diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2006-03-25 06:06:33 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-25 11:22:48 -0500 |
commit | c08b8a49100715b20e6f7c997e992428b5e06078 (patch) | |
tree | 014758fb05908a3d49eeadc77f16dfa7585b12ac /arch/mips/kernel/sysirix.c | |
parent | 185ae6d7a32721e9062030a9f2d24ed714fa45df (diff) |
[PATCH] sys_alarm() unsigned signed conversion fixup
alarm() calls the kernel with an unsigend int timeout in seconds. The
value is stored in the tv_sec field of a struct timeval to setup the
itimer. The tv_sec field of struct timeval is of type long, which causes
the tv_sec value to be negative on 32 bit machines if seconds > INT_MAX.
Before the hrtimer merge (pre 2.6.16) such a negative value was converted
to the maximum jiffies timeout by the timeval_to_jiffies conversion. It's
not clear whether this was intended or just happened to be done by the
timeval_to_jiffies code.
hrtimers expect a timeval in canonical form and treat a negative timeout as
already expired. This breaks the legitimate usage of alarm() with a
timeout value > INT_MAX seconds.
For 32 bit machines it is therefor necessary to limit the internal seconds
value to avoid API breakage. Instead of doing this in all implementations
of sys_alarm the duplicated sys_alarm code is moved into a common function
in itimer.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/mips/kernel/sysirix.c')
-rw-r--r-- | arch/mips/kernel/sysirix.c | 22 |
1 files changed, 1 insertions, 21 deletions
diff --git a/arch/mips/kernel/sysirix.c b/arch/mips/kernel/sysirix.c index 0fc3730a294f..5407b784cd01 100644 --- a/arch/mips/kernel/sysirix.c +++ b/arch/mips/kernel/sysirix.c | |||
@@ -645,27 +645,7 @@ static inline void getitimer_real(struct itimerval *value) | |||
645 | 645 | ||
646 | asmlinkage unsigned int irix_alarm(unsigned int seconds) | 646 | asmlinkage unsigned int irix_alarm(unsigned int seconds) |
647 | { | 647 | { |
648 | struct itimerval it_new, it_old; | 648 | return alarm_setitimer(seconds); |
649 | unsigned int oldalarm; | ||
650 | |||
651 | if (!seconds) { | ||
652 | getitimer_real(&it_old); | ||
653 | del_timer(¤t->real_timer); | ||
654 | } else { | ||
655 | it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0; | ||
656 | it_new.it_value.tv_sec = seconds; | ||
657 | it_new.it_value.tv_usec = 0; | ||
658 | do_setitimer(ITIMER_REAL, &it_new, &it_old); | ||
659 | } | ||
660 | oldalarm = it_old.it_value.tv_sec; | ||
661 | /* | ||
662 | * ehhh.. We can't return 0 if we have an alarm pending ... | ||
663 | * And we'd better return too much than too little anyway | ||
664 | */ | ||
665 | if (it_old.it_value.tv_usec) | ||
666 | oldalarm++; | ||
667 | |||
668 | return oldalarm; | ||
669 | } | 649 | } |
670 | 650 | ||
671 | asmlinkage int irix_pause(void) | 651 | asmlinkage int irix_pause(void) |