From: Jiri Olsa <jolsa@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Song Liu <songliubraving@fb.com>,
lkml <linux-kernel@vger.kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Ingo Molnar <mingo@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Namhyung Kim <namhyung@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Michael Petlan <mpetlan@redhat.com>,
Ian Rogers <irogers@google.com>,
Stephane Eranian <eranian@google.com>,
Alexey Budankov <alexey.budankov@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
Adrian Hunter <adrian.hunter@intel.com>
Subject: [PATCH 02/25] bpf: Add size arg to build_id_parse function
Date: Tue, 24 Nov 2020 00:04:49 +0100 [thread overview]
Message-ID: <20201123230512.2097312-3-jolsa@kernel.org> (raw)
In-Reply-To: <20201123230512.2097312-1-jolsa@kernel.org>
It's possible to have other build id types (other than default SHA1).
Currently there's also ld support for MD5 build id.
Adding size argument to build_id_parse function, that returns (if defined)
size of the parsed build id, so we can recognize the build id type.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/buildid.h | 3 ++-
kernel/bpf/stackmap.c | 2 +-
lib/buildid.c | 29 +++++++++++++++++++++--------
3 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/include/linux/buildid.h b/include/linux/buildid.h
index 3be5b49719f1..72639d433873 100644
--- a/include/linux/buildid.h
+++ b/include/linux/buildid.h
@@ -6,6 +6,7 @@
#define BUILD_ID_SIZE 20
-int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id);
+int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
+ __u32 *size);
#endif
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 7df08f8af5a1..a05fac2cbb05 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -199,7 +199,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
for (i = 0; i < trace_nr; i++) {
vma = find_vma(current->mm, ips[i]);
- if (!vma || build_id_parse(vma, id_offs[i].build_id)) {
+ if (!vma || build_id_parse(vma, id_offs[i].build_id, NULL)) {
/* per entry fall back to ips */
id_offs[i].status = BPF_STACK_BUILD_ID_IP;
id_offs[i].ip = ips[i];
diff --git a/lib/buildid.c b/lib/buildid.c
index e8d5feb7ef20..dbe1b7e247f3 100644
--- a/lib/buildid.c
+++ b/lib/buildid.c
@@ -12,6 +12,7 @@
*/
static inline int parse_build_id(void *page_addr,
unsigned char *build_id,
+ __u32 *size,
void *note_start,
Elf32_Word note_size)
{
@@ -38,6 +39,8 @@ static inline int parse_build_id(void *page_addr,
nhdr->n_descsz);
memset(build_id + nhdr->n_descsz, 0,
BUILD_ID_SIZE - nhdr->n_descsz);
+ if (size)
+ *size = nhdr->n_descsz;
return 0;
}
new_offs = note_offs + sizeof(Elf32_Nhdr) +
@@ -50,7 +53,8 @@ static inline int parse_build_id(void *page_addr,
}
/* 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(void *page_addr, unsigned char *build_id,
+ __u32 *size)
{
Elf32_Ehdr *ehdr = (Elf32_Ehdr *)page_addr;
Elf32_Phdr *phdr;
@@ -65,7 +69,7 @@ static int get_build_id_32(void *page_addr, unsigned char *build_id)
for (i = 0; i < ehdr->e_phnum; ++i) {
if (phdr[i].p_type == PT_NOTE &&
- !parse_build_id(page_addr, build_id,
+ !parse_build_id(page_addr, build_id, size,
page_addr + phdr[i].p_offset,
phdr[i].p_filesz))
return 0;
@@ -74,7 +78,8 @@ 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(void *page_addr, unsigned char *build_id,
+ __u32 *size)
{
Elf64_Ehdr *ehdr = (Elf64_Ehdr *)page_addr;
Elf64_Phdr *phdr;
@@ -89,7 +94,7 @@ static int get_build_id_64(void *page_addr, unsigned char *build_id)
for (i = 0; i < ehdr->e_phnum; ++i) {
if (phdr[i].p_type == PT_NOTE &&
- !parse_build_id(page_addr, build_id,
+ !parse_build_id(page_addr, build_id, size,
page_addr + phdr[i].p_offset,
phdr[i].p_filesz))
return 0;
@@ -97,8 +102,16 @@ static int get_build_id_64(void *page_addr, unsigned char *build_id)
return -EINVAL;
}
-/* Parse build ID of ELF file mapped to vma */
-int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id)
+/*
+ * Parse build ID of ELF file mapped to vma
+ * @vma: vma object
+ * @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).
