meson: kill meson.build as it's not used anymore

Meson.build was added to facilitate systemd integration, but systemd
integration went different direction and we don't need meson.build
anymore. So remove it and not maintain it anymore.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>

BPF-CHECKPOINT-COMMIT

@@ -0,0 +1 @@
+1bd63524593b964934a33afd442df16b8f90e2b5

CHECKPOINT-COMMIT

@@ -1 +1 @@
-66b5f1c439843bcbab01cc7f3854ae2742f3d1e3
+02dc96ef6c25f990452c114c59d75c368a1f4c8f

README.md

@@ -47,24 +47,3 @@ headers in a build directory /build/root/:
 $ cd src
 $ PKG_CONFIG_PATH=/build/root/lib64/pkgconfig DESTDIR=/build/root make install
 ```
-
-To integrate libbpf into a project which uses Meson building system define
-`[wrap-git]` file in `subprojects` folder.
-To add libbpf dependency to the parent parent project, e.g. for
-libbpf_static_dep:
-```
-libbpf_obj = subproject('libbpf', required : true)
-libbpf_static_dep = libbpf_proj.get_variable('libbpf_static_dep')
-```
-
-To validate changes to meson.build
-```bash
-$ python3 meson.py build
-$ ninja -C build/
-```
-
-To install headers, libs and pkgconfig
-```bash
-$ cd build
-$ ninja install
-```

include/linux/filter.h

@@ -96,7 +96,7 @@
 			      MAP_FD, 0)
 
 #define BPF_LD_MAP_VALUE(DST, MAP_FD, VALUE_OFF)		\
-	BPF_LD_IMM64_RAW_FULL(DST, BPF_PSEUDO_MAP_FD, 0, 0,	\
+	BPF_LD_IMM64_RAW_FULL(DST, BPF_PSEUDO_MAP_VALUE, 0, 0,	\
 			      MAP_FD, VALUE_OFF)
 
 #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\

include/uapi/linux/bpf.h

@@ -106,6 +106,7 @@ enum bpf_cmd {
 	BPF_TASK_FD_QUERY,
 	BPF_MAP_LOOKUP_AND_DELETE_ELEM,
 	BPF_MAP_FREEZE,
+	BPF_BTF_GET_NEXT_ID,
 };
 
 enum bpf_map_type {
@@ -134,6 +135,7 @@ enum bpf_map_type {
 	BPF_MAP_TYPE_QUEUE,
 	BPF_MAP_TYPE_STACK,
 	BPF_MAP_TYPE_SK_STORAGE,
+	BPF_MAP_TYPE_DEVMAP_HASH,
 };
 
 /* Note that tracing related programs such as
@@ -283,6 +285,9 @@ enum bpf_attach_type {
  */
 #define BPF_F_TEST_RND_HI32	(1U << 2)
 
+/* The verifier internal test flag. Behavior is undefined */
+#define BPF_F_TEST_STATE_FREQ	(1U << 3)
+
 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
  * two extensions:
  *
@@ -336,6 +341,9 @@ enum bpf_attach_type {
 #define BPF_F_RDONLY_PROG	(1U << 7)
 #define BPF_F_WRONLY_PROG	(1U << 8)
 
+/* Clone map from listener for newly accepted socket */
+#define BPF_F_CLONE		(1U << 9)
+
 /* flags for BPF_PROG_QUERY */
 #define BPF_F_QUERY_EFFECTIVE	(1U << 0)
 
@@ -575,6 +583,8 @@ union bpf_attr {
  * 		limited to five).
  *
  * 		Each time the helper is called, it appends a line to the trace.
+ * 		Lines are discarded while *\/sys/kernel/debug/tracing/trace* is
+ * 		open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this.
  * 		The format of the trace is customizable, and the exact output
  * 		one will get depends on the options set in
  * 		*\/sys/kernel/debug/tracing/trace_options* (see also the
@@ -1013,7 +1023,7 @@ union bpf_attr {
  * 		The realm of the route for the packet associated to *skb*, or 0
  * 		if none was found.
  *
- * int bpf_perf_event_output(struct pt_reg *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
+ * int bpf_perf_event_output(struct pt_regs *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
  * 	Description
  * 		Write raw *data* blob into a special BPF perf event held by
  * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
@@ -1075,7 +1085,7 @@ union bpf_attr {
  * 	Return
  * 		0 on success, or a negative error in case of failure.
  *
- * int bpf_get_stackid(struct pt_reg *ctx, struct bpf_map *map, u64 flags)
+ * int bpf_get_stackid(struct pt_regs *ctx, struct bpf_map *map, u64 flags)
  * 	Description
  * 		Walk a user or a kernel stack and return its id. To achieve
  * 		this, the helper needs *ctx*, which is a pointer to the context
@@ -1466,8 +1476,8 @@ union bpf_attr {
  * 		If no cookie has been set yet, generate a new cookie. Once
  * 		generated, the socket cookie remains stable for the life of the
  * 		socket. This helper can be useful for monitoring per socket
- * 		networking traffic statistics as it provides a unique socket
- * 		identifier per namespace.
+ * 		networking traffic statistics as it provides a global socket
+ * 		identifier that can be assumed unique.
  * 	Return
  * 		A 8-byte long non-decreasing number on success, or 0 if the
  * 		socket field is missing inside *skb*.
@@ -1571,8 +1581,11 @@ union bpf_attr {
  * 		but this is only implemented for native XDP (with driver
  * 		support) as of this writing).
  *
- * 		All values for *flags* are reserved for future usage, and must
- * 		be left at zero.
+ * 		The lower two bits of *flags* are used as the return code if
+ * 		the map lookup fails. This is so that the return value can be
+ * 		one of the XDP program return codes up to XDP_TX, as chosen by
+ * 		the caller. Any higher bits in the *flags* argument must be
+ * 		unset.
  *
  * 		When used to redirect packets to net devices, this helper
  * 		provides a high performance increase over **bpf_redirect**\ ().
@@ -1721,7 +1734,7 @@ union bpf_attr {
  * 	Return
  * 		0 on success, or a negative error in case of failure.
  *
- * int bpf_override_return(struct pt_reg *regs, u64 rc)
+ * int bpf_override_return(struct pt_regs *regs, u64 rc)
  * 	Description
  * 		Used for error injection, this helper uses kprobes to override
  * 		the return value of the probed function, and to set it to *rc*.
@@ -2710,6 +2723,33 @@ union bpf_attr {
  *		**-EPERM** if no permission to send the *sig*.
  *
  *		**-EAGAIN** if bpf program can try again.
+ *
+ * s64 bpf_tcp_gen_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
+ *	Description
+ *		Try to issue a SYN cookie for the packet with corresponding
+ *		IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
+ *
+ *		*iph* points to the start of the IPv4 or IPv6 header, while
+ *		*iph_len* contains **sizeof**\ (**struct iphdr**) or
+ *		**sizeof**\ (**struct ip6hdr**).
+ *
+ *		*th* points to the start of the TCP header, while *th_len*
+ *		contains the length of the TCP header.
+ *
+ *	Return
+ *		On success, lower 32 bits hold the generated SYN cookie in
+ *		followed by 16 bits which hold the MSS value for that cookie,
+ *		and the top 16 bits are unused.
+ *
+ *		On failure, the returned value is one of the following:
+ *
+ *		**-EINVAL** SYN cookie cannot be issued due to error
+ *
+ *		**-ENOENT** SYN cookie should not be issued (no SYN flood)
+ *
+ *		**-EOPNOTSUPP** kernel configuration does not enable SYN cookies
+ *
+ *		**-EPROTONOSUPPORT** IP packet version is not 4 or 6
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2821,7 +2861,8 @@ union bpf_attr {
 	FN(strtoul),			\
 	FN(sk_storage_get),		\
 	FN(sk_storage_delete),		\
-	FN(send_signal),
+	FN(send_signal),		\
+	FN(tcp_gen_syncookie),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -3504,6 +3545,10 @@ enum bpf_task_fd_type {
 	BPF_FD_TYPE_URETPROBE,		/* filename + offset */
 };
 
+#define BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG		(1U << 0)
+#define BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL		(1U << 1)
+#define BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP		(1U << 2)
+
 struct bpf_flow_keys {
 	__u16	nhoff;
 	__u16	thoff;
@@ -3525,6 +3570,8 @@ struct bpf_flow_keys {
 			__u32	ipv6_dst[4];	/* in6_addr; network order */
 		};
 	};
+	__u32	flags;
+	__be32	flow_label;
 };
 
 struct bpf_func_info {

include/uapi/linux/if_link.h

@@ -695,6 +695,7 @@ enum {
 	IFLA_VF_IB_NODE_GUID,	/* VF Infiniband node GUID */
 	IFLA_VF_IB_PORT_GUID,	/* VF Infiniband port GUID */
 	IFLA_VF_VLAN_LIST,	/* nested list of vlans, option for QinQ */
+	IFLA_VF_BROADCAST,	/* VF broadcast */
 	__IFLA_VF_MAX,
 };
 
@@ -705,6 +706,10 @@ struct ifla_vf_mac {
 	__u8 mac[32]; /* MAX_ADDR_LEN */
 };
 
+struct ifla_vf_broadcast {
+	__u8 broadcast[32];
+};
+
 struct ifla_vf_vlan {
 	__u32 vf;
 	__u32 vlan; /* 0 - 4095, 0 disables VLAN filter */

include/uapi/linux/if_xdp.h

@@ -16,6 +16,18 @@
 #define XDP_SHARED_UMEM	(1 << 0)
 #define XDP_COPY	(1 << 1) /* Force copy-mode */
 #define XDP_ZEROCOPY	(1 << 2) /* Force zero-copy mode */
+/* If this option is set, the driver might go sleep and in that case
+ * the XDP_RING_NEED_WAKEUP flag in the fill and/or Tx rings will be
+ * set. If it is set, the application need to explicitly wake up the
+ * driver with a poll() (Rx and Tx) or sendto() (Tx only). If you are
+ * running the driver and the application on the same core, you should
+ * use this option so that the kernel will yield to the user space
+ * application.
+ */
+#define XDP_USE_NEED_WAKEUP (1 << 3)
+
+/* Flags for xsk_umem_config flags */
+#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
 
 struct sockaddr_xdp {
 	__u16 sxdp_family;
@@ -25,10 +37,14 @@ struct sockaddr_xdp {
 	__u32 sxdp_shared_umem_fd;
 };
 
+/* XDP_RING flags */
+#define XDP_RING_NEED_WAKEUP (1 << 0)
+
 struct xdp_ring_offset {
 	__u64 producer;
 	__u64 consumer;
 	__u64 desc;
+	__u64 flags;
 };
 
 struct xdp_mmap_offsets {
@@ -53,6 +69,7 @@ struct xdp_umem_reg {
 	__u64 len; /* Length of packet data area */
 	__u32 chunk_size;
 	__u32 headroom;
+	__u32 flags;
 };
 
 struct xdp_statistics {
@@ -74,6 +91,11 @@ struct xdp_options {
 #define XDP_UMEM_PGOFF_FILL_RING	0x100000000ULL
 #define XDP_UMEM_PGOFF_COMPLETION_RING	0x180000000ULL
 
+/* Masks for unaligned chunks mode */
+#define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
+#define XSK_UNALIGNED_BUF_ADDR_MASK \
+	((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
+
 /* Rx/Tx descriptor */
 struct xdp_desc {
 	__u64 addr;

meson.build

@@ -1,95 +0,0 @@
-# SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
-project('libbpf', 'c',
-        version : '0.0.3',
-        license : 'LGPL-2.1 OR BSD-2-Clause',
-        default_options : [
-                'prefix=/usr',
-        ],
-        meson_version : '>= 0.46',
-        )
-
-patchlevel = meson.project_version().split('.')[1]
-
-libbpf_source_dir = './'
-
-libbpf_sources = files(run_command('find',
-        [
-        '@0@/src'.format(libbpf_source_dir),
-        '-type',
-        'f',
-        '-name',
-        '*.[h|c]']).stdout().split())
-
-libbpf_headers = files(
-        join_paths(libbpf_source_dir, 'src/bpf.h'),
-        join_paths(libbpf_source_dir, 'src/btf.h'),
-        join_paths(libbpf_source_dir, 'src/libbpf.h'))
-
-feature_rellocarray = run_command(join_paths(libbpf_source_dir, 'scripts/check-reallocarray.sh'))
-
-libbpf_c_args = ['-g',
-                '-O2',
-                '-Werror',
-                '-Wall',
-]
-
-if feature_rellocarray.stdout().strip() != ''
-        libbpf_c_args += '-DCOMPAT_NEED_REALLOCARRAY'
-endif
-
-# bpf_includes are required to include bpf.h, btf.h, libbpf.h
-bpf_includes = include_directories(
-        join_paths(libbpf_source_dir, 'src'))
-
-libbpf_includes = include_directories(
-        join_paths(libbpf_source_dir, 'include'),
-        join_paths(libbpf_source_dir, 'include/uapi'))
-
-libelf = dependency('libelf')
-libelf = dependency('libelf', required: false)
-if not libelf.found()
-        libelf = cc.find_library('elf', required: true)
-endif
-
-deps = [libelf]
-
-libbpf_static = static_library(
-        'bpf',
-        libbpf_sources,
-        c_args : libbpf_c_args,
-        dependencies : deps,
-        include_directories : libbpf_includes,
-        install : true)
-
-libbpf_static_dep = declare_dependency(link_with : libbpf_static)
-
-libbpf_map_source_path = join_paths(libbpf_source_dir, 'src/libbpf.map')
-libbpf_map_abs_path = join_paths(meson.current_source_dir(), libbpf_map_source_path)
-
-libbpf_c_args += ['-fPIC', '-fvisibility=hidden']
-
-libbpf_link_args = ['-Wl,--version-script=@0@'.format(libbpf_map_abs_path)]
-
-libbpf_shared = shared_library(
-        'bpf',
-        libbpf_sources,
-        c_args : libbpf_c_args,
-        dependencies : deps,
-        include_directories : libbpf_includes,
-        install : true,
-        link_args : libbpf_link_args,
-        link_depends : libbpf_map_source_path,
-        soversion : patchlevel,
-        version : meson.project_version())
-
-libbpf_shared_dep = declare_dependency(link_with : libbpf_shared)
-
-install_headers(libbpf_headers, subdir : 'bpf')
-
-pkg = import('pkgconfig')
-pkg.generate(
-        name: meson.project_name(),
-        version: meson.project_version(),
-        libraries: libbpf_shared,
-        requires_private: ['libelf'],
-        description: '''BPF library''')

scripts/sync-kernel.sh

@@ -1,40 +1,210 @@
 #!/bin/bash
 
 usage () {
-    echo "USAGE: ./sync-kernel.sh <kernel-repo> <libbpf-repo> [<baseline-commit>]"
-    echo ""
-    echo "If <baseline-commit> is not specified, it's read from <libbpf-repo>/CHECKPOINT-COMMIT"
-    exit 1
+	echo "USAGE: ./sync-kernel.sh <libbpf-repo> <kernel-repo> <bpf-branch>"
+	echo ""
+	echo "Set BPF_NEXT_BASELINE to override bpf-next tree commit, otherwise read from <libbpf-repo>/CHECKPOINT-COMMIT."
