[binutils-gdb] Fix lrealpath memory leak in build_id_to_debug_bfd

[Keith Seitz <kseitz at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=32fad71f9e6cdf73fe3c10123b23f42397b83e7d

commit 32fad71f9e6cdf73fe3c10123b23f42397b83e7d
Author: Keith Seitz <keiths@redhat.com>
Date:   Thu Jun 4 10:13:50 2015 -0700

    Fix lrealpath memory leak in build_id_to_debug_bfd
    
    Valgrind reports memory leaking from build_id_to_debug_bfd:
    ==7261== 88 bytes in 2 blocks are definitely lost in loss record 31,319 of 35,132
    ==7261==    at 0x4A06BCF: malloc (vg_replace_malloc.c:296)
    ==7261==    by 0x32CA88A9B9: strdup (strdup.c:42)
    ==7261==    by 0xFE62AB: lrealpath (lrealpath.c:88)
    ==7261==    by 0x7F7AD6: build_id_to_debug_bfd (build-id.c:116)
    ==7261==    by 0x7F7BB5: find_separate_debug_file_by_buildid (build-id.c:149)
    ==7261==    by 0x6D9382: elf_symfile_read (elfread.c:1348)
    ==7261==    by 0x777F02: read_symbols (symfile.c:875)
    ==7261==    by 0x778505: syms_from_objfile_1 (symfile.c:1078)
    ==7261==    by 0x778548: syms_from_objfile (symfile.c:1094)
    ==7261==    by 0x778746: symbol_file_add_with_addrs (symfile.c:1191)
    ==7261==    by 0x77893B: symbol_file_add_from_bfd (symfile.c:1280)
    ==7261==    by 0x8E51E3: solib_read_symbols (solib.c:706)
    ==7261==    by 0x8E58AF: solib_add (solib.c:1029)
    
    This occurs because commit 1be5090b in bfd, addressing PR 11983, started
    taking a copy of the input filename instead of directly caching it.  It
    appears that this code was never updated to reflect that API change.
    
    This simple patch creates a cleanup to free the return value for lrealpath.
    
    gdb/ChangeLog
    
    	* build-id.c (build_id_to_debug_bfd): Add cleanup to free
    	return value from lrealpath.

Diff:
---
 gdb/ChangeLog  | 5 +++++
 gdb/build-id.c | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 19144ed..a52624b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-24  Keith Seitz  <keiths@redhat.com>
+
+	* build-id.c (build_id_to_debug_bfd): Add cleanup to free
+	return value from lrealpath.
+
 2015-06-24  Mike Frysinger  <vapier@gentoo.org>
 
 	* remote-sim.c (gdbsim_open): Move sysroot update to the top.
diff --git a/gdb/build-id.c b/gdb/build-id.c
index ebf9f45..c89cd55 100644
--- a/gdb/build-id.c
+++ b/gdb/build-id.c
@@ -93,6 +93,7 @@ build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
       size_t size = build_id_len;
       char *s;
       char *filename = NULL;
+      struct cleanup *inner;
 
       memcpy (link, debugdir, debugdir_len);
       s = &link[debugdir_len];
@@ -116,7 +117,10 @@ build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
 	continue;
 
       /* We expect to be silent on the non-existing files.  */
+      inner = make_cleanup (xfree, filename);
       abfd = gdb_bfd_open (filename, gnutarget, -1);
+      do_cleanups (inner);
+
       if (abfd == NULL)
 	continue;