diff --git a/include/linux/buildid.h b/include/linux/buildid.h index 40232f90db6e..ebce93f26d06 100644 --- a/include/linux/buildid.h +++ b/include/linux/buildid.h @@ -8,5 +8,6 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size); +int build_id_parse_buf(const void *buf, unsigned char *build_id, u32 buf_size); #endif diff --git a/lib/buildid.c b/lib/buildid.c index e014636ec3eb..6aea1c4e5e85 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -2,30 +2,23 @@ #include #include +#include #include #define BUILD_ID 3 + /* * Parse build id from the note segment. This logic can be shared between * 32-bit and 64-bit system, because Elf32_Nhdr and Elf64_Nhdr are * identical. */ -static inline int parse_build_id(void *page_addr, - unsigned char *build_id, - __u32 *size, - void *note_start, - Elf32_Word note_size) +static int parse_build_id_buf(unsigned char *build_id, + __u32 *size, + const void *note_start, + Elf32_Word note_size) { Elf32_Word note_offs = 0, new_offs; - /* check for overflow */ - if (note_start < page_addr || note_start + note_size < note_start) - return -EINVAL; - - /* only supports note that fits in the first page */ - if (note_start + note_size > page_addr + PAGE_SIZE) - return -EINVAL; - while (note_offs + sizeof(Elf32_Nhdr) < note_size) { Elf32_Nhdr *nhdr = (Elf32_Nhdr *)(note_start + note_offs); @@ -50,9 +43,27 @@ static inline int parse_build_id(void *page_addr, break; note_offs = new_offs; } + return -EINVAL; } +static inline int parse_build_id(void *page_addr, + unsigned char *build_id, + __u32 *size, + void *note_start, + Elf32_Word note_size) +{ + /* check for overflow */ + if (note_start < page_addr || note_start + note_size < note_start) + return -EINVAL; + + /* only supports note that fits in the first page */ + if (note_start + note_size > page_addr + PAGE_SIZE) + return -EINVAL; + + return parse_build_id_buf(build_id, size, note_start, note_size); +} + /* Parse build ID from 32-bit ELF */ static int get_build_id_32(void *page_addr, unsigned char *build_id, __u32 *size) @@ -148,3 +159,16 @@ out: put_page(page); return ret; } + +/** + * build_id_parse_buf - Get build ID from a buffer + * @buf: Elf note section(s) to parse + * @buf_size: Size of @buf in bytes + * @build_id: Build ID parsed from @buf, at least BUILD_ID_SIZE_MAX long + * + * Return: 0 on success, -EINVAL otherwise + */ +int build_id_parse_buf(const void *buf, unsigned char *build_id, u32 buf_size) +{ + return parse_build_id_buf(build_id, NULL, buf, buf_size); +}