Upstream commit 71dd77fd4bf7 ("libbpf: use LFS (_FILE_OFFSET_BITS) instead
of direct mmap2 syscall") added _FILE_OFFSET_BITS=64 and
_LARGEFILE64_SOURCE CFLAGS. Back-port them to Github's mirror to avoid
compilation problems on ARM.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Add enum definition for Clang's __builtin_preserve_field_info()
second argument (info_kind). Currently only byte offset and existence
are supported. Corresponding Clang changes introducing this built-in can
be found at [0]
[0] https://reviews.llvm.org/D67980
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-5-andriin@fb.com
Add support for BPF_FRK_EXISTS relocation kind to detect existence of
captured field in a destination BTF, allowing conditional logic to
handle incompatible differences between kernels.
Also introduce opt-in relaxed CO-RE relocation handling option, which
makes libbpf emit warning for failed relocations, but proceed with other
relocations. Instruction, for which relocation failed, is patched with
(u32)-1 value.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-4-andriin@fb.com
Refactor all the various bpf_object__open variations to ultimately
specify common bpf_object_open_opts struct. This makes it easy to keep
extending this common struct w/ extra parameters without having to
update all the legacy APIs.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-3-andriin@fb.com
BTF offset reloc was generalized in recent Clang into field relocation,
capturing extra u32 field, specifying what aspect of captured field
needs to be relocated. This changes .BTF.ext's record size for this
relocation from 12 bytes to 16 bytes. Given these format changes
happened in Clang before official released version, it's ok to not
support outdated 12-byte record size w/o breaking ABI.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-2-andriin@fb.com
Old GCC versions are producing invalid typedef for __gnuc_va_list
pointing to void. Special-case this and emit valid:
typedef __builtin_va_list __gnuc_va_list;
Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191011032901.452042-1-andriin@fb.com
Existing BPF_CORE_READ() macro generates slightly suboptimal code. If
there are intermediate pointers to be read, initial source pointer is
going to be assigned into a temporary variable and then temporary
variable is going to be uniformly used as a "source" pointer for all
intermediate pointer reads. Schematically (ignoring all the type casts),
BPF_CORE_READ(s, a, b, c) is expanded into:
({
const void *__t = src;
bpf_probe_read(&__t, sizeof(*__t), &__t->a);
bpf_probe_read(&__t, sizeof(*__t), &__t->b);
typeof(s->a->b->c) __r;
bpf_probe_read(&__r, sizeof(*__r), &__t->c);
})
This initial `__t = src` makes calls more uniform, but causes slightly
less optimal register usage sometimes when compiled with Clang. This can
cascase into, e.g., more register spills.
This patch fixes this issue by generating more optimal sequence:
({
const void *__t;
bpf_probe_read(&__t, sizeof(*__t), &src->a); /* <-- src here */
bpf_probe_read(&__t, sizeof(*__t), &__t->b);
typeof(s->a->b->c) __r;
bpf_probe_read(&__r, sizeof(*__r), &__t->c);
})
Fixes: 7db3822ab991 ("libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191011023847.275936-1-andriin@fb.com
'struct xdp_umem_reg' has 4 bytes of padding at the end that makes
valgrind complain about passing uninitialized stack memory to the
syscall:
Syscall param socketcall.setsockopt() points to uninitialised byte(s)
at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so)
by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172)
Uninitialised value was created by a stack allocation
at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140)
Padding bytes appeared after introducing of a new 'flags' field.
memset() is required to clear them.
Fixes: 10d30e301732 ("libbpf: add flags to umem config")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191009164929.17242-1-i.maximets@ovn.org
Fix a case where explicit padding at the end of a struct is necessary
due to non-standart alignment requirements of fields (which BTF doesn't
capture explicitly).
Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191008231009.2991130-2-andriin@fb.com
Add few macros simplifying BCC-like multi-level probe reads, while also
emitting CO-RE relocations for each read.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-7-andriin@fb.com
Move bpf_helpers.h, bpf_tracing.h, and bpf_endian.h into libbpf. Move
bpf_helper_defs.h generation into libbpf's Makefile. Ensure all those
headers are installed along the other libbpf headers. Also, adjust
selftests and samples include path to include libbpf now.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-6-andriin@fb.com
Add new set of bpf_object__open APIs using new approach to optional
parameters extensibility allowing simpler ABI compatibility approach.
