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>

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 9f764f633e57db0df6560f149276a6fee5575913..adbc36028636cb55c1cf1160b054e57a24b122f9 100644 (file)
--- 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;