Messages in this thread | | | Date | Wed, 7 Nov 2007 22:12:00 -0800 | From | Andrew Morton <> | Subject | Re: compat_sys_times() bogus until jiffies >= 0. |
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> On Thu, 8 Nov 2007 16:36:08 +1100 Paul Mackerras <paulus@samba.org> wrote: > Andrew Morton writes: > > > Yup. But userspace will already have a fit if either the start or end time > > advanced into the glibc-thought-that-was-an-error range. > > Not nearly as much of a fit. The effect on x86 is that values between > -4095 and -1 are reported as -1, so the end-start difference will be > out by less than 41 seconds. That's not nearly as dramatic as a > difference of 21 million seconds (over 16 years). :) > > I really think that wrapping at 0x7fffffff makes the situation worse, > not better. >
Sure.
So we need to do what you say: never return an error from sys_times() and change glibc to not perform error-interpretation on sys_times() return values and recommend that people bypass libc and go direct to the syscall so they'll work correctly on older glibc. Lovely.
I wonder what happens with things like F_GETOWN, shmat() and lseek(/dev/mem) on x86 (things which use force_successful_syscall_return()). According to the comment in include/linux/ptrace.h, glibc should be special-casing these. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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