Re: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread Luck, Tony
On Mon, Jan 04, 2016 at 08:28:52PM +0100, Ard Biesheuvel wrote: > On 4 January 2016 at 20:21, H. Peter Anvin wrote: > > I suspect that means we will also need to go back to arch-specific > > sorting for x86. > > > > AFAICT, Tony's patches are not incompatible with mine. The fixup > address is off

Re: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread Ard Biesheuvel
On 4 January 2016 at 20:21, H. Peter Anvin wrote: > On 01/04/2016 10:20 AM, Luck, Tony wrote: >>> May I humbly ask why the [Finnish] you don't use the equivalent of the >>> x86 _ASM_EXTABLE() macro? In fact, why don't we make that one generic, too? >> >> I'm messing with that right now (with help

Re: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread H. Peter Anvin
On 01/04/2016 10:20 AM, Luck, Tony wrote: >> May I humbly ask why the [Finnish] you don't use the equivalent of the >> x86 _ASM_EXTABLE() macro? In fact, why don't we make that one generic, too? > > I'm messing with that right now (with help from Andy Lutomirski and Boris) to > add different clas

Re: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread H. Peter Anvin
On 01/04/2016 10:20 AM, Luck, Tony wrote: >> May I humbly ask why the [Finnish] you don't use the equivalent of the >> x86 _ASM_EXTABLE() macro? In fact, why don't we make that one generic, too? > > I'm messing with that right now (with help from Andy Lutomirski and Boris) to > add different clas

RE: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread Luck, Tony
> May I humbly ask why the [Finnish] you don't use the equivalent of the > x86 _ASM_EXTABLE() macro? In fact, why don't we make that one generic, too? I'm messing with that right now (with help from Andy Lutomirski and Boris) to add different classes of exception table (so I can tag some instruct

Re: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread H. Peter Anvin
On 01/04/2016 06:46 AM, Will Deacon wrote: > On Sun, Jan 03, 2016 at 05:05:57PM +0100, Ard Biesheuvel wrote: >> Instead of using absolute addresses for both the exception location >> and the fixup, use offsets relative to the exception table entry values. >> Not only does this cut the size of the e

Re: [PATCH 6/6] arm64: switch to relative exception tables

2016-01-04 Thread Will Deacon
On Sun, Jan 03, 2016 at 05:05:57PM +0100, Ard Biesheuvel wrote: > Instead of using absolute addresses for both the exception location > and the fixup, use offsets relative to the exception table entry values. > Not only does this cut the size of the exception table in half, it is > also a prerequis

[PATCH 6/6] arm64: switch to relative exception tables

2016-01-03 Thread Ard Biesheuvel
Instead of using absolute addresses for both the exception location and the fixup, use offsets relative to the exception table entry values. Not only does this cut the size of the exception table in half, it is also a prerequisite for KASLR, since absolute exception table entries are subject to dyn