2_REG scratch.r1
+#define __PT_PARM3_REG scratch.r2
+#define __PT_PARM4_REG scratch.r3
+#define __PT_PARM5_REG scratch.r4
+#define __PT_RET_REG scratch.blink
+#define __PT_FP_REG __unsupported__
+#define __PT_RC_REG scratch.r0
+#define __PT_SP_REG scratch.sp
+#define __PT_IP_REG scratch.ret
+/* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */
+#define PT_REGS_SYSCALL_REGS(ctx) ctx
+
 #endif
 
 #if defined(bpf_target_defined)

src/btf.c

@@ -2626,6 +2626,7 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext,
 	const struct btf_ext_info_sec *sinfo;
 	struct btf_ext_info *ext_info;
 	__u32 info_left, record_size;
+	size_t sec_cnt = 0;
 	/* The start of the info sec (including the __u32 record_size). */
 	void *info;
 
@@ -2689,8 +2690,7 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext,
 			return -EINVAL;
 		}
 
-		total_record_size = sec_hdrlen +
+		total_record_size = sec_hdrlen + (__u64)num_records * record_size;
-				    (__u64)num_records * record_size;
 		if (info_left < total_record_size) {
 			pr_debug("%s section has incorrect num_records in .BTF.ext\n",
 			     ext_sec->desc);
@@ -2699,12 +2699,14 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext,
 
 		info_left -= total_record_size;
 		sinfo = (void *)sinfo + total_record_size;
+		sec_cnt++;
 	}
 
 	ext_info = ext_sec->ext_info;
 	ext_info->len = ext_sec->len - sizeof(__u32);
 	ext_info->rec_size = record_size;
 	ext_info->info = info + sizeof(__u32);
+	ext_info->sec_cnt = sec_cnt;
 
 	return 0;
 }
@@ -2788,6 +2790,9 @@ void btf_ext__free(struct btf_ext *btf_ext)
 {
 	if (IS_ERR_OR_NULL(btf_ext))
 		return;
+	free(btf_ext->func_info.sec_idxs);
+	free(btf_ext->line_info.sec_idxs);
+	free(btf_ext->core_relo_info.sec_idxs);
 	free(btf_ext->data);
 	free(btf_ext);
 }
@@ -2826,10 +2831,8 @@ struct btf_ext *btf_ext__new(const __u8 *data, __u32 size)
 	if (err)
 		goto done;
 
-	if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) {
+	if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len))
-		err = -EINVAL;
+		goto done; /* skip core relos parsing */
-		goto done;
-	}
 
 	err = btf_ext_setup_core_relos(btf_ext);
 	if (err)

src/btf_dump.c

@@ -1505,6 +1505,11 @@ static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id,
 	if (s->name_resolved)
 		return *cached_name ? *cached_name : orig_name;
 
+	if (btf_is_fwd(t) || (btf_is_enum(t) && btf_vlen(t) == 0)) {
+		s->name_resolved = 1;
+		return orig_name;
+	}
+
 	dup_cnt = btf_dump_name_dups(d, name_map, orig_name);
 	if (dup_cnt > 1) {
 		const size_t max_len = 256;

src/gen_loader.c

@@ -1043,18 +1043,27 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue,
 	value = add_data(gen, pvalue, value_size);
 	key = add_data(gen, &zero, sizeof(zero));
 
-	/* if (map_desc[map_idx].initial_value)
+	/* if (map_desc[map_idx].initial_value) {
-	 *    copy_from_user(value, initial_value, value_size);
+	 *    if (ctx->flags & BPF_SKEL_KERNEL)
+	 *        bpf_probe_read_kernel(value, value_size, initial_value);
+	 *    else
+	 *        bpf_copy_from_user(value, value_size, initial_value);
+	 * }
 	 */
 	emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_6,
 			      sizeof(struct bpf_loader_ctx) +
 			      sizeof(struct bpf_map_desc) * map_idx +
 			      offsetof(struct bpf_map_desc, initial_value)));
-	emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 4));
+	emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 8));
 	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE,
 					 0, 0, 0, value));
 	emit(gen, BPF_MOV64_IMM(BPF_REG_2, value_size));
+	emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6,
+			      offsetof(struct bpf_loader_ctx, flags)));
+	emit(gen, BPF_JMP_IMM(BPF_JSET, BPF_REG_0, BPF_SKEL_KERNEL, 2));
 	emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user));
+	emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, 1));
+	emit(gen, BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel));
 
 	map_update_attr = add_data(gen, &attr, attr_size);
 	move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4,

src/libbpf.h

@@ -323,6 +323,24 @@ struct bpf_insn;
  * different.
  */
 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
+
+/**
+ * @brief **bpf_program__set_insns()** can set BPF program's underlying
+ * BPF instructions.
+ *
+ * WARNING: This is a very advanced libbpf API and users need to know
+ * what they are doing. This should be used from prog_prepare_load_fn
+ * callback only.
+ *
+ * @param prog BPF program for which to return instructions
+ * @param new_insns a pointer to an array of BPF instructions
+ * @param new_insn_cnt number of `struct bpf_insn`'s that form
+ * specified BPF program
+ * @return 0, on success; negative error code, otherwise
+ */
+LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
+				      struct bpf_insn *new_insns, size_t new_insn_cnt);
+
 /**
  * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
  * that form specified BPF program.
@@ -378,7 +396,31 @@ struct bpf_link;
 LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
 LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
+/**
+ * @brief **bpf_link__pin()** pins the BPF link to a file
+ * in the BPF FS specified by a path. This increments the links
+ * reference count, allowing it to stay loaded after the process
+ * which loaded it has exited.
+ *
+ * @param link BPF link to pin, must already be loaded
+ * @param path file path in a BPF file system
+ * @return 0, on success; negative error code, otherwise
+ */
+
 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
+
+/**
+ * @brief **bpf_link__unpin()** unpins the BPF link from a file
+ * in the BPFFS specified by a path. This decrements the links
+ * reference count.
+ *
+ * The file pinning the BPF link can also be unlinked by a different
+ * process in which case this function will return an error.
+ *
+ * @param prog BPF program to unpin
+ * @param path file path to the pin in a BPF file system
+ * @return 0, on success; negative error code, otherwise
+ */
 LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
 LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
 					struct bpf_program *prog);
@@ -386,6 +428,22 @@ LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
 LIBBPF_API int bpf_link__detach(struct bpf_link *link);
 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.
+ *
+ * @param prog BPF program to attach
+ * @return Reference to the newly created BPF link; or NULL is returned on error,
+ * error code is stored in errno
+ *
+ * This is supported for:
+ *   - kprobe/kretprobe (depends on SEC() definition)
+ *   - uprobe/uretprobe (depends on SEC() definition)
+ *   - tracepoint
+ *   - raw tracepoint
+ *   - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
+ */
 LIBBPF_API struct bpf_link *
 bpf_program__attach(const struct bpf_program *prog);
 
@@ -425,6 +483,29 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
                                 const char *func_name,
                                 const struct bpf_kprobe_opts *opts);
 
+struct bpf_kprobe_multi_opts {
+	/* size of this struct, for forward/backward compatibility */
+	size_t sz;
+	/* array of function symbols to attach */
+	const char **syms;
+	/* array of function addresses to attach */
+	const unsigned long *addrs;
+	/* array of user-provided values fetchable through bpf_get_attach_cookie */
+	const __u64 *cookies;
+	/* number of elements in syms/addrs/cookies arrays */
+	size_t cnt;
+	/* create return kprobes */
+	bool retprobe;
+	size_t :0;
+};
+
+#define bpf_kprobe_multi_opts__last_field retprobe
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
+				      const char *pattern,
+				      const struct bpf_kprobe_multi_opts *opts);
+
 struct bpf_uprobe_opts {
 	/* size of this struct, for forward/backward compatiblity */
 	size_t sz;
@@ -436,9 +517,17 @@ struct bpf_uprobe_opts {
 	__u64 bpf_cookie;
 	/* uprobe is return probe, invoked at function return time */
 	bool retprobe;
+	/* Function name to attach to.  Could be an unqualified ("abc") or library-qualified
+	 * "abc@LIBXYZ" name.  To specify function entry, func_name should be set while
+	 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0.  To trace an
+	 * offset within a function, specify func_name and use func_offset argument to specify
+	 * offset within the function.  Shared library functions must specify the shared library
+	 * binary_path.
+	 */
+	const char *func_name;
 	size_t :0;
 };
-#define bpf_uprobe_opts__last_field retprobe
+#define bpf_uprobe_opts__last_field func_name
 
 /**
  * @brief **bpf_program__attach_uprobe()** attaches a BPF program
@@ -480,6 +569,37 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 				const char *binary_path, size_t func_offset,
 				const struct bpf_uprobe_opts *opts);
 
+struct bpf_usdt_opts {
+	/* size of this struct, for forward/backward compatibility */
+	size_t sz;
+	/* custom user-provided value accessible through usdt_cookie() */
+	__u64 usdt_cookie;
+	size_t :0;
+};
+#define bpf_usdt_opts__last_field usdt_cookie
+
+/**
+ * @brief **bpf_program__attach_usdt()** is just like
+ * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
+ * Statically Defined Tracepoint) attachment, instead of attaching to
+ * user-space function entry or exit.
+ *
+ * @param prog BPF program to attach
+ * @param pid Process ID to attach the uprobe to, 0 for self (own process),
+ * -1 for all processes
+ * @param binary_path Path to binary that contains provided USDT probe
+ * @param usdt_provider USDT provider name
+ * @param usdt_name USDT probe name
+ * @param opts Options for altering program attachment
+ * @return Reference to the newly created BPF link; or NULL is returned on error,
+ * error code is stored in errno
+ */
+LIBBPF_API struct bpf_link *
+bpf_program__attach_usdt(const struct bpf_program *prog,
+			 pid_t pid, const char *binary_path,
+			 const char *usdt_provider, const char *usdt_name,
+			 const struct bpf_usdt_opts *opts);
+
 struct bpf_tracepoint_opts {
 	/* size of this struct, for forward/backward compatiblity */
 	size_t sz;
@@ -501,8 +621,20 @@ bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
 LIBBPF_API struct bpf_link *
 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
 				   const char *tp_name);
+
+struct bpf_trace_opts {
+	/* size of this struct, for forward/backward compatibility */
+	size_t sz;
+	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
+	__u64 cookie;
+};
+#define bpf_trace_opts__last_field cookie
+
 LIBBPF_API struct bpf_link *
 bpf_program__attach_trace(const struct bpf_program *prog);
+LIBBPF_API struct bpf_link *
+bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
+
 LIBBPF_API struct bpf_link *
 bpf_program__attach_lsm(const struct bpf_program *prog);
 LIBBPF_API struct bpf_link *
@@ -624,12 +756,37 @@ LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_program__set_type() instead")
 LIBBPF_API int bpf_program__set_sk_lookup(struct bpf_program *prog);
 