+	echo "Set BPF_BASELINE to override bpf tree commit, otherwise read from <libbpf-repo>/BPF-CHECKPOINT-COMMIT."
+	echo "Set MANUAL_MODE to 1 to manually control every cherry-picked commits."
+	echo "Set IGNORE_CONSISTENCY to 1 to ignore failed contents consistency check."
+	exit 1
 }
 
-LINUX_REPO=${1-""}
-LIBBPF_REPO=${2-""}
-
-if [ -z "${LINUX_REPO}" ]; then
-    usage
-fi
-if [ -z "${LIBBPF_REPO}" ]; then
-    usage
-fi
-
 set -eu
 
-WORKDIR=$(pwd)
-trap "cd ${WORKDIR}; exit" INT TERM EXIT
+LIBBPF_REPO=${1-""}
+LINUX_REPO=${2-""}
+BPF_BRANCH=${3-""}
+BASELINE_COMMIT=${BPF_NEXT_BASELINE:-$(cat ${LIBBPF_REPO}/CHECKPOINT-COMMIT)}
+BPF_BASELINE_COMMIT=${BPF_BASELINE:-$(cat ${LIBBPF_REPO}/BPF-CHECKPOINT-COMMIT)}
 
-echo "WORKDIR:         ${WORKDIR}"
-echo "LINUX REPO:      ${LINUX_REPO}"
-echo "LIBBPF REPO:     ${LIBBPF_REPO}"
+if [ -z "${LIBBPF_REPO}" ] || [ -z "${LINUX_REPO}" ] || [ -z "${BPF_BRANCH}" ]; then
+	echo "Error: libbpf or linux repos are not specified"
+	usage
+fi
+if [ -z "${BPF_BRANCH}" ]; then
+	echo "Error: linux's bpf tree branch is not specified"
+	usage
+fi
+if [ -z "${BASELINE_COMMIT}" ] || [ -z "${BPF_BASELINE_COMMIT}" ]; then
+	echo "Error: bpf or bpf-next baseline commits are not provided"
+	usage
+fi
 
 SUFFIX=$(date --utc +%Y-%m-%dT%H-%M-%S.%3NZ)
-BASELINE_COMMIT=${3-$(cat ${LIBBPF_REPO}/CHECKPOINT-COMMIT)}
+WORKDIR=$(pwd)
+TMP_DIR=$(mktemp -d)
+
+trap "cd ${WORKDIR}; exit" INT TERM EXIT
+
+declare -A PATH_MAP
+PATH_MAP=(									\
+	[tools/lib/bpf]=src							\
+	[tools/include/uapi/linux/bpf_common.h]=include/uapi/linux/bpf_common.h	\
+	[tools/include/uapi/linux/bpf.h]=include/uapi/linux/bpf.h		\
+	[tools/include/uapi/linux/btf.h]=include/uapi/linux/btf.h		\
+	[tools/include/uapi/linux/if_link.h]=include/uapi/linux/if_link.h	\
+	[tools/include/uapi/linux/if_xdp.h]=include/uapi/linux/if_xdp.h		\
+	[tools/include/uapi/linux/netlink.h]=include/uapi/linux/netlink.h	\
+	[tools/include/tools/libc_compat.h]=include/tools/libc_compat.h		\
+)
+
+LIBBPF_PATHS="${!PATH_MAP[@]}"
+LIBBPF_VIEW_PATHS="${PATH_MAP[@]}"
+LIBBPF_VIEW_EXCLUDE_REGEX='^src/(Makefile|Build|test_libbpf.cpp|\.gitignore)$'
+
+LIBBPF_TREE_FILTER="mkdir -p __libbpf/include/uapi/linux __libbpf/include/tools && "$'\\\n'
+for p in "${!PATH_MAP[@]}"; do
+	LIBBPF_TREE_FILTER+="git mv -kf ${p} __libbpf/${PATH_MAP[${p}]} && "$'\\\n'
+done
+LIBBPF_TREE_FILTER+="git rm --ignore-unmatch -f __libbpf/src/{Makefile,Build,test_libbpf.cpp,.gitignore} >/dev/null"
+
+cd_to()
+{
+	cd ${WORKDIR} && cd "$1"
+}
+
+# Output brief single-line commit description
+# $1 - commit ref
+commit_desc()
+{
+	git log -n1 --pretty='%h ("%s")' $1
+}
+
+# Create commit single-line signature, which consists of:
+# - full commit hash
+# - author date in ISO8601 format
+# - full commit body with newlines replaced with vertical bars (|)
+# - shortstat appended at the end
+# The idea is that this single-line signature is good enough to make final
+# decision about whether two commits are the same, across different repos.
+# $1 - commit ref
+commit_signature()
+{
+	git log -n1 --pretty='("%s")|%aI|%b' --shortstat $1 | tr '\n' '|'
+}
+
+# Validate there are no non-empty merges (we can't handle them)
+# $1 - baseline tag
+# $2 - tip tag
+validate_merges()
+{
+	local baseline_tag=$1
+	local tip_tag=$2
+	local new_merges
+	local merge_change_cnt
+	local ignore_merge_resolutions
+	local desc
+
+	new_merges=$(git rev-list --merges --topo-order --reverse ${baseline_tag}..${tip_tag} ${LIBBPF_PATHS[@]})
+	for new_merge in ${new_merges}; do
+		desc=$(commit_desc ${new_merge})
+		echo "MERGE: ${desc}"
+		merge_change_cnt=$(git show --format='' ${new_merge} | wc -l)
+		if ((${merge_change_cnt} > 0)); then
+			read -p "Merge '${desc}' is non-empty, which will cause conflicts! Do you want to proceed? [y/N]: " ignore_merge_resolutions
+			case "${ignore_merge_resolutions}" in
+				"y" | "Y")
+					echo "Skipping '${desc}'..."
+					continue
+					;;
+			esac
+			exit 3
+		fi
+	done
+}
+
+# Cherry-pick commits touching libbpf-related files
+# $1 - baseline_tag
+# $2 - tip_tag
+cherry_pick_commits()
+{
+	local manual_mode=${MANUAL_MODE:-0}
+	local baseline_tag=$1
+	local tip_tag=$2
+	local new_commits
+	local signature
+	local should_skip
+	local synced_cnt
+	local manual_check
+	local libbpf_conflict_cnt
+	local desc
+
+	new_commits=$(git rev-list --no-merges --topo-order --reverse ${baseline_tag}..${tip_tag} ${LIBBPF_PATHS[@]})
+	for new_commit in ${new_commits}; do
+		desc="$(commit_desc ${new_commit})"
+		signature="$(commit_signature ${new_commit})"
+		synced_cnt=$(grep -F "${signature}" ${TMP_DIR}/libbpf_commits.txt | wc -l)
+		manual_check=0
+		if ((${synced_cnt} > 0)); then
+			# commit with the same subject is already in libbpf, but it's
+			# not 100% the same commit, so check with user
+			echo "Commit '${desc}' is synced into libbpf as:"
+			grep -F "${signature}" ${TMP_DIR}/libbpf_commits.txt | \
+				cut -d'|' -f1 | sed -e 's/^/- /'
+			if ((${manual_mode} != 1 && ${synced_cnt} == 1)); then
+				echo "Skipping '${desc}' due to unique match..."
+				continue
+			fi
+			if ((${synced_cnt} > 1)); then
+				echo "'${desc} matches multiple commits, please, double-check!"
+				manual_check=1
+			fi
+		fi
+		if ((${manual_mode} == 1 || ${manual_check} == 1)); then
+			read -p "Do you want to skip '${desc}'? [y/N]: " should_skip
+			case "${should_skip}" in
+				"y" | "Y")
+					echo "Skipping '${desc}'..."
+					continue
+					;;
+			esac
+		fi
+		# commit hasn't been synced into libbpf yet
+		echo "Picking '${desc}'..."
+		if ! git cherry-pick ${new_commit} &>/dev/null; then
+			echo "Warning! Cherry-picking '${desc} failed, checking if it's non-libbpf files causing problems..."
+			libbpf_conflict_cnt=$(git diff --name-only --diff-filter=U -- ${LIBBPF_PATHS[@]} | wc -l)
+			conflict_cnt=$(git diff --name-only | wc -l)
+
+			if ((${libbpf_conflict_cnt} == 0)); then
+				echo "Looks like only non-libbpf files have conflicts, ignoring..."
+				if ((${conflict_cnt} == 0)); then
+					echo "Empty cherry-pick, skipping it..."
+					git cherry-pick --abort
+					continue
+				fi
+
+				git add .
+				# GIT_EDITOR=true to avoid editor popping up to edit commit message
+				if ! GIT_EDITOR=true git cherry-pick --continue &>/dev/null; then
+					echo "Error! That still failed! Please resolve manually."
+				else
+					echo "Success! All cherry-pick conflicts were resolved for '${desc}'!"
+					continue
+				fi
+			fi
+
+			read -p "Error! Cherry-picking '${desc}' failed, please fix manually and press <return> to proceed..."
+		fi
+	done
+}
+
+cd_to ${LIBBPF_REPO}
+echo "Dumping existing libbpf commit signatures..."
+for h in $(git log --pretty='%h' -n500); do
+	echo $h "$(commit_signature $h)" >> ${TMP_DIR}/libbpf_commits.txt
+done
 
 # Use current kernel repo HEAD as a source of patches
-cd ${LINUX_REPO}
+cd_to ${LINUX_REPO}
 TIP_SYM_REF=$(git symbolic-ref -q --short HEAD || git rev-parse HEAD)
 TIP_COMMIT=$(git rev-parse HEAD)
+BPF_TIP_COMMIT=$(git rev-parse ${BPF_BRANCH})
 BASELINE_TAG=libbpf-baseline-${SUFFIX}
 TIP_TAG=libbpf-tip-${SUFFIX}
+BPF_BASELINE_TAG=libbpf-bpf-baseline-${SUFFIX}
+BPF_TIP_TAG=libbpf-bpf-tip-${SUFFIX}
 VIEW_TAG=libbpf-view-${SUFFIX}
 LIBBPF_SYNC_TAG=libbpf-sync-${SUFFIX}
 
@@ -43,75 +213,41 @@ SQUASH_BASE_TAG=libbpf-squash-base-${SUFFIX}
 SQUASH_TIP_TAG=libbpf-squash-tip-${SUFFIX}
 SQUASH_COMMIT=$(git commit-tree ${BASELINE_COMMIT}^{tree} -m "BASELINE SQUASH ${BASELINE_COMMIT}")
 
-echo "SUFFIX:          ${SUFFIX}"
-echo "BASELINE COMMIT: $(git log --pretty=oneline --no-walk ${BASELINE_COMMIT})"
-echo "TIP COMMIT:      $(git log --pretty=oneline --no-walk ${TIP_COMMIT})"
-echo "SQUASH COMMIT:   ${SQUASH_COMMIT}"
-echo "BASELINE TAG:    ${BASELINE_TAG}"
-echo "TIP TAG:         ${TIP_TAG}"
-echo "SQUASH BASE TAG: ${SQUASH_BASE_TAG}"
-echo "SQUASH TIP TAG:  ${SQUASH_TIP_TAG}"
-echo "VIEW TAG:        ${VIEW_TAG}"
-echo "LIBBPF SYNC TAG: ${LIBBPF_SYNC_TAG}"
-
-TMP_DIR=$(mktemp -d)
-echo "TEMP DIR:        ${TMP_DIR}"
-echo "PATCHES+COVER:   ${TMP_DIR}/patches"
-echo "PATCHSET:        ${TMP_DIR}/patchset.patch"
+echo "WORKDIR:          ${WORKDIR}"
+echo "LINUX REPO:       ${LINUX_REPO}"
+echo "LIBBPF REPO:      ${LIBBPF_REPO}"
+echo "TEMP DIR:         ${TMP_DIR}"
+echo "SUFFIX:           ${SUFFIX}"
+echo "BASE COMMIT:      '$(commit_desc ${BASELINE_COMMIT})'"
+echo "TIP COMMIT:       '$(commit_desc ${TIP_COMMIT})'"
+echo "BPF BASE COMMIT:  '$(commit_desc ${BPF_BASELINE_COMMIT})'"
+echo "BPF TIP COMMIT:   '$(commit_desc ${BPF_TIP_COMMIT})'"
+echo "SQUASH COMMIT:    ${SQUASH_COMMIT}"
+echo "BASELINE TAG:     ${BASELINE_TAG}"
+echo "TIP TAG:          ${TIP_TAG}"
+echo "BPF BASELINE TAG: ${BPF_BASELINE_TAG}"
+echo "BPF TIP TAG:      ${BPF_TIP_TAG}"
+echo "SQUASH BASE TAG:  ${SQUASH_BASE_TAG}"
+echo "SQUASH TIP TAG:   ${SQUASH_TIP_TAG}"
+echo "VIEW TAG:         ${VIEW_TAG}"
+echo "LIBBPF SYNC TAG:  ${LIBBPF_SYNC_TAG}"
+echo "PATCHES:          ${TMP_DIR}/patches"
 
 git branch ${BASELINE_TAG} ${BASELINE_COMMIT}
 git branch ${TIP_TAG} ${TIP_COMMIT}
+git branch ${BPF_BASELINE_TAG} ${BPF_BASELINE_COMMIT}
+git branch ${BPF_TIP_TAG} ${BPF_TIP_COMMIT}
 git branch ${SQUASH_BASE_TAG} ${SQUASH_COMMIT}
 git checkout -b ${SQUASH_TIP_TAG} ${SQUASH_COMMIT}
 
+# Validate there are no non-empty merges in bpf-next and bpf trees
+validate_merges ${BASELINE_TAG} ${TIP_TAG}
+validate_merges ${BPF_BASELINE_TAG} ${BPF_TIP_TAG}
+
 # Cherry-pick new commits onto squashed baseline commit
-LIBBPF_PATHS=(tools/lib/bpf tools/include/uapi/linux/{bpf_common.h,bpf.h,btf.h,if_link.h,if_xdp.h,netlink.h} tools/include/tools/libc_compat.h)
+cherry_pick_commits ${BASELINE_TAG} ${TIP_TAG}
+cherry_pick_commits ${BPF_BASELINE_TAG} ${BPF_TIP_TAG}
 
-LIBBPF_NEW_MERGES=$(git rev-list --merges --topo-order --reverse ${BASELINE_TAG}..${TIP_TAG} ${LIBBPF_PATHS[@]})
-for LIBBPF_NEW_MERGE in ${LIBBPF_NEW_MERGES}; do
-	printf "MERGE:\t" && git log --oneline -n1 ${LIBBPF_NEW_MERGE}
-	MERGE_CHANGES=$(git log --format='' -n1 ${LIBBPF_NEW_MERGE} | wc -l)
-	if ((${MERGE_CHANGES} > 0)); then
-		echo "Merge is non empty, aborting!.."
