diff options
Diffstat (limited to 'lib/buildid.c')
| -rw-r--r-- | lib/buildid.c | 74 |
1 files changed, 58 insertions, 16 deletions
diff --git a/lib/buildid.c b/lib/buildid.c index 6156997c3895..dfc62625cae4 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -1,36 +1,31 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/buildid.h> +#include <linux/cache.h> #include <linux/elf.h> +#include <linux/kernel.h> #include <linux/pagemap.h> #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); if (nhdr->n_type == BUILD_ID && nhdr->n_namesz == sizeof("GNU") && + !strcmp((char *)(nhdr + 1), "GNU") && nhdr->n_descsz > 0 && nhdr->n_descsz <= BUILD_ID_SIZE_MAX) { memcpy(build_id, @@ -49,11 +44,29 @@ static inline int parse_build_id(void *page_addr, break; note_offs = new_offs; } + return -EINVAL; } +static inline int parse_build_id(const void *page_addr, + unsigned char *build_id, + __u32 *size, + const 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, +static int get_build_id_32(const void *page_addr, unsigned char *build_id, __u32 *size) { Elf32_Ehdr *ehdr = (Elf32_Ehdr *)page_addr; @@ -78,7 +91,7 @@ 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(const void *page_addr, unsigned char *build_id, __u32 *size) { Elf64_Ehdr *ehdr = (Elf64_Ehdr *)page_addr; @@ -108,7 +121,7 @@ static int get_build_id_64(void *page_addr, unsigned char *build_id, * @build_id: buffer to store build id, at least BUILD_ID_SIZE long * @size: returns actual build id size in case of success * - * Returns 0 on success, otherwise error (< 0). + * Return: 0 on success, -EINVAL otherwise */ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size) @@ -147,3 +160,32 @@ 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); +} + +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) || IS_ENABLED(CONFIG_CRASH_CORE) +unsigned char vmlinux_build_id[BUILD_ID_SIZE_MAX] __ro_after_init; + +/** + * init_vmlinux_build_id - Compute and stash the running kernel's build ID + */ +void __init init_vmlinux_build_id(void) +{ + extern const void __start_notes __weak; + extern const void __stop_notes __weak; + unsigned int size = &__stop_notes - &__start_notes; + + build_id_parse_buf(&__start_notes, vmlinux_build_id, size); +} +#endif |