On Sat, Feb 24, 2018 at 02:13:34PM -1000, Joey Pabalinas wrote:
> The only fix I could find which didn't requiring substantial
> reimplementation of the memory management functions was to replace
> the malloc() call in calloc() with realloc() instead. With a NULL `p`
> argument realloc() behaves exactly the same as malloc() does, and
> (at least on my system) gcc doesn't seem to consider realloc() a
> candidate for sibling call optimizations; give this patch a try
> and _hopefully_ this is a viable solution.
On second thought, doing it this way is probably a *little* bit better; the
needless initialization of `r` to NULL is avoided, and it also makes the
purpose of using realloc() over malloc() a *tiny* bit more explicit:
Signed-off-by: Joey Pabalinas <joeypabalinas@xxxxxxxxx>
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/Src/mem.c b/Src/mem.c
index 840bbb6e4a4eb6fd73..f1208197b3ddac2139 100644
--- a/Src/mem.c
+++ b/Src/mem.c
@@ -1719,7 +1719,13 @@ calloc(MALLOC_ARG_T n, MALLOC_ARG_T size)
if (!(l = n * size))
return (MALLOC_RET_T) m_high;
- r = malloc(l);
+ /*
+ * use realloc() (with a NULL `p` argument it behaves exactly the same
+ * as malloc() does) to prevent an infinite loop caused by sibling-call
+ * optimizations (the malloc() call would otherwise be replaced by an
+ * unconditional branch back to line 1719 ad infinitum).
+ */
+ r = realloc(NULL, l);
memset(r, 0, l);
--
2.16.2
Attachment:
signature.asc
Description: PGP signature