-		exit 3
-	fi
-done
-
-cd ${WORKDIR} && cd ${LIBBPF_REPO}
-git log --oneline -n500 > ${TMP_DIR}/libbpf_commits.txt
-cd ${WORKDIR} && cd ${LINUX_REPO}
-
-LIBBPF_NEW_COMMITS=$(git rev-list --no-merges --topo-order --reverse ${BASELINE_TAG}..${TIP_TAG} ${LIBBPF_PATHS[@]})
-for LIBBPF_NEW_COMMIT in ${LIBBPF_NEW_COMMITS}; do
-	echo "Checking commit '${LIBBPF_NEW_COMMIT}'"
-	SYNCED_COMMITS=$(grep -F "$(git log -n1 --pretty=format:%s ${LIBBPF_NEW_COMMIT})" ${TMP_DIR}/libbpf_commits.txt || echo "")
-	if [ -n "${SYNCED_COMMITS}" ]; then
-		# commit with the same subject is already in libbpf, but it's not 100% the same commit, so check with user
-		echo "Commit '$(git log -n1 --oneline ${LIBBPF_NEW_COMMIT})' appears to be already synced into libbpf..."
-		echo "Corresponding libbpf commit(s):"
-		echo "${SYNCED_COMMITS}"
-		read -p "Do you want to skip it? [y/N]: " SHOULD_SKIP
-		case "${SHOULD_SKIP}" in 
-			"y" | "Y")
-				echo "Skipping '$(git log -n1 --oneline ${LIBBPF_NEW_COMMIT})'..."
-				continue
-				;;
-		esac
-	fi
-	# commit hasn't been synced into libbpf yet
-	if ! git cherry-pick ${LIBBPF_NEW_COMMIT}; then 
-		read -p "Cherry-picking '$(git log --oneline -n1 ${LIBBPF_NEW_COMMIT})' failed, please fix manually and press <return> to proceed..."
-	fi
-done
-
-LIBBPF_TREE_FILTER='												\
-    mkdir -p __libbpf/include/uapi/linux __libbpf/include/tools &&						\
-    git mv -kf tools/lib/bpf __libbpf/src &&									\
-    git mv -kf tools/include/uapi/linux/{bpf_common.h,bpf.h,btf.h,if_link.h,if_xdp.h,netlink.h}			\
-	       __libbpf/include/uapi/linux &&									\
-    git mv -kf tools/include/tools/libc_compat.h __libbpf/include/tools &&					\
-    git rm --ignore-unmatch -f __libbpf/src/{Makefile,Build,test_libbpf.cpp,.gitignore}				\
-'
 # Move all libbpf files into __libbpf directory.
 git filter-branch --prune-empty -f --tree-filter "${LIBBPF_TREE_FILTER}" ${SQUASH_TIP_TAG} ${SQUASH_BASE_TAG}
 # Make __libbpf a new root directory
@@ -126,59 +262,76 @@ fi
 
 # Exclude baseline commit and generate nice cover letter with summary
 git format-patch ${SQUASH_BASE_TAG}..${SQUASH_TIP_TAG} --cover-letter -o ${TMP_DIR}/patches
-# Now generate single-file patchset w/o cover to apply on top of libbpf repo
-git format-patch ${SQUASH_BASE_TAG}..${SQUASH_TIP_TAG} --stdout > ${TMP_DIR}/patchset.patch
 
-# Now is time to re-apply libbpf-related linux  patches to libbpf repo
-cd ${WORKDIR} && cd ${LIBBPF_REPO}
+# Now is time to re-apply libbpf-related linux patches to libbpf repo
+cd_to ${LIBBPF_REPO}
 git checkout -b ${LIBBPF_SYNC_TAG}
-git am --committer-date-is-author-date ${TMP_DIR}/patchset.patch
+
+for patch in $(ls -1 ${TMP_DIR}/patches | tail -n +2); do
+	if ! git am --committer-date-is-author-date "${TMP_DIR}/patches/${patch}"; then
+		read -p "Applying ${TMP_DIR}/patches/${patch} failed, please resolve manually and press <return> to proceed..."
+	fi
+done
 
 # Use generated cover-letter as a template for "sync commit" with
 # baseline and checkpoint commits from kernel repo (and leave summary
 # from cover letter intact, of course)
 echo ${TIP_COMMIT} > CHECKPOINT-COMMIT &&					      \
+echo ${BPF_TIP_COMMIT} > BPF-CHECKPOINT-COMMIT &&				      \
 git add CHECKPOINT-COMMIT &&							      \
+git add BPF-CHECKPOINT-COMMIT &&						      \
 awk '/\*\*\* BLURB HERE \*\*\*/ {p=1} p' ${TMP_DIR}/patches/0000-cover-letter.patch | \
 sed "s/\*\*\* BLURB HERE \*\*\*/\
 sync: latest libbpf changes from kernel\n\
 \n\
 Syncing latest libbpf commits from kernel repository.\n\
-Baseline commit:   ${BASELINE_COMMIT}\n\
-Checkpoint commit: ${TIP_COMMIT}/" |						      \
+Baseline bpf-next commit:   ${BASELINE_COMMIT}\n\
+Checkpoint bpf-next commit: ${TIP_COMMIT}\n\
+Baseline bpf commit:        ${BPF_BASELINE_COMMIT}\n\
+Checkpoint bpf commit:      ${BPF_TIP_COMMIT}/" |				      \
 git commit --file=-
 
 echo "SUCCESS! ${COMMIT_CNT} commits synced."
 
 echo "Verifying Linux's and Github's libbpf state"
-LIBBPF_VIEW_PATHS=(src include/uapi/linux/{bpf_common.h,bpf.h,btf.h,if_link.h,if_xdp.h,netlink.h} include/tools/libc_compat.h)
-LIBBPF_VIEW_EXCLUDE_REGEX='^src/(Makefile|Build|test_libbpf.cpp|\.gitignore)$'
 
-cd ${WORKDIR} && cd ${LINUX_REPO}
+cd_to ${LINUX_REPO}
 LINUX_ABS_DIR=$(pwd)
 git checkout -b ${VIEW_TAG} ${TIP_COMMIT}
 git filter-branch -f --tree-filter "${LIBBPF_TREE_FILTER}" ${VIEW_TAG}^..${VIEW_TAG}
 git filter-branch -f --subdirectory-filter __libbpf ${VIEW_TAG}^..${VIEW_TAG}
 git ls-files -- ${LIBBPF_VIEW_PATHS[@]} > ${TMP_DIR}/linux-view.ls
 
-cd ${WORKDIR} && cd ${LIBBPF_REPO}
+cd_to ${LIBBPF_REPO}
 GITHUB_ABS_DIR=$(pwd)
 git ls-files -- ${LIBBPF_VIEW_PATHS[@]} | grep -v -E "${LIBBPF_VIEW_EXCLUDE_REGEX}" > ${TMP_DIR}/github-view.ls
 
 echo "Comparing list of files..."
-diff ${TMP_DIR}/linux-view.ls ${TMP_DIR}/github-view.ls
+diff -u ${TMP_DIR}/linux-view.ls ${TMP_DIR}/github-view.ls
 echo "Comparing file contents..."
+CONSISTENT=1
 for F in $(cat ${TMP_DIR}/linux-view.ls); do
-	diff "${LINUX_ABS_DIR}/${F}" "${GITHUB_ABS_DIR}/${F}"
+	if ! diff -u "${LINUX_ABS_DIR}/${F}" "${GITHUB_ABS_DIR}/${F}"; then
+		echo "${LINUX_ABS_DIR}/${F} and ${GITHUB_ABS_DIR}/${F} are different!"
+		CONSISTENT=0
+	fi
 done
-echo "Contents appear identical!"
+if ((${CONSISTENT} == 1)); then
+	echo "Great! Content is identical!"
+else
+	echo "Unfortunately, there are consistency problems!"
+	if ((${IGNORE_CONSISTENCY-0} != 1)); then
+		exit 4
+	fi
+fi
 
 echo "Cleaning up..."
 rm -r ${TMP_DIR}
-cd ${WORKDIR} && cd ${LINUX_REPO}
+cd_to ${LINUX_REPO}
 git checkout ${TIP_SYM_REF}
-git branch -D ${BASELINE_TAG} ${TIP_TAG} ${SQUASH_BASE_TAG} ${SQUASH_TIP_TAG} ${VIEW_TAG}
+git branch -D ${BASELINE_TAG} ${TIP_TAG} ${BPF_BASELINE_TAG} ${BPF_TIP_TAG} \
+	      ${SQUASH_BASE_TAG} ${SQUASH_TIP_TAG} ${VIEW_TAG}
 
-cd ${WORKDIR}
+cd_to .
 echo "DONE."
 

src/.gitignore

@@ -2,3 +2,5 @@
 *.a
 /libbpf.pc
 /libbpf.so*
+/staticobjs
+/sharedobjs

src/Makefile

@@ -1,10 +1,9 @@
 # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 
-VERSION = 0
-PATCHLEVEL = 0
-EXTRAVERSION = 3
-
-LIBBPF_VERSION	= $(VERSION).$(PATCHLEVEL).$(EXTRAVERSION)
+LIBBPF_VERSION := $(shell \
+	grep -oE '^LIBBPF_([0-9.]+)' libbpf.map | \
+	sort -rV | head -n1 | cut -d'_' -f2)
+LIBBPF_MAJOR_VERSION := $(firstword $(subst ., ,$(LIBBPF_VERSION)))
 
 TOPDIR = ..
 
@@ -16,9 +15,7 @@ ifneq ($(FEATURE_REALLOCARRAY),)
 	ALL_CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
 endif
 
-ifndef BUILD_STATIC_ONLY
-	ALL_CFLAGS += -fPIC -fvisibility=hidden
-endif
+SHARED_CFLAGS += -fPIC -fvisibility=hidden -DSHARED
 
 CFLAGS ?= -g -O2 -Werror -Wall
 ALL_CFLAGS += $(CFLAGS)
@@ -32,22 +29,25 @@ else
 endif
 
 OBJDIR ?= .
