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perf-tools: fix perf-buildid-cache when passing a symbolic link

PATCH In review Franck Bui-Huu 2 participants 2 messages Dec 10, 2010 – Dec 22, 2010 perf events

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Franck Bui-Huu

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PATCH 1/1 perf-tools: fix perf-buildid-cache when passing a symbolic link

From: Franck Bui-Huu <[email protected]>

This was broken since link(2) doesn't dereference symbolic links. Instead 'filename' becomes a symbolic link to the same file that 'name' refers to.

This had the bad effect to create dangling symlinks in the case that even can't be removed with perf-buildid-cache(1).

Signed-off-by Franck Bui-Huu <[email protected]>
---
 tools/perf/util/header.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
tools/perf/util/header.c +6 -4
index 64a85ba..7cba055 100644
@@ -265,15 +265,16 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 			  const char *name, bool is_kallsyms)
 {
 	const size_t size = PATH_MAX;
-	char *filename = malloc(size),
+	char *realname = realpath(name, NULL),
+	     *filename = malloc(size),
 	     *linkname = malloc(size), *targetname;
 	int len, err = -1;
 
-	if (filename == NULL || linkname == NULL)
+	if (realname == NULL || filename == NULL || linkname == NULL)
 		goto out_free;
 
 	len = snprintf(filename, size, "%s%s%s",
-		       debugdir, is_kallsyms ? "/" : "", name);
+		       debugdir, is_kallsyms ? "/" : "", realname);
 	if (mkdir_p(filename, 0755))
 		goto out_free;
 

@@ -283,7 +284,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 		if (is_kallsyms) {
 			 if (copyfile("/proc/kallsyms", filename))
 				goto out_free;
-		} else if (link(name, filename) && copyfile(name, filename))
+		} else if (link(realname, filename) && copyfile(name, filename))
 			goto out_free;
 	}
 

@@ -300,6 +301,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 	if (symlink(targetname, linkname) == 0)
 		err = 0;
 out_free:
+	free(realname);
 	free(filename);
 	free(linkname);
 	return err;
Signature · 1 line
1.7.3.2
#1 lore raw

[tip:perf/urgent] perf buildid-cache: Fix symbolic link handling

Commit-ID:  68a7a771ad0e2959983729bf88cbc74a7014438f
Gitweb:     http://git.kernel.org/tip/68a7a771ad0e2959983729bf88cbc74a7014438f
Author:     Franck Bui-Huu <[email protected]>
AuthorDate: Fri, 10 Dec 2010 22:06:26 +0100
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 16 Dec 2010 09:41:45 -0200

perf buildid-cache: Fix symbolic link handling

This was broken since link(2) doesn't dereference symbolic links. Instead 'filename' becomes a symbolic link to the same file that 'name' refers to.

This had the bad effect to create dangling symlinks in the case that even can't be removed with perf-buildid-cache(1).

LKML-Reference: <[email protected]>

Signed-off-by Franck Bui-Huu <[email protected]>
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/header.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
tools/perf/util/header.c +6 -4
index 64a85ba..7cba055 100644
@@ -265,15 +265,16 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 			  const char *name, bool is_kallsyms)
 {
 	const size_t size = PATH_MAX;
-	char *filename = malloc(size),
+	char *realname = realpath(name, NULL),
+	     *filename = malloc(size),
 	     *linkname = malloc(size), *targetname;
 	int len, err = -1;
 
-	if (filename == NULL || linkname == NULL)
+	if (realname == NULL || filename == NULL || linkname == NULL)
 		goto out_free;
 
 	len = snprintf(filename, size, "%s%s%s",
-		       debugdir, is_kallsyms ? "/" : "", name);
+		       debugdir, is_kallsyms ? "/" : "", realname);
 	if (mkdir_p(filename, 0755))
 		goto out_free;
 

@@ -283,7 +284,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 		if (is_kallsyms) {
 			 if (copyfile("/proc/kallsyms", filename))
 				goto out_free;
-		} else if (link(name, filename) && copyfile(name, filename))
+		} else if (link(realname, filename) && copyfile(name, filename))
 			goto out_free;
 	}
 

@@ -300,6 +301,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 	if (symlink(targetname, linkname) == 0)
 		err = 0;
 out_free:
+	free(realname);
 	free(filename);
 	free(linkname);
 	return err;