From 4729d7726bdc86c46aeb525270909b73490ce206 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Mon, 9 Mar 2015 23:40:58 +0000
Subject: [PATCH] re PR go/65349 (go tool crashes, can't compile go code on
32bit linux systems)
PR go/65349
runtime: Don't call malloc from __go_file_line callback.
When crashing, we call runtime_printcreatedby which calls
__go_file_line which used to call the Go malloc. If we are
crashing due to a signal due to heap corruption of some sort,
the GO malloc lock might already be held, leading to a crash
within a crash. Avoid that by assuming that the libbacktrace
strings will stick around, as we already do in go-callers.c.
From-SVN: r221291
---
libgo/runtime/go-caller.c | 36 ++++++------------------------------
1 file changed, 6 insertions(+), 30 deletions(-)
diff --git a/libgo/runtime/go-caller.c b/libgo/runtime/go-caller.c
index 7fcdf2021d39..ad151ecea8ea 100644
--- a/libgo/runtime/go-caller.c
+++ b/libgo/runtime/go-caller.c
@@ -37,36 +37,12 @@ callback (void *data, uintptr_t pc __attribute__ ((unused)),
{
struct caller *c = (struct caller *) data;
- if (function == NULL)
- {
- c->fn.str = NULL;
- c->fn.len = 0;
- }
- else
- {
- byte *s;
-
- c->fn.len = __builtin_strlen (function);
- s = runtime_malloc (c->fn.len);
- __builtin_memcpy (s, function, c->fn.len);
- c->fn.str = s;
- }
-
- if (filename == NULL)
- {
- c->file.str = NULL;
- c->file.len = 0;
- }
- else
- {
- byte *s;
-
- c->file.len = __builtin_strlen (filename);
- s = runtime_malloc (c->file.len);
- __builtin_memcpy (s, filename, c->file.len);
- c->file.str = s;
- }
-
+ /* The libbacktrace library says that these strings might disappear,
+ but with the current implementation they won't. We can't easily
+ allocate memory here, so for now assume that we can save a
+ pointer to the strings. */
+ c->fn = runtime_gostringnocopy ((const byte *) function);
+ c->file = runtime_gostringnocopy ((const byte *) filename);
c->line = lineno;
return 0;