btf__dedup() and struct btf_dedup_opts were added before we figured out
OPTS mechanism. As such, btf_dedup_opts is non-extensible without
breaking an ABI and potentially crashing user application.
Unfortunately, btf__dedup() and btf_dedup_opts are short and succinct
names that would be great to preserve and use going forward. So we use
___libbpf_override() macro approach, used previously for bpf_prog_load()
API, to define a new btf__dedup() variant that accepts only struct btf *
and struct btf_dedup_opts * arguments, and rename the old btf__dedup()
implementation into btf__dedup_deprecated(). This keeps both source and
binary compatibility with old and new applications.
The biggest problem was struct btf_dedup_opts, which wasn't OPTS-based,
and as such doesn't have `size_t sz;` as a first field. But btf__dedup()
is a pretty rarely used API and I believe that the only currently known
users (besides selftests) are libbpf's own bpf_linker and pahole.
Neither use case actually uses options and just passes NULL. So instead
of doing extra hacks, just rewrite struct btf_dedup_opts into OPTS-based
one, move btf_ext argument into those opts (only bpf_linker needs to
dedup btf_ext, so it's not a typical thing to specify), and drop never
used `dont_resolve_fwds` option (it was never used anywhere, AFAIK, it
makes BTF dedup much less useful and efficient).
Just in case, for old implementation, btf__dedup_deprecated(), detect
non-NULL options and error out with helpful message, to help users
migrate, if there are any user playing with btf__dedup().
The last remaining piece is dedup_table_size, which is another
anachronism from very early days of BTF dedup. Since then it has been
reduced to the only valid value, 1, to request forced hash collisions.
This is only used during testing. So instead introduce a bool flag to
force collisions explicitly.
This patch also adapts selftests to new btf__dedup() and btf_dedup_opts
use to avoid selftests breakage.
[0] Closes: https://github.com/libbpf/libbpf/issues/281
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-4-andrii@kernel.org
Few clean ups and single-line simplifications. Also split CLEAN command
into multiple $(RM) invocations as it gets dangerously close to too long
argument list. Make sure that -o <output.o> is used always as the last
argument for saner verbose make output.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-3-andrii@kernel.org
When dealing with verbose Makefile output, it's extremely confusing when
compiler invocation commands don't specify -o <output.o> as the last
argument. Normalize bpftool's Makefile to do just that, as most other
BPF-related Makefiles are already doing that.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-2-andrii@kernel.org
Andrii Nakryiko says:
====================
Fix the ability to request verbose (log_level=1) or very verbose (log_level=2)
logs with test_progs's -vv or -vvv parameters. This ability regressed during
recent bpf_prog_load() API refactoring. Also add
bpf_program__set_extra_flags() API to allow setting extra testing flags
(BPF_F_TEST_RND_HI32), which was also dropped during recent changes.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After recent refactoring bpf_prog_test_load(), used across multiple
selftests, lost ability to specify extra log_level 1 or 2 (for -vv and
-vvv, respectively). Fix that problem by using bpf_object__load_xattr()
API that supports extra log_level flags. Also restore
BPF_F_TEST_RND_HI32 prog_flags by utilizing new bpf_program__set_extra_flags()
API.
Fixes: f87c1930ac ("selftests/bpf: Merge test_stub.c into testing_helpers.c")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111051758.92283-3-andrii@kernel.org
Add bpf_program__flags() API to retrieve prog_flags that will be (or
were) supplied to BPF_PROG_LOAD command.
Also add bpf_program__set_extra_flags() API to allow to set *extra*
flags, in addition to those determined by program's SEC() definition.
Such flags are logically OR'ed with libbpf-derived flags.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111051758.92283-2-andrii@kernel.org
Mark Pashmfouroush says:
====================
BPF_SK_LOOKUP users may want to have access to the ifindex of the skb
which triggered the socket lookup. This may be useful for selectively
applying programmable socket lookup logic to packets that arrive on a
specific interface, or excluding packets from an interface.
v3:
- Rename ifindex field to ingress_ifindex for consistency. (Yonghong)
v2:
- Fix inaccurate comment (Alexei)
- Add more details to commit messages (John)
====================
Revieview-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A new field was added to the bpf_sk_lookup data that users can access.