This patch demonstrates an approach to implementing libbpf APIs that
makes it easy to extend existing APIs with extra optional parameters in
such a way, that ABI compatibility is preserved without having to do
symbol versioning and generating lots of boilerplate code to handle it.
To facilitate succinct code for working with options, add OPTS_VALID,
OPTS_HAS, and OPTS_GET macros that hide all the NULL, size, and zero
checks.
Additionally, newly added libbpf APIs are encouraged to follow similar
pattern of having all mandatory parameters as formal function parameters
and always have optional (NULL-able) xxx_opts struct, which should
always have real struct size as a first field and the rest would be
optional parameters added over time, which tune the behavior of existing
API, if specified by user.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Kernel version enforcement for kprobes/kretprobes was removed from
5.0 kernel in 6c4fc209fcf9 ("bpf: remove useless version check for prog load").
Since then, BPF programs were specifying SEC("version") just to please
libbpf. We should stop enforcing this in libbpf, if even kernel doesn't
care. Furthermore, libbpf now will pre-populate current kernel version
of the host system, in case we are still running on old kernel.
This patch also removes __bpf_object__open_xattr from libbpf.h, as
nothing in libbpf is relying on having it in that header. That function
was never exported as LIBBPF_API and even name suggests its internal
version. So this should be safe to remove, as it doesn't break ABI.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
New release cycle started, let's bump to v0.0.6 proactively.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20190930222503.519782-1-andriin@fb.com
After latest shared vs static libraries fixes, `make install` target
broke as it relied on now removed $(LIBS) variable. This patch fixes
issue by listing $(SHARED_LIBS) and $(STATIC_LIBS) explicitly.
Tested with and without BUILD_STATIC_ONLY.
Fixes: 8b2782a1f2 ("makefile: support libbpf symbol versioning in shared library mode")
Reported-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Similarly to Linux's 1bd63524593b ("libbpf: handle symbol versioning properly
for libbpf.a"), add necessary changes to build static and shared object
files separately with extra shared library flags. This allows to
properly handle symbol versioning in shared library mode, while still
having statically linkable library.
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
bcc uses libbpf repo as a submodule. It brings in libbpf source
code and builds everything together to produce shared libraries.
With latest libbpf, I got the following errors:
/bin/ld: libbcc_bpf.so.0.10.0: version node not found for symbol xsk_umem__create@LIBBPF_0.0.2
/bin/ld: failed to set dynamic section sizes: Bad value
collect2: error: ld returned 1 exit status
make[2]: *** [src/cc/libbcc_bpf.so.0.10.0] Error 1
In xsk.c, we have
asm(".symver xsk_umem__create_v0_0_2, xsk_umem__create@LIBBPF_0.0.2");
asm(".symver xsk_umem__create_v0_0_4, xsk_umem__create@@LIBBPF_0.0.4");
The linker thinks the built is for LIBBPF but cannot find proper version
LIBBPF_0.0.2/4, so emit errors.
I also confirmed that using libbpf.a to produce a shared library also
has issues:
-bash-4.4$ cat t.c
extern void *xsk_umem__create;
void * test() { return xsk_umem__create; }
-bash-4.4$ gcc -c -fPIC t.c
-bash-4.4$ gcc -shared t.o libbpf.a -o t.so
/bin/ld: t.so: version node not found for symbol xsk_umem__create@LIBBPF_0.0.2
/bin/ld: failed to set dynamic section sizes: Bad value
collect2: error: ld returned 1 exit status
-bash-4.4$
Symbol versioning does happens in commonly used libraries, e.g., elfutils
and glibc. For static libraries, for a versioned symbol, the old definitions
will be ignored, and the symbol will be an alias to the latest definition.
For example, glibc sched_setaffinity is versioned.
-bash-4.4$ readelf -s /usr/lib64/libc.so.6 | grep sched_setaffinity
756: 000000000013d3d0 13 FUNC GLOBAL DEFAULT 13 sched_setaffinity@GLIBC_2.3.3
757: 00000000000e2e70 455 FUNC GLOBAL DEFAULT 13 sched_setaffinity@@GLIBC_2.3.4
1800: 0000000000000000 0 FILE LOCAL DEFAULT ABS sched_setaffinity.c
4228: 00000000000e2e70 455 FUNC LOCAL DEFAULT 13 __sched_setaffinity_new
4648: 000000000013d3d0 13 FUNC LOCAL DEFAULT 13 __sched_setaffinity_old
7338: 000000000013d3d0 13 FUNC GLOBAL DEFAULT 13 sched_setaffinity@GLIBC_2
7380: 00000000000e2e70 455 FUNC GLOBAL DEFAULT 13 sched_setaffinity@@GLIBC_
-bash-4.4$
For static library, the definition of sched_setaffinity aliases to the new definition.