 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
-LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
+
-				      enum bpf_prog_type type);
+/**
+ * @brief **bpf_program__set_type()** sets the program
+ * type of the passed BPF program.
+ * @param prog BPF program to set the program type for
+ * @param type program type to set the BPF map to have
+ * @return error code; or 0 if no error. An error occurs
+ * if the object is already loaded.
+ *
+ * This must be called before the BPF object is loaded,
+ * otherwise it has no effect and an error is returned.
+ */
+LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
+				     enum bpf_prog_type type);
 
 LIBBPF_API enum bpf_attach_type
 bpf_program__expected_attach_type(const struct bpf_program *prog);
-LIBBPF_API void
+
+/**
+ * @brief **bpf_program__set_expected_attach_type()** sets the
+ * attach type of the passed BPF program. This is used for
+ * auto-detection of attachment when programs are loaded.
+ * @param prog BPF program to set the attach type for
+ * @param type attach type to set the BPF map to have
+ * @return error code; or 0 if no error. An error occurs
+ * if the object is already loaded.
+ *
+ * This must be called before the BPF object is loaded,
+ * otherwise it has no effect and an error is returned.
+ */
+LIBBPF_API int
 bpf_program__set_expected_attach_type(struct bpf_program *prog,
 				      enum bpf_attach_type type);
 
@@ -645,6 +802,17 @@ LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_le
 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
 
+/**
+ * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
+ * for supported BPF program types:
+ *   - BTF-aware raw tracepoints (tp_btf);
+ *   - fentry/fexit/fmod_ret;
+ *   - lsm;
+ *   - freplace.
+ * @param prog BPF program to set the attach type for
+ * @param type attach type to set the BPF map to have
+ * @return error code; or 0 if no error occurred.
+ */
 LIBBPF_API int
 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
 			       const char *attach_func_name);
@@ -728,6 +896,28 @@ struct bpf_map *bpf_map__prev(const struct bpf_map *map, const struct bpf_object
 LIBBPF_API struct bpf_map *
 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
 
+/**
+ * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
+ * BPF map during BPF object load phase.
+ * @param map the BPF map instance
+ * @param autocreate whether to create BPF map during BPF object load
+ * @return 0 on success; -EBUSY if BPF object was already loaded
+ *
+ * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
+ * BPF map. By default, libbpf will attempt to create every single BPF map
+ * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
+ * and fill in map FD in BPF instructions.
+ *
+ * This API allows to opt-out of this process for specific map instance. This
+ * can be useful if host kernel doesn't support such BPF map type or used
+ * combination of flags and user application wants to avoid creating such
+ * a map in the first place. User is still responsible to make sure that their
+ * BPF-side code that expects to use such missing BPF map is recognized by BPF
+ * verifier as dead code, otherwise BPF verifier will reject such BPF program.
+ */
+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__fd()** gets the file descriptor of the passed
  * BPF map
@@ -800,6 +990,110 @@ LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
 
+/**
+ * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
+ * corresponding to provided key.
+ * @param map BPF map to lookup element in
+ * @param key pointer to memory containing bytes of the key used for lookup
+ * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
+ * @param value pointer to memory in which looked up value will be stored
+ * @param value_sz size in byte of value data memory; it has to match BPF map
+ * definition's **value_size**. For per-CPU BPF maps value size has to be
+ * a product of BPF map value size and number of possible CPUs in the system
+ * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
+ * per-CPU values value size has to be aligned up to closest 8 bytes for
+ * alignment reasons, so expected size is: `round_up(value_size, 8)
+ * * libbpf_num_possible_cpus()`.
+ * @flags extra flags passed to kernel for this operation
+ * @return 0, on success; negative error, otherwise
+ *
+ * **bpf_map__lookup_elem()** is high-level equivalent of
+ * **bpf_map_lookup_elem()** API with added check for key and value size.
+ */
+LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
+				    const void *key, size_t key_sz,
+				    void *value, size_t value_sz, __u64 flags);
+
+/**
+ * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
+ * map that corresponds to provided key.
+ * @param map BPF map to insert to or update element in
+ * @param key pointer to memory containing bytes of the key
+ * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
+ * @param value pointer to memory containing bytes of the value
+ * @param value_sz size in byte of value data memory; it has to match BPF map
+ * definition's **value_size**. For per-CPU BPF maps value size has to be
+ * a product of BPF map value size and number of possible CPUs in the system
+ * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
+ * per-CPU values value size has to be aligned up to closest 8 bytes for
+ * alignment reasons, so expected size is: `round_up(value_size, 8)
+ * * libbpf_num_possible_cpus()`.
+ * @flags extra flags passed to kernel for this operation
+ * @return 0, on success; negative error, otherwise
+ *
+ * **bpf_map__update_elem()** is high-level equivalent of
+ * **bpf_map_update_elem()** API with added check for key and value size.
+ */
+LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
+				    const void *key, size_t key_sz,
+				    const void *value, size_t value_sz, __u64 flags);
+
+/**
+ * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
+ * corresponds to provided key.
+ * @param map BPF map to delete element from
+ * @param key pointer to memory containing bytes of the key
+ * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
+ * @flags extra flags passed to kernel for this operation
+ * @return 0, on success; negative error, otherwise
+ *
+ * **bpf_map__delete_elem()** is high-level equivalent of
+ * **bpf_map_delete_elem()** API with added check for key size.
+ */
+LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
+				    const void *key, size_t key_sz, __u64 flags);
+
+/**
+ * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
+ * corresponding to provided key and atomically delete it afterwards.
+ * @param map BPF map to lookup element in
+ * @param key pointer to memory containing bytes of the key used for lookup
+ * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
+ * @param value pointer to memory in which looked up value will be stored
+ * @param value_sz size in byte of value data memory; it has to match BPF map
+ * definition's **value_size**. For per-CPU BPF maps value size has to be
+ * a product of BPF map value size and number of possible CPUs in the system
+ * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
+ * per-CPU values value size has to be aligned up to closest 8 bytes for
+ * alignment reasons, so expected size is: `round_up(value_size, 8)
+ * * libbpf_num_possible_cpus()`.
+ * @flags extra flags passed to kernel for this operation
+ * @return 0, on success; negative error, otherwise
+ *
+ * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
+ * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
+ */
+LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
+					       const void *key, size_t key_sz,
+					       void *value, size_t value_sz, __u64 flags);
+
+/**
+ * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
+ * fetching next key that follows current key.
+ * @param map BPF map to fetch next key from
+ * @param cur_key pointer to memory containing bytes of current key or NULL to
+ * fetch the first key
+ * @param next_key pointer to memory to write next key into
+ * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
+ * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
+ * negative error, otherwise
+ *
+ * **bpf_map__get_next_key()** is high-level equivalent of
+ * **bpf_map_get_next_key()** API with added check for key size.
+ */
+LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
+				     const void *cur_key, void *next_key, size_t key_sz);
+
 /**
  * @brief **libbpf_get_error()** extracts the error code from the passed
  * pointer
@@ -1289,6 +1583,35 @@ LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
 
+struct bpf_var_skeleton {
+	const char *name;
+	struct bpf_map **map;
+	void **addr;
+};
+
+struct bpf_object_subskeleton {
+	size_t sz; /* size of this struct, for forward/backward compatibility */
+
+	const struct bpf_object *obj;
+
+	int map_cnt;
+	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
+	struct bpf_map_skeleton *maps;
+
+	int prog_cnt;
+	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
+	struct bpf_prog_skeleton *progs;
+
+	int var_cnt;
+	int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
+	struct bpf_var_skeleton *vars;
+};
+
+LIBBPF_API int
+bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
+LIBBPF_API void
+bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
+
 struct gen_loader_opts {
 	size_t sz; /* size of this struct, for forward/backward compatiblity */
 	const char *data;
@@ -1328,6 +1651,115 @@ LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
 
