Messages in this thread | | | Date | Thu, 26 Dec 2013 09:58:19 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] Use __kernel_long_t/__kernel_ulong_t in <linux/resource.h> |
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On 12/26/2013 05:52 AM, H.J. Lu wrote: > >> c) why you suddenly need these changes now and not when the x32 ABI >> support was submitted and hopefully heavily tested > > Kernel headers had been wrong for -m32/-mx32 on x86-64 > for a long long time. Linux/x86-64 normally use header > files from glibc, which avoids broken kernel header files. > Kernel uabi header files fix -m32, but not -mx32, which I am > working on now. >
In other words, this work is really part of making *libc make use the kernel uabi headers, which is a valuable work. The fact that the kernel headers never got fully ported to x32 is a big reason why x32 is still labeled experimental.
MIPS N32 and ARM64 ILP32 are x32-like ABIs which of course need to not be broken. However, currently __kernel_[u]long_t is [unsigned] long for all ABIs other than x32, so changing [unsigned] long to __kernel_[u]long_t will be a null change for anything but x32. They perhaps *SHOULD* be different for N32 or ARM64 ILP32, but that is for those arch maintainers to set.
However, I believe H.J.'s patches from this morning conditionalizing this on __BITS_PER_LONG are just plain wrong.
-hpa
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