!199 mtrace: use a static buffer for printing, fix upstream bug BZ #25947

From: @liqingqing_1229
Reviewed-by: @wangbin224
Signed-off-by: @wangbin224

glibc.spec

@@ -63,7 +63,7 @@
 ##############################################################################
 Name: 	 	glibc
 Version: 	2.34
-Release: 	6
+Release: 	7
 Summary: 	The GNU libc libraries
 License:	%{all_license}
 URL: 		http://www.gnu.org/software/glibc/
@@ -97,6 +97,7 @@ Patch16: 4-5-AArch64-Improve-A64FX-memset-by-removing-unroll3.patch
 Patch17: 5-5-AArch64-Improve-A64FX-memset-medium-loops.patch
 Patch18: elf-Unconditionally-use-__ehdr_start.patch
 Patch19: aarch64-Make-elf_machine_-load_address-dynamic-robus.patch
+Patch20: mtrace-Use-a-static-buffer-for-printing-BZ-25947.patch
 
 #Patch9000: turn-REP_STOSB_THRESHOLD-from-2k-to-1M.patch
 Patch9001: delete-no-hard-link-to-avoid-all_language-package-to.patch 
@@ -1188,6 +1189,10 @@ fi
 %doc hesiod/README.hesiod
 
 %changelog
+* Mon Sep 27 2021 Qingqing Li<liqingqing3@huawei.com> - 2.34-7
+- mtrace: use a static buffer for printing, fix memory leak.
+  upstream link: https://sourceware.org/bugzilla/show_bug.cgi?id=25947
+
 * Sun Sep 26 2021 Qingqing Li<liqingqing3@huawei.com> - 2.34-6
 - elf: Unconditionally use __ehdr_start.
 - aarch64: Make elf_machine_{load_addr,dynamic} robust [BZ #28203].

mtrace-Use-a-static-buffer-for-printing-BZ-25947.patch

@@ -0,0 +1,61 @@
+From dc906e94f7033892dadbd91718349f19e1376391 Mon Sep 17 00:00:00 2001
+From: Siddhesh Poyarekar <siddhesh@sourceware.org>
+Date: Thu, 12 Aug 2021 06:38:15 +0530
+Subject: [PATCH] mtrace: Use a static buffer for printing [BZ #25947]
+
+Use a static buffer for mtrace printing now that it no longer adds to
+default libc footprint.
+
+Reviewed-by: DJ Delorie <dj@redhat.com>
+---
+ malloc/mtrace-impl.c | 14 +++-----------
+ 1 file changed, 3 insertions(+), 11 deletions(-)
+
+diff --git a/malloc/mtrace-impl.c b/malloc/mtrace-impl.c
+index 0e10ab7..83008ca 100644
+--- a/malloc/mtrace-impl.c
++++ b/malloc/mtrace-impl.c
+@@ -34,11 +34,8 @@
+ 
+ #include <kernel-features.h>
+ 
+-#define TRACE_BUFFER_SIZE 512
+-
+ static FILE *mallstream;
+ static const char mallenv[] = "MALLOC_TRACE";
+-static char *malloc_trace_buffer;
+ 
+ static void
+ tr_where (const void *caller, Dl_info *info)
+@@ -184,16 +181,13 @@ do_mtrace (void)
+   mallfile = secure_getenv (mallenv);
+   if (mallfile != NULL)
+     {
+-      char *mtb = malloc (TRACE_BUFFER_SIZE);
+-      if (mtb == NULL)
+-        return;
+-
+       mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "wce");
+       if (mallstream != NULL)
+         {
+           /* Be sure it doesn't malloc its buffer!  */
+-          malloc_trace_buffer = mtb;
+-          setvbuf (mallstream, malloc_trace_buffer, _IOFBF, TRACE_BUFFER_SIZE);
++	  static char tracebuf [512];
++
++	  setvbuf (mallstream, tracebuf, _IOFBF, sizeof (tracebuf));
+           fprintf (mallstream, "= Start\n");
+           if (!added_atexit_handler)
+             {
+@@ -203,8 +197,6 @@ do_mtrace (void)
+             }
+ 	  __malloc_debug_enable (MALLOC_MTRACE_HOOK);
+         }
+-      else
+-        free (mtb);
+     }
+ }
+ 
+-- 
+1.8.3.1
+