+ */
+int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
+ __u32 *size)
{
Elf32_Ehdr *ehdr;
struct page *page;
@@ -126,9 +139,9 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id)
goto out;
if (ehdr->e_ident[EI_CLASS] == ELFCLASS32)
- ret = get_build_id_32(page_addr, build_id);
+ ret = get_build_id_32(page_addr, build_id, size);
else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
- ret = get_build_id_64(page_addr, build_id);
+ ret = get_build_id_64(page_addr, build_id, size);
out:
kunmap_atomic(page_addr);
put_page(page);
--
2.26.2
next prev parent reply other threads:[~2020-11-23 23:05 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-23 23:04 [PATCHv3 00/25] perf: Add mmap2 build id support Jiri Olsa
2020-11-23 23:04 ` [PATCH 01/25] bpf: Move stack_map_get_build_id into lib Jiri Olsa
2020-11-23 23:04 ` Jiri Olsa [this message]
2020-11-23 23:04 ` [PATCH 03/25] perf: Add build id data in mmap2 event Jiri Olsa
2020-11-23 23:04 ` [PATCH 04/25] tools headers uapi: Sync tools/include/uapi/linux/perf_event.h Jiri Olsa
2020-11-23 23:04 ` [PATCH 05/25] tools lib: Adopt memchr_inv() from kernel Jiri Olsa
2020-11-23 23:04 ` [PATCH 06/25] perf tools: Do not swap mmap2 fields in case it contains build id Jiri Olsa
2020-11-23 23:04 ` [PATCH 07/25] perf tools: Add build_id__is_defined function Jiri Olsa
2020-11-23 23:04 ` [PATCH 08/25] perf tools: Add filename__decompress function Jiri Olsa
2020-11-23 23:04 ` [PATCH 09/25] perf tools: Add support to read build id from compressed elf Jiri Olsa
2020-11-23 23:04 ` [PATCH 10/25] perf tools: Add check for existing link in buildid dir Jiri Olsa
2020-11-23 23:04 ` [PATCH 11/25] perf tools: Use struct extra_kernel_map in machine__process_kernel_mmap_event Jiri Olsa
2020-11-23 23:04 ` [PATCH 12/25] perf tools: Try to load vmlinux from buildid database Jiri Olsa
2020-11-23 23:05 ` [PATCH 13/25] perf tools: Store build id from mmap2 events Jiri Olsa
2020-11-25 12:56 ` Namhyung Kim
2020-11-25 14:15 ` Jiri Olsa
2020-11-23 23:05 ` [PATCH 14/25] perf tools: Allow mmap2 event to synthesize kernel image Jiri Olsa
2020-11-23 23:05 ` [PATCH 15/25] perf tools: Allow mmap2 event to synthesize modules Jiri Olsa
2020-11-23 23:05 ` [PATCH 16/25] perf tools: Synthesize build id for kernel/modules/tasks Jiri Olsa
2020-11-23 23:05 ` [PATCH 17/25] perf tools: Add support to display build id for mmap2 events Jiri Olsa
2020-11-23 23:05 ` [PATCH 18/25] perf tools: Use machine__for_each_dso in perf_session__cache_build_ids Jiri Olsa
2020-11-23 23:05 ` [PATCH 19/25] perf tools: Add __perf_session__cache_build_ids function Jiri Olsa
2020-11-23 23:05 ` [PATCH 20/25] perf tools: Add is_perf_data function Jiri Olsa
2020-11-23 23:05 ` [PATCH 21/25] perf tools: Add build_id_cache__add function Jiri Olsa
2020-11-23 23:05 ` [PATCH 22/25] perf buildid-cache: Add support to add build ids from perf data Jiri Olsa
2020-11-25 13:00 ` Namhyung Kim
2020-11-25 13:04 ` Namhyung Kim
2020-11-25 16:36 ` Jiri Olsa
2020-11-26 4:49 ` Namhyung Kim
2020-11-25 13:29 ` Namhyung Kim
2020-11-25 14:20 ` Jiri Olsa
2020-11-23 23:05 ` [PATCH 23/25] perf buildid-cache: Add --debuginfod option Jiri Olsa
2020-11-23 23:05 ` [PATCH 24/25] perf buildid-list: Add support for mmap2's buildid events Jiri Olsa
2020-11-23 23:05 ` [PATCH 25/25] perf record: Add --buildid-mmap option to enable mmap's build id Jiri Olsa
2020-11-25 12:54 ` [PATCHv3 00/25] perf: Add mmap2 build id support Namhyung Kim
2020-11-26 17:00 [PATCHv4 " Jiri Olsa
2020-11-26 17:00 ` [PATCH 02/25] bpf: Add size arg to build_id_parse function Jiri Olsa
2020-12-03 19:24 ` Jiri Olsa
2020-12-03 21:23 ` Song Liu
2020-12-04 23:30 ` Jiri Olsa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201123230512.2097312-3-jolsa@kernel.org \
--to=jolsa@kernel.org \
--cc=a.p.zijlstra@chello.nl \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=ak@linux.intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=alexey.budankov@linux.intel.com \
--cc=ast@kernel.org \
--cc=eranian@google.com \
--cc=irogers@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@kernel.org \
--cc=mpetlan@redhat.com \
--cc=namhyung@kernel.org \
--cc=songliubraving@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).