perf symbols: Kill dso__build_id_is_kmod()

The commit e7ee40475760 ("perf symbols: Fix symbols searching for module
in buildid-cache") added the function to check kernel modules reside in
the build-id cache.  This was because there's no way to identify a DSO
which is actually a kernel module.  So it searched linkname of the file
and find ".ko" suffix.

But this does not work for compressed kernel modules and now such DSOs
hCcave correct symtab_type now.  So no need to check it anymore.  This
patch essentially reverts the commit.

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/20170608073109.30699-10-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 0 insertions, 50 deletions

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 168cc49654e7..e0148b081bdf 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -278,51 +278,6 @@ char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
         return bf;
 }
 
-bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
-{
-        char *id_name = NULL, *ch;
-        struct stat sb;
-        char sbuild_id[SBUILD_ID_SIZE];
-
-        if (!dso->has_build_id)
-                goto err;
-
-        build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
-        id_name = build_id_cache__linkname(sbuild_id, NULL, 0);
-        if (!id_name)
-                goto err;
-        if (access(id_name, F_OK))
-                goto err;
-        if (lstat(id_name, &sb) == -1)
-                goto err;
-        if ((size_t)sb.st_size > size - 1)
-                goto err;
-        if (readlink(id_name, bf, size - 1) < 0)
-                goto err;
-
-        bf[sb.st_size] = '\0';
-
-        /*
-         * link should be:
-         * ../../lib/modules/4.4.0-rc4/kernel/net/ipv4/netfilter/nf_nat_ipv4.ko/a09fe3eb3147dafa4e3b31dbd6257e4d696bdc92
-         */
-        ch = strrchr(bf, '/');
-        if (!ch)
-                goto err;
-        if (ch - 3 < bf)
-                goto err;
-
-        free(id_name);
-        return strncmp(".ko", ch - 3, 3) == 0;
-err:
-        pr_err("Invalid build id: %s\n", id_name ? :
-                                         dso->long_name ? :
-                                         dso->short_name ? :
-                                         "[unknown]");
-        free(id_name);
-        return false;
-}
-
 #define dsos__for_each_with_build_id(pos, head) \
         list_for_each_entry(pos, head, node)    \
                 if (!pos->has_build_id)         \
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index 8a89b195c1fc..96690a55c62c 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -17,7 +17,6 @@ char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
                                     size_t size);
 
 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size);
-bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size);
 
 int build_id__mark_dso_hit(struct perf_tool *tool, union perf_event *event,
                            struct perf_sample *sample, struct perf_evsel *evsel,
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8f2b068ff756..e7a98dbd2aed 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1562,10 +1562,6 @@ int dso__load(struct dso *dso, struct map *map)
         if (!runtime_ss && syms_ss)
                 runtime_ss = syms_ss;
 
-        if (syms_ss && syms_ss->type == DSO_BINARY_TYPE__BUILD_ID_CACHE)
-                if (dso__build_id_is_kmod(dso, name, PATH_MAX))
-                        kmod = true;
-
         if (syms_ss)
                 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
         else