Re: [Outreachy kernel] [PATCH v2] firewire: Replace timeval with timespec64

From: Arnd Bergmann
Date: Wed Oct 21 2015 - 18:59:15 EST


On Thursday 22 October 2015 04:05:00 Amitoj Kaur Chawla wrote:
> 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 <amitoj1606@xxxxxxxxx>

Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>

(adding the y2038 mailing list as well)

> Changes in v2:
> -Replaced timespec with timspec64
> -Modified commit message
> -Used ktime_get_real_ts64() instead of getnstimeofday64()
>
> drivers/firewire/nosy.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firewire/nosy.c b/drivers/firewire/nosy.c
> index 76b2d39..8a46077 100644
> --- a/drivers/firewire/nosy.c
> +++ b/drivers/firewire/nosy.c
> @@ -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;
>

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