Add tests that validate that the new ingress_ifindex field contains the
right data.
Signed-off-by: Mark Pashmfouroush <markpash@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211110111016.5670-3-markpash@cloudflare.com
It may be helpful to have access to the ifindex during bpf socket
lookup. An example may be to scope certain socket lookup logic to
specific interfaces, i.e. an interface may be made exempt from custom
lookup code.
Add the ifindex of the arriving connection to the bpf_sk_lookup API.
Signed-off-by: Mark Pashmfouroush <markpash@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211110111016.5670-2-markpash@cloudflare.com
Bpftool is dual-licensed under GPLv2 and BSD-2-Clause. In commit
907b223651 ("tools: bpftool: dual license all files") we made sure
that all its source files were indeed covered by the two licenses, and
that they had the correct SPDX tags.
However, bpftool's Makefile, the Makefile for its documentation, and the
.gitignore file were skipped at the time (their GPL-2.0-only tag was
added later). Let's update the tags.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Joe Stringer <joe@cilium.io>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/bpf/20211105221904.3536-1-quentin@isovalent.com
The minimum supported C standard version is C89, with use of GNU
extensions, hence make sure to catch any instances that would break
the build for this mode by passing -std=gnu89.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211105234243.390179-4-memxor@gmail.com
Exception handling is triggered in BPF tracing programs when a NULL pointer
is dereferenced; the exception handler zeroes the target register and
execution of the BPF program progresses.
To test exception handling then, we need to trigger a NULL pointer dereference
for a field which should never be zero; if it is, the only explanation is the
exception handler ran. task->task_works is the NULL pointer chosen (for a new
task from fork() no work is associated), and the task_works->func field should
not be zero if task_works is non-NULL. The test verifies that task_works and
task_works->func are 0.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1636131046-5982-3-git-send-email-alan.maguire@oracle.com
Commit 91fc957c9b ("arm64/bpf: don't allocate BPF JIT programs in module
memory") restricts BPF JIT program allocation to a 128MB region to ensure
BPF programs are still in branching range of each other. However this
restriction should not apply to the aarch64 JIT, since BPF_JMP | BPF_CALL
are implemented as a 64-bit move into a register and then a BLR instruction -
which has the effect of being able to call anything without proximity
limitation.
The practical reason to relax this restriction on JIT memory is that 128MB of
JIT memory can be quickly exhausted, especially where PAGE_SIZE is 64KB - one
page is needed per program. In cases where seccomp filters are applied to
multiple VMs on VM launch - such filters are classic BPF but converted to
BPF - this can severely limit the number of VMs that can be launched. In a
world where we support BPF JIT always on, turning off the JIT isn't always an
option either.
Fixes: 91fc957c9b ("arm64/bpf: don't allocate BPF JIT programs in module memory")
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <russell.king@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/1636131046-5982-2-git-send-email-alan.maguire@oracle.com
Song Liu says:
====================
Changes v4 => v5:
1. Clean up and style change in 2/2. (Andrii)
Changes v3 => v4:
1. Move mmap_unlock_work to task_iter.c to fix build for .config without
!CONFIG_PERF_EVENTS. (kernel test robot <lkp@intel.com>)
Changes v2 => v3:
1. Avoid using x86 only function in selftests. (Yonghong)
2. Add struct file and struct vm_area_struct to btf_task_struct_ids, and
use it in bpf_find_vma and stackmap.c. (Yonghong)
3. Fix inaccurate comments. (Yonghong)
Changes v1 => v2:
1. Share irq_work with stackmap.c. (Daniel)
2. Add tests for illegal writes to task/vma from the callback function.
(Daniel)
3. Other small fixes.
Add helper bpf_find_vma. This can be used in some profiling use cases. It
might also be useful for LSM.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add tests for bpf_find_vma in perf_event program and kprobe program. The
perf_event program is triggered from NMI context, so the second call of
bpf_find_vma() will return -EBUSY (irq_work busy). The kprobe program,
on the other hand, does not have this constraint.
