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| author | Andrii Nakryiko <andrii@kernel.org> | 2021-12-10 16:40:43 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-12-14 15:47:56 +0100 |
| commit | 9fc205b413b3f3e9502fa92151fba63b91230454 (patch) | |
| tree | 9964b204c6a1721168b7041e060df59b5123ce7a /tools/lib/bpf/btf_dump.c | |
| parent | 4581e676d3be9d8c921a48bf18e92c5a8f31bf13 (diff) | |
| download | linux-9fc205b413b3f3e9502fa92151fba63b91230454.tar.gz linux-9fc205b413b3f3e9502fa92151fba63b91230454.tar.bz2 linux-9fc205b413b3f3e9502fa92151fba63b91230454.zip | |
libbpf: Add sane strncpy alternative and use it internally
strncpy() has a notoriously error-prone semantics which makes GCC
complain about it a lot (and quite often completely completely falsely
at that). Instead of pleasing GCC all the time (-Wno-stringop-truncation
is unfortunately only supported by GCC, so it's a bit too messy to just
enable it in Makefile), add libbpf-internal libbpf_strlcpy() helper
which follows what FreeBSD's strlcpy() does and what most people would
expect from strncpy(): copies up to N-1 first bytes from source string
into destination string and ensures zero-termination afterwards.
Replace all the relevant uses of strncpy/strncat/memcpy in libbpf with
libbpf_strlcpy().
This also fixes the issue reported by Emmanuel Deloget in xsk.c where
memcpy() could access source string beyond its end.
Fixes: 2f6324a3937f8 (libbpf: Support shared umems between queues and devices)
Reported-by: Emmanuel Deloget <emmanuel.deloget@eho.link>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211211004043.2374068-1-andrii@kernel.org
Diffstat (limited to 'tools/lib/bpf/btf_dump.c')
| -rw-r--r-- | tools/lib/bpf/btf_dump.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index f06a1d343c92..b9a3260c83cb 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -2321,8 +2321,8 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id, if (!opts->indent_str) d->typed_dump->indent_str[0] = '\t'; else - strncat(d->typed_dump->indent_str, opts->indent_str, - sizeof(d->typed_dump->indent_str) - 1); + libbpf_strlcpy(d->typed_dump->indent_str, opts->indent_str, + sizeof(d->typed_dump->indent_str)); d->typed_dump->compact = OPTS_GET(opts, compact, false); d->typed_dump->skip_names = OPTS_GET(opts, skip_names, false); |