firewire: nosy: Replace timeval with timespec64

PATCH In review Tina Ruchandani 3 participants 5 messages Mar 21, 2016 – Mar 22, 2016 Firewire

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Tina Ruchandani

author

2016-03-21 05:59 UTC #0 lore raw

PATCH 1/1 firewire: nosy: Replace timeval with timespec64

'struct timeval' uses a 32 bit field for its 'seconds' value which will overflow in year 2038 and beyond. This patch replaces the use of timeval in nosy.c with timespec64 which doesn't suffer from y2038 issue. The code is correct as is - since it is only using the microseconds portion of timeval. However, this patch does the replacement as part of a larger effort to remove all instances of 'struct timeval' from the kernel (that would help identify cases where the code is actually broken).

Signed-off-by Tina Ruchandani <[email protected]>

---
 drivers/firewire/nosy.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

drivers/firewire/nosy.c +5 -3

index 8a46077..631c977 100644
@@ -446,14 +446,16 @@ static void
 bus_reset_irq_handler(struct pcilynx *lynx)
 {
 	struct client *client;
-	struct timeval tv;
+	struct timespec64 ts64;
+	u32    timestamp;
 
-	do_gettimeofday(&tv);
+	ktime_get_real_ts64(&ts64);
+	timestamp = ts64.tv_nsec / NSEC_PER_USEC;
 
 	spin_lock(&lynx->client_list_lock);
 
 	list_for_each_entry(client, &lynx->client_list, link)
-		packet_buffer_put(&client->buffer, &tv.tv_usec, 4);
+		packet_buffer_put(&client->buffer, &timestamp, 4);
 
 	spin_unlock(&lynx->client_list_lock);
 }

--
2.8.0.rc3.226.g39d4020

Arnd Bergmann

Reviewed-by on v1 1/1

2016-03-21 19:55 UTC #1 lore raw

Quoted 9 lines · On Sunday 20 March 2016 22:59:11 Tina Ruchandani wrote:

'struct timeval' uses a 32 bit field for its 'seconds' value which will overflow in year 2038 and beyond. This patch replaces the use of timeval in nosy.c with timespec64 which doesn't suffer from y2038 issue. The code is correct as is - since it is only using the microseconds portion of timeval. However, this patch does the replacement as part of a larger effort to remove all instances of 'struct timeval' from the kernel (that would help identify cases where the code is actually broken).

Quoted 4 lines

Signed-off-by Tina Ruchandani <[email protected]>
---
 drivers/firewire/nosy.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

The patch looks correct to me, but it seems the same one has just been merged into mainline Linux on Saturday (the patch was posted back in October).

commit 2ae4b6b20e2004dccf80d804ae52b073377c2f5b

Author: Amitoj Kaur Chawla <[email protected]>
Date:   Thu Oct 22 04:05:00 2015 +0530

firewire: nosy: Replace timeval with timespec64

32 bit systems using 'struct timeval' will break in the year 2038, so we replace the code appropriately. However, this driver is not broken in 2038 since we are using only the microseconds portion of the current time.

This patch replaces timeval with timespec64.

Signed-off-by Amitoj Kaur Chawla <[email protected]>

Reviewed-by Arnd Bergmann <[email protected]>

Signed-off-by Stefan Richter <[email protected]>

drivers/firewire/nosy.c +6 -4

index 76b2d390f6ec..8a46077129ac 100644
@@ -33,6 +33,7 @@
 #include <linux/sched.h> /* required for linux/wait.h */
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/time64.h>
 #include <linux/timex.h>
 #include <linux/uaccess.h>
 #include <linux/wait.h>

@@ -413,17 +414,18 @@ static void
 packet_irq_handler(struct pcilynx *lynx)
 {
 	struct client *client;
-	u32 tcode_mask, tcode;
+	u32 tcode_mask, tcode, timestamp;
 	size_t length;
-	struct timeval tv;
+	struct timespec64 ts64;
 
 	/* FIXME: Also report rcv_speed. */
 
 	length = __le32_to_cpu(lynx->rcv_pcl->pcl_status) & 0x00001fff;
 	tcode  = __le32_to_cpu(lynx->rcv_buffer[1]) >> 4 & 0xf;
 