+/*
+ * Custom handling of BPF program's SEC() definitions
+ */
+
+struct bpf_prog_load_opts; /* defined in bpf.h */
+
+/* Called during bpf_object__open() for each recognized BPF program. Callback
+ * can use various bpf_program__set_*() setters to adjust whatever properties
+ * are necessary.
+ */
+typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
+
+/* Called right before libbpf performs bpf_prog_load() to load BPF program
+ * into the kernel. Callback can adjust opts as necessary.
+ */
+typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
+					     struct bpf_prog_load_opts *opts, long cookie);
+
+/* Called during skeleton attach or through bpf_program__attach(). If
+ * auto-attach is not supported, callback should return 0 and set link to
+ * NULL (it's not considered an error during skeleton attach, but it will be
+ * an error for bpf_program__attach() calls). On error, error should be
+ * returned directly and link set to NULL. On success, return 0 and set link
+ * to a valid struct bpf_link.
+ */
+typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
+				       struct bpf_link **link);
+
+struct libbpf_prog_handler_opts {
+	/* size of this struct, for forward/backward compatiblity */
+	size_t sz;
+	/* User-provided value that is passed to prog_setup_fn,
+	 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
+	 * register one set of callbacks for multiple SEC() definitions and
+	 * still be able to distinguish them, if necessary. For example,
+	 * libbpf itself is using this to pass necessary flags (e.g.,
+	 * sleepable flag) to a common internal SEC() handler.
+	 */
+	long cookie;
+	/* BPF program initialization callback (see libbpf_prog_setup_fn_t).
+	 * Callback is optional, pass NULL if it's not necessary.
+	 */
+	libbpf_prog_setup_fn_t prog_setup_fn;
+	/* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
+	 * Callback is optional, pass NULL if it's not necessary.
+	 */
+	libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
+	/* BPF program attach callback (see libbpf_prog_attach_fn_t).
+	 * Callback is optional, pass NULL if it's not necessary.
+	 */
+	libbpf_prog_attach_fn_t prog_attach_fn;
+};
+#define libbpf_prog_handler_opts__last_field prog_attach_fn
+
+/**
+ * @brief **libbpf_register_prog_handler()** registers a custom BPF program
+ * SEC() handler.
+ * @param sec section prefix for which custom handler is registered
+ * @param prog_type BPF program type associated with specified section
+ * @param exp_attach_type Expected BPF attach type associated with specified section
+ * @param opts optional cookie, callbacks, and other extra options
+ * @return Non-negative handler ID is returned on success. This handler ID has
+ * to be passed to *libbpf_unregister_prog_handler()* to unregister such
+ * custom handler. Negative error code is returned on error.
+ *
+ * *sec* defines which SEC() definitions are handled by this custom handler
+ * registration. *sec* can have few different forms:
+ *   - if *sec* is just a plain string (e.g., "abc"), it will match only
+ *   SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
+ *   in an error;
+ *   - if *sec* is of the form "abc/", proper SEC() form is
+ *   SEC("abc/something"), where acceptable "something" should be checked by
+ *   *prog_init_fn* callback, if there are additional restrictions;
+ *   - if *sec* is of the form "abc+", it will successfully match both
+ *   SEC("abc") and SEC("abc/whatever") forms;
+ *   - if *sec* is NULL, custom handler is registered for any BPF program that
+ *   doesn't match any of the registered (custom or libbpf's own) SEC()
+ *   handlers. There could be only one such generic custom handler registered
+ *   at any given time.
+ *
+ * All custom handlers (except the one with *sec* == NULL) are processed
+ * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
+ * SEC() handlers by registering custom ones for the same section prefix
+ * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
+ * handler).
+ *
+ * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
+ * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
+ * to ensure synchronization if there is a risk of running this API from
+ * multiple threads simultaneously.
+ */
+LIBBPF_API int libbpf_register_prog_handler(const char *sec,
+					    enum bpf_prog_type prog_type,
+					    enum bpf_attach_type exp_attach_type,
+					    const struct libbpf_prog_handler_opts *opts);
+/**
+ * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
+ * custom BPF program SEC() handler.
+ * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
+ * after successful registration
+ * @return 0 on success, negative error code if handler isn't found
+ *
+ * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
+ * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
+ * to ensure synchronization if there is a risk of running this API from
+ * multiple threads simultaneously.
+ */
+LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

src/libbpf.map

@@ -438,4 +438,24 @@ LIBBPF_0.7.0 {
 		libbpf_probe_bpf_map_type;
 		libbpf_probe_bpf_prog_type;
 		libbpf_set_memlock_rlim_max;
-};
+} LIBBPF_0.6.0;
+
+LIBBPF_0.8.0 {
+	global:
+		bpf_map__autocreate;
+		bpf_map__get_next_key;
+		bpf_map__delete_elem;
+		bpf_map__lookup_and_delete_elem;
+		bpf_map__lookup_elem;
+		bpf_map__set_autocreate;
+		bpf_map__update_elem;
+		bpf_map_delete_elem_flags;
+		bpf_object__destroy_subskeleton;
+		bpf_object__open_subskeleton;
+		bpf_program__attach_kprobe_multi_opts;
+		bpf_program__attach_trace_opts;
+		bpf_program__attach_usdt;
+		bpf_program__set_insns;
+		libbpf_register_prog_handler;
+		libbpf_unregister_prog_handler;
+} LIBBPF_0.7.0;

src/libbpf_internal.h

@@ -103,6 +103,17 @@
 #define str_has_pfx(str, pfx) \
 	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
 
+/* suffix check */
+static inline bool str_has_sfx(const char *str, const char *sfx)
+{
+	size_t str_len = strlen(str);
+	size_t sfx_len = strlen(sfx);
+
+	if (sfx_len <= str_len)
+		return strcmp(str + str_len - sfx_len, sfx);
+	return false;
+}
+
 /* Symbol versioning is different between static and shared library.
  * Properly versioned symbols are needed for shared library, but
  * only the symbol of the new version is needed for static library.
@@ -148,6 +159,15 @@ do {				\
 #ifndef __has_builtin
 #define __has_builtin(x) 0
 #endif
+
+struct bpf_link {
+	int (*detach)(struct bpf_link *link);
+	void (*dealloc)(struct bpf_link *link);
+	char *pin_path;		/* NULL, if not pinned */
+	int fd;			/* hook FD, -1 if not applicable */
+	bool disconnected;
+};
+
 /*
  * Re-implement glibc's reallocarray() for libbpf internal-only use.
  * reallocarray(), unfortunately, is not available in all versions of glibc,
@@ -329,6 +349,8 @@ enum kern_feature_id {
 	FEAT_BTF_TYPE_TAG,
 	/* memcg-based accounting for BPF maps and progs */
 	FEAT_MEMCG_ACCOUNT,
+	/* BPF cookie (bpf_get_attach_cookie() BPF helper) support */
+	FEAT_BPF_COOKIE,
 	__FEAT_CNT,
 };
 
@@ -354,6 +376,13 @@ struct btf_ext_info {
 	void *info;
 	__u32 rec_size;
 	__u32 len;
+	/* optional (maintained internally by libbpf) mapping between .BTF.ext
+	 * section and corresponding ELF section. This is used to join
+	 * information like CO-RE relocation records with corresponding BPF
+	 * programs defined in ELF sections
+	 */
+	__u32 *sec_idxs;
+	int sec_cnt;
 };
 
 #define for_each_btf_ext_sec(seg, sec)					\
@@ -449,6 +478,11 @@ __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name,
 
 extern enum libbpf_strict_mode libbpf_mode;
 
+typedef int (*kallsyms_cb_t)(unsigned long long sym_addr, char sym_type,
+			     const char *sym_name, void *ctx);
+
+int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *arg);
+
 /* handle direct returned errors */
 static inline int libbpf_err(int ret)
 {
@@ -529,4 +563,21 @@ static inline int ensure_good_fd(int fd)
 	return fd;
 }
 
+/* The following two functions are exposed to bpftool */
+int bpf_core_add_cands(struct bpf_core_cand *local_cand,
+		       size_t local_essent_len,
+		       const struct btf *targ_btf,
+		       const char *targ_btf_name,
+		       int targ_start_id,
+		       struct bpf_core_cand_list *cands);
+void bpf_core_free_cands(struct bpf_core_cand_list *cands);
+
+struct usdt_manager *usdt_manager_new(struct bpf_object *obj);
+void usdt_manager_free(struct usdt_manager *man);
+struct bpf_link * usdt_manager_attach_usdt(struct usdt_manager *man,
+					   const struct bpf_program *prog,
+					   pid_t pid, const char *path,
+					   const char *usdt_provider, const char *usdt_name,
+					   __u64 usdt_cookie);
+
 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */

src/libbpf_legacy.h

@@ -54,6 +54,10 @@ enum libbpf_strict_mode {
 	 *
 	 * Note, in this mode the program pin path will be based on the
 	 * function name instead of section name.
+	 *
+	 * Additionally, routines in the .text section are always considered
+	 * sub-programs. Legacy behavior allows for a single routine in .text
+	 * to be a program.
 	 */
 	LIBBPF_STRICT_SEC_NAME = 0x04,
 	/*

src/libbpf_version.h

@@ -4,6 +4,6 @@
 #define __LIBBPF_VERSION_H
 
 #define LIBBPF_MAJOR_VERSION 0
-#define LIBBPF_MINOR_VERSION 7
+#define LIBBPF_MINOR_VERSION 8
 
 #endif /* __LIBBPF_VERSION_H */

src/netlink.c

@@ -87,29 +87,75 @@ enum {
 	NL_DONE,
 };
 
+static int netlink_recvmsg(int sock, struct msghdr *mhdr, int flags)
+{
+	int len;
+
+	do {
+		len = recvmsg(sock, mhdr, flags);
+	} while (len < 0 && (errno == EINTR || errno == EAGAIN));
+
+	if (len < 0)
+		return -errno;
+	return len;
+}
+
+static int alloc_iov(struct iovec *iov, int len)
+{
+	void *nbuf;
+
+	nbuf = realloc(iov->iov_base, len);
+	if (!nbuf)
+		return -ENOMEM;
+
+	iov->iov_base = nbuf;
+	iov->iov_len = len;
+	return 0;
+}
+
 static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq,
 			       __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
 			       void *cookie)
 {
+	struct iovec iov = {};
+	struct msghdr mhdr = {
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+	};
 	bool multipart = true;
 	struct nlmsgerr *err;
 	struct nlmsghdr *nh;
-	char buf[4096];
 	int len, ret;
 
+	ret = alloc_iov(&iov, 4096);
+	if (ret)
+		goto done;
+
 	while (multipart) {
 start:
 		multipart = false;
-		len = recv(sock, buf, sizeof(buf), 0);
+		len = netlink_recvmsg(sock, &mhdr, MSG_PEEK | MSG_TRUNC);
 		if (len < 0) {
-			ret = -errno;
+			ret = len;
+			goto done;
+		}
+
+		if (len > iov.iov_len) {
+			ret = alloc_iov(&iov, len);
+			if (ret)
+				goto done;
+		}
+
+		len = netlink_recvmsg(sock, &mhdr, 0);
+		if (len < 0) {
+			ret = len;
 			goto done;
 		}
 
 		if (len == 0)
 			break;
 
