perf tools: Add filename__decompress function

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>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201126170026.2619053-9-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 89b5fd2..d786cf6 100644 (file)
--- 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 d8cb4f5..cd2fe64 100644 (file)
--- 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)