Re: [BUG] settimeofday(2) succeeds for microsecond value more than USEC_PER_SEC and for negative value

[george anzinger <george@mvista.com>]

Aniruddha M Marathe wrote:
> Even then, I think, we can modify the settimeofday  code to check -1 and USEC_PER_SEC
> Conditions, can't we?
> 
Uh, sure.  This is the test I prefer:

	if( (unsigned long)tv->usec > USEC_PER_SEC)
		return EINVAL;

Note that the unsigned picks up the negative value as well as the > 
(and it does it in only one machine code test/jmp :)

This change should go in do_sys_settimeofday() in kernel/time.c.  It 
will fix both settimeofday and clock_settime(CLOCK_REALTIME,...  And 
also fixes it in all archs.

-g
		
> 
> |-----Original Message-----
> |From: george anzinger [mailto:george@mvista.com] 
> |Sent: Friday, April 11, 2003 11:56 AM
> |To: Aniruddha M Marathe
> |Cc: linux-kernel@vger.kernel.org; Chandrashekhar RS
> |Subject: Re: [BUG] settimeofday(2) succeeds for microsecond 
> |value more than USEC_PER_SEC and for negative value
> |
> |
> |Aniruddha M Marathe wrote:
> |> Settimeofday(2) should return EINVAL in case where 
> |tv.tv_usec parameter is more than 
> |> USEC_PER_SEC (more than 10^6 ) or for negative values of tv.tv_usec. 
> |> It returns 0 (success) instead.
> |> 
> |> Clock_settimeofday(2) (kernel/posix-timers.c) also uses 
> |do_sys_settimeofday() and faces the
> |> Same problem.
> |> 
> |> I think this is a bug. If you confirm, I will send a patch.
> |
> |Yes, it is a known problem, turned up by some the posix timers tests. 
> |  I suppose it is too much to ask, but it would be nice if 
> |do_sys_settimeofday() took a timespec instead of a timeval.  Of course 
> |this changes the interface for all the archs, but it would allow the 
> |clock_settimeofday to send in the nsec value.
> |
> |-g
> |
> |> 
> |> Regards,
> |> Aniruddha Marathe
> |> WIPRO Technologies, India
> |> -
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> |
> |-- 
> |George Anzinger   george@mvista.com
> |High-res-timers:  http://sourceforge.net/projects/high-res-timers/
> |Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml
> |
> |
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-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml