Re: [PATCH] ia64: add support for TIF_NOTIFY_SIGNAL

[Jens Axboe <axboe@kernel.dk>]

On 1/18/21 6:50 PM, John Paul Adrian Glaubitz wrote:
> Hi Jens!
> 
> On 10/29/20 5:15 PM, Jens Axboe wrote:
>> Wire up TIF_NOTIFY_SIGNAL handling for ia64.
>>
>> Cc: linux-ia64@vger.kernel.org
>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>> ---
>>
>> 5.11 has support queued up for TIF_NOTIFY_SIGNAL, see this posting
>> for details:
>>
>> https://lore.kernel.org/io-uring/20201026203230.386348-1-axboe@kernel.dk/
>>
>> As part of that work, I'm adding TIF_NOTIFY_SIGNAL support to all archs,
>> as that will enable a set of cleanups once all of them support it. I'm
>> happy carrying this patch if need be, or it can be funelled through the
>> arch tree. Let me know.
>>
>>  arch/ia64/include/asm/thread_info.h | 4 +++-
>>  arch/ia64/kernel/process.c          | 3 ++-
>>  2 files changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
>> index 64a1011f6812..759d7d68a5f2 100644
>> --- a/arch/ia64/include/asm/thread_info.h
>> +++ b/arch/ia64/include/asm/thread_info.h
>> @@ -104,6 +104,7 @@ struct thread_info {
>>  #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
>>  #define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
>>  #define TIF_NOTIFY_RESUME	6	/* resumption notification requested */
>> +#define TIF_NOTIFY_SIGNAL	7	/* signal notification exist */
>>  #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
>>  #define TIF_MCA_INIT		18	/* this task is processing MCA or INIT */
>>  #define TIF_DB_DISABLED		19	/* debug trap disabled for fsyscall */
>> @@ -115,6 +116,7 @@ struct thread_info {
>>  #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
>>  #define _TIF_SYSCALL_TRACEAUDIT	(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP)
>>  #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
>> +#define _TIF_SIGNAL_NOTIFY	(1 << TIF_SIGNAL_NOTIFY)
>>  #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
>>  #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
>>  #define _TIF_MCA_INIT		(1 << TIF_MCA_INIT)
>> @@ -124,7 +126,7 @@ struct thread_info {
>>  
>>  /* "work to do on user-return" bits */
>>  #define TIF_ALLWORK_MASK	(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\
>> -				 _TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE)
>> +				 _TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_NOTIFY_SIGNAL)
>>  /* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
>>  #define TIF_WORK_MASK		(TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
>>  
>> diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
>> index 6b61a703bcf5..0e0146daa88d 100644
>> --- a/arch/ia64/kernel/process.c
>> +++ b/arch/ia64/kernel/process.c
>> @@ -171,7 +171,8 @@ do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
>>  	}
>>  
>>  	/* deal with pending signal delivery */
>> -	if (test_thread_flag(TIF_SIGPENDING)) {
>> +	if (test_thread_flag(TIF_SIGPENDING) ||
>> +	    test_thread_flags(TIF_NOTIFY_SIGNAL)) {
>>  		local_irq_enable();	/* force interrupt enable */
>>  		ia64_do_signal(scr, in_syscall);
>>  	}
>>
> 
> This change broke the hpsa driver on my RX-2600 ia64 workstation in the sense that the
> driver no longer loads and hence hard disks are no longer recognized.

What does "no longer loads" mean? Does it hang?

> Any idea what could be wrong?

Can you try current -git? There's a task_work related fix in there which is
related to this series, maybe that's it...

-- 
Jens Axboe