-
-OBJS := $(addprefix $(OBJDIR)/,bpf.o btf.o libbpf.o libbpf_errno.o netlink.o \
+SHARED_OBJDIR := $(OBJDIR)/sharedobjs
+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)
+	btf_dump.o hashmap.o
+SHARED_OBJS := $(addprefix $(SHARED_OBJDIR)/,$(OBJS))
+STATIC_OBJS := $(addprefix $(STATIC_OBJDIR)/,$(OBJS))
 
-LIBS := $(OBJDIR)/libbpf.a
+STATIC_LIBS := $(OBJDIR)/libbpf.a
 ifndef BUILD_STATIC_ONLY
-	LIBS += $(OBJDIR)/libbpf.so \
-		$(OBJDIR)/libbpf.so.$(VERSION) \
-		$(OBJDIR)/libbpf.so.$(LIBBPF_VERSION)
+	SHARED_LIBS := $(OBJDIR)/libbpf.so \
+		       $(OBJDIR)/libbpf.so.$(LIBBPF_MAJOR_VERSION) \
+		       $(OBJDIR)/libbpf.so.$(LIBBPF_VERSION)
 	VERSION_SCRIPT := libbpf.map
 endif
 
 HEADERS := bpf.h libbpf.h btf.h xsk.h libbpf_util.h
-UAPI_HEADERS := $(addprefix $(TOPDIR)/include/uapi/linux/,bpf.h bpf_common.h \
-	btf.h)
+UAPI_HEADERS := $(addprefix $(TOPDIR)/include/uapi/linux/,\
+			    bpf.h bpf_common.h btf.h)
 
 PC_FILE := $(OBJDIR)/libbpf.pc
 
@@ -66,21 +66,21 @@ LIBDIR ?= $(PREFIX)/$(LIBSUBDIR)
 INCLUDEDIR ?= $(PREFIX)/include
 UAPIDIR ?= $(PREFIX)/include
 
-all: $(LIBS) $(PC_FILE)
+all: $(STATIC_LIBS) $(SHARED_LIBS) $(PC_FILE)
 
-$(OBJDIR)/libbpf.a: $(OBJS)
+$(OBJDIR)/libbpf.a: $(STATIC_OBJS)
 	$(AR) rcs $@ $^
 
-$(OBJDIR)/libbpf.so: $(OBJDIR)/libbpf.so.$(VERSION)
+$(OBJDIR)/libbpf.so: $(OBJDIR)/libbpf.so.$(LIBBPF_MAJOR_VERSION)
 	ln -sf $(^F) $@
 
-$(OBJDIR)/libbpf.so.$(VERSION): $(OBJDIR)/libbpf.so.$(LIBBPF_VERSION)
+$(OBJDIR)/libbpf.so.$(LIBBPF_MAJOR_VERSION): $(OBJDIR)/libbpf.so.$(LIBBPF_VERSION)
 	ln -sf $(^F) $@
 
-$(OBJDIR)/libbpf.so.$(LIBBPF_VERSION): $(OBJS)
-	$(CC) -shared $(ALL_LDFLAGS) -Wl,--version-script=$(VERSION_SCRIPT) \
-				     -Wl,-soname,libbpf.so.$(VERSION) \
-				     $^ -o $@
+$(OBJDIR)/libbpf.so.$(LIBBPF_VERSION): $(SHARED_OBJS)
+	$(CC) -shared -Wl,--version-script=$(VERSION_SCRIPT) \
+		      -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \
+		      $^ $(ALL_LDFLAGS) -o $@
 
 $(OBJDIR)/libbpf.pc:
 	sed -e "s|@PREFIX@|$(PREFIX)|" \
@@ -88,9 +88,18 @@ $(OBJDIR)/libbpf.pc:
 		-e "s|@VERSION@|$(LIBBPF_VERSION)|" \
 		< libbpf.pc.template > $@
 
-$(OBJDIR)/%.o: %.c
+$(STATIC_OBJDIR):
+	mkdir -p $(STATIC_OBJDIR)
+
+$(SHARED_OBJDIR):
+	mkdir -p $(SHARED_OBJDIR)
+
+$(STATIC_OBJDIR)/%.o: %.c | $(STATIC_OBJDIR)
 	$(CC) $(ALL_CFLAGS) $(CPPFLAGS) -c $< -o $@
 
+$(SHARED_OBJDIR)/%.o: %.c | $(SHARED_OBJDIR)
+	$(CC) $(ALL_CFLAGS) $(SHARED_CFLAGS) $(CPPFLAGS) -c $< -o $@
+
 define do_install
 	if [ ! -d '$(DESTDIR)$2' ]; then		\
 		$(INSTALL) -d -m 755 '$(DESTDIR)$2';	\
@@ -107,7 +116,7 @@ define do_s_install
 endef
 
 install: all install_headers install_pkgconfig
-	$(call do_s_install,$(LIBS),$(LIBDIR))
+	$(call do_s_install,$(STATIC_LIBS) $(SHARED_LIBS),$(LIBDIR))
 
 install_headers:
 	$(call do_install,$(HEADERS),$(INCLUDEDIR)/bpf,644)
@@ -121,4 +130,4 @@ install_pkgconfig: $(PC_FILE)
 	$(call do_install,$(PC_FILE),$(LIBDIR)/pkgconfig,644)
 
 clean:
-	rm -f *.o *.a *.so *.so.* *.pc
+	rm -rf *.o *.a *.so *.so.* *.pc $(SHARED_OBJDIR) $(STATIC_OBJDIR)

src/bpf.c

@@ -568,7 +568,7 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
 	return ret;
 }
 
-int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
+static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd)
 {
 	union bpf_attr attr;
 	int err;
@@ -576,26 +576,26 @@ int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
 	memset(&attr, 0, sizeof(attr));
 	attr.start_id = start_id;
 
-	err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
+	err = sys_bpf(cmd, &attr, sizeof(attr));
 	if (!err)
 		*next_id = attr.next_id;
 
 	return err;
 }
 
+int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
+{
+	return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID);
+}
+
 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
 {
-	union bpf_attr attr;
-	int err;
+	return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID);
+}
 
-	memset(&attr, 0, sizeof(attr));
-	attr.start_id = start_id;
-
-	err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
-	if (!err)
-		*next_id = attr.next_id;
-
-	return err;
+int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id)
+{
+	return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID);
 }
 
 int bpf_prog_get_fd_by_id(__u32 id)

src/bpf.h

@@ -156,6 +156,7 @@ LIBBPF_API int bpf_prog_test_run(int prog_fd, int repeat, void *data,
 				 __u32 *retval, __u32 *duration);
 LIBBPF_API int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id);
 LIBBPF_API int bpf_map_get_next_id(__u32 start_id, __u32 *next_id);
+LIBBPF_API int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id);
 LIBBPF_API int bpf_prog_get_fd_by_id(__u32 id);
 LIBBPF_API int bpf_map_get_fd_by_id(__u32 id);
 LIBBPF_API int bpf_btf_get_fd_by_id(__u32 id);

src/btf.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 /* Copyright (c) 2018 Facebook */
 
+#include <endian.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -19,13 +20,6 @@
 #define BTF_MAX_NR_TYPES 0x7fffffff
 #define BTF_MAX_STR_OFFSET 0x7fffffff
 
-#define IS_MODIFIER(k) (((k) == BTF_KIND_TYPEDEF) || \
-		((k) == BTF_KIND_VOLATILE) || \
-		((k) == BTF_KIND_CONST) || \
-		((k) == BTF_KIND_RESTRICT))
-
-#define IS_VAR(k) ((k) == BTF_KIND_VAR)
-
 static struct btf_type btf_void;
 
 struct btf {
@@ -42,47 +36,6 @@ struct btf {
 	int fd;
 };
 
-struct btf_ext_info {
-	/*
-	 * info points to the individual info section (e.g. func_info and
-	 * line_info) from the .BTF.ext. It does not include the __u32 rec_size.
-	 */
-	void *info;
-	__u32 rec_size;
-	__u32 len;
-};
-
-struct btf_ext {
-	union {
-		struct btf_ext_header *hdr;
-		void *data;
-	};
-	struct btf_ext_info func_info;
-	struct btf_ext_info line_info;
-	__u32 data_size;
-};
-
-struct btf_ext_info_sec {
-	__u32	sec_name_off;
-	__u32	num_info;
-	/* Followed by num_info * record_size number of bytes */
-	__u8	data[0];
-};
-
-/* The minimum bpf_func_info checked by the loader */
-struct bpf_func_info_min {
-	__u32   insn_off;
-	__u32   type_id;
-};
-
-/* The minimum bpf_line_info checked by the loader */
-struct bpf_line_info_min {
-	__u32	insn_off;
-	__u32	file_name_off;
-	__u32	line_off;
-	__u32	line_col;
-};
-
 static inline __u64 ptr_to_u64(const void *ptr)
 {
 	return (__u64) (unsigned long) ptr;
@@ -192,9 +145,9 @@ static int btf_parse_str_sec(struct btf *btf)
 static int btf_type_size(struct btf_type *t)
 {
 	int base_size = sizeof(struct btf_type);
-	__u16 vlen = BTF_INFO_VLEN(t->info);
+	__u16 vlen = btf_vlen(t);
 
-	switch (BTF_INFO_KIND(t->info)) {
+	switch (btf_kind(t)) {
 	case BTF_KIND_FWD:
 	case BTF_KIND_CONST:
 	case BTF_KIND_VOLATILE:
@@ -219,7 +172,7 @@ static int btf_type_size(struct btf_type *t)
 	case BTF_KIND_DATASEC:
 		return base_size + vlen * sizeof(struct btf_var_secinfo);
 	default:
-		pr_debug("Unsupported BTF_KIND:%u\n", BTF_INFO_KIND(t->info));
+		pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t));
 		return -EINVAL;
 	}
 }
@@ -263,7 +216,7 @@ const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
 
 static bool btf_type_is_void(const struct btf_type *t)
 {
-	return t == &btf_void || BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
+	return t == &btf_void || btf_is_fwd(t);
 }
 
 static bool btf_type_is_void_or_null(const struct btf_type *t)
@@ -284,7 +237,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 	t = btf__type_by_id(btf, type_id);
 	for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t);
 	     i++) {
-		switch (BTF_INFO_KIND(t->info)) {
+		switch (btf_kind(t)) {
 		case BTF_KIND_INT:
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
@@ -303,7 +256,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 			type_id = t->type;
 			break;
 		case BTF_KIND_ARRAY:
-			array = (const struct btf_array *)(t + 1);
+			array = btf_array(t);
 			if (nelems && array->nelems > UINT32_MAX / nelems)
 				return -E2BIG;
 			nelems *= array->nelems;
@@ -334,8 +287,7 @@ int btf__resolve_type(const struct btf *btf, __u32 type_id)
 	t = btf__type_by_id(btf, type_id);
 	while (depth < MAX_RESOLVE_DEPTH &&
 	       !btf_type_is_void_or_null(t) &&
-	       (IS_MODIFIER(BTF_INFO_KIND(t->info)) ||
-		IS_VAR(BTF_INFO_KIND(t->info)))) {
+	       (btf_is_mod(t) || btf_is_typedef(t) || btf_is_var(t))) {
 		type_id = t->type;
 		t = btf__type_by_id(btf, type_id);
 		depth++;
@@ -419,9 +371,9 @@ done:
 
 static bool btf_check_endianness(const GElf_Ehdr *ehdr)
 {
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#if __BYTE_ORDER == __LITTLE_ENDIAN
 	return ehdr->e_ident[EI_DATA] == ELFDATA2LSB;
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#elif __BYTE_ORDER == __BIG_ENDIAN
 	return ehdr->e_ident[EI_DATA] == ELFDATA2MSB;
 #else
 # error "Unrecognized __BYTE_ORDER__"
@@ -554,11 +506,11 @@ static int compare_vsi_off(const void *_a, const void *_b)
 static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
 			     struct btf_type *t)
 {
-	__u32 size = 0, off = 0, i, vars = BTF_INFO_VLEN(t->info);
+	__u32 size = 0, off = 0, i, vars = btf_vlen(t);
 	const char *name = btf__name_by_offset(btf, t->name_off);
 	const struct btf_type *t_var;
 	struct btf_var_secinfo *vsi;
-	struct btf_var *var;
+	const struct btf_var *var;
 	int ret;
 
 	if (!name) {
@@ -574,12 +526,11 @@ static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
 
 	t->size = size;
 
-	for (i = 0, vsi = (struct btf_var_secinfo *)(t + 1);
-	     i < vars; i++, vsi++) {
+	for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) {
 		t_var = btf__type_by_id(btf, vsi->type);
-		var = (struct btf_var *)(t_var + 1);
+		var = btf_var(t_var);
 
-		if (BTF_INFO_KIND(t_var->info) != BTF_KIND_VAR) {
+		if (!btf_is_var(t_var)) {
 			pr_debug("Non-VAR type seen in section %s\n", name);
 			return -EINVAL;
 		}
@@ -595,7 +546,8 @@ static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
 
 		ret = bpf_object__variable_offset(obj, name, &off);
 		if (ret) {
-			pr_debug("No offset found in symbol table for VAR %s\n", name);
+			pr_debug("No offset found in symbol table for VAR %s\n",
+				 name);
 			return -ENOENT;
 		}
 
@@ -619,7 +571,7 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
 		 * is section size and global variable offset. We use
 		 * the info from the ELF itself for this purpose.
 		 */
-		if (BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC) {
+		if (btf_is_datasec(t)) {
 			err = btf_fixup_datasec(obj, btf, t);
 			if (err)
 				break;
@@ -774,14 +726,13 @@ int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
 		return -EINVAL;
 	}
 
-	if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT ||
-	    BTF_INFO_VLEN(container_type->info) < 2) {
+	if (!btf_is_struct(container_type) || btf_vlen(container_type) < 2) {
 		pr_warning("map:%s container_name:%s is an invalid container struct\n",
 			   map_name, container_name);
 		return -EINVAL;
 	}
 
-	key = (struct btf_member *)(container_type + 1);
+	key = btf_members(container_type);
 	value = key + 1;
 
 	key_size = btf__resolve_size(btf, key->type);
@@ -831,6 +782,9 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext,
 	/* The start of the info sec (including the __u32 record_size). */
 	void *info;
 
+	if (ext_sec->len == 0)
+		return 0;
+
 	if (ext_sec->off & 0x03) {
 		pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n",
 		     ext_sec->desc);
@@ -934,11 +888,24 @@ static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
 	return btf_ext_setup_info(btf_ext, &param);
 }
 
+static int btf_ext_setup_offset_reloc(struct btf_ext *btf_ext)
+{
+	struct btf_ext_sec_setup_param param = {
