On 2024/10/29 22:37, Mark Rutland wrote:
> On Fri, Oct 25, 2024 at 06:06:45PM +0800, Jinjie Ruan wrote:
>> The __enter_from_kernel_mode() is only called by enter_from_kernel_mode(),
>> remove it.
>
> The point of this split is to cleanly separate the raw entry logic (in
> __enter_from_kernel_mode() from pieces that run later and can safely be
> instrumented (later in enter_from_kernel_mode()).
Hi, Mark,
I reviewed your commit bc29b71f53b1 ("arm64: entry: clarify entry/exit
helpers"), and keep these functions is to make instrumentation
boundaries more clear, and will not change them.
>
> I had expected that a later patch would replace
> __enter_from_kernel_mode() with the generic equivalent, leaving
> enter_from_kernel_mode() unchanged. It looks like patch 16 could do that
> without this patch being necessary -- am I missing something?
Yes, you are right! these useless cleanup patches will be removed.
And when switched to generic syscall, I found that proper refactoring
would also facilitate clear code switching.
Thank you.
>
> Mark.
>
>>
>> No functional changes.
>>
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>> ---
>> arch/arm64/kernel/entry-common.c | 9 +--------
>> 1 file changed, 1 insertion(+), 8 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
>> index ccf59b44464d..a7fd4d6c7650 100644
>> --- a/arch/arm64/kernel/entry-common.c
>> +++ b/arch/arm64/kernel/entry-common.c
>> @@ -36,7 +36,7 @@
>> * This is intended to match the logic in irqentry_enter(), handling the kernel
>> * mode transitions only.
>> */
>> -static __always_inline irqentry_state_t __enter_from_kernel_mode(struct pt_regs *regs)
>> +static noinstr irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs)
>> {
>> irqentry_state_t ret = {
>> .exit_rcu = false,
>> @@ -55,13 +55,6 @@ static __always_inline irqentry_state_t __enter_from_kernel_mode(struct pt_regs
>> rcu_irq_enter_check_tick();
>> trace_hardirqs_off_finish();
>>
>> - return ret;
>> -}
>> -
>> -static noinstr irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs)
>> -{
>> - irqentry_state_t ret = __enter_from_kernel_mode(regs);
>> -
>> mte_check_tfsr_entry();
>> mte_disable_tco_entry(current);
>>
>> --
>> 2.34.1
>>
>