Commit 74910e6c authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

[PATCH] select: time comparison fixes 



I got all of these backwards.  We want to return

	min(input timeout, new timeout)

to userspace to prevent increasing the time-remaining value.

Thanks to Ernst Herzberg <earny@net4u.de> for reporting and diagnosing.

Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 200a4552

fs/compat.c

+3 −3
Original line number Diff line number Diff line
@@ -1757,7 +1757,7 @@ asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp, 
			goto sticky;

		rtv.tv_usec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ));

		rtv.tv_sec = timeout;

		if (compat_timeval_compare(&rtv, &tv) < 0)

		if (compat_timeval_compare(&rtv, &tv) >= 0)

			rtv = tv;

		if (copy_to_user(tvp, &rtv, sizeof(rtv))) {

sticky:
@@ -1834,7 +1834,7 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp, 
			rts.tv_sec++;

			rts.tv_nsec -= NSEC_PER_SEC;

		}

		if (compat_timespec_compare(&rts, &ts) < 0)

		if (compat_timespec_compare(&rts, &ts) >= 0)

			rts = ts;

		copy_to_user(tsp, &rts, sizeof(rts));

	}
@@ -1934,7 +1934,7 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds, 
		rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *

					1000;

		rts.tv_sec = timeout;

		if (compat_timespec_compare(&rts, &ts) < 0)

		if (compat_timespec_compare(&rts, &ts) >= 0)

			rts = ts;

		if (copy_to_user(tsp, &rts, sizeof(rts))) {

sticky:

fs/select.c

+3 −3
Original line number Diff line number Diff line
@@ -404,7 +404,7 @@ asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp, 
			goto sticky;

		rtv.tv_usec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ));

		rtv.tv_sec = timeout;

		if (timeval_compare(&rtv, &tv) < 0)

		if (timeval_compare(&rtv, &tv) >= 0)

			rtv = tv;

		if (copy_to_user(tvp, &rtv, sizeof(rtv))) {

sticky:
@@ -471,7 +471,7 @@ asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp, 
		rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *

						1000;

		rts.tv_sec = timeout;

		if (timespec_compare(&rts, &ts) < 0)

		if (timespec_compare(&rts, &ts) >= 0)

			rts = ts;

		if (copy_to_user(tsp, &rts, sizeof(rts))) {

sticky:
@@ -775,7 +775,7 @@ asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds, 
		rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *

						1000;

		rts.tv_sec = timeout;

		if (timespec_compare(&rts, &ts) < 0)

		if (timespec_compare(&rts, &ts) >= 0)

			rts = ts;

		if (copy_to_user(tsp, &rts, sizeof(rts))) {

		sticky:

CRA Git | Maintained and supported by SUSTech CRA and CCSE