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Date: Thu, 17 May 2012 17:37:00 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: David Daney <ddaney.cavm@gmail.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>,
        Ralf Baechle <ralf@linux-mips.org>, "H.J. Lu" <hjl.tools@gmail.com>,
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        mingo@kernel.org, tglx@linutronix.de
Subject: Re: [PATCH 08/10] Use __kernel_ulong_t in struct msqid64_ds
References: <1337292816-10839-1-git-send-email-hjl.tools@gmail.com> <1337292816-10839-9-git-send-email-hjl.tools@gmail.com> <4FB58EFD.7010302@zytor.com> <CA+55aFy+XOc350sVuLKDHAaKtz9GdLcVmjxs98N8XLTK4zmMYg@mail.gmail.com> <4FB59474.2020505@zytor.com> <4FB597F3.3060909@gmail.com>
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It looks like MIPS has a private definition of struct msqid64_ds, as do
most other architectures; the MIPS one is completely broken for user
space usages as it uses CONFIG_* macros:

#if defined(CONFIG_32BIT) && !defined(CONFIG_CPU_LITTLE_ENDIAN)
        unsigned long   __unused2;
#endif
        __kernel_time_t msg_rtime;      /* last msgrcv time */
#if defined(CONFIG_32BIT) && defined(CONFIG_CPU_LITTLE_ENDIAN)
        unsigned long   __unused2;
#endif

It looks like the only users of asm-generic here are:

arch/microblaze/include/asm/msgbuf.h:#include <asm-generic/msgbuf.h>
arch/score/include/asm/msgbuf.h:#include <asm-generic/msgbuf.h>
arch/sh/include/asm/msgbuf.h:#include <asm-generic/msgbuf.h>
arch/x86/include/asm/msgbuf.h:#include <asm-generic/msgbuf.h>

... and unless I'm mistaken, x86 is the only one of those which isn't 32
bits only, which explains the reason it "works"...

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.