Also add tests for illegal writes to task or vma from the callback
function. The verifier should reject both cases.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211105232330.1936330-3-songliubraving@fb.com
In some profiler use cases, it is necessary to map an address to the
backing file, e.g., a shared library. bpf_find_vma helper provides a
flexible way to achieve this. bpf_find_vma maps an address of a task to
the vma (vm_area_struct) for this address, and feed the vma to an callback
BPF function. The callback function is necessary here, as we need to
ensure mmap_sem is unlocked.
It is necessary to lock mmap_sem for find_vma. To lock and unlock mmap_sem
safely when irqs are disable, we use the same mechanism as stackmap with
build_id. Specifically, when irqs are disabled, the unlocked is postponed
in an irq_work. Refactor stackmap.c so that the irq_work is shared among
bpf_find_vma and stackmap helpers.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211105232330.1936330-2-songliubraving@fb.com
Andrii Nakryiko says:
====================
Fix all the memory leaks reported by ASAN. All but one are just improper
resource clean up in selftests. But one memory leak was discovered in libbpf,
leaving inner map's name leaked.
First patch fixes selftests' Makefile by passing through SAN_CFLAGS to linker.
Without that compiling with SAN_CFLAGS=-fsanitize=address kept failing.
Running selftests under ASAN in BPF CI is the next step, we just need to make
sure all the necessary libraries (libasan and liblsan) are installed on the
host and inside the VM. Would be great to get some help with that, but for now
make sure that test_progs run is clean from leak sanitizer errors.
v3->v4:
- rebase on latest bpf-next;
v2->v3:
- fix per-cpu array memory leaks in btf_iter.c selftests (Hengqi);
v1->v2:
- call bpf_map__destroy() conditionally if map->inner_map is present.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
skb_ctx selftest didn't close bpf_object implicitly allocated by
bpf_prog_test_load() helper. Fix the problem by explicitly calling
bpf_object__close() at the end of the test.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20211107165521.9240-10-andrii@kernel.org
bpf_link__detach() was confused with bpf_link__destroy() and leaves
leaked FD in the process. Fix the problem.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20211107165521.9240-9-andrii@kernel.org
Free up used resources at the end and on error. Also make it more
obvious that there is btf__parse() call that creates struct btf
instance.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20211107165521.9240-7-andrii@kernel.org
It's not enough to just free(map->inner_map), as inner_map itself can
have extra memory allocated, like map name.
Fixes: 646f02ffdd ("libbpf: Add BTF-defined map-in-map support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20211107165521.9240-3-andrii@kernel.org
When adding -fsanitize=address to SAN_CFLAGS, it has to be passed both
to compiler through CFLAGS as well as linker through LDFLAGS. Add
SAN_CFLAGS into LDFLAGS to allow building selftests with ASAN.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20211107165521.9240-2-andrii@kernel.org
Andrii Nakryiko says:
====================
This patch set adds unified OPTS-based low-level bpf_prog_load() API for
loading BPF programs directly into kernel without utilizing libbpf's
bpf_object abstractions. This OPTS-based interface allows for future
extensions without breaking backwards or forward API and ABI compatibility.
Similar approach will be used for other low-level APIs that require extensive
sets of parameters, like BPF_MAP_CREATE command.
First half of the patch set adds libbpf API, cleans up internal usage of
to-be-deprecated APIs, etc. Second half cleans up and converts selftests away
from using deprecated APIs. See individual patches for more details.
v1->v2:
- dropped exposing sys_bpf() into public API (Alexei, Daniel);
- also dropped bpftool/cgroup.c fix for unistd.h include because it's not
necessary due to sys_bpf() staying as is.
Cc: Hengqi Chen <hengqi.chen@gmail.com>
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Remove the second part of prog loading testing helper re-definition:
-Dbpf_load_program=bpf_test_load_program
This completes the clean up of deprecated libbpf program loading APIs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-13-andrii@kernel.org
-Dbpf_prog_load_deprecated=bpf_prog_test_load trick is both ugly and
breaks when deprecation goes into effect due to macro magic. Convert all
the uses to explicit bpf_prog_test_load() calls which avoid deprecation
errors and makes everything less magical.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-12-andrii@kernel.org
Move testing prog and object load wrappers (bpf_prog_test_load and
bpf_test_load_program) into testing_helpers.{c,h} and get rid of
otherwise useless test_stub.c. Make testing_helpers.c available to
non-test_progs binaries as well.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-11-andrii@kernel.org
Convert all the uses of legacy low-level BPF program loading APIs
(mostly bpf_load_program_xattr(), but also some bpf_verify_program()) to
bpf_prog_load() uses.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-10-andrii@kernel.org
Fix few more SEC() definitions that were previously missed.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-9-andrii@kernel.org
This deprecation annotation has no effect because for struct deprecation
attribute has to be declared after struct definition. But instead of
moving it to the end of struct definition, remove it. When deprecation
will go in effect at libbpf v0.7, this deprecation attribute will cause
libbpf's own source code compilation to trigger deprecation warnings,
which is unavoidable because libbpf still has to support that API.