+		.off = btf_ext->hdr->offset_reloc_off,
+		.len = btf_ext->hdr->offset_reloc_len,
+		.min_rec_size = sizeof(struct bpf_offset_reloc),
+		.ext_info = &btf_ext->offset_reloc_info,
+		.desc = "offset_reloc",
+	};
+
+	return btf_ext_setup_info(btf_ext, &param);
+}
+
 static int btf_ext_parse_hdr(__u8 *data, __u32 data_size)
 {
 	const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
 
-	if (data_size < offsetof(struct btf_ext_header, func_info_off) ||
+	if (data_size < offsetofend(struct btf_ext_header, hdr_len) ||
 	    data_size < hdr->hdr_len) {
 		pr_debug("BTF.ext header not found");
 		return -EINVAL;
@@ -996,6 +963,9 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
 	}
 	memcpy(btf_ext->data, data, size);
 
+	if (btf_ext->hdr->hdr_len <
+	    offsetofend(struct btf_ext_header, line_info_len))
+		goto done;
 	err = btf_ext_setup_func_info(btf_ext);
 	if (err)
 		goto done;
@@ -1004,6 +974,13 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
 	if (err)
 		goto done;
 
+	if (btf_ext->hdr->hdr_len <
+	    offsetofend(struct btf_ext_header, offset_reloc_len))
+		goto done;
+	err = btf_ext_setup_offset_reloc(btf_ext);
+	if (err)
+		goto done;
+
 done:
 	if (err) {
 		btf_ext__free(btf_ext);
@@ -1440,10 +1417,9 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
 	d->map[0] = 0;
 	for (i = 1; i <= btf->nr_types; i++) {
 		struct btf_type *t = d->btf->types[i];
-		__u16 kind = BTF_INFO_KIND(t->info);
 
 		/* VAR and DATASEC are never deduped and are self-canonical */
-		if (kind == BTF_KIND_VAR || kind == BTF_KIND_DATASEC)
+		if (btf_is_var(t) || btf_is_datasec(t))
 			d->map[i] = i;
 		else
 			d->map[i] = BTF_UNPROCESSED_ID;
@@ -1484,11 +1460,11 @@ static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx)
 		if (r)
 			return r;
 
-		switch (BTF_INFO_KIND(t->info)) {
+		switch (btf_kind(t)) {
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION: {
-			struct btf_member *m = (struct btf_member *)(t + 1);
-			__u16 vlen = BTF_INFO_VLEN(t->info);
+			struct btf_member *m = btf_members(t);
+			__u16 vlen = btf_vlen(t);
 
 			for (j = 0; j < vlen; j++) {
 				r = fn(&m->name_off, ctx);
@@ -1499,8 +1475,8 @@ static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx)
 			break;
 		}
 		case BTF_KIND_ENUM: {
-			struct btf_enum *m = (struct btf_enum *)(t + 1);
-			__u16 vlen = BTF_INFO_VLEN(t->info);
+			struct btf_enum *m = btf_enum(t);
+			__u16 vlen = btf_vlen(t);
 
 			for (j = 0; j < vlen; j++) {
 				r = fn(&m->name_off, ctx);
@@ -1511,8 +1487,8 @@ static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx)
 			break;
 		}
 		case BTF_KIND_FUNC_PROTO: {
-			struct btf_param *m = (struct btf_param *)(t + 1);
-			__u16 vlen = BTF_INFO_VLEN(t->info);
+			struct btf_param *m = btf_params(t);
+			__u16 vlen = btf_vlen(t);
 
 			for (j = 0; j < vlen; j++) {
 				r = fn(&m->name_off, ctx);
@@ -1801,16 +1777,16 @@ static long btf_hash_enum(struct btf_type *t)
 /* Check structural equality of two ENUMs. */
 static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2)
 {
-	struct btf_enum *m1, *m2;
+	const struct btf_enum *m1, *m2;
 	__u16 vlen;
 	int i;
 
 	if (!btf_equal_common(t1, t2))
 		return false;
 
-	vlen = BTF_INFO_VLEN(t1->info);
-	m1 = (struct btf_enum *)(t1 + 1);
-	m2 = (struct btf_enum *)(t2 + 1);
+	vlen = btf_vlen(t1);
+	m1 = btf_enum(t1);
+	m2 = btf_enum(t2);
 	for (i = 0; i < vlen; i++) {
 		if (m1->name_off != m2->name_off || m1->val != m2->val)
 			return false;
@@ -1822,8 +1798,7 @@ static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2)
 
 static inline bool btf_is_enum_fwd(struct btf_type *t)
 {
-	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM &&
-	       BTF_INFO_VLEN(t->info) == 0;
+	return btf_is_enum(t) && btf_vlen(t) == 0;
 }
 
 static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2)
@@ -1843,8 +1818,8 @@ static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2)
  */
 static long btf_hash_struct(struct btf_type *t)
 {
-	struct btf_member *member = (struct btf_member *)(t + 1);
-	__u32 vlen = BTF_INFO_VLEN(t->info);
+	const struct btf_member *member = btf_members(t);
+	__u32 vlen = btf_vlen(t);
 	long h = btf_hash_common(t);
 	int i;
 
@@ -1864,16 +1839,16 @@ static long btf_hash_struct(struct btf_type *t)
  */
 static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2)
 {
-	struct btf_member *m1, *m2;
+	const struct btf_member *m1, *m2;
 	__u16 vlen;
 	int i;
 
 	if (!btf_equal_common(t1, t2))
 		return false;
 
-	vlen = BTF_INFO_VLEN(t1->info);
-	m1 = (struct btf_member *)(t1 + 1);
-	m2 = (struct btf_member *)(t2 + 1);
+	vlen = btf_vlen(t1);
+	m1 = btf_members(t1);
+	m2 = btf_members(t2);
 	for (i = 0; i < vlen; i++) {
 		if (m1->name_off != m2->name_off || m1->offset != m2->offset)
 			return false;
@@ -1890,7 +1865,7 @@ static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2)
  */
 static long btf_hash_array(struct btf_type *t)
 {
-	struct btf_array *info = (struct btf_array *)(t + 1);
+	const struct btf_array *info = btf_array(t);
 	long h = btf_hash_common(t);
 
 	h = hash_combine(h, info->type);
@@ -1908,13 +1883,13 @@ static long btf_hash_array(struct btf_type *t)
  */
 static bool btf_equal_array(struct btf_type *t1, struct btf_type *t2)
 {
-	struct btf_array *info1, *info2;
+	const struct btf_array *info1, *info2;
 
 	if (!btf_equal_common(t1, t2))
 		return false;
 
-	info1 = (struct btf_array *)(t1 + 1);
-	info2 = (struct btf_array *)(t2 + 1);
+	info1 = btf_array(t1);
+	info2 = btf_array(t2);
 	return info1->type == info2->type &&
 	       info1->index_type == info2->index_type &&
 	       info1->nelems == info2->nelems;
@@ -1927,14 +1902,10 @@ static bool btf_equal_array(struct btf_type *t1, struct btf_type *t2)
  */
 static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2)
 {
-	struct btf_array *info1, *info2;
-
 	if (!btf_equal_common(t1, t2))
 		return false;
 
-	info1 = (struct btf_array *)(t1 + 1);
-	info2 = (struct btf_array *)(t2 + 1);
-	return info1->nelems == info2->nelems;
+	return btf_array(t1)->nelems == btf_array(t2)->nelems;
 }
 
 /*
@@ -1944,8 +1915,8 @@ static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2)
  */
 static long btf_hash_fnproto(struct btf_type *t)
 {
-	struct btf_param *member = (struct btf_param *)(t + 1);
-	__u16 vlen = BTF_INFO_VLEN(t->info);
+	const struct btf_param *member = btf_params(t);
+	__u16 vlen = btf_vlen(t);
 	long h = btf_hash_common(t);
 	int i;
 
@@ -1966,16 +1937,16 @@ static long btf_hash_fnproto(struct btf_type *t)
  */
 static bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2)
 {
-	struct btf_param *m1, *m2;
+	const struct btf_param *m1, *m2;
 	__u16 vlen;
 	int i;
 
 	if (!btf_equal_common(t1, t2))
 		return false;
 
-	vlen = BTF_INFO_VLEN(t1->info);
-	m1 = (struct btf_param *)(t1 + 1);
-	m2 = (struct btf_param *)(t2 + 1);
+	vlen = btf_vlen(t1);
+	m1 = btf_params(t1);
+	m2 = btf_params(t2);
 	for (i = 0; i < vlen; i++) {
 		if (m1->name_off != m2->name_off || m1->type != m2->type)
 			return false;
@@ -1992,7 +1963,7 @@ static bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2)
  */
 static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
 {
-	struct btf_param *m1, *m2;
+	const struct btf_param *m1, *m2;
 	__u16 vlen;
 	int i;
 
@@ -2000,9 +1971,9 @@ static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
 	if (t1->name_off != t2->name_off || t1->info != t2->info)
 		return false;
 
-	vlen = BTF_INFO_VLEN(t1->info);
-	m1 = (struct btf_param *)(t1 + 1);
-	m2 = (struct btf_param *)(t2 + 1);
+	vlen = btf_vlen(t1);
+	m1 = btf_params(t1);
+	m2 = btf_params(t2);
 	for (i = 0; i < vlen; i++) {
 		if (m1->name_off != m2->name_off)
 			return false;
@@ -2028,7 +1999,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 	__u32 cand_id;
 	long h;
 
-	switch (BTF_INFO_KIND(t->info)) {
+	switch (btf_kind(t)) {
 	case BTF_KIND_CONST:
 	case BTF_KIND_VOLATILE:
 	case BTF_KIND_RESTRICT:
@@ -2141,13 +2112,13 @@ static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id)
 {
 	__u32 orig_type_id = type_id;
 
-	if (BTF_INFO_KIND(d->btf->types[type_id]->info) != BTF_KIND_FWD)
+	if (!btf_is_fwd(d->btf->types[type_id]))
 		return type_id;
 
 	while (is_type_mapped(d, type_id) && d->map[type_id] != type_id)
 		type_id = d->map[type_id];
 
-	if (BTF_INFO_KIND(d->btf->types[type_id]->info) != BTF_KIND_FWD)
+	if (!btf_is_fwd(d->btf->types[type_id]))
 		return type_id;
 
 	return orig_type_id;
@@ -2156,7 +2127,7 @@ static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id)
 
 static inline __u16 btf_fwd_kind(struct btf_type *t)
 {
-	return BTF_INFO_KFLAG(t->info) ? BTF_KIND_UNION : BTF_KIND_STRUCT;
+	return btf_kflag(t) ? BTF_KIND_UNION : BTF_KIND_STRUCT;
 }
 
 /*
@@ -2277,8 +2248,8 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 
 	cand_type = d->btf->types[cand_id];
 	canon_type = d->btf->types[canon_id];
-	cand_kind = BTF_INFO_KIND(cand_type->info);
-	canon_kind = BTF_INFO_KIND(canon_type->info);
+	cand_kind = btf_kind(cand_type);
+	canon_kind = btf_kind(canon_type);
 
 	if (cand_type->name_off != canon_type->name_off)
 		return 0;
@@ -2327,12 +2298,12 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 		return btf_dedup_is_equiv(d, cand_type->type, canon_type->type);
 
 	case BTF_KIND_ARRAY: {
-		struct btf_array *cand_arr, *canon_arr;
+		const struct btf_array *cand_arr, *canon_arr;
 
 		if (!btf_compat_array(cand_type, canon_type))
 			return 0;
-		cand_arr = (struct btf_array *)(cand_type + 1);
-		canon_arr = (struct btf_array *)(canon_type + 1);
+		cand_arr = btf_array(cand_type);
+		canon_arr = btf_array(canon_type);
 		eq = btf_dedup_is_equiv(d,
 			cand_arr->index_type, canon_arr->index_type);
 		if (eq <= 0)
@@ -2342,14 +2313,14 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION: {
-		struct btf_member *cand_m, *canon_m;
+		const struct btf_member *cand_m, *canon_m;
 		__u16 vlen;
 
 		if (!btf_shallow_equal_struct(cand_type, canon_type))
 			return 0;
-		vlen = BTF_INFO_VLEN(cand_type->info);
-		cand_m = (struct btf_member *)(cand_type + 1);
-		canon_m = (struct btf_member *)(canon_type + 1);
+		vlen = btf_vlen(cand_type);
+		cand_m = btf_members(cand_type);
+		canon_m = btf_members(canon_type);
 		for (i = 0; i < vlen; i++) {
 			eq = btf_dedup_is_equiv(d, cand_m->type, canon_m->type);
 			if (eq <= 0)
@@ -2362,7 +2333,7 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 	}
 
 	case BTF_KIND_FUNC_PROTO: {
-		struct btf_param *cand_p, *canon_p;
+		const struct btf_param *cand_p, *canon_p;
 		__u16 vlen;
 
 		if (!btf_compat_fnproto(cand_type, canon_type))
@@ -2370,9 +2341,9 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 		eq = btf_dedup_is_equiv(d, cand_type->type, canon_type->type);
 		if (eq <= 0)
 			return eq;
-		vlen = BTF_INFO_VLEN(cand_type->info);
-		cand_p = (struct btf_param *)(cand_type + 1);
-		canon_p = (struct btf_param *)(canon_type + 1);
+		vlen = btf_vlen(cand_type);
+		cand_p = btf_params(cand_type);
+		canon_p = btf_params(canon_type);
 		for (i = 0; i < vlen; i++) {
 			eq = btf_dedup_is_equiv(d, cand_p->type, canon_p->type);
 			if (eq <= 0)
@@ -2427,8 +2398,8 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d)
 		targ_type_id = d->hypot_map[cand_type_id];
 		t_id = resolve_type_id(d, targ_type_id);
 		c_id = resolve_type_id(d, cand_type_id);
-		t_kind = BTF_INFO_KIND(d->btf->types[t_id]->info);
-		c_kind = BTF_INFO_KIND(d->btf->types[c_id]->info);
+		t_kind = btf_kind(d->btf->types[t_id]);
+		c_kind = btf_kind(d->btf->types[c_id]);
 		/*
 		 * Resolve FWD into STRUCT/UNION.
