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| author | Andrii Nakryiko <andrii@kernel.org> | 2024-08-29 10:42:27 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-09-11 09:58:30 -0700 |
| commit | 45b8fc3096542a53bfd245a9ad8ef870384b4897 (patch) | |
| tree | aa3e8ebc9186ed39d591841f629451762240801c /lib | |
| parent | 4e9d360c4cdf2dc11a30fd5caf39e8c31f0896cb (diff) | |
| download | linux-45b8fc3096542a53bfd245a9ad8ef870384b4897.tar.gz linux-45b8fc3096542a53bfd245a9ad8ef870384b4897.tar.bz2 linux-45b8fc3096542a53bfd245a9ad8ef870384b4897.zip | |
lib/buildid: rename build_id_parse() into build_id_parse_nofault()
Make it clear that build_id_parse() assumes that it can take no page
fault by renaming it and current few users to build_id_parse_nofault().
Also add build_id_parse() stub which for now falls back to non-sleepable
implementation, but will be changed in subsequent patches to take
advantage of sleepable context. PROCMAP_QUERY ioctl() on
/proc/<pid>/maps file is using build_id_parse() and will automatically
take advantage of more reliable sleepable context implementation.
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240829174232.3133883-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/buildid.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/lib/buildid.c b/lib/buildid.c index e8fc4aeb01f2..c1cbd34f3685 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -293,10 +293,12 @@ static int get_build_id_64(struct freader *r, unsigned char *build_id, __u32 *si * @build_id: buffer to store build id, at least BUILD_ID_SIZE long * @size: returns actual build id size in case of success * - * Return: 0 on success, -EINVAL otherwise + * Assumes no page fault can be taken, so if relevant portions of ELF file are + * not already paged in, fetching of build ID fails. + * + * Return: 0 on success; negative error, otherwise */ -int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, - __u32 *size) +int build_id_parse_nofault(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size) { const Elf32_Ehdr *ehdr; struct freader r; @@ -335,6 +337,23 @@ out: return ret; } +/* + * Parse build ID of ELF file mapped to VMA + * @vma: vma object + * @build_id: buffer to store build id, at least BUILD_ID_SIZE long + * @size: returns actual build id size in case of success + * + * Assumes faultable context and can cause page faults to bring in file data + * into page cache. + * + * Return: 0 on success; negative error, otherwise + */ +int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size) +{ + /* fallback to non-faultable version for now */ + return build_id_parse_nofault(vma, build_id, size); +} + /** * build_id_parse_buf - Get build ID from a buffer * @buf: ELF note section(s) to parse |