-	do_gettimeofday(&tv);
-	lynx->rcv_buffer[0] = (__force __le32)tv.tv_usec;
+	ktime_get_real_ts64(&ts64);
+	timestamp = ts64.tv_nsec / NSEC_PER_USEC;
+	lynx->rcv_buffer[0] = (__force __le32)timestamp;
 
 	if (length == PHY_PACKET_SIZE)
 		tcode_mask = 1 << TCODE_PHY_PACKET;

Stefan Richter

2016-03-21 20:19 UTC #2 lore raw

Quoted 15 lines · On Mar 21 Arnd Bergmann wrote:

Quoted 9 lines · On Sunday 20 March 2016 22:59:11 Tina Ruchandani wrote:
'struct timeval' uses a 32 bit field for its 'seconds' value which will overflow in year 2038 and beyond. This patch replaces the use of timeval in nosy.c with timespec64 which doesn't suffer from y2038 issue. The code is correct as is - since it is only using the microseconds portion of timeval. However, this patch does the replacement as part of a larger effort to remove all instances of 'struct timeval' from the kernel (that would help identify cases where the code is actually broken).
Quoted 4 lines
Signed-off-by Tina Ruchandani <[email protected]>
---
 drivers/firewire/nosy.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)  

Quoted 5 lines

The patch looks correct to me, but it seems the same one has just been merged into mainline Linux on Saturday (the patch was posted back in October).
commit 2ae4b6b20e2004dccf80d804ae52b073377c2f5b

[...]

No, Amitoj's patch from October changed nosy.c::packet_irq_hander, whereas Tina' patch changes nosy.c::bus_reset_irq_handler. IOW the new patch completes what the former patch (and us reviewers) missed.

Signature · 3 lines

Stefan Richter
-======----- --== =-=-=
http://arcgraph.de/sr/

Arnd Bergmann

Reviewed-by

2016-03-21 21:36 UTC #3 lore raw

Quoted 20 lines · On Monday 21 March 2016 21:19:17 Stefan Richter wrote:

Quoted 19 lines · On Mar 21 Arnd Bergmann wrote:
Quoted 9 lines · On Sunday 20 March 2016 22:59:11 Tina Ruchandani wrote:
'struct timeval' uses a 32 bit field for its 'seconds' value which will overflow in year 2038 and beyond. This patch replaces the use of timeval in nosy.c with timespec64 which doesn't suffer from y2038 issue. The code is correct as is - since it is only using the microseconds portion of timeval. However, this patch does the replacement as part of a larger effort to remove all instances of 'struct timeval' from the kernel (that would help identify cases where the code is actually broken).
Quoted 4 lines
Signed-off-by Tina Ruchandani <[email protected]>
---
 drivers/firewire/nosy.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)  
The patch looks correct to me, but it seems the same one has just been merged into mainline Linux on Saturday (the patch was posted back in October).

Quoted 7 lines

Quoted 1 line
commit 2ae4b6b20e2004dccf80d804ae52b073377c2f5b
[...]
No, Amitoj's patch from October changed nosy.c::packet_irq_hander, whereas Tina' patch changes nosy.c::bus_reset_irq_handler. IOW the new patch completes what the former patch (and us reviewers) missed.

Ah, I see. Sorry for my confusion.

Reviewed-by Arnd Bergmann <[email protected]>

Stefan Richter

2016-03-22 14:28 UTC #4 lore raw

Quoted 11 lines · On Mar 21 Arnd Bergmann wrote:

Quoted 11 lines
Quoted 11 lines · On Sunday 20 March 2016 22:59:11 Tina Ruchandani wrote:
Quoted 10 lines
'struct timeval' uses a 32 bit field for its 'seconds' value which will overflow in year 2038 and beyond. This patch replaces the use of timeval in nosy.c with timespec64 which doesn't suffer from y2038 issue. The code is correct as is - since it is only using the microseconds portion of timeval. However, this patch does the replacement as part of a larger effort to remove all instances of 'struct timeval' from the kernel (that would help identify cases where the code is actually broken).
Signed-off-by Tina Ruchandani <[email protected]>

[...]

Quoted 1 line

Reviewed-by Arnd Bergmann <[email protected]>

Committed to linux1394.git.
I will try to get this pulled upstream in the next few days.

Signature · 3 lines

Stefan Richter
-======----- --== =-==-
http://arcgraph.de/sr/