From: Stephen Boyd <swboyd@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, Jiri Olsa <jolsa@kernel.org>,
Alexei Starovoitov <ast@kernel.org>, Jessica Yu <jeyu@kernel.org>,
Evan Green <evgreen@chromium.org>,
Hsin-Yi Wang <hsinyi@chromium.org>
Subject: [PATCH v5 02/13] buildid: Add API to parse build ID out of buffer
Date: Tue, 20 Apr 2021 14:49:52 -0700 [thread overview]
Message-ID: <20210420215003.3510247-3-swboyd@chromium.org> (raw)
In-Reply-To: <20210420215003.3510247-1-swboyd@chromium.org>
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.
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>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
include/linux/buildid.h | 1 +
lib/buildid.c | 50 ++++++++++++++++++++++++++++++-----------
2 files changed, 38 insertions(+), 13 deletions(-)
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 <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 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
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);
+}
--
https://chromeos.dev
next prev parent reply other threads:[~2021-04-20 21:50 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 21:49 [PATCH v5 00/13] Add build ID to stacktraces Stephen Boyd
2021-04-20 21:49 ` [PATCH v5 01/13] buildid: Only consider GNU notes for build ID parsing Stephen Boyd
2021-04-20 21:49 ` Stephen Boyd [this message]
2021-04-20 21:49 ` [PATCH v5 03/13] buildid: Stash away kernels build ID on init Stephen Boyd
2021-04-28 10:02 ` Baoquan He
2021-04-20 21:49 ` [PATCH v5 04/13] dump_stack: Add vmlinux build ID to stack traces Stephen Boyd
2021-04-26 11:04 ` Petr Mladek
2021-04-26 23:40 ` Stephen Boyd
2021-04-20 21:49 ` [PATCH v5 05/13] module: Add printk formats to add module build ID to stacktraces Stephen Boyd
2021-04-21 11:49 ` Andy Shevchenko
2021-04-22 23:46 ` Stephen Boyd
2021-04-23 13:24 ` Andy Shevchenko
2021-04-23 13:45 ` Rasmus Villemoes
2021-04-23 14:08 ` Andy Shevchenko
2021-04-26 23:42 ` Stephen Boyd
2021-04-20 21:49 ` [PATCH v5 06/13] arm64: stacktrace: Use %pSb for backtrace printing Stephen Boyd
2021-04-21 9:58 ` Catalin Marinas
2021-04-20 21:49 ` [PATCH v5 07/13] x86/dumpstack: Use %pSb/%pBb " Stephen Boyd
2021-04-20 21:49 ` [PATCH v5 08/13] scripts/decode_stacktrace.sh: Support debuginfod Stephen Boyd
2021-04-20 21:49 ` [PATCH v5 09/13] scripts/decode_stacktrace.sh: Silence stderr messages from addr2line/nm Stephen Boyd
2021-04-20 21:50 ` [PATCH v5 10/13] scripts/decode_stacktrace.sh: Indicate 'auto' can be used for base path Stephen Boyd
2021-04-20 21:50 ` [PATCH v5 11/13] buildid: Mark some arguments const Stephen Boyd
2021-04-20 21:50 ` [PATCH v5 12/13] buildid: Fix kernel-doc notation Stephen Boyd
2021-04-20 21:50 ` [PATCH v5 13/13] kdump: Use vmlinux_build_id to simplify Stephen Boyd
2021-04-28 10:13 ` Baoquan He
2021-04-28 23:14 ` Stephen Boyd
2021-05-07 3:54 ` Baoquan He
2021-05-07 4:04 ` Baoquan He
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