perf buildid-cache: Consolidate .build-id cache path generators

Consolidate .build-id cache path generating routines to
build_id__filename() function. Other functions must use it to get the
buildid cache path (link path) from build-id.  This can reduce the risk
of partial-update.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150210091853.19264.58513.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 41 insertions, 17 deletions

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 9f764f633e57..adbc36028636 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -93,6 +93,35 @@ int build_id__sprintf(const u8 *build_id, int len, char *bf)
         return raw - build_id;
 }
 
+/* asnprintf consolidates asprintf and snprintf */
+static int asnprintf(char **strp, size_t size, const char *fmt, ...)
+{
+        va_list ap;
+        int ret;
+
+        if (!strp)
+                return -EINVAL;
+
+        va_start(ap, fmt);
+        if (*strp)
+                ret = vsnprintf(*strp, size, fmt, ap);
+        else
+                ret = vasprintf(strp, fmt, ap);
+        va_end(ap);
+
+        return ret;
+}
+
+static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
+{
+        char *tmp = bf;
+        int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
+                            sbuild_id, sbuild_id + 2);
+        if (ret < 0 || (tmp && size < (unsigned int)ret))
+                return NULL;
+        return bf;
+}
+
 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 {
         char build_id_hex[BUILD_ID_SIZE * 2 + 1];
@@ -101,14 +130,7 @@ char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
                 return NULL;
 
         build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
-        if (bf == NULL) {
-                if (asprintf(&bf, "%s/.build-id/%.2s/%s", buildid_dir,
-                             build_id_hex, build_id_hex + 2) < 0)
-                        return NULL;
-        } else
-                snprintf(bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
-                         build_id_hex, build_id_hex + 2);
-        return bf;
+        return build_id__filename(build_id_hex, bf, size);
 }
 
 #define dsos__for_each_with_build_id(pos, head) \
@@ -264,7 +286,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 {
         const size_t size = PATH_MAX;
         char *realname, *filename = zalloc(size),
-             *linkname = zalloc(size), *targetname;
+             *linkname = zalloc(size), *targetname, *tmp;
         int len, err = -1;
         bool slash = is_kallsyms || is_vdso;
 
@@ -297,13 +319,15 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
                         goto out_free;
         }
 
-        len = scnprintf(linkname, size, "%s/.build-id/%.2s",
-                        buildid_dir, sbuild_id);
+        if (!build_id__filename(sbuild_id, linkname, size))
+                goto out_free;
+        tmp = strrchr(linkname, '/');
+        *tmp = '\0';
 
         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
                 goto out_free;
 
-        snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
+        *tmp = '/';
         targetname = filename + strlen(buildid_dir) - 5;
         memcpy(targetname, "../..", 5);
 
@@ -332,14 +356,14 @@ int build_id_cache__remove_s(const char *sbuild_id)
 {
         const size_t size = PATH_MAX;
         char *filename = zalloc(size),
-             *linkname = zalloc(size);
+             *linkname = zalloc(size), *tmp;
         int err = -1;
 
         if (filename == NULL || linkname == NULL)
                 goto out_free;
 
-        snprintf(linkname, size, "%s/.build-id/%.2s/%s",
-                 buildid_dir, sbuild_id, sbuild_id + 2);
+        if (!build_id__filename(sbuild_id, linkname, size))
+                goto out_free;
 
         if (access(linkname, F_OK))
                 goto out_free;
@@ -353,8 +377,8 @@ int build_id_cache__remove_s(const char *sbuild_id)
         /*
          * Since the link is relative, we must make it absolute:
          */
-        snprintf(linkname, size, "%s/.build-id/%.2s/%s",
-                 buildid_dir, sbuild_id, filename);
+        tmp = strrchr(linkname, '/') + 1;
+        snprintf(tmp, size - (tmp - linkname), "%s", filename);
 
         if (unlink(linkname))
                 goto out_free;