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 <jo...@kernel.org>
Cc: Alexei Starovoitov <a...@kernel.org>
Cc: Jessica Yu <j...@kernel.org>
Cc: Evan Green <evgr...@chromium.org>
Cc: Hsin-Yi Wang <hsi...@chromium.org>
Cc: Dave Young <dyo...@redhat.com>
Cc: Baoquan He <b...@redhat.com>
Cc: Vivek Goyal <vgo...@redhat.com>
Cc: <ke...@lists.infradead.org>
Signed-off-by: Stephen Boyd <swb...@chromium.org>
---
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;
+}
--
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