[binutils-gdb] Fix leak in record-full.c

[Philippe Waroquiers <philippe at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ec70d8db32462176e7da60d28b0c1978fc6b70d3

commit ec70d8db32462176e7da60d28b0c1978fc6b70d3
Author: Philippe Waroquiers <philippe.waroquiers@skynet.be>
Date:   Tue Jan 1 14:12:30 2019 +0100

    Fix leak in record-full.c
    
    valgrind detects leaks in several gdb.reverse tests,
    such as the below in gdb.reverse/watch-precsave.exp.
    
    Fix the leak by rewriting the loop that frees
    record_full_core_buf_list.
    
    gdb/ChangeLog
    2019-01-01  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
    
    	* record-full.c (record_full_base_target::close): Rewrite
    	record_full_core_buf_list free logic.
    
    ==18847== VALGRIND_GDB_ERROR_BEGIN
    ==18847== 4,120 (24 direct, 4,096 indirect) bytes in 1 blocks are definitely lost in loss record 3,094 of 3,199
    ==18847==    at 0x4C2BE6D: malloc (vg_replace_malloc.c:309)
    ==18847==    by 0x405097: xmalloc (common-utils.c:44)
    ==18847==    by 0x5AF8EA: xnew<record_full_core_buf_entry> (poison.h:110)
    ==18847==    by 0x5AF8EA: record_full_core_target::xfer_partial(target_object, char const*, unsigned char*, unsigned char const*, unsigned long, unsigned long, unsigned long*) (record-full.c:2182)
    ==18847==    by 0x64677D: raw_memory_xfer_partial(target_ops*, unsigned char*, unsigned char const*, unsigned long, long, unsigned long*) (target.c:956)
    ==18847==    by 0x64691E: memory_xfer_partial_1(target_ops*, target_object, unsigned char*, unsigned char const*, unsigned long, unsigned long, unsigned long*) (target.c:1086)

Diff:
---
 gdb/ChangeLog     |  5 +++++
 gdb/record-full.c | 12 ++++--------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2402d73..a2d3601 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2019-01-01  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
 
+	* record-full.c (record_full_base_target::close): Rewrite
+	record_full_core_buf_list free logic.
+
+2019-01-01  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
 	* break-catch-syscall.c (print_one_catch_syscall): xfree
 	the last text.
 
diff --git a/gdb/record-full.c b/gdb/record-full.c
index 2b918ea..8738512 100644
--- a/gdb/record-full.c
+++ b/gdb/record-full.c
@@ -1014,15 +1014,11 @@ record_full_base_target::close ()
     }
 
   /* Release record_full_core_buf_list.  */
-  if (record_full_core_buf_list)
+  while (record_full_core_buf_list)
     {
-      for (entry = record_full_core_buf_list->prev; entry;
-	   entry = entry->prev)
-	{
-	  xfree (record_full_core_buf_list);
-	  record_full_core_buf_list = entry;
-	}
-      record_full_core_buf_list = NULL;
+      entry = record_full_core_buf_list;
+      record_full_core_buf_list = record_full_core_buf_list->prev;
+      xfree (entry);
     }
 
   if (record_full_async_inferior_event_token)