Commit 7e732bfc authored Jan 19, 2006 by David S. Miller Committed by Linus Torvalds Jan 19, 2006

[PATCH] Fix regression added by ppoll/pselect code.



The compat layer timeout handling changes in:

9f72949f

are busted.  This is most easily seen with an X application
that uses sub-second select/poll timeout such as emacs.  You
hit a key and it takes a second or so before the app responds.

The two ROUND_UP() calls upon entry are using {tv,ts}_sec where it
should instead be using {tv_usec,ts_nsec}, which perfectly explains
the observed incorrect behavior.

Another bug shot down with git bisect.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 0f36b018

fs/compat.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1743,7 +1743,7 @@ asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
		if ((u64)tv.tv_sec >= (u64)MAX_INT64_SECONDS)
		timeout = -1; /* infinite */
		else {
		timeout = ROUND_UP(tv.tv_sec, 1000000/HZ);
		timeout = ROUND_UP(tv.tv_usec, 1000000/HZ);
		timeout += tv.tv_sec * HZ;
		}
		}
		@@ -1884,7 +1884,7 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
		/* We assume that ts.tv_sec is always lower than
		the number of seconds that can be expressed in
		an s64. Otherwise the compiler bitches at us */
		timeout = ROUND_UP(ts.tv_sec, 1000000000/HZ);
		timeout = ROUND_UP(ts.tv_nsec, 1000000000/HZ);
		timeout += ts.tv_sec * HZ;
		}