[ Upstream commit 236d3910117e9f97ebf75e511d8bcc950f1a4e5f ]

In `set_kcfg_value_str`, an untrusted string is accessed with the assumption
that it will be at least two characters long due to the presence of checks for
opening and closing quotes. But the check for the closing quote
(value[len - 1] != '"') misses the fact that it could be checking the opening
quote itself in case of an invalid input that consists of just the opening
quote.

This commit adds an explicit check to make sure the string is at least two
characters long.

Signed-off-by: Nandakumar Edamana <nandakumar@nandakumar.co.in>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250221210110.3182084-1-nandakumar@nandakumar.co.in
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 0a7c2a84359612e54328aa52030eb202093da6e2 ]

Update btf_ext_parse_info() to ensure the core_relo header is present
before reading its fields. This avoids a potential buffer read overflow
reported by the OSS Fuzz project.

Fixes: cf579164e9ea ("libbpf: Support BTF.ext loading and output in either endianness")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://issues.oss-fuzz.com/issues/388905046
Link: https://lore.kernel.org/bpf/20250125065236.2603346-1-itugrok@yahoo.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 307ef667e94530c2f2f77797bfe9ea85c22bec7d ]

When statically linking symbols can be replaced with those from other
statically linked libraries depending on the link order and the hoped
for "multiple definition" error may not appear. To avoid conflicts it
is good practice to namespace symbols, this change renames errstr to
libbpf_errstr. To avoid churn a #define is used to turn use of
errstr(err) to libbpf_errstr(err).

Fixes: 1633a83bf993 ("libbpf: Introduce errstr() for stringifying errno")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250320222439.1350187-1-irogers@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e0525cd72b5979d8089fe524a071ea93fd011dc9 ]

Fix theoretical NULL dereference in linker when resolving *extern*
STT_SECTION symbol against not-yet-existing ELF section. Not sure if
it's possible in practice for valid ELF object files (this would require
embedded assembly manipulations, at which point BTF will be missing),
but fix the s/dst_sym/dst_sec/ typo guarding this condition anyways.

Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs")
Fixes: a46349227cd8 ("libbpf: Add linker extern resolution support for functions and global variables")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250220002821.834400-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix tools/ quiet build Makefile infrastructure that was broken when
   working on tools/perf/ without testing on other tools/ living
   utilities.

* tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  tools: Remove redundant quiet setup
  tools: Unify top-level quiet infrastructure

Q is exported from Makefile.include so it is not necessary to manually
set it.

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Benjamin Tissoires <bentiss@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Mykola Lysenko <mykolal@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Some versions of kernel were stripping out '.llvm.<hash>' suffix from
kerne symbols (produced by Clang LTO compilation) from function names
reported in available_filter_functions, while kallsyms reported full
original name. This confuses libbpf's multi-kprobe logic of finding all
matching kernel functions for specified user glob pattern by joining
available_filter_functions and kallsyms contents, because joining by
full symbol name won't work for symbols containing '.llvm.<hash>' suffix.

This was eventually fixed by [0] in the kernel, but we'd like to not
regress multi-kprobe experience and add a work around for this bug on
libbpf side, stripping kallsym's name if it matches user pattern and
contains '.llvm.' suffix.

  [0] fb6a421fb615 ("kallsyms: Match symbols exactly with CONFIG_LTO_CLANG")

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250117003957.179331-1-andrii@kernel.org

When redirecting the split BTF to the vmlinux base BTF, we need to mark
the distilled base struct/union members of split BTF structs/unions in
id_map with BTF_IS_EMBEDDED. This indicates that these types must match
both name and size later. Therefore, we need to traverse the entire
split BTF, which involves traversing type IDs from nr_dist_base_types to
nr_types. However, the current implementation uses an incorrect
traversal end type ID, so let's correct it.

Fixes: 19e00c897d50 ("libbpf: Split BTF relocation")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250115100241.4171581-3-pulehui@huaweicloud.com

The error number of elf_begin is omitted when encapsulating the
btf_find_elf_sections function.

Fixes: c86f180ffc99 ("libbpf: Make btf_parse_elf process .BTF.base transparently")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250115100241.4171581-2-pulehui@huaweicloud.com

Jordan reported an issue in Meta production environment where func
try_to_wake_up() is renamed to try_to_wake_up.llvm.<hash>() by clang
compiler at lto mode. The original 'kprobe/try_to_wake_up' does not
work any more since try_to_wake_up() does not match the actual func
name in /proc/kallsyms.

There are a couple of ways to resolve this issue. For example, in
attach_kprobe(), we could do lookup in /proc/kallsyms so try_to_wake_up()
can be replaced by try_to_wake_up.llvm.<hach>(). Or we can force users
to use bpf_program__attach_kprobe() where they need to lookup
/proc/kallsyms to find out try_to_wake_up.llvm.<hach>(). But these two
approaches requires extra work by either libbpf or user.

Luckily, suggested by Andrii, multi kprobe already supports wildcard ('*')
for symbol matching. In the above example, 'try_to_wake_up*' can match
to try_to_wake_up() or try_to_wake_up.llvm.<hash>() and this allows
bpf prog works for different kernels as some kernels may have
try_to_wake_up() and some others may have try_to_wake_up.llvm.<hash>().

The original intention is to kprobe try_to_wake_up() only, so an optional
field unique_match is added to struct bpf_kprobe_multi_opts. If the
field is set to true, the number of matched functions must be one.
Otherwise, the attachment will fail. In the above case, multi kprobe
with 'try_to_wake_up*' and unique_match preserves user functionality.

Reported-by: Jordan Rome <linux@jordanrome.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250109174023.3368432-1-yonghong.song@linux.dev