-		for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
+		for (nh = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(nh, len);
 		     nh = NLMSG_NEXT(nh, len)) {
 			if (nh->nlmsg_pid != nl_pid) {
 				ret = -LIBBPF_ERRNO__WRNGPID;
@@ -130,7 +176,8 @@ start:
 				libbpf_nla_dump_errormsg(nh);
 				goto done;
 			case NLMSG_DONE:
-				return 0;
+				ret = 0;
+				goto done;
 			default:
 				break;
 			}
@@ -142,15 +189,17 @@ start:
 				case NL_NEXT:
 					goto start;
 				case NL_DONE:
-					return 0;
+					ret = 0;
+					goto done;
 				default:
-					return ret;
+					goto done;
 				}
 			}
 		}
 	}
 	ret = 0;
 done:
+	free(iov.iov_base);
 	return ret;
 }
 

src/relo_core.c

@@ -178,29 +178,28 @@ static bool core_relo_is_enumval_based(enum bpf_core_relo_kind kind)
  * Enum value-based relocations (ENUMVAL_EXISTS/ENUMVAL_VALUE) use access
  * string to specify enumerator's value index that need to be relocated.
  */
-static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
+int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
-			       __u32 type_id,
+			const struct bpf_core_relo *relo,
-			       const char *spec_str,
+			struct bpf_core_spec *spec)
-			       enum bpf_core_relo_kind relo_kind,
-			       struct bpf_core_spec *spec)
 {
 	int access_idx, parsed_len, i;
 	struct bpf_core_accessor *acc;
 	const struct btf_type *t;
-	const char *name;
+	const char *name, *spec_str;
 	__u32 id;
 	__s64 sz;
 
+	spec_str = btf__name_by_offset(btf, relo->access_str_off);
 	if (str_is_empty(spec_str) || *spec_str == ':')
 		return -EINVAL;
 
 	memset(spec, 0, sizeof(*spec));
 	spec->btf = btf;
-	spec->root_type_id = type_id;
+	spec->root_type_id = relo->type_id;
-	spec->relo_kind = relo_kind;
+	spec->relo_kind = relo->kind;
 
 	/* type-based relocations don't have a field access string */
-	if (core_relo_is_type_based(relo_kind)) {
+	if (core_relo_is_type_based(relo->kind)) {
 		if (strcmp(spec_str, "0"))
 			return -EINVAL;
 		return 0;
@@ -221,7 +220,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
 	if (spec->raw_len == 0)
 		return -EINVAL;
 
-	t = skip_mods_and_typedefs(btf, type_id, &id);
+	t = skip_mods_and_typedefs(btf, relo->type_id, &id);
 	if (!t)
 		return -EINVAL;
 
@@ -231,7 +230,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
 	acc->idx = access_idx;
 	spec->len++;
 
-	if (core_relo_is_enumval_based(relo_kind)) {
+	if (core_relo_is_enumval_based(relo->kind)) {
 		if (!btf_is_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t))
 			return -EINVAL;
 
@@ -240,7 +239,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
 		return 0;
 	}
 
-	if (!core_relo_is_field_based(relo_kind))
+	if (!core_relo_is_field_based(relo->kind))
 		return -EINVAL;
 
 	sz = btf__resolve_size(btf, id);
@@ -301,7 +300,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
 			spec->bit_offset += access_idx * sz * 8;
 		} else {
 			pr_warn("prog '%s': relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %s\n",
-				prog_name, type_id, spec_str, i, id, btf_kind_str(t));
+				prog_name, relo->type_id, spec_str, i, id, btf_kind_str(t));
 			return -EINVAL;
 		}
 	}
@@ -775,31 +774,6 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
 	return 0;
 }
 
-struct bpf_core_relo_res
-{
-	/* expected value in the instruction, unless validate == false */
-	__u32 orig_val;
-	/* new value that needs to be patched up to */
-	__u32 new_val;
-	/* relocation unsuccessful, poison instruction, but don't fail load */
-	bool poison;
-	/* some relocations can't be validated against orig_val */
-	bool validate;
-	/* for field byte offset relocations or the forms:
-	 *     *(T *)(rX + <off>) = rY
-	 *     rX = *(T *)(rY + <off>),
-	 * we remember original and resolved field size to adjust direct
-	 * memory loads of pointers and integers; this is necessary for 32-bit
-	 * host kernel architectures, but also allows to automatically
-	 * relocate fields that were resized from, e.g., u32 to u64, etc.
-	 */
-	bool fail_memsz_adjust;
-	__u32 orig_sz;
-	__u32 orig_type_id;
-	__u32 new_sz;
-	__u32 new_type_id;
-};
-
 /* Calculate original and target relocation values, given local and target
  * specs and relocation kind. These values are calculated for each candidate.
  * If there are multiple candidates, resulting values should all be consistent
@@ -951,9 +925,9 @@ static int insn_bytes_to_bpf_size(__u32 sz)
  * 5. *(T *)(rX + <off>) = rY, where T is one of {u8, u16, u32, u64};
  * 6. *(T *)(rX + <off>) = <imm>, where T is one of {u8, u16, u32, u64}.
  */
-static int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
+int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
-			       int insn_idx, const struct bpf_core_relo *relo,
+			int insn_idx, const struct bpf_core_relo *relo,
-			       int relo_idx, const struct bpf_core_relo_res *res)
+			int relo_idx, const struct bpf_core_relo_res *res)
 {
 	__u32 orig_val, new_val;
 	__u8 class;
@@ -1080,55 +1054,70 @@ poison:
  * [<type-id>] (<type-name>) + <raw-spec> => <offset>@<spec>,
  * where <spec> is a C-syntax view of recorded field access, e.g.: x.a[3].b
  */
-static void bpf_core_dump_spec(const char *prog_name, int level, const struct bpf_core_spec *spec)
+int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec)
 {
 	const struct btf_type *t;
 	const struct btf_enum *e;
 	const char *s;
 	__u32 type_id;
-	int i;
+	int i, len = 0;
+
+#define append_buf(fmt, args...)				\
+	({							\
+		int r;						\
+		r = snprintf(buf, buf_sz, fmt, ##args);		\
+		len += r;					\
+		if (r >= buf_sz)				\
+			r = buf_sz;				\
+		buf += r;					\
+		buf_sz -= r;					\
+	})
 
 	type_id = spec->root_type_id;
 	t = btf_type_by_id(spec->btf, type_id);
 	s = btf__name_by_offset(spec->btf, t->name_off);
 
-	libbpf_print(level, "[%u] %s %s", type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s);
+	append_buf("<%s> [%u] %s %s",
+		   core_relo_kind_str(spec->relo_kind),
+		   type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s);
 
 	if (core_relo_is_type_based(spec->relo_kind))
-		return;
+		return len;
 
 	if (core_relo_is_enumval_based(spec->relo_kind)) {
 		t = skip_mods_and_typedefs(spec->btf, type_id, NULL);
 		e = btf_enum(t) + spec->raw_spec[0];
 		s = btf__name_by_offset(spec->btf, e->name_off);
 
-		libbpf_print(level, "::%s = %u", s, e->val);
+		append_buf("::%s = %u", s, e->val);
-		return;
+		return len;
 	}
 
 	if (core_relo_is_field_based(spec->relo_kind)) {
 		for (i = 0; i < spec->len; i++) {
 			if (spec->spec[i].name)
-				libbpf_print(level, ".%s", spec->spec[i].name);
+				append_buf(".%s", spec->spec[i].name);
 			else if (i > 0 || spec->spec[i].idx > 0)
-				libbpf_print(level, "[%u]", spec->spec[i].idx);
+				append_buf("[%u]", spec->spec[i].idx);
 		}
 
-		libbpf_print(level, " (");
+		append_buf(" (");
 		for (i = 0; i < spec->raw_len; i++)
-			libbpf_print(level, "%s%d", i == 0 ? "" : ":", spec->raw_spec[i]);
+			append_buf("%s%d", i == 0 ? "" : ":", spec->raw_spec[i]);
 
 		if (spec->bit_offset % 8)
-			libbpf_print(level, " @ offset %u.%u)",
+			append_buf(" @ offset %u.%u)", spec->bit_offset / 8, spec->bit_offset % 8);
-				     spec->bit_offset / 8, spec->bit_offset % 8);
 		else
-			libbpf_print(level, " @ offset %u)", spec->bit_offset / 8);
+			append_buf(" @ offset %u)", spec->bit_offset / 8);
-		return;
+		return len;
 	}
+
+	return len;
+#undef append_buf
 }
 
 /*
- * CO-RE relocate single instruction.
+ * Calculate CO-RE relocation target result.
  *
  * The outline and important points of the algorithm:
  * 1. For given local type, find corresponding candidate target types.
@@ -1177,22 +1166,22 @@ static void bpf_core_dump_spec(const char *prog_name, int level, const struct bp
  *    between multiple relocations for the same type ID and is updated as some
  *    of the candidates are pruned due to structural incompatibility.
  */
-int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
+int bpf_core_calc_relo_insn(const char *prog_name,
-			     int insn_idx,
+			    const struct bpf_core_relo *relo,
-			     const struct bpf_core_relo *relo,
+			    int relo_idx,
-			     int relo_idx,
+			    const struct btf *local_btf,
-			     const struct btf *local_btf,
+			    struct bpf_core_cand_list *cands,
-			     struct bpf_core_cand_list *cands,
+			    struct bpf_core_spec *specs_scratch,
-			     struct bpf_core_spec *specs_scratch)
+			    struct bpf_core_relo_res *targ_res)
 {
 	struct bpf_core_spec *local_spec = &specs_scratch[0];
 	struct bpf_core_spec *cand_spec = &specs_scratch[1];
 	struct bpf_core_spec *targ_spec = &specs_scratch[2];
-	struct bpf_core_relo_res cand_res, targ_res;
+	struct bpf_core_relo_res cand_res;
 	const struct btf_type *local_type;
 	const char *local_name;
 	__u32 local_id;
-	const char *spec_str;
+	char spec_buf[256];
 	int i, j, err;
 
 	local_id = relo->type_id;
@@ -1201,38 +1190,34 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
 	if (!local_name)
 		return -EINVAL;
 
-	spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
+	err = bpf_core_parse_spec(prog_name, local_btf, relo, local_spec);
-	if (str_is_empty(spec_str))
-		return -EINVAL;
-
-	err = bpf_core_parse_spec(prog_name, local_btf, local_id, spec_str,
-				  relo->kind, local_spec);
 	if (err) {
+		const char *spec_str;
+
+		spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
 		pr_warn("prog '%s': relo #%d: parsing [%d] %s %s + %s failed: %d\n",
 			prog_name, relo_idx, local_id, btf_kind_str(local_type),
 			str_is_empty(local_name) ? "<anon>" : local_name,
-			spec_str, err);
+			spec_str ?: "<?>", err);
 		return -EINVAL;
 	}
 
