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authorStephen Boyd <swboyd@chromium.org>2021-07-07 18:09:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-08 11:48:22 -0700
commit7eaf3cf3b7c5a49b3ca60e1ceb3d1d7430cc9d0e (patch)
treeb1344261638c66aface7be395988b1353ef3d278 /lib
parenta010d79b6683b6b1e66be2ea7204944f1323661c (diff)
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buildid: add API to parse build ID out of buffer
Add an API that can parse the build ID out of a buffer, instead of a vma, to support printing a kernel module's build ID for stack traces. Link: https://lkml.kernel.org/r/20210511003845.2429846-3-swboyd@chromium.org Signed-off-by: Stephen Boyd <swboyd@chromium.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Evan Green <evgreen@chromium.org> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sasha Levin <sashal@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/buildid.c50
1 files changed, 37 insertions, 13 deletions
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 <linux/buildid.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);
@@ -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);
+}