On 21 May 2015 at 16:13, Arnd Bergmann arnd@linaro.org wrote:
On Thursday 21 May 2015 10:24:50 Baolin Wang wrote:
SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock, const struct timespec __user *, tp) { +#ifdef CONFIG_64BIT
struct timespec64 new_tp;+#else struct timespec new_tp;
struct timespec64 new_tp64;+#endif
if (copy_from_user(&new_tp, tp, sizeof (*tp))) return -EFAULT;+#ifdef CONFIG_64BIT return __clock_settime(which_clock, &new_tp); +#else
new_tp64 = timespec_to_timespec64(new_tp);return __clock_settime(which_clock, &new_tp64);+#endif }
Please just have two clock_settime functions wrapped by the ifdef conditional. You should always try to avoid ifdefs inside of functions.
Thanks for your comments. I'll fix that to make it look easily.
I think it's best to do it the way I have in my patch series: keep one __clock_settime() function that takes a timespec64 argument, but introduce a get_timespec64() function that copies a __user timespec to a kernel timespec64. By copying the two members individually with get_user(), you can avoid the difference between 32-bit and 64-bit platforms.
Arnd
I'll try to modify this patch following the method you suggested in private. Thanks.