[PATCH 1/3] perf core: Fix a mmap and munmap mismatched bug

[PATCH 1/3] perf core: Fix a mmap and munmap mismatched bug

[Chenggang Qin]

From: root <root@core097011.sqa.cm4>

In function filename__read_debuglink(), while the ELF file is opend and mmapped
in elf_begin(), but if this file is considered to not be usable during the
following code, we will goto the close(fd) directly. The elf_end() is skipped.
So, the mmaped ELF file cannot be munmapped. The memory areas are mmapped is
exist during the life of perf. This is a memory leak.
This patch fixed this bug.
Thanks.

Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Yanmin Zhang <yanmin.zhang@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>

---
 tools/perf/util/symbol-elf.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 4b12bf8..b4df870 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -471,27 +471,27 @@ int filename__read_debuglink(const char *filename, char *debuglink,
 
 	ek = elf_kind(elf);
 	if (ek != ELF_K_ELF)
-		goto out_close;
+		goto out_elf_end;
 
 	if (gelf_getehdr(elf, &ehdr) == NULL) {
 		pr_err("%s: cannot get elf header.\n", __func__);
-		goto out_close;
+		goto out_elf_end;
 	}
 
 	sec = elf_section_by_name(elf, &ehdr, &shdr,
 				  ".gnu_debuglink", NULL);
 	if (sec == NULL)
-		goto out_close;
+		goto out_elf_end;
 
 	data = elf_getdata(sec, NULL);
 	if (data == NULL)
-		goto out_close;
+		goto out_elf_end;
 
 	/* the start of this section is a zero-terminated string */
 	strncpy(debuglink, data->d_buf, size);
 
+out_elf_end:
 	elf_end(elf);
-
 out_close:
 	close(fd);
 out:
-- 
1.7.8.rc2.5.g815b

[PATCH 2/3] perf core: Fix a mmap & munmap mismatches bug in dso__load

[Chenggang Qin]

From: Chenggang Qin <chenggang.qcg@taobao.com>

Some dsos' symsrc is neither syms_ss or runtime_ss. In this situation, the
corresponding ELF file is opened and mmapped in symsrc__init(), but they will
be not closed and munmapped in any place.
This bug can lead to mmap & munmap mismatched, the mmap areas will exist during
the life of perf. We can think this is a memory leak.
This patch fixed the bug. symsrc__destroy() is called while the opened and
mmaped ELF file has neither symtlb section nor dynsym section, and opdsec
section.
Thanks.

Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Yanmin Zhang <yanmin.zhang@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>

---
 tools/perf/util/symbol.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index d5528e1..9675866 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -828,7 +828,8 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 
 			if (syms_ss && runtime_ss)
 				break;
-		}
+		} else
+			symsrc__destroy(ss);
 
 	}
 
-- 
1.7.8.rc2.5.g815b

[PATCH 3/3] perf core: Fix a memory leak bug because symbol__delete is ignored

[Chenggang Qin]

From: Chenggang Qin <chenggang.qcg@taobao.com>

In function symbols__fixup_duplicate(), while the duplicated symbols are found,
only the rb_node are deleted. The symbol structures themself are ignored.
Then, these memory areas are lost.
This patch fixed the bug. 
Thanks.

Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Yanmin Zhang <yanmin.zhang@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>

---
 tools/perf/util/symbol.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 9675866..3c9aa6f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -148,10 +148,12 @@ again:
 
 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
 			rb_erase(&next->rb_node, symbols);
+			symbol__delete(next);
 			goto again;
 		} else {
 			nd = rb_next(&curr->rb_node);
 			rb_erase(&curr->rb_node, symbols);
+			symbol__delete(curr);
 		}
 	}
 }
-- 
1.7.8.rc2.5.g815b

[tip:perf/core] perf symbols: Fix a memory leak due to symbol__delete not being used

[tip-bot for Chenggang Qin]

Commit-ID:  d4f74eb89199dc7bde5579783e9188841e1271e3
Gitweb:     http://git.kernel.org/tip/d4f74eb89199dc7bde5579783e9188841e1271e3
Author:     Chenggang Qin <chenggang.qcg@taobao.com>
AuthorDate: Fri, 11 Oct 2013 08:27:59 +0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 14 Oct 2013 12:21:20 -0300

perf symbols: Fix a memory leak due to symbol__delete not being used

In function symbols__fixup_duplicate(), while duplicated symbols are
found, only the rb_node is removed from the tree. The symbol structures
themself are ignored.  Then, these memory areas are lost.

Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Yanmin Zhang <yanmin.zhang@intel.com>
Link: http://lkml.kernel.org/r/1381451279-4109-3-git-send-email-chenggang.qin@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/symbol.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index b66c1ee..c0c3696 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -160,10 +160,12 @@ again:
 
 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
 			rb_erase(&next->rb_node, symbols);
+			symbol__delete(next);
 			goto again;
 		} else {
 			nd = rb_next(&curr->rb_node);
 			rb_erase(&curr->rb_node, symbols);
+			symbol__delete(curr);
 		}
 	}
 }

Re: [PATCH 1/3] perf core: Fix a mmap and munmap mismatched bug

[Arnaldo Carvalho de Melo]

Please use "perf tools: " as the prefix, I was assuming that "perf core:
" was related to the kernel code and was skipping those patches.

I'll fix up the prefix to use the standard used for the various files in
tools/perf, "perf symbols: " for this patch, for instance.

Applied this one and I'm checking the other patches from you, thanks,

- Arnaldo

[tip:perf/core] perf symbols: Fix a mmap and munmap mismatched bug

[tip-bot for Chenggang Qin]

Commit-ID:  784f3390f9bd900adfb3b0373615e105a0d9749a
Gitweb:     http://git.kernel.org/tip/784f3390f9bd900adfb3b0373615e105a0d9749a
Author:     Chenggang Qin <chenggang.qcg@taobao.com>
AuthorDate: Fri, 11 Oct 2013 08:27:57 +0800
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 14 Oct 2013 12:21:23 -0300

perf symbols: Fix a mmap and munmap mismatched bug

In function filename__read_debuglink(), while the ELF file is opend and
mmapped in elf_begin(), but if this file is considered to not be usable
during the following code, we will goto the close(fd) directly. The
elf_end() is skipped.  So, the mmaped ELF file cannot be munmapped. The
mmapped areas exist during the life of perf.

This is a memory leak.  This patch fixed this bug.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Chenggang Qin <chenggang.qcg@taobao.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Yanmin Zhang <yanmin.zhang@intel.com>
Link: http://lkml.kernel.org/r/1381451279-4109-1-git-send-email-chenggang.qin@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/symbol-elf.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index d6b8af3..eed0b96 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -487,27 +487,27 @@ int filename__read_debuglink(const char *filename, char *debuglink,
 
 	ek = elf_kind(elf);
 	if (ek != ELF_K_ELF)
-		goto out_close;
+		goto out_elf_end;
 
 	if (gelf_getehdr(elf, &ehdr) == NULL) {
 		pr_err("%s: cannot get elf header.\n", __func__);
-		goto out_close;
+		goto out_elf_end;
 	}
 
 	sec = elf_section_by_name(elf, &ehdr, &shdr,
 				  ".gnu_debuglink", NULL);
 	if (sec == NULL)
-		goto out_close;
+		goto out_elf_end;
 
 	data = elf_getdata(sec, NULL);
 	if (data == NULL)
-		goto out_close;
+		goto out_elf_end;
 
 	/* the start of this section is a zero-terminated string */
 	strncpy(debuglink, data->d_buf, size);
 
+out_elf_end:
 	elf_end(elf);
-
 out_close:
 	close(fd);
 out:

[PATCH 1/3] perf core: Fix a mmap and munmap mismatched bug

[Chenggang Qin]

From: root <root@core097011.sqa.cm4>

In function filename__read_debuglink(), while the ELF file is opend and mmapped
in elf_begin(), but if this file is considered to not be usable during the
following code, we will goto the close(fd) directly. The elf_end() is skipped.
So, the mmaped ELF file cannot be munmapped. The memory areas are mmapped is
exist during the life of perf. This is a memory leak.
This patch fixed this bug.
Thanks.

Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Yanmin Zhang <yanmin.zhang@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com>

---
 tools/perf/util/symbol-elf.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 4b12bf8..b4df870 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -471,27 +471,27 @@ int filename__read_debuglink(const char *filename, char *debuglink,
 
 	ek = elf_kind(elf);
 	if (ek != ELF_K_ELF)
-		goto out_close;
+		goto out_elf_end;
 
 	if (gelf_getehdr(elf, &ehdr) == NULL) {
 		pr_err("%s: cannot get elf header.\n", __func__);
-		goto out_close;
+		goto out_elf_end;
 	}
 
 	sec = elf_section_by_name(elf, &ehdr, &shdr,
 				  ".gnu_debuglink", NULL);
 	if (sec == NULL)
-		goto out_close;
+		goto out_elf_end;
 
 	data = elf_getdata(sec, NULL);
 	if (data == NULL)
-		goto out_close;
+		goto out_elf_end;
 
 	/* the start of this section is a zero-terminated string */
 	strncpy(debuglink, data->d_buf, size);
 
+out_elf_end:
 	elf_end(elf);
-
 out_close:
 	close(fd);
 out:
-- 
1.7.8.rc2.5.g815b

Re: [PATCH 1/3] perf core: Fix a mmap and munmap mismatched bug

[Namhyung Kim]

Hi Chenggang,

On Sun,  1 Sep 2013 23:29:43 +0800, Chenggang Qin wrote:
> From: root <root@core097011.sqa.cm4>
>
> In function filename__read_debuglink(), while the ELF file is opend and mmapped
> in elf_begin(), but if this file is considered to not be usable during the
> following code, we will goto the close(fd) directly. The elf_end() is skipped.
> So, the mmaped ELF file cannot be munmapped. The memory areas are mmapped is
> exist during the life of perf. This is a memory leak.
> This patch fixed this bug.
> Thanks.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung