On Mon, Jan 20, 2014 at 05:46:41PM +0000, H. Peter Anvin wrote: > On 12/28/2013 08:33 AM, Christoph Hellwig wrote: > > On Fri, Dec 27, 2013 at 02:14:16PM -0800, H.J. Lu wrote: > >> X32 uses the same kernel system call interface as x86-64 for many > >> system calls. However, "long" is 64-bit for x86-64 and is 32-bit for > >> x32. Where long or unsigned long are used in struct types for such > >> system calls, they are wrong for x32. __kernel_[u]long_t is [unsigned] > >> long for all ABIs other than x32. I am submitting 8 patches to replace > >> long or unsigned long with __kernel_[u]long_t so that those struct types > >> can be used with x32 system calls. Does this mean that you are changing the x32 ABI (or it hasn't been declared stable yet)? > This comment by Christoph was literally the only feedback on this > patchset. The definition of __kernel_[u]long_t is "the size of 'long' > for the native kernel for the ABI". H.J.'s patchset only affects x86 > (specifically x86-64) since on all other platforms __kernel_[u]long_t is > simply defined as long/unsigned long. > > That being said, x32 is not the only ABI of this type. In particular, > if the MIPS N32 and ARM64 ILP32 maintainers have suggestions which would > make this work more applicable to them, it would be highly useful to > receive any such feedback. ILP32 for arm64 is still work in progress and subject to change. So far the preliminary ABI (http://git.kernel.org/cgit/linux/kernel/git/cmarinas/linux-aarch64.git/log/?h=ilp32) redefines kernel_(u)long_t is defined as (unsigned) long long. Most of the syscalls are 64-bit generic with ~23 routed to compat. I would like to simplify these further and even use native 64-bit signal handling but it requires some changes to generic structures. I'll have a look at H.J.'s patches and give comments, they may come in handy. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