-	pr_debug("prog '%s': relo #%d: kind <%s> (%d), spec is ", prog_name,
+	bpf_core_format_spec(spec_buf, sizeof(spec_buf), local_spec);
-		 relo_idx, core_relo_kind_str(relo->kind), relo->kind);
+	pr_debug("prog '%s': relo #%d: %s\n", prog_name, relo_idx, spec_buf);
-	bpf_core_dump_spec(prog_name, LIBBPF_DEBUG, local_spec);
-	libbpf_print(LIBBPF_DEBUG, "\n");
 
 	/* TYPE_ID_LOCAL relo is special and doesn't need candidate search */
 	if (relo->kind == BPF_CORE_TYPE_ID_LOCAL) {
 		/* bpf_insn's imm value could get out of sync during linking */
-		memset(&targ_res, 0, sizeof(targ_res));
+		memset(targ_res, 0, sizeof(*targ_res));
-		targ_res.validate = false;
+		targ_res->validate = false;
-		targ_res.poison = false;
+		targ_res->poison = false;
-		targ_res.orig_val = local_spec->root_type_id;
+		targ_res->orig_val = local_spec->root_type_id;
-		targ_res.new_val = local_spec->root_type_id;
+		targ_res->new_val = local_spec->root_type_id;
-		goto patch_insn;
+		return 0;
 	}
 
 	/* libbpf doesn't support candidate search for anonymous types */
-	if (str_is_empty(spec_str)) {
+	if (str_is_empty(local_name)) {
 		pr_warn("prog '%s': relo #%d: <%s> (%d) relocation doesn't support anonymous types\n",
 			prog_name, relo_idx, core_relo_kind_str(relo->kind), relo->kind);
 		return -EOPNOTSUPP;
@@ -1242,17 +1227,15 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
 		err = bpf_core_spec_match(local_spec, cands->cands[i].btf,
 					  cands->cands[i].id, cand_spec);
 		if (err < 0) {
-			pr_warn("prog '%s': relo #%d: error matching candidate #%d ",
+			bpf_core_format_spec(spec_buf, sizeof(spec_buf), cand_spec);
-				prog_name, relo_idx, i);
+			pr_warn("prog '%s': relo #%d: error matching candidate #%d %s: %d\n ",
-			bpf_core_dump_spec(prog_name, LIBBPF_WARN, cand_spec);
+				prog_name, relo_idx, i, spec_buf, err);
-			libbpf_print(LIBBPF_WARN, ": %d\n", err);
 			return err;
 		}
 
-		pr_debug("prog '%s': relo #%d: %s candidate #%d ", prog_name,
+		bpf_core_format_spec(spec_buf, sizeof(spec_buf), cand_spec);
-			 relo_idx, err == 0 ? "non-matching" : "matching", i);
+		pr_debug("prog '%s': relo #%d: %s candidate #%d %s\n", prog_name,
-		bpf_core_dump_spec(prog_name, LIBBPF_DEBUG, cand_spec);
+			 relo_idx, err == 0 ? "non-matching" : "matching", i, spec_buf);
-		libbpf_print(LIBBPF_DEBUG, "\n");
 
 		if (err == 0)
 			continue;
@@ -1262,7 +1245,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
 			return err;
 
 		if (j == 0) {
-			targ_res = cand_res;
+			*targ_res = cand_res;
 			*targ_spec = *cand_spec;
 		} else if (cand_spec->bit_offset != targ_spec->bit_offset) {
 			/* if there are many field relo candidates, they
@@ -1272,7 +1255,8 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
 				prog_name, relo_idx, cand_spec->bit_offset,
 				targ_spec->bit_offset);
 			return -EINVAL;
-		} else if (cand_res.poison != targ_res.poison || cand_res.new_val != targ_res.new_val) {
+		} else if (cand_res.poison != targ_res->poison ||
+			   cand_res.new_val != targ_res->new_val) {
 			/* all candidates should result in the same relocation
 			 * decision and value, otherwise it's dangerous to
 			 * proceed due to ambiguity
@@ -1280,7 +1264,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
 			pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %u != %s %u\n",
 				prog_name, relo_idx,
 				cand_res.poison ? "failure" : "success", cand_res.new_val,
-				targ_res.poison ? "failure" : "success", targ_res.new_val);
+				targ_res->poison ? "failure" : "success", targ_res->new_val);
 			return -EINVAL;
 		}
 
@@ -1314,19 +1298,10 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
 			 prog_name, relo_idx);
 
 		/* calculate single target relo result explicitly */
-		err = bpf_core_calc_relo(prog_name, relo, relo_idx, local_spec, NULL, &targ_res);
+		err = bpf_core_calc_relo(prog_name, relo, relo_idx, local_spec, NULL, targ_res);
 		if (err)
 			return err;
 	}
 
-patch_insn:
-	/* bpf_core_patch_insn() should know how to handle missing targ_spec */
-	err = bpf_core_patch_insn(prog_name, insn, insn_idx, relo, relo_idx, &targ_res);
-	if (err) {
-		pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n",
-			prog_name, relo_idx, relo->insn_off / 8, err);
-		return -EINVAL;
-	}
-
 	return 0;
 }

src/relo_core.h

@@ -44,14 +44,50 @@ struct bpf_core_spec {
 	__u32 bit_offset;
 };
 
-int bpf_core_apply_relo_insn(const char *prog_name,
+struct bpf_core_relo_res {
-			     struct bpf_insn *insn, int insn_idx,
+	/* expected value in the instruction, unless validate == false */
-			     const struct bpf_core_relo *relo, int relo_idx,
+	__u32 orig_val;
-			     const struct btf *local_btf,
+	/* new value that needs to be patched up to */
-			     struct bpf_core_cand_list *cands,
+	__u32 new_val;
-			     struct bpf_core_spec *specs_scratch);
+	/* relocation unsuccessful, poison instruction, but don't fail load */
+	bool poison;
+	/* some relocations can't be validated against orig_val */
+	bool validate;
+	/* for field byte offset relocations or the forms:
+	 *     *(T *)(rX + <off>) = rY
+	 *     rX = *(T *)(rY + <off>),
+	 * we remember original and resolved field size to adjust direct
+	 * memory loads of pointers and integers; this is necessary for 32-bit
+	 * host kernel architectures, but also allows to automatically
+	 * relocate fields that were resized from, e.g., u32 to u64, etc.
+	 */
+	bool fail_memsz_adjust;
+	__u32 orig_sz;
+	__u32 orig_type_id;
+	__u32 new_sz;
+	__u32 new_type_id;
+};
+
 int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
 			      const struct btf *targ_btf, __u32 targ_id);
 
 size_t bpf_core_essential_name_len(const char *name);
+
+int bpf_core_calc_relo_insn(const char *prog_name,
+			    const struct bpf_core_relo *relo, int relo_idx,
+			    const struct btf *local_btf,
+			    struct bpf_core_cand_list *cands,
+			    struct bpf_core_spec *specs_scratch,
+			    struct bpf_core_relo_res *targ_res);
+
+int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
+			int insn_idx, const struct bpf_core_relo *relo,
+			int relo_idx, const struct bpf_core_relo_res *res);
+
+int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
+		        const struct bpf_core_relo *relo,
+		        struct bpf_core_spec *spec);
+
+int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec);
+
 #endif

src/skel_internal.h

@@ -3,9 +3,19 @@
 #ifndef __SKEL_INTERNAL_H
 #define __SKEL_INTERNAL_H
 
+#ifdef __KERNEL__
+#include <linux/fdtable.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/slab.h>
+#include <linux/bpf.h>
+#else
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <sys/mman.h>
+#include <stdlib.h>
+#include "bpf.h"
+#endif
 
 #ifndef __NR_bpf
 # if defined(__mips__) && defined(_ABIO32)
@@ -25,24 +35,23 @@
  * requested during loader program generation.
  */
 struct bpf_map_desc {
-	union {
+	/* output of the loader prog */
-		/* input for the loader prog */
+	int map_fd;
-		struct {
+	/* input for the loader prog */
-			__aligned_u64 initial_value;
+	__u32 max_entries;
-			__u32 max_entries;
+	__aligned_u64 initial_value;
-		};
-		/* output of the loader prog */
-		struct {
-			int map_fd;
-		};
-	};
 };
 struct bpf_prog_desc {
 	int prog_fd;
 };
 
+enum {
+	BPF_SKEL_KERNEL = (1ULL << 0),
+};
+
 struct bpf_loader_ctx {
-	size_t sz;
+	__u32 sz;
+	__u32 flags;
 	__u32 log_level;
 	__u32 log_size;
 	__u64 log_buf;
@@ -57,12 +66,144 @@ struct bpf_load_and_run_opts {
 	const char *errstr;
 };
 
+long bpf_sys_bpf(__u32 cmd, void *attr, __u32 attr_size);
+
 static inline int skel_sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
 			  unsigned int size)
 {
+#ifdef __KERNEL__
+	return bpf_sys_bpf(cmd, attr, size);
+#else
 	return syscall(__NR_bpf, cmd, attr, size);
+#endif
 }
 
