Messages in this thread | | | Date | Wed, 07 Nov 2007 22:24:06 -0800 (PST) | Subject | Re: compat_sys_times() bogus until jiffies >= 0. | From | David Miller <> |
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From: Paul Mackerras <paulus@samba.org> 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. - 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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