[8/9] select/restart_block: Convert poll's timeout to u64

Submitted by Jann Horn via Containers on Sept. 9, 2019, 10:23 a.m.

Details

Message ID 20190909102340.8592-9-dima@arista.com
State New
Series "restart_block: Prepare the ground for dumping timeout"
Headers show

Commit Message

Jann Horn via Containers Sept. 9, 2019, 10:23 a.m.
All preparations have been done - now poll() can set u64 timeout in
restart_block. It allows to do the next step - unifying all timeouts in
restart_block and provide ptrace() API to read it.

Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 fs/select.c                   | 27 +++++++--------------------
 include/linux/restart_block.h |  4 +---
 2 files changed, 8 insertions(+), 23 deletions(-)

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diff --git a/fs/select.c b/fs/select.c
index 4af88feaa2fe..ff2b9c4865cd 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -1001,14 +1001,9 @@  static long do_restart_poll(struct restart_block *restart_block)
 {
 	struct pollfd __user *ufds = restart_block->poll.ufds;
 	int nfds = restart_block->poll.nfds;
-	ktime_t timeout = 0;
+	ktime_t timeout = restart_block->poll.timeout;
 	int ret;
 
-	if (restart_block->poll.has_timeout) {
-		timeout = ktime_set(restart_block->poll.tv_sec,
-				    restart_block->poll.tv_nsec);
-	}
-
 	ret = do_sys_poll(ufds, nfds, timeout);
 
 	if (ret == -ERESTARTNOHAND) {
@@ -1021,14 +1016,12 @@  static long do_restart_poll(struct restart_block *restart_block)
 SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
 		int, timeout_msecs)
 {
-	struct timespec64 end_time;
 	ktime_t timeout = 0;
 	int ret;
 
 	if (timeout_msecs >= 0) {
-		poll_select_set_timeout(&end_time, timeout_msecs / MSEC_PER_SEC,
-			NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC));
-		timeout = timespec64_to_ktime(end_time);
+		timeout = ktime_add_ms(0, timeout_msecs);
+		timeout = ktime_add_safe(ktime_get(), timeout);
 	}
 
 	ret = do_sys_poll(ufds, nfds, timeout);
@@ -1037,16 +1030,10 @@  SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
 		struct restart_block *restart_block;
 
 		restart_block = &current->restart_block;
-		restart_block->fn = do_restart_poll;
-		restart_block->poll.ufds = ufds;
-		restart_block->poll.nfds = nfds;
-
-		if (timeout_msecs >= 0) {
-			restart_block->poll.tv_sec = end_time.tv_sec;
-			restart_block->poll.tv_nsec = end_time.tv_nsec;
-			restart_block->poll.has_timeout = 1;
-		} else
-			restart_block->poll.has_timeout = 0;
+		restart_block->fn		= do_restart_poll;
+		restart_block->poll.ufds	= ufds;
+		restart_block->poll.nfds	= nfds;
+		restart_block->poll.timeout	= timeout;
 
 		ret = -ERESTART_RESTARTBLOCK;
 	}
diff --git a/include/linux/restart_block.h b/include/linux/restart_block.h
index e66e982105f4..63d647b65395 100644
--- a/include/linux/restart_block.h
+++ b/include/linux/restart_block.h
@@ -49,11 +49,9 @@  struct restart_block {
 		} nanosleep;
 		/* For poll */
 		struct {
+			u64 timeout;
 			struct pollfd __user *ufds;
 			int nfds;
-			int has_timeout;
-			unsigned long tv_sec;
-			unsigned long tv_nsec;
 		} poll;
 	};
 };

Comments

David Laight Sept. 9, 2019, 1:07 p.m.
From: Dmitry Safonov
> Sent: 09 September 2019 11:24
> 
> All preparations have been done - now poll() can set u64 timeout in
> restart_block. It allows to do the next step - unifying all timeouts in
> restart_block and provide ptrace() API to read it.
> 
> Signed-off-by: Dmitry Safonov <dima@arista.com>
> ---
>  fs/select.c                   | 27 +++++++--------------------
>  include/linux/restart_block.h |  4 +---
>  2 files changed, 8 insertions(+), 23 deletions(-)
> 
> diff --git a/fs/select.c b/fs/select.c
> index 4af88feaa2fe..ff2b9c4865cd 100644
> --- a/fs/select.c
> +++ b/fs/select.c
...
> @@ -1037,16 +1030,10 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
>  		struct restart_block *restart_block;
> 
>  		restart_block = &current->restart_block;
> -		restart_block->fn = do_restart_poll;
> -		restart_block->poll.ufds = ufds;
> -		restart_block->poll.nfds = nfds;
> -
> -		if (timeout_msecs >= 0) {
> -			restart_block->poll.tv_sec = end_time.tv_sec;
> -			restart_block->poll.tv_nsec = end_time.tv_nsec;
> -			restart_block->poll.has_timeout = 1;
> -		} else
> -			restart_block->poll.has_timeout = 0;
> +		restart_block->fn		= do_restart_poll;
> +		restart_block->poll.ufds	= ufds;
> +		restart_block->poll.nfds	= nfds;
> +		restart_block->poll.timeout	= timeout;

What is all that whitespace for?

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
Jann Horn via Containers Sept. 16, 2019, 3:19 p.m.
On 9/9/19 2:07 PM, David Laight wrote:
> From: Dmitry Safonov
>> Sent: 09 September 2019 11:24
>>
>> All preparations have been done - now poll() can set u64 timeout in
>> restart_block. It allows to do the next step - unifying all timeouts in
>> restart_block and provide ptrace() API to read it.
>>
>> Signed-off-by: Dmitry Safonov <dima@arista.com>
>> ---
>>  fs/select.c                   | 27 +++++++--------------------
>>  include/linux/restart_block.h |  4 +---
>>  2 files changed, 8 insertions(+), 23 deletions(-)
>>
>> diff --git a/fs/select.c b/fs/select.c
>> index 4af88feaa2fe..ff2b9c4865cd 100644
>> --- a/fs/select.c
>> +++ b/fs/select.c
> ...
>> @@ -1037,16 +1030,10 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
>>  		struct restart_block *restart_block;
>>
>>  		restart_block = &current->restart_block;
>> -		restart_block->fn = do_restart_poll;
>> -		restart_block->poll.ufds = ufds;
>> -		restart_block->poll.nfds = nfds;
>> -
>> -		if (timeout_msecs >= 0) {
>> -			restart_block->poll.tv_sec = end_time.tv_sec;
>> -			restart_block->poll.tv_nsec = end_time.tv_nsec;
>> -			restart_block->poll.has_timeout = 1;
>> -		} else
>> -			restart_block->poll.has_timeout = 0;
>> +		restart_block->fn		= do_restart_poll;
>> +		restart_block->poll.ufds	= ufds;
>> +		restart_block->poll.nfds	= nfds;
>> +		restart_block->poll.timeout	= timeout;
> 
> What is all that whitespace for?

Aligned them with tabs just to make it look better.
I've no hard feelings about this - I can do it with spaces or drop the
align at all.

Thanks,
          Dmitry