-bash-4.4$ readelf -s /usr/lib64/libc.a | grep sched_setaffinity
File: /usr/lib64/libc.a(sched_setaffinity.o)
8: 0000000000000000 455 FUNC GLOBAL DEFAULT 1 __sched_setaffinity_new
12: 0000000000000000 455 FUNC WEAK DEFAULT 1 sched_setaffinity
For both elfutils and glibc, additional macros are used to control different handling
of symbol versioning w.r.t static and shared libraries.
For elfutils, the macro is SYMBOL_VERSIONING
(https://sourceware.org/git/?p=elfutils.git;a=blob;f=lib/eu-config.h).
For glibc, the macro is SHARED
(https://sourceware.org/git/?p=glibc.git;a=blob;f=include/shlib-compat.h;hb=refs/heads/master)
This patch used SHARED as the macro name. After this patch, the libbpf.a has
-bash-4.4$ readelf -s libbpf.a | grep xsk_umem__create
372: 0000000000017145 1190 FUNC GLOBAL DEFAULT 1 xsk_umem__create_v0_0_4
405: 0000000000017145 1190 FUNC GLOBAL DEFAULT 1 xsk_umem__create
499: 00000000000175eb 103 FUNC GLOBAL DEFAULT 1 xsk_umem__create_v0_0_2
-bash-4.4$
No versioned symbols for xsk_umem__create.
The libbpf.a can be used to build a shared library succesfully.
-bash-4.4$ cat t.c
extern void *xsk_umem__create;
void * test() { return xsk_umem__create; }
-bash-4.4$ gcc -c -fPIC t.c
-bash-4.4$ gcc -shared t.o libbpf.a -o t.so
-bash-4.4$
Fixes: 10d30e301732 ("libbpf: add flags to umem config")
Cc: Kevin Laatz <kevin.laatz@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When appying urgent fix to Github mirror, before it was pushed to linux
repo, there were some indentation issues, which eventually got fixed
upstream, but are still in Github mirror. Fix it to prevent future merge
conflicts.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
BTF-to-C converter previously skipped anonymous enums in an assumption
that those are embedded in struct's field definitions. This is not
always the case and a lot of kernel constants are defined as part of
anonymous enums. This change fixes the logic by eagerly marking all
types as either referenced by any other type or not. This is enough to
distinguish two classes of anonymous enums and emit previously omitted
enum definitions.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20190925203745.3173184-1-andriin@fb.com
Some compilers emit warning for potential uninitialized next_id usage.
The code is correct, but control flow is too complicated for some
compilers to figure this out. Re-initialize next_id to satisfy
compiler.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The xsk_socket__create() function fails and returns an error if it cannot
get the XDP_OPTIONS through getsockopt(). However, support for XDP_OPTIONS
was not added until kernel 5.3, so this means that creating XSK sockets
always fails on older kernels.
Since the option is just used to set the zero-copy flag in the xsk struct,
and that flag is not really used for anything yet, just remove the
getsockopt() call until a proper use for it is introduced.
Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch adds a 'flags' field to the umem_config and umem_reg structs.
This will allow for more options to be added for configuring umems.
The first use for the flags field is to add a flag for unaligned chunks
mode. These flags can either be user-provided or filled with a default.
Since we change the size of the xsk_umem_config struct, we need to version
the ABI. This patch includes the ABI versioning for xsk_umem__create. The
Makefile was also updated to handle multiple function versions in
check-abi.
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The -lelf flag needs to be specified *after* the object files, otherwise
the output library produced by some compilers doesn't contain a link to
libelf.so:
(Example from Debian testing run on Travis.)
