lkml.org 
[lkml]   [2021]   [Feb]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v4 20/23] powerpc/syscall: Do not check unsupported scv vector on PPC32
From
Date


Le 26/01/2021 à 11:16, Nicholas Piggin a écrit :
> Excerpts from Christophe Leroy's message of January 26, 2021 12:48 am:
>> Only PPC64 has scv. No need to check the 0x7ff0 trap on PPC32.
>>
>> And ignore the scv parameter in syscall_exit_prepare (Save 14 cycles
>> 346 => 332 cycles)
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>> arch/powerpc/kernel/entry_32.S | 1 -
>> arch/powerpc/kernel/syscall.c | 7 +++++--
>> 2 files changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
>> index 9922a04650f7..6ae9c7bcb06c 100644
>> --- a/arch/powerpc/kernel/entry_32.S
>> +++ b/arch/powerpc/kernel/entry_32.S
>> @@ -343,7 +343,6 @@ transfer_to_syscall:
>>
>> ret_from_syscall:
>> addi r4,r1,STACK_FRAME_OVERHEAD
>> - li r5,0
>> bl syscall_exit_prepare
>> #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
>> /* If the process has its own DBCR0 value, load it up. The internal
>> diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
>> index 476909b11051..30f8a397a522 100644
>> --- a/arch/powerpc/kernel/syscall.c
>> +++ b/arch/powerpc/kernel/syscall.c
>> @@ -86,7 +86,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
>> local_irq_enable();
>>
>> if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) {
>> - if (unlikely(regs->trap == 0x7ff0)) {
>> + if (IS_ENABLED(CONFIG_PPC64) && unlikely(regs->trap == 0x7ff0)) {
>> /* Unsupported scv vector */
>> _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
>> return regs->gpr[3];
>> @@ -109,7 +109,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
>> r8 = regs->gpr[8];
>>
>> } else if (unlikely(r0 >= NR_syscalls)) {
>> - if (unlikely(regs->trap == 0x7ff0)) {
>> + if (IS_ENABLED(CONFIG_PPC64) && unlikely(regs->trap == 0x7ff0)) {
>
> Perhaps this could be hidden behind a function like trap_is_scv()?
>
> trap_is_unsupported_scv() ?
>

Ok, I did that in v5

Thanks
Christophe

\
 
 \ /
  Last update: 2021-02-08 21:04    [W:0.055 / U:1.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site