So keep deprecation of APIs, but don't mark structs used in API as
deprecated.
Fixes: e21d585cb3 ("libbpf: Deprecate multi-instance bpf_program APIs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-8-andrii@kernel.org
Add a new unified OPTS-based low-level API for program loading,
bpf_prog_load() ([0]). bpf_prog_load() accepts few "mandatory"
parameters as input arguments (program type, name, license,
instructions) and all the other optional (as in not required to specify
for all types of BPF programs) fields into struct bpf_prog_load_opts.
This makes all the other non-extensible APIs variant for BPF_PROG_LOAD
obsolete and they are slated for deprecation in libbpf v0.7:
- bpf_load_program();
- bpf_load_program_xattr();
- bpf_verify_program().
Implementation-wise, internal helper libbpf__bpf_prog_load is refactored
to become a public bpf_prog_load() API. struct bpf_prog_load_params used
internally is replaced by public struct bpf_prog_load_opts.
Unfortunately, while conceptually all this is pretty straightforward,
the biggest complication comes from the already existing bpf_prog_load()
*high-level* API, which has nothing to do with BPF_PROG_LOAD command.
We try really hard to have a new API named bpf_prog_load(), though,
because it maps naturally to BPF_PROG_LOAD command.
For that, we rename old bpf_prog_load() into bpf_prog_load_deprecated()
and mark it as COMPAT_VERSION() for shared library users compiled
against old version of libbpf. Statically linked users and shared lib
users compiled against new version of libbpf headers will get "rerouted"
to bpf_prog_deprecated() through a macro helper that decides whether to
use new or old bpf_prog_load() based on number of input arguments (see
___libbpf_overload in libbpf_common.h).
To test that existing
bpf_prog_load()-using code compiles and works as expected, I've compiled
and ran selftests as is. I had to remove (locally) selftest/bpf/Makefile
-Dbpf_prog_load=bpf_prog_test_load hack because it was conflicting with
the macro-based overload approach. I don't expect anyone else to do
something like this in practice, though. This is testing-specific way to
replace bpf_prog_load() calls with special testing variant of it, which
adds extra prog_flags value. After testing I kept this selftests hack,
but ensured that we use a new bpf_prog_load_deprecated name for this.
This patch also marks bpf_prog_load() and bpf_prog_load_xattr() as deprecated.
bpf_object interface has to be used for working with struct bpf_program.
Libbpf doesn't support loading just a bpf_program.
The silver lining is that when we get to libbpf 1.0 all these
complication will be gone and we'll have one clean bpf_prog_load()
low-level API with no backwards compatibility hackery surrounding it.
[0] Closes: https://github.com/libbpf/libbpf/issues/284
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-4-andrii@kernel.org
Allow to control number of BPF_PROG_LOAD attempts from outside the
sys_bpf_prog_load() helper.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-3-andrii@kernel.org
It's confusing that libbpf-provided helper macro doesn't start with
LIBBPF. Also "declare" vs "define" is confusing terminology, I can never
remember and always have to look up previous examples.
Bypass both issues by renaming DECLARE_LIBBPF_OPTS into a short and
clean LIBBPF_OPTS. To avoid breaking existing code, provide:
#define DECLARE_LIBBPF_OPTS LIBBPF_OPTS
in libbpf_legacy.h. We can decide later if we ever want to remove it or
we'll keep it forever because it doesn't add any maintainability burden.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-2-andrii@kernel.org
Add few sanity checks for relocations to prevent div-by-zero and
out-of-bounds array accesses in libbpf.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-6-andrii@kernel.org
e_shnum does include section #0 and as such is exactly the number of ELF
sections that we need to allocate memory for to use section indices as
array indices. Fix the off-by-one error.