$ ldd libelf.so
linux-vdso.so.1 (0x00007ffcbfda9000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f75f8d24000)
/lib64/ld-linux-x86-64.so.2 (0x00007f75f8f0f000)
Linking against such library then produces 'undefined reference to ...'
errors unless the target links against libelf as well. After this commit
the built library references the libelf library correctly:
$ ldd libbpf.so
linux-vdso.so.1 (0x00007ffc821f1000)
libelf.so.1 => /usr/lib/x86_64-linux-gnu/libelf.so.1 (0x00007f70ea3ec000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f70ea22c000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f70ea20f000)
/lib64/ld-linux-x86-64.so.2 (0x00007f70ea433000)
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Drop __NR_mmap2 fork in flavor of LFS, that is _FILE_OFFSET_BITS=64
(glibc & bionic) / LARGEFILE64_SOURCE (for musl) decision. It allows
mmap() to use 64bit offset that is passed to mmap2 syscall. As result
pgoff is not truncated and no need to use direct access to mmap2 for
32 bits systems.
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add an API function taking a BTF object id and providing the id of the
next BTF object in the kernel. This can be used to list all BTF objects
loaded on the system.
v2:
- Rebase on top of Andrii's changes regarding libbpf versioning.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In preparation for the introduction of a similar function for retrieving
the id of the next BTF object, consolidate the code from
bpf_prog_get_next_id() and bpf_map_get_next_id() in libbpf.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds support for the new need_wakeup flag in AF_XDP. The
xsk_socket__create function is updated to handle this and a new
function is introduced called xsk_ring_prod__needs_wakeup(). This
function can be used by the application to check if Rx and/or Tx
processing needs to be explicitly woken up.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Currently libbpf version is specified in 2 places: libbpf.map and
Makefile. They easily get out of sync and it's very easy to update one,
but forget to update another one. In addition, Github projection of
libbpf has to maintain its own version which has to be remembered to be
kept in sync manually, which is very error-prone approach.
This patch makes libbpf.map a source of truth for libbpf version and
uses shell invocation to parse out correct full and major libbpf version
to use during build. Now we need to make sure that once new release
cycle starts, we need to add (initially) empty section to libbpf.map
with correct latest version.
This also will make it possible to keep Github projection consistent
with kernel sources version of libbpf by adopting similar parsing of
version from libbpf.map.
v2->v3:
- grep -o + sort -rV (Andrey);
v1->v2:
- eager version vars evaluation (Jakub);
- simplified version regex (Andrey);
Cc: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Similarly to kernel-side Makefile ([0]), get libbpf version by looking
at latest version in libbpf.map.
[0] https://patchwork.ozlabs.org/patch/1147232/
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Add support for loading kernel BTF from sysfs (/sys/kernel/btf/vmlinux)
as a target BTF. Also extend the list of on disk search paths for
vmlinux ELF image with entries that perf is searching for.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
hashmap.h depends on __WORDSIZE being defined. It is defined by
glibc/musl in different headers. It's an explicit goal for musl to be
"non-detectable" at compilation time, so instead include glibc header if
glibc is explicitly detected and fall back to musl header otherwise.
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap")
Link: https://lkml.kernel.org/r/20190718173021.2418606-1-andriin@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch implements the core logic for BPF CO-RE offsets relocations.
Every instruction that needs to be relocated has corresponding
bpf_offset_reloc as part of BTF.ext. Relocations are performed by trying
to match recorded "local" relocation spec against potentially many
compatible "target" types, creating corresponding spec. Details of the
algorithm are noted in corresponding comments in the code.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for BPF CO-RE offset relocations. Add section/record
iteration macros for .BTF.ext. These macro are useful for iterating over
each .BTF.ext record, either for dumping out contents or later for BPF
CO-RE relocation handling.
To enable other parts of libbpf to work with .BTF.ext contents, moved
a bunch of type definitions into libbpf_internal.h.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add lots of frequently used helpers that simplify working with BTF
types.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This adds the definition for BPF_MAP_TYPE_DEVMAP_HASH to libbpf_probes.c in
tools/lib/bpf.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
By returning previously set print callback from libbpf_set_print, it's
possible to restore it, eventually. This is useful when running many
independent test with one default print function, but overriding log
verbosity for particular subset of tests.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When BPF program defines uninitialized global variable, it's put into
a special COMMON section. Libbpf will reject such programs, but will
provide very unhelpful message with garbage-looking section index.
This patch detects special section cases and gives more explicit error
message.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
5d01ab7bac46 ("libbpf: fix erroneous multi-closing of BTF FD")
introduced backwards-compatibility issue, manifesting itself as -E2BIG
error returned on program load due to unknown non-zero btf_fd attribute
value for BPF_PROG_LOAD sys_bpf() sub-command.
