Re: [PATCH 0/5] x86: CVE-2017-5715, aka Spectre

2018-01-18 Thread Woodhouse, David
On Thu, 2018-01-18 at 08:52 +0100, Uros Bizjak wrote: > This puts an extra burden on the developer, which has to use correct > thunk name in their code. Sure, this can be solved trivially with > #ifdef __x86_64__, so the issue is minor, but I thought it has to be > mentioned before the name is set

Re: [PATCH 0/5] x86: CVE-2017-5715, aka Spectre

2018-01-17 Thread Woodhouse, David
ture requirement that I am not understanding, and that is so hard? Back to real computer and will stop top-posting HTML soon, I promise! On 14 Jan 2018 19:22, Uros Bizjak wrote: On Sun, Jan 14, 2018 at 6:44 PM, Woodhouse, David wrote: > This won't make the list; I'll send a more

Re: [PATCH 0/5] x86: CVE-2017-5715, aka Spectre

2018-01-14 Thread Woodhouse, David
This won't make the list; I'll send a more coherent and less HTML-afflicted version later. The bare 'ax' naming made it painful to instantiate the external thunks for 32-bit and 64-bot code because we had to put the e/r back again inside the .irp reg ax bx... code. We could probably have lived

Re: [PATCH 4/4] x86: Add 'V' register operand modifier

2018-01-13 Thread Woodhouse, David
On Sat, 2018-01-13 at 08:36 -0800, H.J. Lu wrote: > On Sat, Jan 13, 2018 at 8:28 AM, Florian Weimer wrote: > > > > * H. J. Lu: > > > > > > > > On Fri, Jan 12, 2018 at 10:00 AM, Jan Hubicka wrote: > > > > > > > > > > > > > > Add 'V', a special modifier which prints the name of the full intege

Re: [PATCH 2/4] x86: Add -mfunction-return=

2018-01-13 Thread Woodhouse, David
On Sat, 2018-01-13 at 08:09 -0800, H.J. Lu wrote: > > > Again please extend both documentation hunks so it is clear what is purpose > > of this hack. > > David, can you help here? On most older CPUs the indirect branch issue is limited to actual indirect branches. On Skylake-era CPUs, however,

Re: [PATCH 1/5] x86: Add -mindirect-branch=

2018-01-08 Thread Woodhouse, David
On Tue, 2018-01-09 at 00:02 +0100, Michael Matz wrote: > Hi, > > On Mon, 8 Jan 2018, Woodhouse, David wrote: > > > > > > > > > > > > > > That can be done via asm aliases or direct assembler use; the kernel > > > > doesn

Re: [PATCH 1/5] x86: Add -mindirect-branch=

2018-01-08 Thread Woodhouse, David
On Mon, 2018-01-08 at 09:25 -0800, H.J. Lu wrote: > On Mon, Jan 8, 2018 at 9:18 AM, Michael Matz wrote: > > > > Hi, > > > > On Mon, 8 Jan 2018, H.J. Lu wrote: > > > > > > > > On Mon, Jan 8, 2018 at 4:00 AM, Jakub Jelinek wrote: > > > > > > > > On Mon, Jan 08, 2018 at 03:55:52AM -0800, H.J. L