From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 28 Jul 2011 17:05:33 +0000 (-0700)
Subject: * alloc.c (memory_full) [!SYNC_INPUT]: Fix signal-related race.
X-Git-Tag: emacs-pretest-24.0.90~104^2~157^2~14
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=66606eea1f69d1b35dfc006c2901f2c7ca08d487;p=emacs.git

* alloc.c (memory_full) [!SYNC_INPUT]: Fix signal-related race.

Without this fix, if a signal arrives just after memory fills up,
'malloc' might be invoked reentrantly.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 045c4311789..eef9cede561 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2011-07-28  Paul Eggert  <eggert@cs.ucla.edu>
 
+	* alloc.c (memory_full) [!SYNC_INPUT]: Fix signal-related race.
+	Without this fix, if a signal arrives just after memory fills up,
+	'malloc' might be invoked reentrantly.
+
 	* image.c (x_check_image_size) [!HAVE_X_WINDOWS]: Return 1.
 	In other words, assume that every image size is allowed, on non-X
 	hosts.  This assumption is probably wrong, but it lets Emacs compile.
diff --git a/src/alloc.c b/src/alloc.c
index eb0185a8e35..b96fc1f0642 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -3282,12 +3282,16 @@ memory_full (size_t nbytes)
   int enough_free_memory = 0;
   if (SPARE_MEMORY < nbytes)
     {
-      void *p = malloc (SPARE_MEMORY);
+      void *p;
+
+      MALLOC_BLOCK_INPUT;
+      p = malloc (SPARE_MEMORY);
       if (p)
 	{
 	  free (p);
 	  enough_free_memory = 1;
 	}
+      MALLOC_UNBLOCK_INPUT;
     }
 
   if (! enough_free_memory)