 		 * It's ok to resolve FWD into STRUCT/UNION that's not yet
@@ -2497,7 +2468,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
 		return 0;
 
 	t = d->btf->types[type_id];
-	kind = BTF_INFO_KIND(t->info);
+	kind = btf_kind(t);
 
 	if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION)
 		return 0;
@@ -2592,7 +2563,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 	t = d->btf->types[type_id];
 	d->map[type_id] = BTF_IN_PROGRESS_ID;
 
-	switch (BTF_INFO_KIND(t->info)) {
+	switch (btf_kind(t)) {
 	case BTF_KIND_CONST:
 	case BTF_KIND_VOLATILE:
 	case BTF_KIND_RESTRICT:
@@ -2616,7 +2587,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 		break;
 
 	case BTF_KIND_ARRAY: {
-		struct btf_array *info = (struct btf_array *)(t + 1);
+		struct btf_array *info = btf_array(t);
 
 		ref_type_id = btf_dedup_ref_type(d, info->type);
 		if (ref_type_id < 0)
@@ -2650,8 +2621,8 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 			return ref_type_id;
 		t->type = ref_type_id;
 
-		vlen = BTF_INFO_VLEN(t->info);
-		param = (struct btf_param *)(t + 1);
+		vlen = btf_vlen(t);
+		param = btf_params(t);
 		for (i = 0; i < vlen; i++) {
 			ref_type_id = btf_dedup_ref_type(d, param->type);
 			if (ref_type_id < 0)
@@ -2791,7 +2762,7 @@ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
 	struct btf_type *t = d->btf->types[type_id];
 	int i, r;
 
-	switch (BTF_INFO_KIND(t->info)) {
+	switch (btf_kind(t)) {
 	case BTF_KIND_INT:
 	case BTF_KIND_ENUM:
 		break;
@@ -2811,7 +2782,7 @@ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
 		break;
 
 	case BTF_KIND_ARRAY: {
-		struct btf_array *arr_info = (struct btf_array *)(t + 1);
+		struct btf_array *arr_info = btf_array(t);
 
 		r = btf_dedup_remap_type_id(d, arr_info->type);
 		if (r < 0)
@@ -2826,8 +2797,8 @@ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
 
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION: {
-		struct btf_member *member = (struct btf_member *)(t + 1);
-		__u16 vlen = BTF_INFO_VLEN(t->info);
+		struct btf_member *member = btf_members(t);
+		__u16 vlen = btf_vlen(t);
 
 		for (i = 0; i < vlen; i++) {
 			r = btf_dedup_remap_type_id(d, member->type);
@@ -2840,8 +2811,8 @@ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
 	}
 
 	case BTF_KIND_FUNC_PROTO: {
-		struct btf_param *param = (struct btf_param *)(t + 1);
-		__u16 vlen = BTF_INFO_VLEN(t->info);
+		struct btf_param *param = btf_params(t);
+		__u16 vlen = btf_vlen(t);
 
 		r = btf_dedup_remap_type_id(d, t->type);
 		if (r < 0)
@@ -2859,8 +2830,8 @@ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
 	}
 
 	case BTF_KIND_DATASEC: {
-		struct btf_var_secinfo *var = (struct btf_var_secinfo *)(t + 1);
-		__u16 vlen = BTF_INFO_VLEN(t->info);
+		struct btf_var_secinfo *var = btf_var_secinfos(t);
+		__u16 vlen = btf_vlen(t);
 
 		for (i = 0; i < vlen; i++) {
 			r = btf_dedup_remap_type_id(d, var->type);

src/btf.h

@@ -5,6 +5,7 @@
 #define __LIBBPF_BTF_H
 
 #include <stdarg.h>
+#include <linux/btf.h>
 #include <linux/types.h>
 
 #ifdef __cplusplus
@@ -57,6 +58,10 @@ struct btf_ext_header {
 	__u32	func_info_len;
 	__u32	line_info_off;
 	__u32	line_info_len;
+
+	/* optional part of .BTF.ext header */
+	__u32	offset_reloc_off;
+	__u32	offset_reloc_len;
 };
 
 LIBBPF_API void btf__free(struct btf *btf);
@@ -120,6 +125,183 @@ LIBBPF_API void btf_dump__free(struct btf_dump *d);
 
 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
 
+/*
+ * A set of helpers for easier BTF types handling
+ */
+static inline __u16 btf_kind(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info);
+}
+
+static inline __u16 btf_vlen(const struct btf_type *t)
+{
+	return BTF_INFO_VLEN(t->info);
+}
+
+static inline bool btf_kflag(const struct btf_type *t)
+{
+	return BTF_INFO_KFLAG(t->info);
+}
+
+static inline bool btf_is_int(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_INT;
+}
+
+static inline bool btf_is_ptr(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_PTR;
+}
+
+static inline bool btf_is_array(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ARRAY;
+}
+
+static inline bool btf_is_struct(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_STRUCT;
+}
+
+static inline bool btf_is_union(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_UNION;
+}
+
+static inline bool btf_is_composite(const struct btf_type *t)
+{
+	__u16 kind = btf_kind(t);
+
+	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
+}
+
+static inline bool btf_is_enum(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ENUM;
+}
+
+static inline bool btf_is_fwd(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_FWD;
+}
+
+static inline bool btf_is_typedef(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_TYPEDEF;
+}
+
+static inline bool btf_is_volatile(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_VOLATILE;
+}
+
+static inline bool btf_is_const(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_CONST;
+}
+
+static inline bool btf_is_restrict(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_RESTRICT;
+}
+
+static inline bool btf_is_mod(const struct btf_type *t)
+{
+	__u16 kind = btf_kind(t);
+
+	return kind == BTF_KIND_VOLATILE ||
+	       kind == BTF_KIND_CONST ||
+	       kind == BTF_KIND_RESTRICT;
+}
+
+static inline bool btf_is_func(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_FUNC;
+}
+
+static inline bool btf_is_func_proto(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_FUNC_PROTO;
+}
+
+static inline bool btf_is_var(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_VAR;
+}
+
+static inline bool btf_is_datasec(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_DATASEC;
+}
+
+static inline __u8 btf_int_encoding(const struct btf_type *t)
+{
+	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
+}
+
+static inline __u8 btf_int_offset(const struct btf_type *t)
+{
+	return BTF_INT_OFFSET(*(__u32 *)(t + 1));
+}
+
+static inline __u8 btf_int_bits(const struct btf_type *t)
+{
+	return BTF_INT_BITS(*(__u32 *)(t + 1));
+}
+
+static inline struct btf_array *btf_array(const struct btf_type *t)
+{
+	return (struct btf_array *)(t + 1);
+}
+
+static inline struct btf_enum *btf_enum(const struct btf_type *t)
+{
+	return (struct btf_enum *)(t + 1);
+}
+
+static inline struct btf_member *btf_members(const struct btf_type *t)
+{
+	return (struct btf_member *)(t + 1);
+}
+
+/* Get bit offset of a member with specified index. */
+static inline __u32 btf_member_bit_offset(const struct btf_type *t,
+					  __u32 member_idx)
+{
+	const struct btf_member *m = btf_members(t) + member_idx;
+	bool kflag = btf_kflag(t);
+
+	return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
+}
+/*
+ * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
+ * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
+ */
+static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
+					     __u32 member_idx)
+{
+	const struct btf_member *m = btf_members(t) + member_idx;
+	bool kflag = btf_kflag(t);
+
+	return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
+}
+
+static inline struct btf_param *btf_params(const struct btf_type *t)
+{
+	return (struct btf_param *)(t + 1);
+}
+
+static inline struct btf_var *btf_var(const struct btf_type *t)
+{
+	return (struct btf_var *)(t + 1);
+}
+
+static inline struct btf_var_secinfo *
+btf_var_secinfos(const struct btf_type *t)
+{
+	return (struct btf_var_secinfo *)(t + 1);
+}
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

src/btf_dump.c

@@ -48,6 +48,8 @@ struct btf_dump_type_aux_state {
 	__u8 fwd_emitted: 1;
 	/* whether unique non-duplicate name was already assigned */
 	__u8 name_resolved: 1;
+	/* whether type is referenced from any other type */
+	__u8 referenced: 1;
 };
 
 struct btf_dump {
@@ -100,21 +102,6 @@ static bool str_equal_fn(const void *a, const void *b, void *ctx)
 	return strcmp(a, b) == 0;
 }
 
-static __u16 btf_kind_of(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info);
-}
-
-static __u16 btf_vlen_of(const struct btf_type *t)
-{
-	return BTF_INFO_VLEN(t->info);
-}
-
-static bool btf_kflag_of(const struct btf_type *t)
-{
-	return BTF_INFO_KFLAG(t->info);
-}
-
 static const char *btf_name_of(const struct btf_dump *d, __u32 name_off)
 {
 	return btf__name_by_offset(d->btf, name_off);
@@ -188,6 +175,7 @@ void btf_dump__free(struct btf_dump *d)
 	free(d);
 }
 
+static int btf_dump_mark_referenced(struct btf_dump *d);
 static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr);
 static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id);
 
@@ -228,6 +216,11 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
 		/* VOID is special */
 		d->type_states[0].order_state = ORDERED;
 		d->type_states[0].emit_state = EMITTED;
+
+		/* eagerly determine referenced types for anon enums */
+		err = btf_dump_mark_referenced(d);
+		if (err)
+			return err;
 	}
 
 	d->emit_queue_cnt = 0;
@@ -241,6 +234,79 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
 	return 0;
 }
 
+/*
+ * Mark all types that are referenced from any other type. This is used to
+ * determine top-level anonymous enums that need to be emitted as an
+ * independent type declarations.
+ * Anonymous enums come in two flavors: either embedded in a struct's field
+ * definition, in which case they have to be declared inline as part of field
+ * type declaration; or as a top-level anonymous enum, typically used for
+ * declaring global constants. It's impossible to distinguish between two
+ * without knowning whether given enum type was referenced from other type:
+ * top-level anonymous enum won't be referenced by anything, while embedded
+ * one will.
+ */
+static int btf_dump_mark_referenced(struct btf_dump *d)
+{
+	int i, j, n = btf__get_nr_types(d->btf);
+	const struct btf_type *t;
+	__u16 vlen;
+
+	for (i = 1; i <= n; i++) {
+		t = btf__type_by_id(d->btf, i);
+		vlen = btf_vlen(t);
+
+		switch (btf_kind(t)) {
+		case BTF_KIND_INT:
+		case BTF_KIND_ENUM:
+		case BTF_KIND_FWD:
+			break;
+
+		case BTF_KIND_VOLATILE:
+		case BTF_KIND_CONST:
+		case BTF_KIND_RESTRICT:
+		case BTF_KIND_PTR:
+		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_FUNC:
+		case BTF_KIND_VAR:
+			d->type_states[t->type].referenced = 1;
+			break;
+
+		case BTF_KIND_ARRAY: {
+			const struct btf_array *a = btf_array(t);
+
+			d->type_states[a->index_type].referenced = 1;
+			d->type_states[a->type].referenced = 1;
+			break;
+		}
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION: {
+			const struct btf_member *m = btf_members(t);
+
+			for (j = 0; j < vlen; j++, m++)
+				d->type_states[m->type].referenced = 1;
+			break;
+		}
+		case BTF_KIND_FUNC_PROTO: {
+			const struct btf_param *p = btf_params(t);
+
+			for (j = 0; j < vlen; j++, p++)
+				d->type_states[p->type].referenced = 1;
+			break;
+		}
+		case BTF_KIND_DATASEC: {
+			const struct btf_var_secinfo *v = btf_var_secinfos(t);
+
+			for (j = 0; j < vlen; j++, v++)
+				d->type_states[v->type].referenced = 1;
+			break;
+		}
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
 static int btf_dump_add_emit_queue_id(struct btf_dump *d, __u32 id)
 {
 	__u32 *new_queue;
@@ -349,7 +415,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	 */
 	struct btf_dump_type_aux_state *tstate = &d->type_states[id];
 	const struct btf_type *t;
-	__u16 kind, vlen;
+	__u16 vlen;
 	int err, i;
 
 	/* return true, letting typedefs know that it's ok to be emitted */
@@ -357,18 +423,16 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		return 1;
 
 	t = btf__type_by_id(d->btf, id);
-	kind = btf_kind_of(t);
 
 	if (tstate->order_state == ORDERING) {
 		/* type loop, but resolvable through fwd declaration */
-		if ((kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION) &&
-		    through_ptr && t->name_off != 0)
+		if (btf_is_composite(t) && through_ptr && t->name_off != 0)
 			return 0;
 		pr_warning("unsatisfiable type cycle, id:[%u]\n", id);
 		return -ELOOP;
 	}
 
-	switch (kind) {
+	switch (btf_kind(t)) {
 	case BTF_KIND_INT:
 		tstate->order_state = ORDERED;
 		return 0;
@@ -378,14 +442,12 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		tstate->order_state = ORDERED;
 		return err;
 
-	case BTF_KIND_ARRAY: {
-		const struct btf_array *a = (void *)(t + 1);
+	case BTF_KIND_ARRAY:
+		return btf_dump_order_type(d, btf_array(t)->type, through_ptr);
 
-		return btf_dump_order_type(d, a->type, through_ptr);
-	}
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION: {
-		const struct btf_member *m = (void *)(t + 1);
+		const struct btf_member *m = btf_members(t);
 		/*
 		 * struct/union is part of strong link, only if it's embedded
 		 * (so no ptr in a path) or it's anonymous (so has to be
@@ -396,7 +458,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 
 		tstate->order_state = ORDERING;
 
-		vlen = btf_vlen_of(t);
+		vlen = btf_vlen(t);
 		for (i = 0; i < vlen; i++, m++) {
 			err = btf_dump_order_type(d, m->type, false);
 			if (err < 0)
@@ -414,7 +476,12 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	}
 	case BTF_KIND_ENUM:
 	case BTF_KIND_FWD:
-		if (t->name_off != 0) {
+		/*
+		 * non-anonymous or non-referenced enums are top-level
+		 * declarations and should be emitted. Same logic can be
+		 * applied to FWDs, it won't hurt anyways.
+		 */
+		if (t->name_off != 0 || !tstate->referenced) {
 			err = btf_dump_add_emit_queue_id(d, id);
 			if (err)
 				return err;
@@ -447,7 +514,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		return btf_dump_order_type(d, t->type, through_ptr);
 
 	case BTF_KIND_FUNC_PROTO: {
-		const struct btf_param *p = (void *)(t + 1);
+		const struct btf_param *p = btf_params(t);
 		bool is_strong;
 
 		err = btf_dump_order_type(d, t->type, through_ptr);
@@ -455,7 +522,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 			return err;
 		is_strong = err > 0;
 
-		vlen = btf_vlen_of(t);
+		vlen = btf_vlen(t);
 		for (i = 0; i < vlen; i++, p++) {
 			err = btf_dump_order_type(d, p->type, through_ptr);
 			if (err < 0)
@@ -553,12 +620,7 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 		return;
 
 	t = btf__type_by_id(d->btf, id);
-	kind = btf_kind_of(t);
-
-	if (top_level_def && t->name_off == 0) {
-		pr_warning("unexpected nameless definition, id:[%u]\n", id);
-		return;
-	}
+	kind = btf_kind(t);
 
 	if (tstate->emit_state == EMITTING) {
 		if (tstate->fwd_emitted)
