[tip:perf/core] perf symbols: Do not read symbols/ data from device files

[tip-bot for Jiri Olsa <tipbot@zytor.com>]

Commit-ID:  403567217d3fa5d4801f820317ada52e5c5f0e53
Gitweb:     http://git.kernel.org/tip/403567217d3fa5d4801f820317ada52e5c5f0e53
Author:     Jiri Olsa <jolsa@kernel.org>
AuthorDate: Wed, 20 Jan 2016 12:56:32 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 26 Jan 2016 11:52:43 -0300

perf symbols: Do not read symbols/data from device files

With mem sampling we could get data source within mapped device file.
Processing such sample would block during report phase on trying to read
the device file.

Chacking for device files and skip the processing if it's detected.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1453290995-18485-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/dso.c    |  5 +++++
 tools/perf/util/symbol.c |  6 +++++-
 tools/perf/util/util.c   | 10 ++++++++++
 tools/perf/util/util.h   |  1 +
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index e8e9a9d..8e639543 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -52,6 +52,11 @@ int dso__read_binary_type_filename(const struct dso *dso,
 			debuglink--;
 		if (*debuglink == '/')
 			debuglink++;
+
+		ret = -1;
+		if (!is_regular_file(filename))
+			break;
+
 		ret = filename__read_debuglink(filename, debuglink,
 					       size - (debuglink - filename));
 		}
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index ab02209..90cedfa 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1466,7 +1466,8 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 	 * Read the build id if possible. This is required for
 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
 	 */
-	if (filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0)
+	if (is_regular_file(name) &&
+	    filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0)
 		dso__set_build_id(dso, build_id);
 
 	/*
@@ -1487,6 +1488,9 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 						   root_dir, name, PATH_MAX))
 			continue;
 
+		if (!is_regular_file(name))
+			continue;
+
 		/* Name is now the name of the next image to try */
 		if (symsrc__init(ss, dso, name, symtab_type) < 0)
 			continue;
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index ead9509..7a2da7e 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -691,3 +691,13 @@ out:
 
 	return tip;
 }
+
+bool is_regular_file(const char *file)
+{
+	struct stat st;
+
+	if (stat(file, &st))
+		return false;
+
+	return S_ISREG(st.st_mode);
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index fe915e6..61650f0 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -343,5 +343,6 @@ int fetch_kernel_version(unsigned int *puint,
 #define KVER_PARAM(x)	KVER_VERSION(x), KVER_PATCHLEVEL(x), KVER_SUBLEVEL(x)
 
 const char *perf_tip(const char *dirpath);
+bool is_regular_file(const char *file);
 
 #endif /* GIT_COMPAT_UTIL_H */