Re: sys_times() return value

From: Andrew Morton
Date: Sat Jul 23 2005 - 00:37:38 EST


Russell King <rmk+lkml@xxxxxxxxxxxxxxxx> wrote:
>
> Guys,
>
> ARM folk have recently pointed out a problem with sys_times().
> When the kernel boots, we set jiffies to -5 minutes. This causes
> sys_times() to return a negative number, which increments through
> zero.
>
> However, some negative numbers are used to return error codes.
> Hence, there's a period of time when sys_times() returns values
> which are indistinguishable from error codes shortly after boot.

What a strange system call.

> This probably only affects 32-bit architectures. However, one
> wonders whether sys_times() needs force_successful_syscall_return().

I'd say so, yes. But lots of architectures seem to have a no-op there.

> Also, it appears that glibc does indeed interpret the return value
> from sys_times in the way I describe above on at least ARM and x86.
> Other architectures may be similarly affected. Hopefully the ARM
> glibc folk will raise a cross-architecture bug in glibc for this.
>

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