@@ -618,12 +680,9 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 	case BTF_KIND_RESTRICT:
 		btf_dump_emit_type(d, t->type, cont_id);
 		break;
-	case BTF_KIND_ARRAY: {
-		const struct btf_array *a = (void *)(t + 1);
-
-		btf_dump_emit_type(d, a->type, cont_id);
+	case BTF_KIND_ARRAY:
+		btf_dump_emit_type(d, btf_array(t)->type, cont_id);
 		break;
-	}
 	case BTF_KIND_FWD:
 		btf_dump_emit_fwd_def(d, id, t);
 		btf_dump_printf(d, ";\n\n");
@@ -656,8 +715,8 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 		 * applicable
 		 */
 		if (top_level_def || t->name_off == 0) {
-			const struct btf_member *m = (void *)(t + 1);
-			__u16 vlen = btf_vlen_of(t);
+			const struct btf_member *m = btf_members(t);
+			__u16 vlen = btf_vlen(t);
 			int i, new_cont_id;
 
 			new_cont_id = t->name_off == 0 ? cont_id : id;
@@ -678,8 +737,8 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 		}
 		break;
 	case BTF_KIND_FUNC_PROTO: {
-		const struct btf_param *p = (void *)(t + 1);
-		__u16 vlen = btf_vlen_of(t);
+		const struct btf_param *p = btf_params(t);
+		__u16 vlen = btf_vlen(t);
 		int i;
 
 		btf_dump_emit_type(d, t->type, cont_id);
@@ -696,7 +755,7 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 static int btf_align_of(const struct btf *btf, __u32 id)
 {
 	const struct btf_type *t = btf__type_by_id(btf, id);
-	__u16 kind = btf_kind_of(t);
+	__u16 kind = btf_kind(t);
 
 	switch (kind) {
 	case BTF_KIND_INT:
@@ -709,15 +768,12 @@ static int btf_align_of(const struct btf *btf, __u32 id)
 	case BTF_KIND_CONST:
 	case BTF_KIND_RESTRICT:
 		return btf_align_of(btf, t->type);
-	case BTF_KIND_ARRAY: {
-		const struct btf_array *a = (void *)(t + 1);
-
-		return btf_align_of(btf, a->type);
-	}
+	case BTF_KIND_ARRAY:
+		return btf_align_of(btf, btf_array(t)->type);
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION: {
-		const struct btf_member *m = (void *)(t + 1);
-		__u16 vlen = btf_vlen_of(t);
+		const struct btf_member *m = btf_members(t);
+		__u16 vlen = btf_vlen(t);
 		int i, align = 1;
 
 		for (i = 0; i < vlen; i++, m++)
@@ -726,7 +782,7 @@ static int btf_align_of(const struct btf *btf, __u32 id)
 		return align;
 	}
 	default:
-		pr_warning("unsupported BTF_KIND:%u\n", btf_kind_of(t));
+		pr_warning("unsupported BTF_KIND:%u\n", btf_kind(t));
 		return 1;
 	}
 }
@@ -737,20 +793,18 @@ static bool btf_is_struct_packed(const struct btf *btf, __u32 id,
 	const struct btf_member *m;
 	int align, i, bit_sz;
 	__u16 vlen;
-	bool kflag;
 
 	align = btf_align_of(btf, id);
 	/* size of a non-packed struct has to be a multiple of its alignment*/
 	if (t->size % align)
 		return true;
 
-	m = (void *)(t + 1);
-	kflag = btf_kflag_of(t);
-	vlen = btf_vlen_of(t);
+	m = btf_members(t);
+	vlen = btf_vlen(t);
 	/* all non-bitfield fields have to be naturally aligned */
 	for (i = 0; i < vlen; i++, m++) {
 		align = btf_align_of(btf, m->type);
-		bit_sz = kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
+		bit_sz = btf_member_bitfield_size(t, i);
 		if (bit_sz == 0 && m->offset % (8 * align) != 0)
 			return true;
 	}
@@ -807,7 +861,7 @@ static void btf_dump_emit_struct_fwd(struct btf_dump *d, __u32 id,
 				     const struct btf_type *t)
 {
 	btf_dump_printf(d, "%s %s",
-			btf_kind_of(t) == BTF_KIND_STRUCT ? "struct" : "union",
+			btf_is_struct(t) ? "struct" : "union",
 			btf_dump_type_name(d, id));
 }
 
@@ -816,12 +870,11 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 				     const struct btf_type *t,
 				     int lvl)
 {
-	const struct btf_member *m = (void *)(t + 1);
-	bool kflag = btf_kflag_of(t), is_struct;
+	const struct btf_member *m = btf_members(t);
+	bool is_struct = btf_is_struct(t);
 	int align, i, packed, off = 0;
-	__u16 vlen = btf_vlen_of(t);
+	__u16 vlen = btf_vlen(t);
 
-	is_struct = btf_kind_of(t) == BTF_KIND_STRUCT;
 	packed = is_struct ? btf_is_struct_packed(d->btf, id, t) : 0;
 	align = packed ? 1 : btf_align_of(d->btf, id);
 
@@ -835,8 +888,8 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 		int m_off, m_sz;
 
 		fname = btf_name_of(d, m->name_off);
-		m_sz = kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
-		m_off = kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
+		m_sz = btf_member_bitfield_size(t, i);
+		m_off = btf_member_bit_offset(t, i);
 		align = packed ? 1 : btf_align_of(d->btf, m->type);
 
 		btf_dump_emit_bit_padding(d, off, m_off, m_sz, align, lvl + 1);
@@ -870,8 +923,8 @@ static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
 				   const struct btf_type *t,
 				   int lvl)
 {
-	const struct btf_enum *v = (void *)(t+1);
-	__u16 vlen = btf_vlen_of(t);
+	const struct btf_enum *v = btf_enum(t);
+	__u16 vlen = btf_vlen(t);
 	const char *name;
 	size_t dup_cnt;
 	int i;
@@ -905,7 +958,7 @@ static void btf_dump_emit_fwd_def(struct btf_dump *d, __u32 id,
 {
 	const char *name = btf_dump_type_name(d, id);
 
-	if (btf_kflag_of(t))
+	if (btf_kflag(t))
 		btf_dump_printf(d, "union %s", name);
 	else
 		btf_dump_printf(d, "struct %s", name);
@@ -987,7 +1040,6 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 	struct id_stack decl_stack;
 	const struct btf_type *t;
 	int err, stack_start;
-	__u16 kind;
 
 	stack_start = d->decl_stack_cnt;
 	for (;;) {
@@ -1008,8 +1060,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			break;
 
 		t = btf__type_by_id(d->btf, id);
-		kind = btf_kind_of(t);
-		switch (kind) {
+		switch (btf_kind(t)) {
 		case BTF_KIND_PTR:
 		case BTF_KIND_VOLATILE:
 		case BTF_KIND_CONST:
@@ -1017,12 +1068,9 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 		case BTF_KIND_FUNC_PROTO:
 			id = t->type;
 			break;
-		case BTF_KIND_ARRAY: {
-			const struct btf_array *a = (void *)(t + 1);
-
-			id = a->type;
+		case BTF_KIND_ARRAY:
+			id = btf_array(t)->type;
 			break;
-		}
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
 		case BTF_KIND_FWD:
@@ -1032,7 +1080,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			goto done;
 		default:
 			pr_warning("unexpected type in decl chain, kind:%u, id:[%u]\n",
-				   kind, id);
+				   btf_kind(t), id);
 			goto done;
 		}
 	}
@@ -1070,7 +1118,7 @@ static void btf_dump_emit_mods(struct btf_dump *d, struct id_stack *decl_stack)
 		id = decl_stack->ids[decl_stack->cnt - 1];
 		t = btf__type_by_id(d->btf, id);
 
-		switch (btf_kind_of(t)) {
+		switch (btf_kind(t)) {
 		case BTF_KIND_VOLATILE:
 			btf_dump_printf(d, "volatile ");
 			break;
@@ -1087,20 +1135,6 @@ static void btf_dump_emit_mods(struct btf_dump *d, struct id_stack *decl_stack)
 	}
 }
 
-static bool btf_is_mod_kind(const struct btf *btf, __u32 id)
-{
-	const struct btf_type *t = btf__type_by_id(btf, id);
-
-	switch (btf_kind_of(t)) {
-	case BTF_KIND_VOLATILE:
-	case BTF_KIND_CONST:
-	case BTF_KIND_RESTRICT:
-		return true;
-	default:
-		return false;
-	}
-}
-
 static void btf_dump_emit_name(const struct btf_dump *d,
 			       const char *name, bool last_was_ptr)
 {
@@ -1139,7 +1173,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 		}
 
 		t = btf__type_by_id(d->btf, id);
-		kind = btf_kind_of(t);
+		kind = btf_kind(t);
 
 		switch (kind) {
 		case BTF_KIND_INT:
@@ -1185,7 +1219,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			btf_dump_printf(d, " restrict");
 			break;
 		case BTF_KIND_ARRAY: {
-			const struct btf_array *a = (void *)(t + 1);
+			const struct btf_array *a = btf_array(t);
 			const struct btf_type *next_t;
 			__u32 next_id;
 			bool multidim;
@@ -1201,7 +1235,8 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			 */
 			while (decls->cnt) {
 				next_id = decls->ids[decls->cnt - 1];
-				if (btf_is_mod_kind(d->btf, next_id))
+				next_t = btf__type_by_id(d->btf, next_id);
+				if (btf_is_mod(next_t))
 					decls->cnt--;
 				else
 					break;
@@ -1213,8 +1248,9 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 				return;
 			}
 
+			next_id = decls->ids[decls->cnt - 1];
 			next_t = btf__type_by_id(d->btf, next_id);
-			multidim = btf_kind_of(next_t) == BTF_KIND_ARRAY;
+			multidim = btf_is_array(next_t);
 			/* we need space if we have named non-pointer */
 			if (fname[0] && !last_was_ptr)
 				btf_dump_printf(d, " ");
@@ -1228,8 +1264,8 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			return;
 		}
 		case BTF_KIND_FUNC_PROTO: {
-			const struct btf_param *p = (void *)(t + 1);
-			__u16 vlen = btf_vlen_of(t);
+			const struct btf_param *p = btf_params(t);
+			__u16 vlen = btf_vlen(t);
 			int i;
 
 			btf_dump_emit_mods(d, decls);

src/hashmap.h

@@ -10,6 +10,11 @@
 
 #include <stdbool.h>
 #include <stddef.h>
+#ifdef __GLIBC__
+#include <bits/wordsize.h>
+#else
+#include <bits/reg.h>
+#endif
 #include "libbpf_internal.h"
 
 static inline size_t hash_bits(size_t h, int bits)

src/libbpf.h

@@ -57,7 +57,7 @@ enum libbpf_print_level {
 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
 				 const char *, va_list ap);
 
-LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn);
+LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
 
 /* Hide internal to user */
 struct bpf_object;
@@ -92,6 +92,7 @@ LIBBPF_API void bpf_object__close(struct bpf_object *object);
 struct bpf_object_load_attr {
 	struct bpf_object *obj;
 	int log_level;
+	const char *target_btf_path;
 };
 
 /* Load/unload object into/from kernel */

src/libbpf.map

@@ -183,4 +183,10 @@ LIBBPF_0.0.4 {
 		perf_buffer__new;
 		perf_buffer__new_raw;
 		perf_buffer__poll;
+		xsk_umem__create;
 } LIBBPF_0.0.3;
+
+LIBBPF_0.0.5 {
+	global:
+		bpf_btf_get_next_id;
+} LIBBPF_0.0.4;

src/libbpf_internal.h

@@ -29,6 +29,26 @@
 #ifndef max
 # define max(x, y) ((x) < (y) ? (y) : (x))
 #endif
+#ifndef offsetofend
+# define offsetofend(TYPE, FIELD) \
+	(offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD))
+#endif
+
+/* 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.
+ */
+#ifdef SHARED
+# define COMPAT_VERSION(internal_name, api_name, version) \
+	asm(".symver " #internal_name "," #api_name "@" #version);
+# define DEFAULT_VERSION(internal_name, api_name, version) \
+	asm(".symver " #internal_name "," #api_name "@@" #version);
+#else
+# define COMPAT_VERSION(internal_name, api_name, version)
+# define DEFAULT_VERSION(internal_name, api_name, version) \
+	extern typeof(internal_name) api_name \
+	__attribute__((alias(#internal_name)));
+#endif
 
 extern void libbpf_print(enum libbpf_print_level level,
 			 const char *format, ...)
@@ -46,4 +66,105 @@ do {				\
 int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
 			 const char *str_sec, size_t str_len);
 
+struct btf_ext_info {
+	/*
+	 * info points to the individual info section (e.g. func_info and
+	 * line_info) from the .BTF.ext. It does not include the __u32 rec_size.
+	 */
+	void *info;
+	__u32 rec_size;
+	__u32 len;
+};
+
+#define for_each_btf_ext_sec(seg, sec)					\
+	for (sec = (seg)->info;						\
+	     (void *)sec < (seg)->info + (seg)->len;			\
+	     sec = (void *)sec + sizeof(struct btf_ext_info_sec) +	\
+		   (seg)->rec_size * sec->num_info)
+
+#define for_each_btf_ext_rec(seg, sec, i, rec)				\
+	for (i = 0, rec = (void *)&(sec)->data;				\
+	     i < (sec)->num_info;					\
+	     i++, rec = (void *)rec + (seg)->rec_size)
+
+struct btf_ext {
+	union {
+		struct btf_ext_header *hdr;
+		void *data;
+	};
+	struct btf_ext_info func_info;
+	struct btf_ext_info line_info;
+	struct btf_ext_info offset_reloc_info;
+	__u32 data_size;
+};
+
+struct btf_ext_info_sec {
+	__u32	sec_name_off;
+	__u32	num_info;
+	/* Followed by num_info * record_size number of bytes */
+	__u8	data[0];
+};
+
+/* The minimum bpf_func_info checked by the loader */
+struct bpf_func_info_min {
+	__u32   insn_off;
+	__u32   type_id;
+};
+
+/* The minimum bpf_line_info checked by the loader */
+struct bpf_line_info_min {
+	__u32	insn_off;
+	__u32	file_name_off;
+	__u32	line_off;
+	__u32	line_col;
+};
+
+/* The minimum bpf_offset_reloc checked by the loader
+ *
+ * Offset relocation captures the following data:
+ * - insn_off - instruction offset (in bytes) within a BPF program that needs
+ *   its insn->imm field to be relocated with actual offset;
+ * - type_id - BTF type ID of the "root" (containing) entity of a relocatable
+ *   offset;
+ * - access_str_off - offset into corresponding .BTF string section. String
+ *   itself encodes an accessed field using a sequence of field and array
+ *   indicies, separated by colon (:). It's conceptually very close to LLVM's
+ *   getelementptr ([0]) instruction's arguments for identifying offset to 
+ *   a field.
+ *
+ * Example to provide a better feel.
+ *
+ *   struct sample {
+ *       int a;
+ *       struct {
+ *           int b[10];
+ *       };
+ *   };
+ *
+ *   struct sample *s = ...;
+ *   int x = &s->a;     // encoded as "0:0" (a is field #0)
+ *   int y = &s->b[5];  // encoded as "0:1:0:5" (anon struct is field #1, 
+ *                      // b is field #0 inside anon struct, accessing elem #5)
+ *   int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array)
+ *
+ * type_id for all relocs in this example  will capture BTF type id of
+ * `struct sample`.
+ *
+ * Such relocation is emitted when using __builtin_preserve_access_index()
+ * Clang built-in, passing expression that captures field address, e.g.:
+ *
+ * bpf_probe_read(&dst, sizeof(dst),
+ *		  __builtin_preserve_access_index(&src->a.b.c));
+ *
+ * In this case Clang will emit offset relocation recording necessary data to
+ * be able to find offset of embedded `a.b.c` field within `src` struct.
+ *
+ *   [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
+ */
+struct bpf_offset_reloc {
+	__u32   insn_off;
+	__u32   type_id;
+	__u32   access_str_off;
+};
+
 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */

src/libbpf_probes.c

@@ -244,6 +244,7 @@ bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex)
 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
 	case BPF_MAP_TYPE_HASH_OF_MAPS:
 	case BPF_MAP_TYPE_DEVMAP:
+	case BPF_MAP_TYPE_DEVMAP_HASH:
 	case BPF_MAP_TYPE_SOCKMAP:
 	case BPF_MAP_TYPE_CPUMAP:
 	case BPF_MAP_TYPE_XSKMAP:

src/xsk.c

@@ -65,7 +65,6 @@ struct xsk_socket {
 	int xsks_map_fd;
 	__u32 queue_id;
 	char ifname[IFNAMSIZ];
-	bool zc;
 };
 
 struct xsk_nl_info {
@@ -74,23 +73,6 @@ struct xsk_nl_info {
 	int fd;
 };
 
-/* For 32-bit systems, we need to use mmap2 as the offsets are 64-bit.
- * Unfortunately, it is not part of glibc.
