* [PATCH] Fix PR82488 - signed integer overflow in expr.c
@ 2017-11-26 12:56 Markus Trippelsdorf
2017-11-27 8:22 ` Jeff Law
0 siblings, 1 reply; 2+ messages in thread
From: Markus Trippelsdorf @ 2017-11-26 12:56 UTC (permalink / raw)
To: gcc-patches
bootstrap-ubsan shows:
gcc/expr.c:4103:17: runtime error: signed integer overflow: 0 - -9223372036854775808 cannot be represented in type 'long int'
Fix by handling the saw_unknown case earlier.
bootstrap-ubsan on X86_64 and ppc64le. Tested on ppc64le.
OK for trunk?
PR rtl-optimization/82488
* expr.c (fixup_args_size_notes): Avoid signed integer overflow.
diff --git a/gcc/expr.c b/gcc/expr.c
index ee07de5aaa44..e9d8555c9452 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -4100,10 +4100,13 @@ fixup_args_size_notes (rtx_insn *prev, rtx_insn *last, int end_args_size)
if (STACK_GROWS_DOWNWARD)
this_delta = -(unsigned HOST_WIDE_INT) this_delta;
- args_size -= this_delta;
+ if (saw_unknown)
+ args_size = INT_MIN;
+ else
+ args_size -= this_delta;
}
- return saw_unknown ? INT_MIN : args_size;
+ return args_size;
}
#ifdef PUSH_ROUNDING
--
Markus
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] Fix PR82488 - signed integer overflow in expr.c
2017-11-26 12:56 [PATCH] Fix PR82488 - signed integer overflow in expr.c Markus Trippelsdorf
@ 2017-11-27 8:22 ` Jeff Law
0 siblings, 0 replies; 2+ messages in thread
From: Jeff Law @ 2017-11-27 8:22 UTC (permalink / raw)
To: Markus Trippelsdorf, gcc-patches
On 11/26/2017 02:12 AM, Markus Trippelsdorf wrote:
> bootstrap-ubsan shows:
> gcc/expr.c:4103:17: runtime error: signed integer overflow: 0 - -9223372036854775808 cannot be represented in type 'long int'
>
> Fix by handling the saw_unknown case earlier.
>
> bootstrap-ubsan on X86_64 and ppc64le. Tested on ppc64le.
>
> OK for trunk?
>
> PR rtl-optimization/82488
> * expr.c (fixup_args_size_notes): Avoid signed integer overflow.
OK.
jeff
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2017-11-26 12:56 [PATCH] Fix PR82488 - signed integer overflow in expr.c Markus Trippelsdorf
2017-11-27 8:22 ` Jeff Law
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