[PATCH 08/25] perf tools: Add filename__decompress function

Jiri Olsa
2020-11-23T23:06:23Z

Factor filename__decompress from decompress_kmodule function.
It can decompress files with compressions supported in perf -
xz and gz, the support needs to be compiled in.

It will to be used in following changes to get build id out of
compressed elf objects.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/dso.c | 31 +++++++++++++++++++------------
tools/perf/util/dso.h | 2 ++
2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 89b5fd2b5de3..d786cf6b0cfa 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -279,18 +279,12 @@ bool dso__needs_decompress(struct dso *dso)
dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
}

-static int decompress_kmodule(struct dso *dso, const char *name,
- char *pathname, size_t len)
+int filename__decompress(const char *name, char *pathname,
+ size_t len, int comp, int *err)
{
char tmpbuf[] = KMOD_DECOMP_NAME;
int fd = -1;

- if (!dso__needs_decompress(dso))
- return -1;
-
- if (dso->comp == COMP_ID__NONE)
- return -1;
-
/*
* We have proper compression id for DSO and yet the file
* behind the 'name' can still be plain uncompressed object.
@@ -304,17 +298,17 @@ static int decompress_kmodule(struct dso *dso, const char *name,
* To keep this transparent, we detect this and return the file
* descriptor to the uncompressed file.
*/
- if (!compressions[dso->comp].is_compressed(name))
+ if (!compressions[comp].is_compressed(name))
return open(name, O_RDONLY);

fd = mkstemp(tmpbuf);
if (fd < 0) {
- dso->load_errno = errno;
+ *err = errno;
return -1;
}

- if (compressions[dso->comp].decompress(name, fd)) {
- dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
+ if (compressions[comp].decompress(name, fd)) {
+ *err = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
close(fd);
fd = -1;
}
@@ -328,6 +322,19 @@ static int decompress_kmodule(struct dso *dso, const char *name,
return fd;
}

+static int decompress_kmodule(struct dso *dso, const char *name,
+ char *pathname, size_t len)
+{
+ if (!dso__needs_decompress(dso))
+ return -1;
+
+ if (dso->comp == COMP_ID__NONE)
+ return -1;
+
+ return filename__decompress(name, pathname, len, dso->comp,
+ &dso->load_errno);
+}
+
int dso__decompress_kmodule_fd(struct dso *dso, const char *name)
{
return decompress_kmodule(dso, name, NULL, 0);
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index d8cb4f5680a4..cd2fe64a3c5d 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -274,6 +274,8 @@ bool dso__needs_decompress(struct dso *dso);
int dso__decompress_kmodule_fd(struct dso *dso, const char *name);
int dso__decompress_kmodule_path(struct dso *dso, const char *name,
char *pathname, size_t len);
+int filename__decompress(const char *name, char *pathname,
+ size_t len, int comp, int *err);

#define KMOD_DECOMP_NAME "/tmp/perf-kmod-XXXXXX"
#define KMOD_DECOMP_LEN sizeof(KMOD_DECOMP_NAME)
--
2.26.2