From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH v2] signals, pkeys: make si_pkey 32 bits Date: Mon, 29 Feb 2016 08:57:32 +0100 Message-ID: <20160229075732.GA31950@gmail.com> References: <20160226173427.54A6949F@viggo.jf.intel.com> <6C5C3B9B-CAD6-4010-9A3E-AFFF7E13FAE3@zytor.com> <20160227091013.6e0606d1@canb.auug.org.au> <20160227114154.GA16200@gmail.com> <56D1F61C.5050308@sr71.net> <9E8119F8-1F37-4084-AE31-34CA6DE8C15E@zytor.com> <20160228102629.0ef4ef4f@canb.auug.org.au> <20160228104019.429defad@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:33819 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751925AbcB2H5i (ORCPT ); Mon, 29 Feb 2016 02:57:38 -0500 Content-Disposition: inline In-Reply-To: <20160228104019.429defad@canb.auug.org.au> Sender: linux-next-owner@vger.kernel.org List-ID: To: Stephen Rothwell Cc: "H. Peter Anvin" , tglx@linutronix.de, peterz@infradead.org, Dave Hansen , linux-kernel@vger.kernel.org, dave.hansen@linux.intel.com, akpm@linux-foundation.org, mingo@elte.hu, linux-next@vger.kernel.org, deller@gmx.de * Stephen Rothwell wrote: > In order to prevent a change of alignment of the _sifields union in the > siginfo structure on (some) 32 bit platforms and an ABI breakage, we > change the type of _pkey to unsigned int. If more bits are needed in > the future, a second unsigned int could be added. > > Fixes: cd0ea35ff551 ("signals, pkeys: Notify userspace about protection key faults") > Acked-by: Dave Hansen > Signed-off-by: Stephen Rothwell > --- > arch/ia64/include/uapi/asm/siginfo.h | 2 +- > arch/mips/include/uapi/asm/siginfo.h | 2 +- > include/uapi/asm-generic/siginfo.h | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/ia64/include/uapi/asm/siginfo.h b/arch/ia64/include/uapi/asm/siginfo.h > index 0151cfab929d..19e7db0c9453 100644 > --- a/arch/ia64/include/uapi/asm/siginfo.h > +++ b/arch/ia64/include/uapi/asm/siginfo.h > @@ -70,7 +70,7 @@ typedef struct siginfo { > void __user *_upper; > } _addr_bnd; > /* used when si_code=SEGV_PKUERR */ > - u64 _pkey; > + unsigned int _pkey; > }; > } _sigfault; > > diff --git a/arch/mips/include/uapi/asm/siginfo.h b/arch/mips/include/uapi/asm/siginfo.h > index 6f4edf0d794c..3cc14f4a5936 100644 > --- a/arch/mips/include/uapi/asm/siginfo.h > +++ b/arch/mips/include/uapi/asm/siginfo.h > @@ -93,7 +93,7 @@ typedef struct siginfo { > void __user *_upper; > } _addr_bnd; > /* used when si_code=SEGV_PKUERR */ > - u64 _pkey; > + unsigned int _pkey; > }; > } _sigfault; > > diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h > index 90384d55225b..f4459dc3d31b 100644 > --- a/include/uapi/asm-generic/siginfo.h > +++ b/include/uapi/asm-generic/siginfo.h > @@ -98,7 +98,7 @@ typedef struct siginfo { > void __user *_upper; > } _addr_bnd; > /* used when si_code=SEGV_PKUERR */ > - u64 _pkey; > + unsigned int _pkey; > }; > } _sigfault; > Please use the standard ABI integer type pattern: __u32. The advantage of only using __[su][8|16|32|64] integer types is that it's "obvious" at a glance that an ABI is bitness-invariant. For example include/uapi/linux/perf_event.h only uses such ABI-safe types, and arch/x86/include/uapi is using these types 95%+ of the time. ( The various struct siginfo definitions should probably be harmonized as well, but in a separate patch. ) Thanks, Ingo