- */
-static inline void *xsk_mmap(void *addr, size_t length, int prot, int flags,
-			     int fd, __u64 offset)
-{
-#ifdef __NR_mmap2
-	unsigned int page_shift = __builtin_ffs(getpagesize()) - 1;
-	long ret = syscall(__NR_mmap2, addr, length, prot, flags, fd,
-			   (off_t)(offset >> page_shift));
-
-	return (void *)ret;
-#else
-	return mmap(addr, length, prot, flags, fd, offset);
-#endif
-}
-
 int xsk_umem__fd(const struct xsk_umem *umem)
 {
 	return umem ? umem->fd : -EINVAL;
@@ -116,6 +98,7 @@ static void xsk_set_umem_config(struct xsk_umem_config *cfg,
 		cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
 		cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
 		cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
+		cfg->flags = XSK_UMEM__DEFAULT_FLAGS;
 		return;
 	}
 
@@ -123,6 +106,7 @@ static void xsk_set_umem_config(struct xsk_umem_config *cfg,
 	cfg->comp_size = usr_cfg->comp_size;
 	cfg->frame_size = usr_cfg->frame_size;
 	cfg->frame_headroom = usr_cfg->frame_headroom;
+	cfg->flags = usr_cfg->flags;
 }
 
 static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
@@ -149,9 +133,10 @@ static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
 	return 0;
 }
 
-int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
-		     struct xsk_ring_prod *fill, struct xsk_ring_cons *comp,
-		     const struct xsk_umem_config *usr_config)
+int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area,
+			    __u64 size, struct xsk_ring_prod *fill,
+			    struct xsk_ring_cons *comp,
+			    const struct xsk_umem_config *usr_config)
 {
 	struct xdp_mmap_offsets off;
 	struct xdp_umem_reg mr;
@@ -182,6 +167,7 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
 	mr.len = size;
 	mr.chunk_size = umem->config.frame_size;
 	mr.headroom = umem->config.frame_headroom;
+	mr.flags = umem->config.flags;
 
 	err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr));
 	if (err) {
@@ -210,10 +196,9 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
 		goto out_socket;
 	}
 
-	map = xsk_mmap(NULL, off.fr.desc +
-		       umem->config.fill_size * sizeof(__u64),
-		       PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
-		       umem->fd, XDP_UMEM_PGOFF_FILL_RING);
+	map = mmap(NULL, off.fr.desc + umem->config.fill_size * sizeof(__u64),
+		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, umem->fd,
+		   XDP_UMEM_PGOFF_FILL_RING);
 	if (map == MAP_FAILED) {
 		err = -errno;
 		goto out_socket;
@@ -224,13 +209,13 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
 	fill->size = umem->config.fill_size;
 	fill->producer = map + off.fr.producer;
 	fill->consumer = map + off.fr.consumer;
+	fill->flags = map + off.fr.flags;
 	fill->ring = map + off.fr.desc;
 	fill->cached_cons = umem->config.fill_size;
 
-	map = xsk_mmap(NULL,
-		       off.cr.desc + umem->config.comp_size * sizeof(__u64),
-		       PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
-		       umem->fd, XDP_UMEM_PGOFF_COMPLETION_RING);
+	map = mmap(NULL, off.cr.desc + umem->config.comp_size * sizeof(__u64),
+		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, umem->fd,
+		   XDP_UMEM_PGOFF_COMPLETION_RING);
 	if (map == MAP_FAILED) {
 		err = -errno;
 		goto out_mmap;
@@ -241,6 +226,7 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
 	comp->size = umem->config.comp_size;
 	comp->producer = map + off.cr.producer;
 	comp->consumer = map + off.cr.consumer;
+	comp->flags = map + off.cr.flags;
 	comp->ring = map + off.cr.desc;
 
 	*umem_ptr = umem;
@@ -255,6 +241,29 @@ out_umem_alloc:
 	return err;
 }
 
+struct xsk_umem_config_v1 {
+	__u32 fill_size;
+	__u32 comp_size;
+	__u32 frame_size;
+	__u32 frame_headroom;
+};
+
+int xsk_umem__create_v0_0_2(struct xsk_umem **umem_ptr, void *umem_area,
+			    __u64 size, struct xsk_ring_prod *fill,
+			    struct xsk_ring_cons *comp,
+			    const struct xsk_umem_config *usr_config)
+{
+	struct xsk_umem_config config;
+
+	memcpy(&config, usr_config, sizeof(struct xsk_umem_config_v1));
+	config.flags = 0;
+
+	return xsk_umem__create_v0_0_4(umem_ptr, umem_area, size, fill, comp,
+					&config);
+}
+COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2)
+DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4)
+
 static int xsk_load_xdp_prog(struct xsk_socket *xsk)
 {
 	static const int log_buf_size = 16 * 1024;
@@ -317,17 +326,16 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk)
 
 static int xsk_get_max_queues(struct xsk_socket *xsk)
 {
-	struct ethtool_channels channels;
-	struct ifreq ifr;
+	struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
+	struct ifreq ifr = {};
 	int fd, err, ret;
 
 	fd = socket(AF_INET, SOCK_DGRAM, 0);
 	if (fd < 0)
 		return -errno;
 
-	channels.cmd = ETHTOOL_GCHANNELS;
 	ifr.ifr_data = (void *)&channels;
-	strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
+	memcpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
 	ifr.ifr_name[IFNAMSIZ - 1] = '\0';
 	err = ioctl(fd, SIOCETHTOOL, &ifr);
 	if (err && errno != EOPNOTSUPP) {
@@ -335,7 +343,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk)
 		goto out;
 	}
 
-	if (channels.max_combined == 0 || errno == EOPNOTSUPP)
+	if (err || channels.max_combined == 0)
 		/* If the device says it has no channels, then all traffic
 		 * is sent to a single stream, so max queues = 1.
 		 */
@@ -482,7 +490,6 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 	void *rx_map = NULL, *tx_map = NULL;
 	struct sockaddr_xdp sxdp = {};
 	struct xdp_mmap_offsets off;
-	struct xdp_options opts;
 	struct xsk_socket *xsk;
 	socklen_t optlen;
 	int err;
@@ -517,7 +524,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 		err = -errno;
 		goto out_socket;
 	}
-	strncpy(xsk->ifname, ifname, IFNAMSIZ - 1);
+	memcpy(xsk->ifname, ifname, IFNAMSIZ - 1);
 	xsk->ifname[IFNAMSIZ - 1] = '\0';
 
 	err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
@@ -551,11 +558,10 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 	}
 
 	if (rx) {
-		rx_map = xsk_mmap(NULL, off.rx.desc +
-				  xsk->config.rx_size * sizeof(struct xdp_desc),
-				  PROT_READ | PROT_WRITE,
-				  MAP_SHARED | MAP_POPULATE,
-				  xsk->fd, XDP_PGOFF_RX_RING);
+		rx_map = mmap(NULL, off.rx.desc +
+			      xsk->config.rx_size * sizeof(struct xdp_desc),
+			      PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+			      xsk->fd, XDP_PGOFF_RX_RING);
 		if (rx_map == MAP_FAILED) {
 			err = -errno;
 			goto out_socket;
@@ -565,16 +571,16 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 		rx->size = xsk->config.rx_size;
 		rx->producer = rx_map + off.rx.producer;
 		rx->consumer = rx_map + off.rx.consumer;
+		rx->flags = rx_map + off.rx.flags;
 		rx->ring = rx_map + off.rx.desc;
 	}
 	xsk->rx = rx;
 
 	if (tx) {
-		tx_map = xsk_mmap(NULL, off.tx.desc +
-				  xsk->config.tx_size * sizeof(struct xdp_desc),
-				  PROT_READ | PROT_WRITE,
-				  MAP_SHARED | MAP_POPULATE,
-				  xsk->fd, XDP_PGOFF_TX_RING);
+		tx_map = mmap(NULL, off.tx.desc +
+			      xsk->config.tx_size * sizeof(struct xdp_desc),
+			      PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+			      xsk->fd, XDP_PGOFF_TX_RING);
 		if (tx_map == MAP_FAILED) {
 			err = -errno;
 			goto out_mmap_rx;
@@ -584,6 +590,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 		tx->size = xsk->config.tx_size;
 		tx->producer = tx_map + off.tx.producer;
 		tx->consumer = tx_map + off.tx.consumer;
+		tx->flags = tx_map + off.tx.flags;
 		tx->ring = tx_map + off.tx.desc;
 		tx->cached_cons = xsk->config.tx_size;
 	}
@@ -602,15 +609,6 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 
 	xsk->prog_fd = -1;
 
-	optlen = sizeof(opts);
-	err = getsockopt(xsk->fd, SOL_XDP, XDP_OPTIONS, &opts, &optlen);
-	if (err) {
-		err = -errno;
-		goto out_mmap_tx;
-	}
-
-	xsk->zc = opts.flags & XDP_OPTIONS_ZEROCOPY;
-
 	if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
 		err = xsk_setup_xdp_prog(xsk);
 		if (err)

src/xsk.h

@@ -32,6 +32,7 @@ struct name { \
 	__u32 *producer; \
 	__u32 *consumer; \
 	void *ring; \
+	__u32 *flags; \
 }
 
 DEFINE_XSK_RING(xsk_ring_prod);
@@ -76,6 +77,11 @@ xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx, __u32 idx)
 	return &descs[idx & rx->mask];
 }
 
+static inline int xsk_ring_prod__needs_wakeup(const struct xsk_ring_prod *r)
+{
+	return *r->flags & XDP_RING_NEED_WAKEUP;
+}
+
 static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb)
 {
 	__u32 free_entries = r->cached_cons - r->cached_prod;
@@ -162,6 +168,21 @@ static inline void *xsk_umem__get_data(void *umem_area, __u64 addr)
 	return &((char *)umem_area)[addr];
 }
 
+static inline __u64 xsk_umem__extract_addr(__u64 addr)
+{
+	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
+}
+
+static inline __u64 xsk_umem__extract_offset(__u64 addr)
+{
+	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
+}
+
+static inline __u64 xsk_umem__add_offset_to_addr(__u64 addr)
+{
+	return xsk_umem__extract_addr(addr) + xsk_umem__extract_offset(addr);
+}
+
 LIBBPF_API int xsk_umem__fd(const struct xsk_umem *umem);
 LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk);
 
@@ -170,12 +191,14 @@ LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk);
 #define XSK_UMEM__DEFAULT_FRAME_SHIFT    12 /* 4096 bytes */
 #define XSK_UMEM__DEFAULT_FRAME_SIZE     (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT)
 #define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0
+#define XSK_UMEM__DEFAULT_FLAGS 0
 
 struct xsk_umem_config {
 	__u32 fill_size;
 	__u32 comp_size;
 	__u32 frame_size;
 	__u32 frame_headroom;
+	__u32 flags;
 };
 
 /* Flags for the libbpf_flags field. */
@@ -195,6 +218,16 @@ LIBBPF_API int xsk_umem__create(struct xsk_umem **umem,
 				struct xsk_ring_prod *fill,
 				struct xsk_ring_cons *comp,
 				const struct xsk_umem_config *config);
+LIBBPF_API int xsk_umem__create_v0_0_2(struct xsk_umem **umem,
+				       void *umem_area, __u64 size,
+				       struct xsk_ring_prod *fill,
+				       struct xsk_ring_cons *comp,
+				       const struct xsk_umem_config *config);
+LIBBPF_API int xsk_umem__create_v0_0_4(struct xsk_umem **umem,
+				       void *umem_area, __u64 size,
+				       struct xsk_ring_prod *fill,
+				       struct xsk_ring_cons *comp,
+				       const struct xsk_umem_config *config);
 LIBBPF_API int xsk_socket__create(struct xsk_socket **xsk,
 				  const char *ifname, __u32 queue_id,
 				  struct xsk_umem *umem,

travis-ci/managers/debian.sh

@@ -13,6 +13,10 @@ function info() {
     echo -e "\033[33;1m$1\033[0m"
 }
 
+function error() {
+    echo -e "\033[31;1m$1\033[0m"
+}
+
 function docker_exec() {
     docker exec $ENV_VARS -it $CONT_NAME "$@"
 }
@@ -26,43 +30,41 @@ for phase in "${PHASES[@]}"; do
         SETUP)
             info "Setup phase"
             info "Using Debian $DEBIAN_RELEASE"
-	    docker pull debian:$DEBIAN_RELEASE
+            docker pull debian:$DEBIAN_RELEASE
             info "Starting container $CONT_NAME"
             $DOCKER_RUN -v $REPO_ROOT:/build:rw \
                         -w /build --privileged=true --name $CONT_NAME \
-			-dit --net=host debian:$DEBIAN_RELEASE /bin/bash
+                        -dit --net=host debian:$DEBIAN_RELEASE /bin/bash
             docker_exec bash -c "echo deb-src http://deb.debian.org/debian $DEBIAN_RELEASE main >>/etc/apt/sources.list"
             docker_exec apt-get -y update
             docker_exec apt-get -y build-dep libelf-dev
             docker_exec apt-get -y install libelf-dev
             docker_exec apt-get -y install "${ADDITIONAL_DEPS[@]}"
             ;;
-        RUN|RUN_CLANG|RUN_GCC8)
-            if [[ "$phase" = "RUN_CLANG" ]]; then
+        RUN|RUN_CLANG|RUN_GCC8|RUN_ASAN|RUN_CLANG_ASAN|RUN_GCC8_ASAN)
+            if [[ "$phase" = *"CLANG"* ]]; then
                 ENV_VARS="-e CC=clang -e CXX=clang++"
                 CC="clang"
-            elif [[ "$phase" = "RUN_GCC8" ]]; then
+            elif [[ "$phase" = *"GCC8"* ]]; then
                 ENV_VARS="-e CC=gcc-8 -e CXX=g++-8"
                 CC="gcc-8"
             fi
-            docker_exec mkdir build
-            docker_exec ${CC:-cc} --version
-            docker_exec make CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
-            docker_exec rm -rf build
-            ;;
-        RUN_ASAN|RUN_CLANG_ASAN|RUN_GCC8_ASAN)
-            if [[ "$phase" = "RUN_CLANG_ASAN" ]]; then
-                ENV_VARS="-e CC=clang -e CXX=clang++"
-                CC="clang"
-            elif [[ "$phase" = "RUN_GCC8_ASAN" ]]; then
-                ENV_VARS="-e CC=gcc-8 -e CXX=g++-8"
-                CC="gcc-8"
+            if [[ "$phase" = *"ASAN"* ]]; then
+                CFLAGS="${CFLAGS} -fsanitize=address,undefined"
             fi
-            CFLAGS="${CFLAGS} -fsanitize=address,undefined"
-            docker_exec mkdir build
+            docker_exec mkdir build install
             docker_exec ${CC:-cc} --version
+            info "build"
             docker_exec make CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
-            docker_exec rm -rf build
+            info "ldd build/libbpf.so:"
+            docker_exec ldd build/libbpf.so
+            if ! docker_exec ldd build/libbpf.so | grep -q libelf; then
+                error "No reference to libelf.so in libbpf.so!"
+                exit 1
+            fi
+            info "install"
+            docker_exec make -C src OBJDIR=../build DESTDIR=../install install
+            docker_exec rm -rf build install
             ;;
         CLEANUP)
             info "Cleanup phase"

travis-ci/managers/xenial.sh

@@ -11,7 +11,13 @@ source "$(dirname $0)/travis_wait.bash"
 cd $REPO_ROOT
 
 CFLAGS="-g -O2 -Werror -Wall -fsanitize=address,undefined"
-mkdir build
+mkdir build install
 cc --version
 make CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
-rm -rf build
+ldd build/libbpf.so
+if ! ldd build/libbpf.so | grep -q libelf; then
+    echo "FAIL: No reference to libelf.so in libbpf.so!"
+    exit 1
+fi
+make -C src OBJDIR=../build DESTDIR=../install install
+rm -rf build install