This is purely accounting fix, previously we were overallocating one
too many array items. But no correctness errors otherwise.
Fixes: 25bbbd7a44 ("libbpf: Remove assumptions about uniqueness of .rodata/.data/.bss maps")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-5-andrii@kernel.org
.BTF and .BTF.ext ELF sections should have SHT_PROGBITS type and contain
data. If they are not, ELF is invalid or corrupted, so bail out.
Otherwise this can lead to data->d_buf being NULL and SIGSEGV later on.
Reported by oss-fuzz project.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-4-andrii@kernel.org
If BTF is corrupted DATASEC's variable type ID might be incorrect.
Prevent this easy to detect situation with extra NULL check.
Reported by oss-fuzz project.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-3-andrii@kernel.org
Prevent divide-by-zero if ELF is corrupted and has zero sh_entsize.
Reported by oss-fuzz project.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-2-andrii@kernel.org
Dave Marchevsky says:
====================
bpf_program__get_prog_info_linear is a helper which wraps the
bpf_obj_get_info_by_fd BPF syscall with some niceties that put
all dynamic-length bpf_prog_info in one buffer contiguous with struct
bpf_prog_info, and simplify the selection of which dynamic data to grab.
The resultant combined struct, bpf_prog_info_linear, is persisted to
file by 'perf' to enable later annotation of BPF prog data. libbpf
includes some vaddr <-> offset conversion helpers for
struct bpf_prog_info_linear to simplify this.
This functionality is heavily tailored to perf's usecase, so its use as
a general prog info API should be deemphasized in favor of just calling
bpf_obj_get_info_by_fd, which can be more easily fit to purpose. Some
examples from caller migrations in this series:
* Some callers weren't requesting or using dynamic-sized prog info and
are well served by a simple get_info_by_fd call (e.g.
dump_prog_id_as_func_ptr in bpftool)
* Some callers were requesting all of a specific dynamic info type but
only using the first record, so can avoid unnecessary malloc by
only requesting 1 (e.g. profile_target_name in bpftool)
* bpftool's do_dump saves some malloc/free by growing and reusing its
dynamic prog_info buf as it loops over progs to grab info and dump.
Perf does need the full functionality of
bpf_program__get_prog_info_linear and its accompanying structs +
helpers, so copy the code to its codebase, migrate all other uses in the
tree, and deprecate the helper in libbpf.
Since the deprecated symbols continue to be included in perf some
renaming was necessary in perf's copy, otherwise functionality is
unchanged.
This work was previously discussed in libbpf's issue tracker [0].
[0]: https://github.com/libbpf/libbpf/issues/313
v2->v3:
* Remove v2's patch 1 ("libbpf: Migrate internal use of
bpf_program__get_prog_info_linear"), which was applied [Andrii]
* Add new patch 1 migrating error checking of libbpf calls to
new scheme [Andrii, Quentin]
* In patch 2, fix != -1 error check of libbpf call, improper realloc
handling, and get rid of confusing macros [Andrii]
* In patch 4, deprecate starting from 0.6 instead of 0.7 [Andrii]
v1->v2: fix bpftool do_dump changes to clear bpf_prog_info after use and
correctly pass realloc'd ptr back (patch 2)
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
As part of the road to libbpf 1.0, and discussed in libbpf issue tracker
[0], bpf_program__get_prog_info_linear and its associated structs and
helper functions should be deprecated. The functionality is too specific
to the needs of 'perf', and there's little/no out-of-tree usage to
preclude introduction of a more general helper in the future.
[0] Closes: https://github.com/libbpf/libbpf/issues/313
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211101224357.2651181-5-davemarchevsky@fb.com
To prepare for impending deprecation of libbpf's
bpf_program__get_prog_info_linear, pull in the function and associated
helpers into the perf codebase and migrate existing uses to the perf
copy.
Since libbpf's deprecated definitions will still be visible to perf, it
is necessary to rename perf's definitions.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211101224357.2651181-4-davemarchevsky@fb.com
