2022-12-15 19:31:09

by Namhyung Kim

[permalink] [raw]
Subject: [PATCH 3/9] perf symbol: Add filename__has_section()

The filename__has_section() is to check if the given section name is in
the binary. It'd be used for checking debug info for srcline.

Signed-off-by: Namhyung Kim <[email protected]>
---
tools/perf/util/symbol-elf.c | 28 ++++++++++++++++++++++++++++
tools/perf/util/symbol-minimal.c | 5 +++++
tools/perf/util/symbol.h | 1 +
3 files changed, 34 insertions(+)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 80345695b136..96767d1b3f1c 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -233,6 +233,34 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
return NULL;
}

+bool filename__has_section(const char *filename, const char *sec)
+{
+ int fd;
+ Elf *elf;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ bool found = false;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ return false;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ goto out;
+
+ if (gelf_getehdr(elf, &ehdr) == NULL)
+ goto elf_out;
+
+ found = !!elf_section_by_name(elf, &ehdr, &shdr, sec, NULL);
+
+elf_out:
+ elf_end(elf);
+out:
+ close(fd);
+ return found;
+}
+
static int elf_read_program_header(Elf *elf, u64 vaddr, GElf_Phdr *phdr)
{
size_t i, phdrnum;
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index f9eb0bee7f15..de84da3b0d96 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -385,3 +385,8 @@ char *dso__demangle_sym(struct dso *dso __maybe_unused,
{
return NULL;
}
+
+bool filename__has_section(const char *filename, const char *sec)
+{
+ return false;
+}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index e297de14184c..f735108c4d4e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -165,6 +165,7 @@ int modules__parse(const char *filename, void *arg,
u64 start, u64 size));
int filename__read_debuglink(const char *filename, char *debuglink,
size_t size);
+bool filename__has_section(const char *filename, const char *sec);

struct perf_env;
int symbol__init(struct perf_env *env);
--
2.39.0.314.g84b9a713c41-goog