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[PATCH] Ensure entries pid_map are initialized to NULL
- From: Neil Vachharajani <nvachhar at google dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: ian at airs dot com, Xinliang David Li <davidxl at google dot com>, Diego Novillo <dnovillo at google dot com>
- Date: Wed, 5 Aug 2009 10:59:06 -0700
- Subject: [PATCH] Ensure entries pid_map are initialized to NULL
gimple_ic_transform calls find_func_by_pid and compares the resulting
cgraph_node* to NULL.? This cgraph_node* comes from pid_map.? When
pid_map is created in init_pid_map, the memory is xmalloc'ed (i.e., is
uninitialized) and only certain entries are explicitly set in the
subsequent loop. Consequently, if gimple_ic_transform calls
find_func_by_pid for a PID which was not explicitly set, it will get a
garbage value and not NULL. I have observed this resulting in an ICE
although I cannot reliably reproduce the problem. This patch
initializes pid_map by using xcalloc instead of xmalloc. While this
does not fix the root cause of the ICE (my analysis suggests that
gimple_ic_transform should not be querying uninitialized PIDs in the
map), this patch does make the code more robust to bad .gcda files.
Bootstrapped/regtested on x86_64-linux and i686-linux. Ok for trunk?
2009-08-04 Neil Vachharajani <nvachhar@google.com>
* value-prof.c (init_pid_map): Replace xmalloc with xcalloc.
--- gcc/value-prof.c.orig 2009-08-04 17:10:24.000000000 -0700
+++ gcc/value-prof.c 2009-08-04 16:41:00.021142462 -0700
@@ -1060,7 +1060,7 @@
return;
pid_map
- = (struct cgraph_node**) xmalloc (sizeof (struct cgraph_node*) *
cgraph_max_pid);
+ = (struct cgraph_node**) xcalloc (cgraph_max_pid, sizeof (struct
cgraph_node*));
for (n = cgraph_nodes; n; n = n->next)
{