Add vmlinux_build_id() so that callers can print a hex format string representation of the running kernel's build ID. This will be used in the kdump and dump_stack code so that developers can easily locate the vmlinux debug symbols for a crash/stacktrace.
Cc: Jiri Olsa <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Jessica Yu <[email protected]> Cc: Evan Green <[email protected]> Cc: Hsin-Yi Wang <[email protected]> Cc: Dave Young <[email protected]> Cc: Baoquan He <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: <[email protected]> Signed-off-by: Stephen Boyd <[email protected]> --- include/linux/buildid.h | 2 ++ lib/buildid.c | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/linux/buildid.h b/include/linux/buildid.h index ebce93f26d06..2ff6b1b7cc9b 100644 --- a/include/linux/buildid.h +++ b/include/linux/buildid.h @@ -10,4 +10,6 @@ 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); +const unsigned char *vmlinux_build_id(void); + #endif diff --git a/lib/buildid.c b/lib/buildid.c index 010ab0674cb9..fa1b6466b4b8 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -4,6 +4,7 @@ #include <linux/elf.h> #include <linux/kernel.h> #include <linux/pagemap.h> +#include <linux/string.h> #define BUILD_ID 3 @@ -171,3 +172,21 @@ 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); } + +/** + * vmlinux_build_id - Get the running kernel's build ID + * + * Return: Running kernel's build ID + */ +const unsigned char *vmlinux_build_id(void) +{ + extern const void __start_notes __weak; + extern const void __stop_notes __weak; + unsigned int size = &__stop_notes - &__start_notes; + static unsigned char vmlinux_build_id[BUILD_ID_SIZE_MAX]; + + if (!memchr_inv(vmlinux_build_id, 0, BUILD_ID_SIZE_MAX)) + build_id_parse_buf(&__start_notes, vmlinux_build_id, size); + + return vmlinux_build_id; +} -- https://chromeos.dev
