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[PATCH] Remove more instances of unsafe alloca
- From: Siddhesh Poyarekar <siddhesh at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Mon, 23 Jul 2012 18:11:16 +0530
- Subject: [PATCH] Remove more instances of unsafe alloca
Hi,
I found another couple of instances of unsafe alloca usage in gdb, both
to do with trying to allocate memory on stack for a baseclass type. The
fix is on the lines of what was done in the following changeset:
http://sourceware.org/ml/gdb-cvs/2012-07/msg00044.html
I have verified that the fix does not cause any regressions on x86_64.
OK to commit?
Regards,
Siddhesh
gdb/ChangeLog:
2012-07-23 Siddhesh Poyarekar <siddhesh@redhat.com>
* p-valprint.c (pascal_object_print_value): Replace potentially
unsafe alloca with xmalloc/xfree.
* valops.c (search_struct_method): Likewise.
? alloca-cleanup.patch
Index: gdb/p-valprint.c
===================================================================
RCS file: /cvs/src/src/gdb/p-valprint.c,v
retrieving revision 1.100
diff -u -r1.100 p-valprint.c
--- gdb/p-valprint.c 18 May 2012 21:02:49 -0000 1.100
+++ gdb/p-valprint.c 23 Jul 2012 12:34:37 -0000
@@ -797,8 +797,11 @@
if (boffset < 0 || boffset >= TYPE_LENGTH (type))
{
- /* FIXME (alloc): not safe is baseclass is really really big. */
- gdb_byte *buf = alloca (TYPE_LENGTH (baseclass));
+ gdb_byte *buf;
+ struct cleanup *back_to;
+
+ buf = xmalloc (TYPE_LENGTH (baseclass));
+ back_to = make_cleanup (xfree, buf);
base_valaddr = buf;
if (target_read_memory (address + boffset, buf,
@@ -807,6 +810,7 @@
address = address + boffset;
thisoffset = 0;
boffset = 0;
+ do_cleanups (back_to);
}
else
base_valaddr = valaddr;
Index: gdb/valops.c
===================================================================
RCS file: /cvs/src/src/gdb/valops.c,v
retrieving revision 1.297
diff -u -r1.297 valops.c
--- gdb/valops.c 24 Jun 2012 07:28:10 -0000 1.297
+++ gdb/valops.c 23 Jul 2012 12:34:40 -0000
@@ -2281,8 +2281,13 @@
if (offset < 0 || offset >= TYPE_LENGTH (type))
{
- gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
- CORE_ADDR address = value_address (*arg1p);
+ gdb_byte *tmp;
+ struct cleanup *back_to;
+ CORE_ADDR address;
+
+ tmp = xmalloc (TYPE_LENGTH (baseclass));
+ back_to = make_cleanup (xfree, tmp);
+ address = value_address (*arg1p);
if (target_read_memory (address + offset,
tmp, TYPE_LENGTH (baseclass)) != 0)
@@ -2293,6 +2298,7 @@
address + offset);
base_valaddr = value_contents_for_printing (base_val);
this_offset = 0;
+ do_cleanups (back_to);
}
else
{