Re: sys_times() return value

[Andrew Morton <akpm@osdl.org>]

Russell King <rmk+lkml@arm.linux.org.uk> 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.
>