It's possible to have other build id types (other than default SHA1). Currently there's also ld support for MD5 build id.
Adding build_id_parse_size function, that returns also size of the parsed build id, so we can recognize the build id type. Cc: Alexei Starovoitov <[email protected]> Cc: Song Liu <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> --- include/linux/buildid.h | 2 ++ lib/buildid.c | 31 ++++++++++++++++++++++++------- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/include/linux/buildid.h b/include/linux/buildid.h index 3be5b49719f1..edba89834b4c 100644 --- a/include/linux/buildid.h +++ b/include/linux/buildid.h @@ -7,5 +7,7 @@ #define BUILD_ID_SIZE 20 int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id); +int build_id_parse_size(struct vm_area_struct *vma, unsigned char *build_id, + __u32 *size); #endif diff --git a/lib/buildid.c b/lib/buildid.c index e8d5feb7ef20..c52f86110635 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -12,6 +12,7 @@ */ static inline int parse_build_id(void *page_addr, unsigned char *build_id, + __u32 *size, void *note_start, Elf32_Word note_size) { @@ -38,6 +39,8 @@ static inline int parse_build_id(void *page_addr, nhdr->n_descsz); memset(build_id + nhdr->n_descsz, 0, BUILD_ID_SIZE - nhdr->n_descsz); + if (size) + *size = nhdr->n_descsz; return 0; } new_offs = note_offs + sizeof(Elf32_Nhdr) + @@ -50,7 +53,8 @@ static inline int parse_build_id(void *page_addr, } /* Parse build ID from 32-bit ELF */ -static int get_build_id_32(void *page_addr, unsigned char *build_id) +static int get_build_id_32(void *page_addr, unsigned char *build_id, + __u32 *size) { Elf32_Ehdr *ehdr = (Elf32_Ehdr *)page_addr; Elf32_Phdr *phdr; @@ -65,7 +69,7 @@ static int get_build_id_32(void *page_addr, unsigned char *build_id) for (i = 0; i < ehdr->e_phnum; ++i) { if (phdr[i].p_type == PT_NOTE && - !parse_build_id(page_addr, build_id, + !parse_build_id(page_addr, build_id, size, page_addr + phdr[i].p_offset, phdr[i].p_filesz)) return 0; @@ -74,7 +78,8 @@ static int get_build_id_32(void *page_addr, unsigned char *build_id) } /* Parse build ID from 64-bit ELF */ -static int get_build_id_64(void *page_addr, unsigned char *build_id) +static int get_build_id_64(void *page_addr, unsigned char *build_id, + __u32 *size) { Elf64_Ehdr *ehdr = (Elf64_Ehdr *)page_addr; Elf64_Phdr *phdr; @@ -89,7 +94,7 @@ static int get_build_id_64(void *page_addr, unsigned char *build_id) for (i = 0; i < ehdr->e_phnum; ++i) { if (phdr[i].p_type == PT_NOTE && - !parse_build_id(page_addr, build_id, + !parse_build_id(page_addr, build_id, size, page_addr + phdr[i].p_offset, phdr[i].p_filesz)) return 0; @@ -98,7 +103,8 @@ static int get_build_id_64(void *page_addr, unsigned char *build_id) } /* Parse build ID of ELF file mapped to vma */ -int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id) +static int __build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, + __u32 *size) { Elf32_Ehdr *ehdr; struct page *page; @@ -126,11 +132,22 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id) goto out; if (ehdr->e_ident[EI_CLASS] == ELFCLASS32) - ret = get_build_id_32(page_addr, build_id); + ret = get_build_id_32(page_addr, build_id, size); else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64) - ret = get_build_id_64(page_addr, build_id); + ret = get_build_id_64(page_addr, build_id, size); out: kunmap_atomic(page_addr); put_page(page); return ret; } + +int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id) +{ + return __build_id_parse(vma, build_id, NULL); +} + +int build_id_parse_size(struct vm_area_struct *vma, unsigned char *build_id, + __u32 *size) +{ + return __build_id_parse(vma, build_id, size); +} -- 2.26.2
