Re: [Y2038] [PATCH v2] Staging: rts5208: Replace timeval with timespec64

On Tuesday 21 April 2015 19:27:38 Ksenija Stanojevic wrote:

struct timeval tv is used to get current time. 32-bit systems using 'struct timeval' will break in the year 2038, so we have to replace that code with more appropriate types.

Signed-off-by: Ksenija Stanojevic ksenija.stanojevic@gmail.com

This version looks correct, but I'd do one more change for clarity:

• do_gettimeofday(&tv);

• getnstimeofday64(&ts64);

• timeval_buf[0] = (u8)(tv.tv_sec >> 24);
• timeval_buf[1] = (u8)(tv.tv_sec >> 16);
• timeval_buf[2] = (u8)(tv.tv_sec >> 8);
• timeval_buf[3] = (u8)(tv.tv_sec);
• timeval_buf[4] = (u8)(tv.tv_usec >> 24);
• timeval_buf[5] = (u8)(tv.tv_usec >> 16);
• timeval_buf[6] = (u8)(tv.tv_usec >> 8);
• timeval_buf[7] = (u8)(tv.tv_usec);

• timeval_buf[0] = (u8)(ts64.tv_sec >> 24);
• timeval_buf[1] = (u8)(ts64.tv_sec >> 16);
• timeval_buf[2] = (u8)(ts64.tv_sec >> 8);
• timeval_buf[3] = (u8)(ts64.tv_sec);
• timeval_buf[4] = (u8)(ts64.tv_nsec/NSEC_PER_USEC >> 24);
• timeval_buf[5] = (u8)(ts64.tv_nsec/NSEC_PER_USEC >> 16);
• timeval_buf[6] = (u8)(ts64.tv_nsec/NSEC_PER_USEC >> 8);
• timeval_buf[7] = (u8)(ts64.tv_nsec/NSEC_PER_USEC);

}

You are doing the 'ts64.tv_nsec/NSEC_PER_USEC' division four times. I'm pretty sure the compiler can figure that out, but it would be more obvious if you just create a temporary u32 variable that contains the usec number.

Arnd