perf tools: Introduce dso__decompress_kmodule_{fd,path}

Move decompress_kmodule() to util/dso.c and split it into two functions
returning fd and (decompressed) file path.  The existing user only wants
the fd version but the path version will be used soon.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 65 insertions, 35 deletions

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 1f29e4fe7af0..b346b8eba65c 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -248,6 +248,64 @@ 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 *tmpbuf)
+{
+        int fd = -1;
+        struct kmod_path m;
+
+        if (!dso__needs_decompress(dso))
+                return -1;
+
+        if (kmod_path__parse_ext(&m, dso->long_name))
+                return -1;
+
+        if (!m.comp)
+                goto out;
+
+        fd = mkstemp(tmpbuf);
+        if (fd < 0) {
+                dso->load_errno = errno;
+                goto out;
+        }
+
+        if (!decompress_to_file(m.ext, name, fd)) {
+                dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
+                close(fd);
+                fd = -1;
+        }
+
+out:
+        free(m.ext);
+        return fd;
+}
+
+int dso__decompress_kmodule_fd(struct dso *dso, const char *name)
+{
+        char tmpbuf[] = KMOD_DECOMP_NAME;
+        int fd;
+
+        fd = decompress_kmodule(dso, name, tmpbuf);
+        unlink(tmpbuf);
+        return fd;
+}
+
+int dso__decompress_kmodule_path(struct dso *dso, const char *name,
+                                 char *pathname, size_t len)
+{
+        char tmpbuf[] = KMOD_DECOMP_NAME;
+        int fd;
+
+        fd = decompress_kmodule(dso, name, tmpbuf);
+        if (fd < 0) {
+                unlink(tmpbuf);
+                return -1;
+        }
+
+        strncpy(pathname, tmpbuf, len);
+        close(fd);
+        return 0;
+}
+
 /*
  * Parses kernel module specified in @path and updates
  * @m argument like:
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 5fe2ab5877bd..bd061ba7b47c 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -244,6 +244,12 @@ bool is_supported_compression(const char *ext);
 bool is_kernel_module(const char *pathname, int cpumode);
 bool decompress_to_file(const char *ext, const char *filename, int output_fd);
 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);
+
+#define KMOD_DECOMP_NAME  "/tmp/perf-kmod-XXXXXX"
+#define KMOD_DECOMP_LEN   sizeof(KMOD_DECOMP_NAME)
 
 struct kmod_path {
         char *name;
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 1fb2efae4f02..d342e771dbad 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -637,40 +637,6 @@ static int dso__swap_init(struct dso *dso, unsigned char eidata)
         return 0;
 }
 
-static int decompress_kmodule(struct dso *dso, const char *name,
-                              enum dso_binary_type type)
-{
-        int fd = -1;
-        char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
-        struct kmod_path m;
-
-        if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
-            type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
-            type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
-                return -1;
-
-        if (kmod_path__parse_ext(&m, dso->long_name) || !m.comp)
-                return -1;
-
-        fd = mkstemp(tmpbuf);
-        if (fd < 0) {
-                dso->load_errno = errno;
-                goto out;
-        }
-
-        if (!decompress_to_file(m.ext, name, fd)) {
-                dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
-                close(fd);
-                fd = -1;
-        }
-
-        unlink(tmpbuf);
-
-out:
-        free(m.ext);
-        return fd;
-}
-
 bool symsrc__possibly_runtime(struct symsrc *ss)
 {
         return ss->dynsym || ss->opdsec;
@@ -702,7 +668,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
         int fd;
 
         if (dso__needs_decompress(dso)) {
-                fd = decompress_kmodule(dso, name, type);
+                fd = dso__decompress_kmodule_fd(dso, name);
                 if (fd < 0)
                         return -1;
         } else {