From: Ivan Maidanski <ivmai@mail.ru>
Date: Wed, 7 Dec 2016 08:02:59 +0000 (+0300)
Subject: Fix 'bogus LR' detection in FindTopOfStack (Darwin)
X-Git-Tag: v7.6.2~294
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9fcf315df54fdce8177219965b10f0eb811e3a9c;p=gc

Fix 'bogus LR' detection in FindTopOfStack (Darwin)
(fix commit 5742f86)

* darwin_stop_world.c [!DARWIN_DONT_PARSE_STACK] (GC_FindTopOfStack):
Use "UL" suffix (instead of "U") for 0x3 (on the right side of the
comparison) to avoid implicit unsigned int-to-long value extension
of "~" operator result.
---

diff --git a/darwin_stop_world.c b/darwin_stop_world.c
index 7cd5775f..37aee97d 100644
--- a/darwin_stop_world.c
+++ b/darwin_stop_world.c
@@ -83,7 +83,7 @@ GC_INNER ptr_t GC_FindTopOfStack(unsigned long stack_start)
     /* we do these next two checks after going to the next frame
        because the LR for the first stack frame in the loop
        is not set up on purpose, so we shouldn't check it. */
-    if ((frame->savedLR & ~0x3) == 0 || (frame->savedLR & ~0x3) == ~0x3U)
+    if ((frame->savedLR & ~0x3) == 0 || (frame->savedLR & ~0x3) == ~0x3UL)
       break; /* if the next LR is bogus, stop */
   }
 # ifdef DEBUG_THREADS_EXTRA