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    SubjectRe: compat_sys_times() bogus until jiffies >= 0.
    From: Paul Mackerras <>
    Date: Thu, 8 Nov 2007 16:15:51 +1100

    > David Miller writes:
    > > I can't see where x86 is doing this though, so perhaps for x86
    > > glibc does make the negative value check. But I doubt it is
    > > checking the range 0x80000000-0xffffffff, otherwise mmap() would
    > > be busted.
    > At least for the INTERNAL_SYSCALL macro in glibc, the error check is:
    > #define INTERNAL_SYSCALL_ERROR_P(val, err) \
    > ((unsigned int) (val) >= 0xfffff001u)
    > in sysdeps/unix/sysv/linux/i386/sysdep.h. Similarly the PSEUDO macro
    > in that file does a cmpl $-4095,%eax to test for error. (There is also
    > a PSEUDO_NOERRNO which doesn't test for error.)
    > So the convention on (32-bit) x86 is that -4095 .. -1 are error
    > values, and other values are successful return values.

    Thanks for figuring that out.

    Really there is no way to fix sys_times() return values
    universally. Each proposed solution either doesn't fix
    the problem, or adds a new failure mode.
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      Last update: 2007-11-08 07:27    [W:0.022 / U:0.932 seconds]
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