+#ifdef __KERNEL__
+static inline int close(int fd)
+{
+	return close_fd(fd);
+}
+
+static inline void *skel_alloc(size_t size)
+{
+	struct bpf_loader_ctx *ctx = kzalloc(size, GFP_KERNEL);
+
+	if (!ctx)
+		return NULL;
+	ctx->flags |= BPF_SKEL_KERNEL;
+	return ctx;
+}
+
+static inline void skel_free(const void *p)
+{
+	kfree(p);
+}
+
+/* skel->bss/rodata maps are populated the following way:
+ *
+ * For kernel use:
+ * skel_prep_map_data() allocates kernel memory that kernel module can directly access.
+ * Generated lskel stores the pointer in skel->rodata and in skel->maps.rodata.initial_value.
+ * 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.
+ *
+ * For user space:
+ * skel_prep_map_data() mmaps anon memory into skel->rodata that can be accessed directly.
+ * Generated lskel stores the pointer in skel->rodata and in skel->maps.rodata.initial_value.
+ * The loader program will perform copy_from_user() from maps.rodata.initial_value.
+ * skel_finalize_map_data() remaps bpf array map value from the kernel memory into
+ * skel->rodata address.
+ *
+ * The "bpftool gen skeleton -L" command generates lskel.h that is suitable for
+ * both kernel and user space. The generated loader program does
+ * either bpf_probe_read_kernel() or bpf_copy_from_user() from initial_value
+ * depending on bpf_loader_ctx->flags.
+ */
+static inline void skel_free_map_data(void *p, __u64 addr, size_t sz)
+{
+	if (addr != ~0ULL)
+		kvfree(p);
+	/* When addr == ~0ULL the 'p' points to
+	 * ((struct bpf_array *)map)->value. See skel_finalize_map_data.
+	 */
+}
+
+static inline void *skel_prep_map_data(const void *val, size_t mmap_sz, size_t val_sz)
+{
+	void *addr;
+
+	addr = kvmalloc(val_sz, GFP_KERNEL);
+	if (!addr)
+		return NULL;
+	memcpy(addr, val, val_sz);
+	return addr;
+}
+
+static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz, int flags, int fd)
+{
+	struct bpf_map *map;
+	void *addr = NULL;
+
+	kvfree((void *) (long) *init_val);
+	*init_val = ~0ULL;
+
+	/* At this point bpf_load_and_run() finished without error and
+	 * 'fd' is a valid bpf map FD. All sanity checks below should succeed.
+	 */
+	map = bpf_map_get(fd);
+	if (IS_ERR(map))
+		return NULL;
+	if (map->map_type != BPF_MAP_TYPE_ARRAY)
+		goto out;
+	addr = ((struct bpf_array *)map)->value;
+	/* the addr stays valid, since FD is not closed */
+out:
+	bpf_map_put(map);
+	return addr;
+}
+
+#else
+
+static inline void *skel_alloc(size_t size)
+{
+	return calloc(1, size);
+}
+
+static inline void skel_free(void *p)
+{
+	free(p);
+}
+
+static inline void skel_free_map_data(void *p, __u64 addr, size_t sz)
+{
+	munmap(p, sz);
+}
+
+static inline void *skel_prep_map_data(const void *val, size_t mmap_sz, size_t val_sz)
+{
+	void *addr;
+
+	addr = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE,
+		    MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+	if (addr == (void *) -1)
+		return NULL;
+	memcpy(addr, val, val_sz);
+	return addr;
+}
+
+static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz, int flags, int fd)
+{
+	void *addr;
+
+	addr = mmap((void *) (long) *init_val, mmap_sz, flags, MAP_SHARED | MAP_FIXED, fd, 0);
+	if (addr == (void *) -1)
+		return NULL;
+	return addr;
+}
+#endif
+
 static inline int skel_closenz(int fd)
 {
 	if (fd > 0)
@@ -136,22 +277,28 @@ static inline int skel_link_create(int prog_fd, int target_fd,
 	return skel_sys_bpf(BPF_LINK_CREATE, &attr, attr_sz);
 }
 
+#ifdef __KERNEL__
+#define set_err
+#else
+#define set_err err = -errno
+#endif
+
 static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 {
 	int map_fd = -1, prog_fd = -1, key = 0, err;
 	union bpf_attr attr;
 
-	map_fd = skel_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1);
+	err = map_fd = skel_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1);
 	if (map_fd < 0) {
 		opts->errstr = "failed to create loader map";
-		err = -errno;
+		set_err;
 		goto out;
 	}
 
 	err = skel_map_update_elem(map_fd, &key, opts->data, 0);
 	if (err < 0) {
 		opts->errstr = "failed to update loader map";
-		err = -errno;
+		set_err;
 		goto out;
 	}
 
@@ -166,10 +313,10 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 	attr.log_size = opts->ctx->log_size;
 	attr.log_buf = opts->ctx->log_buf;
 	attr.prog_flags = BPF_F_SLEEPABLE;
-	prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+	err = prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
 	if (prog_fd < 0) {
 		opts->errstr = "failed to load loader prog";
-		err = -errno;
+		set_err;
 		goto out;
 	}
 
@@ -181,10 +328,12 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 	if (err < 0 || (int)attr.test.retval < 0) {
 		opts->errstr = "failed to execute loader prog";
 		if (err < 0) {
-			err = -errno;
+			set_err;
 		} else {
 			err = (int)attr.test.retval;
+#ifndef __KERNEL__
 			errno = -err;
+#endif
 		}
 		goto out;
 	}

