on 2024/1/8 19:44, Richard Biener wrote:
> On Mon, Jan 8, 2024 at 3:35 AM Kewen.Lin <li...@linux.ibm.com> wrote:
>>
>> Hi,
>>
>> As PR113100 shows, the unbiasing introduced by r14-6737 can
>> cause the scrubbing to overrun and screw some critical data
>> on stack like saved toc base consequently cause segfault on
>> Power.
>>
>> By checking PR112917, IMHO we should keep this unbiasing
>> guarded under SPARC_STACK_BOUNDARY_HACK (TARGET_ARCH64 &&
>> TARGET_STACK_BIAS), similar to some existing code special
>> treating SPARC stack bias.
>>
>> Bootstrapped and regtested on x86_64-redhat-linux and
>> powerpc64{,le}-linux-gnu. All reported failures in
>> PR113100 are gone. I also expect the culprit commit can
>> affect those ports with nonzero STACK_POINTER_OFFSET.
>>
>> Is it ok for trunk?
>
> OK
Thanks! Pushed as r14-7089.
BR,
Kewen
>
>> BR,
>> Kewen
>> -----
>> PR middle-end/113100
>>
>> gcc/ChangeLog:
>>
>> * builtins.cc (expand_builtin_stack_address): Guard stack point
>> adjustment with SPARC_STACK_BOUNDARY_HACK.
>> ---
>> gcc/builtins.cc | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/gcc/builtins.cc b/gcc/builtins.cc
>> index 125ea158ebf..9bad1e962b4 100644
>> --- a/gcc/builtins.cc
>> +++ b/gcc/builtins.cc
>> @@ -5450,6 +5450,7 @@ expand_builtin_stack_address ()
>> rtx ret = convert_to_mode (ptr_mode, copy_to_reg (stack_pointer_rtx),
>> STACK_UNSIGNED);
>>
>> +#ifdef SPARC_STACK_BOUNDARY_HACK
>> /* Unbias the stack pointer, bringing it to the boundary between the
>> stack area claimed by the active function calling this builtin,
>> and stack ranges that could get clobbered if it called another
>> @@ -5476,7 +5477,9 @@ expand_builtin_stack_address ()
>> (caller) function's active area as well, whereas those pushed or
>> allocated temporarily for a call are regarded as part of the
>> callee's stack range, rather than the caller's. */
>> - ret = plus_constant (ptr_mode, ret, STACK_POINTER_OFFSET);
>> + if (SPARC_STACK_BOUNDARY_HACK)
>> + ret = plus_constant (ptr_mode, ret, STACK_POINTER_OFFSET);
>> +#endif
>>
>> return force_reg (ptr_mode, ret);
>> }
>> --
>> 2.39.3
