Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-29 Thread Stephen Rothwell
Hi Ingo, On Mon, 29 Feb 2016 09:01:43 +0100 Ingo Molnar wrote: > > * Stephen Rothwell wrote: > > > > u32? > > > > It would have to be __u32, but we already use int and unsigned int > > extensively in the siginfo structure (which are both always assumed to > > be 32 bits). So "unsigned int"

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-29 Thread Ingo Molnar
* Stephen Rothwell wrote: > > u32? > > It would have to be __u32, but we already use int and unsigned int > extensively in the siginfo structure (which are both always assumed to > be 32 bits). So "unsigned int" probably makes most sense. No. This whole mishap is an object lesson in why it's

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-27 Thread Stephen Rothwell
Hi H., On Sat, 27 Feb 2016 11:35:08 -0800 "H. Peter Anvin" wrote: > > On February 27, 2016 11:16:44 AM PST, Dave Hansen wrote: > >On 02/27/2016 03:41 AM, Ingo Molnar wrote: > >> * Stephen Rothwell wrote: > >>> > On Fri, 26 Feb 2016 09:44:00 -0800 "H. Peter Anvin" > > wrote: > > > _

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-27 Thread H. Peter Anvin
On February 27, 2016 11:16:44 AM PST, Dave Hansen wrote: >On 02/27/2016 03:41 AM, Ingo Molnar wrote: >> * Stephen Rothwell wrote: >>> > On Fri, 26 Feb 2016 09:44:00 -0800 "H. Peter Anvin" > wrote: > > __u64 is okay, "unsigned long" is really messy in the presence >of 32-on-64 bit ABIs... >>>

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-27 Thread Dave Hansen
On 02/27/2016 03:41 AM, Ingo Molnar wrote: > * Stephen Rothwell wrote: >> > On Fri, 26 Feb 2016 09:44:00 -0800 "H. Peter Anvin" wrote: >>> > > __u64 is okay, "unsigned long" is really messy in the presence of >>> > > 32-on-64 bit ABIs... >> > >> > Yeah, but unfortunately, any 64 bit scalar type

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-27 Thread Ingo Molnar
* Stephen Rothwell wrote: > Hi, > > On Fri, 26 Feb 2016 09:44:00 -0800 "H. Peter Anvin" wrote: > > > > > > __u64 is okay, "unsigned long" is really messy in the presence of 32-on-64 > > bit ABIs... > > Yeah, but unfortunately, any 64 bit scalar type here will change the > alignment of the e

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-26 Thread Stephen Rothwell
Hi, On Fri, 26 Feb 2016 09:44:00 -0800 "H. Peter Anvin" wrote: > > > __u64 is okay, "unsigned long" is really messy in the presence of 32-on-64 > bit ABIs... Yeah, but unfortunately, any 64 bit scalar type here will change the alignment of the enclosing unions on (some) 32 bit platforms and th

Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-26 Thread H. Peter Anvin
On February 26, 2016 9:34:27 AM PST, Dave Hansen wrote: > >From: Dave Hansen > >Stephen Rothwell reported: > > http://lkml.kernel.org/r/20160226164406.065a1...@canb.auug.org.au > >that the Memory Protection Keys patches from the tip tree broke >a build-time check on an ARM build because the

[PATCH] x86, pkeys: fix siginfo ABI breakage from new field

2016-02-26 Thread Dave Hansen
From: Dave Hansen Stephen Rothwell reported: http://lkml.kernel.org/r/20160226164406.065a1...@canb.auug.org.au that the Memory Protection Keys patches from the tip tree broke a build-time check on an ARM build because they changed the ABI of siginfo. A u64 was used for the protection