src/usdt.bpf.h

@@ -0,0 +1,259 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+#ifndef __USDT_BPF_H__
+#define __USDT_BPF_H__
+
+#include <linux/errno.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+/* Below types and maps are internal implementation details of libbpf's USDT
+ * support and are subjects to change. Also, bpf_usdt_xxx() API helpers should
+ * be considered an unstable API as well and might be adjusted based on user
+ * feedback from using libbpf's USDT support in production.
+ */
+
+/* User can override BPF_USDT_MAX_SPEC_CNT to change default size of internal
+ * map that keeps track of USDT argument specifications. This might be
+ * necessary if there are a lot of USDT attachments.
+ */
+#ifndef BPF_USDT_MAX_SPEC_CNT
+#define BPF_USDT_MAX_SPEC_CNT 256
+#endif
+/* User can override BPF_USDT_MAX_IP_CNT to change default size of internal
+ * map that keeps track of IP (memory address) mapping to USDT argument
+ * specification.
+ * Note, if kernel supports BPF cookies, this map is not used and could be
+ * resized all the way to 1 to save a bit of memory.
+ */
+#ifndef BPF_USDT_MAX_IP_CNT
+#define BPF_USDT_MAX_IP_CNT (4 * BPF_USDT_MAX_SPEC_CNT)
+#endif
+/* We use BPF CO-RE to detect support for BPF cookie from BPF side. This is
+ * the only dependency on CO-RE, so if it's undesirable, user can override
+ * BPF_USDT_HAS_BPF_COOKIE to specify whether to BPF cookie is supported or not.
+ */
+#ifndef BPF_USDT_HAS_BPF_COOKIE
+#define BPF_USDT_HAS_BPF_COOKIE \
+	bpf_core_enum_value_exists(enum bpf_func_id___usdt, BPF_FUNC_get_attach_cookie___usdt)
+#endif
+
+enum __bpf_usdt_arg_type {
+	BPF_USDT_ARG_CONST,
+	BPF_USDT_ARG_REG,
+	BPF_USDT_ARG_REG_DEREF,
+};
+
+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 */
+	enum __bpf_usdt_arg_type arg_type;
+	/* offset of referenced register within struct pt_regs */
+	short reg_off;
+	/* whether arg should be interpreted as signed value */
+	bool arg_signed;
+	/* number of bits that need to be cleared and, optionally,
+	 * sign-extended to cast arguments that are 1, 2, or 4 bytes
+	 * long into final 8-byte u64/s64 value returned to user
+	 */
+	char arg_bitshift;
+};
+
+/* should match USDT_MAX_ARG_CNT in usdt.c exactly */
+#define BPF_USDT_MAX_ARG_CNT 12
+struct __bpf_usdt_spec {
+	struct __bpf_usdt_arg_spec args[BPF_USDT_MAX_ARG_CNT];
+	__u64 usdt_cookie;
+	short arg_cnt;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, BPF_USDT_MAX_SPEC_CNT);
+	__type(key, int);
+	__type(value, struct __bpf_usdt_spec);
+} __bpf_usdt_specs SEC(".maps") __weak;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, BPF_USDT_MAX_IP_CNT);
+	__type(key, long);
+	__type(value, __u32);
+} __bpf_usdt_ip_to_spec_id SEC(".maps") __weak;
+
+/* don't rely on user's BPF code to have latest definition of bpf_func_id */
+enum bpf_func_id___usdt {
+	BPF_FUNC_get_attach_cookie___usdt = 0xBAD, /* value doesn't matter */
+};
+
+static __always_inline
+int __bpf_usdt_spec_id(struct pt_regs *ctx)
+{
+	if (!BPF_USDT_HAS_BPF_COOKIE) {
+		long ip = PT_REGS_IP(ctx);
+		int *spec_id_ptr;
+
+		spec_id_ptr = bpf_map_lookup_elem(&__bpf_usdt_ip_to_spec_id, &ip);
+		return spec_id_ptr ? *spec_id_ptr : -ESRCH;
+	}
+
+	return bpf_get_attach_cookie(ctx);
+}
+
+/* Return number of USDT arguments defined for currently traced USDT. */
+__weak __hidden
+int bpf_usdt_arg_cnt(struct pt_regs *ctx)
+{
+	struct __bpf_usdt_spec *spec;
+	int spec_id;
+
+	spec_id = __bpf_usdt_spec_id(ctx);
+	if (spec_id < 0)
+		return -ESRCH;
+
+	spec = bpf_map_lookup_elem(&__bpf_usdt_specs, &spec_id);
+	if (!spec)
+		return -ESRCH;
+
+	return spec->arg_cnt;
+}
+
+/* Fetch USDT argument #*arg_num* (zero-indexed) and put its value into *res.
+ * Returns 0 on success; negative error, otherwise.
+ * On error *res is guaranteed to be set to zero.
+ */
+__weak __hidden
+int bpf_usdt_arg(struct pt_regs *ctx, __u64 arg_num, long *res)
+{
+	struct __bpf_usdt_spec *spec;
+	struct __bpf_usdt_arg_spec *arg_spec;
+	unsigned long val;
+	int err, spec_id;
+
+	*res = 0;
+
+	spec_id = __bpf_usdt_spec_id(ctx);
+	if (spec_id < 0)
+		return -ESRCH;
+
+	spec = bpf_map_lookup_elem(&__bpf_usdt_specs, &spec_id);
+	if (!spec)
+		return -ESRCH;
+
+	if (arg_num >= BPF_USDT_MAX_ARG_CNT || arg_num >= spec->arg_cnt)
+		return -ENOENT;
+
+	arg_spec = &spec->args[arg_num];
+	switch (arg_spec->arg_type) {
+	case BPF_USDT_ARG_CONST:
+		/* Arg is just a constant ("-4@$-9" in USDT arg spec).
+		 * value is recorded in arg_spec->val_off directly.
+		 */
+		val = arg_spec->val_off;
+		break;
+	case BPF_USDT_ARG_REG:
+		/* Arg is in a register (e.g, "8@%rax" in USDT arg spec),
+		 * so we read the contents of that register directly from
+		 * struct pt_regs. To keep things simple user-space parts
+		 * record offsetof(struct pt_regs, <regname>) in arg_spec->reg_off.
+		 */
+		err = bpf_probe_read_kernel(&val, sizeof(val), (void *)ctx + arg_spec->reg_off);
+		if (err)
+			return err;
+		break;
+	case BPF_USDT_ARG_REG_DEREF:
+		/* Arg is in memory addressed by register, plus some offset
+		 * (e.g., "-4@-1204(%rbp)" in USDT arg spec). Register is
+		 * identified like with BPF_USDT_ARG_REG case, and the offset
+		 * is in arg_spec->val_off. We first fetch register contents
+		 * from pt_regs, then do another user-space probe read to
+		 * fetch argument value itself.
+		 */
+		err = bpf_probe_read_kernel(&val, sizeof(val), (void *)ctx + arg_spec->reg_off);
+		if (err)
+			return err;
+		err = bpf_probe_read_user(&val, sizeof(val), (void *)val + arg_spec->val_off);
+		if (err)
+			return err;
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+		val >>= arg_spec->arg_bitshift;
+#endif
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* cast arg from 1, 2, or 4 bytes to final 8 byte size clearing
+	 * necessary upper arg_bitshift bits, with sign extension if argument
+	 * is signed
+	 */
+	val <<= arg_spec->arg_bitshift;
+	if (arg_spec->arg_signed)
+		val = ((long)val) >> arg_spec->arg_bitshift;
+	else
+		val = val >> arg_spec->arg_bitshift;
+	*res = val;
+	return 0;
+}
+
+/* Retrieve user-specified cookie value provided during attach as
+ * bpf_usdt_opts.usdt_cookie. This serves the same purpose as BPF cookie
+ * returned by bpf_get_attach_cookie(). Libbpf's support for USDT is itself
+ * utilizing BPF cookies internally, so user can't use BPF cookie directly
+ * for USDT programs and has to use bpf_usdt_cookie() API instead.
+ */
+__weak __hidden
+long bpf_usdt_cookie(struct pt_regs *ctx)
+{
+	struct __bpf_usdt_spec *spec;
+	int spec_id;
+
+	spec_id = __bpf_usdt_spec_id(ctx);
+	if (spec_id < 0)
+		return 0;
+
+	spec = bpf_map_lookup_elem(&__bpf_usdt_specs, &spec_id);
+	if (!spec)
+		return 0;
+
+	return spec->usdt_cookie;
+}
+
+/* we rely on ___bpf_apply() and ___bpf_narg() macros already defined in bpf_tracing.h */
+#define ___bpf_usdt_args0() ctx
+#define ___bpf_usdt_args1(x) ___bpf_usdt_args0(), ({ long _x; bpf_usdt_arg(ctx, 0, &_x); (void *)_x; })
+#define ___bpf_usdt_args2(x, args...) ___bpf_usdt_args1(args), ({ long _x; bpf_usdt_arg(ctx, 1, &_x); (void *)_x; })
+#define ___bpf_usdt_args3(x, args...) ___bpf_usdt_args2(args), ({ long _x; bpf_usdt_arg(ctx, 2, &_x); (void *)_x; })
+#define ___bpf_usdt_args4(x, args...) ___bpf_usdt_args3(args), ({ long _x; bpf_usdt_arg(ctx, 3, &_x); (void *)_x; })
+#define ___bpf_usdt_args5(x, args...) ___bpf_usdt_args4(args), ({ long _x; bpf_usdt_arg(ctx, 4, &_x); (void *)_x; })
+#define ___bpf_usdt_args6(x, args...) ___bpf_usdt_args5(args), ({ long _x; bpf_usdt_arg(ctx, 5, &_x); (void *)_x; })
+#define ___bpf_usdt_args7(x, args...) ___bpf_usdt_args6(args), ({ long _x; bpf_usdt_arg(ctx, 6, &_x); (void *)_x; })
+#define ___bpf_usdt_args8(x, args...) ___bpf_usdt_args7(args), ({ long _x; bpf_usdt_arg(ctx, 7, &_x); (void *)_x; })
+#define ___bpf_usdt_args9(x, args...) ___bpf_usdt_args8(args), ({ long _x; bpf_usdt_arg(ctx, 8, &_x); (void *)_x; })
+#define ___bpf_usdt_args10(x, args...) ___bpf_usdt_args9(args), ({ long _x; bpf_usdt_arg(ctx, 9, &_x); (void *)_x; })
+#define ___bpf_usdt_args11(x, args...) ___bpf_usdt_args10(args), ({ long _x; bpf_usdt_arg(ctx, 10, &_x); (void *)_x; })
+#define ___bpf_usdt_args12(x, args...) ___bpf_usdt_args11(args), ({ long _x; bpf_usdt_arg(ctx, 11, &_x); (void *)_x; })
+#define ___bpf_usdt_args(args...) ___bpf_apply(___bpf_usdt_args, ___bpf_narg(args))(args)
+
+/*
+ * BPF_USDT serves the same purpose for USDT handlers as BPF_PROG for
+ * tp_btf/fentry/fexit BPF programs and BPF_KPROBE for kprobes.
+ * Original struct pt_regs * context is preserved as 'ctx' argument.
+ */
+#define BPF_USDT(name, args...)						    \
+name(struct pt_regs *ctx);						    \
+static __attribute__((always_inline)) typeof(name(0))			    \
+____##name(struct pt_regs *ctx, ##args);				    \
+typeof(name(0)) name(struct pt_regs *ctx)				    \
+{									    \
+        _Pragma("GCC diagnostic push")					    \
+        _Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
+        return ____##name(___bpf_usdt_args(args));			    \
+        _Pragma("GCC diagnostic pop")					    \
+}									    \
+static __attribute__((always_inline)) typeof(name(0))			    \
+____##name(struct pt_regs *ctx, ##args)
+
+#endif /* __USDT_BPF_H__ */

src/xsk.c

@@ -481,8 +481,8 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk)
 		BPF_EMIT_CALL(BPF_FUNC_redirect_map),
 		BPF_EXIT_INSN(),
 	};
-	size_t insns_cnt[] = {sizeof(prog) / sizeof(struct bpf_insn),
+	size_t insns_cnt[] = {ARRAY_SIZE(prog),
-			      sizeof(prog_redirect_flags) / sizeof(struct bpf_insn),
+			      ARRAY_SIZE(prog_redirect_flags),
 	};
 	struct bpf_insn *progs[] = {prog, prog_redirect_flags};
 	enum xsk_prog option = get_xsk_prog();
@@ -1193,12 +1193,23 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 
 int xsk_umem__delete(struct xsk_umem *umem)
 {
+	struct xdp_mmap_offsets off;
+	int err;
+
 	if (!umem)
 		return 0;
 
 	if (umem->refcount)
 		return -EBUSY;
 
+	err = xsk_get_mmap_offsets(umem->fd, &off);
+	if (!err && umem->fill_save && umem->comp_save) {
+		munmap(umem->fill_save->ring - off.fr.desc,
+		       off.fr.desc + umem->config.fill_size * sizeof(__u64));
+		munmap(umem->comp_save->ring - off.cr.desc,
+		       off.cr.desc + umem->config.comp_size * sizeof(__u64));
+	}
+
 	close(umem->fd);
 	free(umem);
 

travis-ci/rootfs/mkrootfs_arch.sh

@@ -80,6 +80,7 @@ packages=(
 	# selftests test_progs dependencies.
 	binutils
 	elfutils
+	ethtool
 	glibc
 	iproute2
 	# selftests test_verifier dependencies.

travis-ci/rootfs/mkrootfs_debian.sh

@@ -2,6 +2,11 @@
 # This script builds a Debian root filesystem image for testing libbpf in a
 # virtual machine. Requires debootstrap >= 1.0.95 and zstd.
 
+# Use e.g. ./mkrootfs_debian.sh --arch=s390x to generate a rootfs for a
+# foreign architecture. Requires configured binfmt_misc, e.g. using
+# Debian/Ubuntu's qemu-user-binfmt package or
+# https://github.com/multiarch/qemu-user-static.
+
 set -e -u -x -o pipefail
 
 # Check whether we are root now in order to avoid confusing errors later.
@@ -15,8 +20,8 @@ root=$(mktemp -d -p "$PWD")
 trap 'rm -r "$root"' EXIT
 
 # Install packages.
-packages=binutils,busybox,elfutils,iproute2,libcap2,libelf1,strace,zlib1g
+packages=binutils,busybox,elfutils,ethtool,iproute2,libcap2,libelf1,strace,zlib1g
-debootstrap --include="$packages" --variant=minbase bullseye "$root"
+debootstrap --include="$packages" --variant=minbase "$@" bookworm "$root"
 
 # Remove the init scripts (tests use their own). Also remove various
 # unnecessary files in order to save space.

travis-ci/rootfs/s390x-self-hosted-builder/README.md

@@ -1,16 +1,25 @@
 # IBM Z self-hosted builder
 
 libbpf CI uses an IBM-provided z15 self-hosted builder. There are no IBM Z
-builds of GitHub Actions runner, and stable qemu-user has problems with .NET
+builds of GitHub (GH) Actions runner, and stable qemu-user has problems with .NET
 apps, so the builder runs the x86_64 runner version with qemu-user built from
 the master branch.
 
+We are currently supporting runners for the following repositories:
+* libbpf/libbpf
+* kernel-patches/bpf
+* kernel-patches/vmtest
+
+Below instructions are directly applicable to libbpf, and require minor
+modifications for kernel-patches repos. Currently, qemu-user-static Docker
+image is shared between all GitHub runners, but separate actions-runner-\*
+service / Docker image is created for each runner type.
+
 ## Configuring the builder.
 
 ### Install prerequisites.
 
 ```
-$ sudo dnf install docker        # RHEL
 $ sudo apt install -y docker.io  # Ubuntu
 ```
 
@@ -35,6 +44,10 @@ for details.
 
