USB: usbmon: Remove timeval usage for timestamp
PATCH v2 1/1 USB: usbmon: Remove timeval usage for timestamp
struct timeval' uses 32-bits for its seconds field and will overflow in the year 2038 and beyond. This patch replaces the usage of 'struct timeval' in mon_get_timestamp() with timespec64 which uses a 64-bit seconds field and is y2038-safe. mon_get_timestamp() truncates the timestamp at 4096 seconds, so the correctness of the code is not affected. This patch is part of a larger attempt to remove instances of struct timeval and other 32-bit timekeeping (time_t, struct timespec) from the kernel.
---
Changes in v2:
- Switch to monotonic time since we only care about time elapsed.
--- drivers/usb/mon/mon_text.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
drivers/usb/mon/mon_text.c +5 -4
@@ -9,6 +9,7 @@#include <linux/usb.h> #include <linux/slab.h> #include <linux/time.h> +#include <linux/ktime.h> #include <linux/export.h> #include <linux/mutex.h> #include <linux/debugfs.h>
@@ -176,12 +177,12 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,static inline unsigned int mon_get_timestamp (void ) { -struct timeval tval; +struct timespec64 now;unsigned int stamp; -do_gettimeofday (&tval); - stamp = tval.tv_sec &0xFFF ;/* 2^32 = 4294967296. Limit to 4096s. */ - stamp = stamp *1000000 + tval.tv_usec; +ktime_get_ts64 (&now); + stamp = now.tv_sec &0xFFF ;/* 2^32 = 4294967296. Limit to 4096s. */ + stamp = stamp *USEC_PER_SEC + now.tv_nsec /NSEC_PER_USEC ;return stamp; }
Signature · 1 line
2.6.0.rc2.230.g3dd15c0
Quoted 10 lines · On Thursday 29 October 2015 22:58:28 Tina Ruchandani wrote:
struct timeval' uses 32-bits for its seconds field and will overflow in the year 2038 and beyond. This patch replaces the usage of 'struct timeval' in
mon_get_timestamp()with timespec64 which uses a 64-bit seconds field and is y2038-safe.mon_get_timestamp()truncates the timestamp at 4096 seconds, so the correctness of the code is not affected. This patch is part of a larger attempt to remove instances of struct timeval and other 32-bit timekeeping (time_t, struct timespec) from the kernel.Signed-off-by Tina Ruchandani <[email protected]>Suggested-by Arnd Bergmann <[email protected]>