This patch fixes bug by ensuring that we only ever associate BTF FD with
program if there is a BTF.ext data that was successfully loaded into
kernel, which automatically means kernel supports func_info/line_info
and associated BTF FD for progs (checked and ensured also by BTF
sanitization code).
Fixes: 5d01ab7bac46 ("libbpf: fix erroneous multi-closing of BTF FD")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Having static variable `cpus` in libbpf_num_possible_cpus function
without guarding it with mutex makes this function thread-unsafe.
If multiple threads accessing this function, in the current form; it
leads to incrementing the static variable value `cpus` in the multiple
of total available CPUs.
Used local stack variable to calculate the number of possible CPUs and
then updated the static variable using WRITE_ONCE().
Changes since v1:
* added stack variable to calculate cpus
* serialized static variable update using WRITE_ONCE()
* fixed Fixes tag
Fixes: 6446b3155521 ("bpf: add a new API libbpf_num_possible_cpus()")
Signed-off-by: Takshak Chahande <ctakshak@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Libbpf stores associated BTF FD per each instance of bpf_program. When
program is unloaded, that FD is closed. This is wrong, because leads to
a race and possibly closing of unrelated files, if application
simultaneously opens new files while bpf_programs are unloaded.
It's also unnecessary, because struct btf "owns" that FD, and
btf__free(), called from bpf_object__close() will close it. Thus the fix
is to never have per-program BTF FD and fetch it from obj->btf, when
necessary.
Fixes: 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Despite a proper NULL-termination after strncpy(..., ..., IFNAMSIZ - 1),
GCC8 still complains about *expected* string truncation:
xsk.c:330:2: error: 'strncpy' output may be truncated copying 15 bytes
from a string of length 15 [-Werror=stringop-truncation]
strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
This patch gets rid of the issue altogether by using memcpy instead.
There is no performance regression, as strncpy will still copy and fill
all of the bytes anyway.
v1->v2:
- rebase against bpf tree.
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
'channels.max_combined' initialized only on ioctl success and
errno is only valid on ioctl failure.
The code doesn't produce any runtime issues, but makes memory
sanitizers angry:
Conditional jump or move depends on uninitialised value(s)
at 0x55C056F: xsk_get_max_queues (xsk.c:336)
by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
by 0x55C0E57: xsk_socket__create (xsk.c:601)
Uninitialised value was created by a stack allocation
at 0x55C04CD: xsk_get_max_queues (xsk.c:318)
Additionally fixed warning on uninitialized bytes in ioctl arguments:
Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s)
at 0x648D45B: ioctl (in /usr/lib64/libc-2.28.so)
by 0x55C0546: xsk_get_max_queues (xsk.c:330)
by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
by 0x55C0E57: xsk_socket__create (xsk.c:601)
Address 0x1ffefff378 is on thread 1's stack
in frame #1, created by xsk_get_max_queues (xsk.c:318)
Uninitialised value was created by a stack allocation
at 0x55C04CD: xsk_get_max_queues (xsk.c:318)
CC: Magnus Karlsson <magnus.karlsson@intel.com>
Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As it fails to build in some systems with:
libbpf.c: In function 'perf_buffer__new':
libbpf.c:4515: error: unknown field 'sample_period' specified in initializer
libbpf.c:4516: error: unknown field 'wakeup_events' specified in initializer
Doing as:
attr.sample_period = 1;
I.e. not as a designated initializer makes it build everywhere.
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Link: https://lkml.kernel.org/n/tip-hnlmch8qit1ieksfppmr32si@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Using endian.h and its endianness macros makes this code build in a
wider range of compilers, as some don't have those macros
(__BYTE_ORDER__, __ORDER_LITTLE_ENDIAN__, __ORDER_BIG_ENDIAN__),
so use instead endian.h's macros (__BYTE_ORDER, __LITTLE_ENDIAN,
__BIG_ENDIAN) which makes this code even shorter :-)
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 12ef5634a855 ("libbpf: simplify endianness check")
Fixes: e6c64855fd7a ("libbpf: add btf__parse_elf API to load .BTF and .BTF.ext")
Link: https://lkml.kernel.org/n/tip-eep5n8vgwcdphw3uc058k03u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