 ### Autostart the x86_64 emulation support.
 
+This step is important, you would not be able to build docker container
+without having this service running. If container build fails, make sure
+service is running properly.
+
 ```
 $ sudo systemctl enable --now qemu-user-static
 ```
@@ -72,3 +85,23 @@ $ sudo systemctl stop actions-runner-libbpf
 $ sudo docker rm -f actions-runner-libbpf
 $ sudo docker volume rm actions-runner-libbpf
 ```
+
+## Troubleshooting
+
+In order to check if service is running, use the following command:
+
+```
+$ sudo systemctl status <service name>
+```
+
+In order to get logs for service:
+
+```
+$ journalctl -u <service name>
+```
+
+In order to check which containers are currently active:
+
+```
+$ sudo docker ps
+```

travis-ci/vmtest/configs/blacklist/BLACKLIST-latest.s390x

@@ -25,11 +25,13 @@ ksyms_module_libbpf                      # JIT does not support calling kernel f
 ksyms_module_lskel                       # test_ksyms_module_lskel__open_and_load unexpected error: -9                 (?)
 modify_return                            # modify_return attach failed: -524                                           (trampoline)
 module_attach                            # skel_attach skeleton attach failed: -524                                    (trampoline)
+kprobe_multi_test                        # relies on fentry
 netcnt                                   # failed to load BPF skeleton 'netcnt_prog': -7                               (?)
 probe_user                               # check_kprobe_res wrong kprobe res from probe read                           (?)
 recursion                                # skel_attach unexpected error: -524                                          (trampoline)
 ringbuf                                  # skel_load skeleton load failed                                              (?)
 sk_assign                                # Can't read on server: Invalid argument                                      (?)
+sk_lookup                                # endianness problem
 sk_storage_tracing                       # test_sk_storage_tracing__attach unexpected error: -524                      (trampoline)
 skc_to_unix_sock                         # could not attach BPF object unexpected error: -524                          (trampoline)
 socket_cookie                            # prog_attach unexpected error: -524                                          (trampoline)
@@ -44,6 +46,7 @@ test_lsm                                 # failed to find kernel BTF type ID of
 test_overhead                            # attach_fentry unexpected error: -524                                        (trampoline)
 test_profiler                            # unknown func bpf_probe_read_str#45                                          (overlapping)
 timer                                    # failed to auto-attach program 'test1': -524                                 (trampoline)
+timer_crash                              # trampoline
 timer_mim                                # failed to auto-attach program 'test1': -524                                 (trampoline)
 trace_ext                                # failed to auto-attach program 'test_pkt_md_access_new': -524                (trampoline)
 trace_printk                             # trace_printk__load unexpected error: -2 (errno 2)                           (?)
@@ -54,3 +57,8 @@ vmlinux                                  # failed to auto-attach program 'handle
 xdp_adjust_tail                          # case-128 err 0 errno 28 retval 1 size 128 expect-size 3520                  (?)
 xdp_bonding                              # failed to auto-attach program 'trace_on_entry': -524                        (trampoline)
 xdp_bpf2bpf                              # failed to auto-attach program 'trace_on_entry': -524                        (trampoline)
+map_kptr                                 # failed to open_and_load program: -524 (trampoline)
+bpf_cookie                               # failed to open_and_load program: -524 (trampoline)
+xdp_do_redirect                          # prog_run_max_size unexpected error: -22 (errno 22)
+send_signal                              # intermittently fails to receive signal
+select_reuseport                         # intermittently fails on new s390x setup

travis-ci/vmtest/configs/config-latest.s390x

@@ -784,6 +784,7 @@ CONFIG_NETFILTER_NETLINK=y
 # CONFIG_NETFILTER_NETLINK_OSF is not set
 CONFIG_NF_CONNTRACK=y
 # CONFIG_NF_LOG_SYSLOG is not set
+CONFIG_NETFILTER_SYNPROXY=y
 CONFIG_NF_TABLES=y
 # CONFIG_NF_TABLES_INET is not set
 # CONFIG_NF_TABLES_NETDEV is not set
@@ -814,6 +815,7 @@ CONFIG_NETFILTER_XT_MARK=y
 #
 # CONFIG_NETFILTER_XT_TARGET_AUDIT is not set
 # CONFIG_NETFILTER_XT_TARGET_CLASSIFY is not set
+CONFIG_NETFILTER_XT_TARGET_CT=y
 # CONFIG_NETFILTER_XT_TARGET_HMARK is not set
 # CONFIG_NETFILTER_XT_TARGET_IDLETIMER is not set
 # CONFIG_NETFILTER_XT_TARGET_LOG is not set
@@ -858,6 +860,7 @@ CONFIG_NETFILTER_XT_MATCH_BPF=y
 # CONFIG_NETFILTER_XT_MATCH_RECENT is not set
 # CONFIG_NETFILTER_XT_MATCH_SCTP is not set
 # CONFIG_NETFILTER_XT_MATCH_SOCKET is not set
+CONFIG_NETFILTER_XT_MATCH_STATE=y
 # CONFIG_NETFILTER_XT_MATCH_STATISTIC is not set
 # CONFIG_NETFILTER_XT_MATCH_STRING is not set
 # CONFIG_NETFILTER_XT_MATCH_TCPMSS is not set
@@ -885,9 +888,10 @@ CONFIG_IP_NF_IPTABLES=y
 # CONFIG_IP_NF_MATCH_ECN is not set
 # CONFIG_IP_NF_MATCH_TTL is not set
 CONFIG_IP_NF_FILTER=y
+CONFIG_IP_NF_TARGET_SYNPROXY=y
 # CONFIG_IP_NF_TARGET_REJECT is not set
 # CONFIG_IP_NF_MANGLE is not set
-# CONFIG_IP_NF_RAW is not set
+CONFIG_IP_NF_RAW=y
 # CONFIG_IP_NF_SECURITY is not set
 # CONFIG_IP_NF_ARPTABLES is not set
 # end of IP: Netfilter Configuration
@@ -2586,6 +2590,7 @@ CONFIG_FUNCTION_TRACER=y
 CONFIG_FUNCTION_GRAPH_TRACER=y
 CONFIG_DYNAMIC_FTRACE=y
 CONFIG_DYNAMIC_FTRACE_WITH_REGS=y
+CONFIG_FPROBE=y
 CONFIG_FUNCTION_PROFILER=y
 CONFIG_STACK_TRACER=y
 # CONFIG_IRQSOFF_TRACER is not set

travis-ci/vmtest/configs/config-latest.x86_64

@@ -979,6 +979,7 @@ CONFIG_NETFILTER_NETLINK_LOG=y
 # CONFIG_NETFILTER_NETLINK_OSF is not set
 CONFIG_NF_CONNTRACK=y
 # CONFIG_NF_LOG_NETDEV is not set
+CONFIG_NETFILTER_SYNPROXY=y
 # CONFIG_NF_TABLES is not set
 CONFIG_NETFILTER_XTABLES=y
 
@@ -992,6 +993,7 @@ CONFIG_NETFILTER_XTABLES=y
 #
 # CONFIG_NETFILTER_XT_TARGET_AUDIT is not set
 # CONFIG_NETFILTER_XT_TARGET_CLASSIFY is not set
+CONFIG_NETFILTER_XT_TARGET_CT=y
 # CONFIG_NETFILTER_XT_TARGET_HMARK is not set
 # CONFIG_NETFILTER_XT_TARGET_IDLETIMER is not set
 # CONFIG_NETFILTER_XT_TARGET_LOG is not set
@@ -1037,6 +1039,7 @@ CONFIG_NETFILTER_XT_MATCH_BPF=y
 # CONFIG_NETFILTER_XT_MATCH_RECENT is not set
 # CONFIG_NETFILTER_XT_MATCH_SCTP is not set
 # CONFIG_NETFILTER_XT_MATCH_SOCKET is not set
+CONFIG_NETFILTER_XT_MATCH_STATE=y
 CONFIG_NETFILTER_XT_MATCH_STATISTIC=y
 # CONFIG_NETFILTER_XT_MATCH_STRING is not set
 # CONFIG_NETFILTER_XT_MATCH_TCPMSS is not set
@@ -1061,9 +1064,10 @@ CONFIG_IP_NF_IPTABLES=y
 # CONFIG_IP_NF_MATCH_AH is not set
 # CONFIG_IP_NF_MATCH_ECN is not set
 # CONFIG_IP_NF_MATCH_TTL is not set
-# CONFIG_IP_NF_FILTER is not set
+CONFIG_IP_NF_FILTER=y
+CONFIG_IP_NF_TARGET_SYNPROXY=y
 # CONFIG_IP_NF_MANGLE is not set
-# CONFIG_IP_NF_RAW is not set
+CONFIG_IP_NF_RAW=y
 # CONFIG_IP_NF_SECURITY is not set
 # CONFIG_IP_NF_ARPTABLES is not set
 # end of IP: Netfilter Configuration
@@ -2789,6 +2793,7 @@ CONFIG_DEBUG_BUGVERBOSE=y
 # Compile-time checks and compiler options
 #
 CONFIG_DEBUG_INFO=y
+CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
 # CONFIG_DEBUG_INFO_REDUCED is not set
 # CONFIG_DEBUG_INFO_COMPRESSED is not set
 # CONFIG_DEBUG_INFO_SPLIT is not set
@@ -2976,6 +2981,7 @@ CONFIG_FUNCTION_GRAPH_TRACER=y
 CONFIG_DYNAMIC_FTRACE=y
 CONFIG_DYNAMIC_FTRACE_WITH_REGS=y
 CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS=y
+CONFIG_FPROBE=y
 # CONFIG_FUNCTION_PROFILER is not set
 # CONFIG_STACK_TRACER is not set
 # CONFIG_IRQSOFF_TRACER is not set

travis-ci/vmtest/configs/whitelist/WHITELIST-5.5.0

@@ -43,13 +43,13 @@ spinlock
 stacktrace_map
 stacktrace_map_raw_tp
 static_linked
-subprogs
 task_fd_query_rawtp
 task_fd_query_tp
 tc_bpf
 tcp_estats
 tcp_rtt
 tp_attach_query
+usdt/urand_pid_attach
 xdp
 xdp_info
 xdp_noinline