Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-16 Thread Peter Zijlstra
On Wed, Dec 16, 2020 at 10:56:05AM -0600, Josh Poimboeuf wrote: > On Wed, Dec 16, 2020 at 09:40:59AM +0100, Peter Zijlstra wrote: > > > Could we make it easier by caching the shared > > > per-alt-group CFI state somewhere along the way? > > > > Yes, but when I tried it grew the code required.

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-16 Thread Josh Poimboeuf
On Wed, Dec 16, 2020 at 09:40:59AM +0100, Peter Zijlstra wrote: > > So much algorithm. > > :-) > > It's not really hard, but it has a few pesky details (as always). It really hurt my brain to look at it. > > Could we make it easier by caching the shared > > per-alt-group CFI state somewhere

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-16 Thread Peter Zijlstra
On Tue, Dec 15, 2020 at 06:38:02PM -0600, Josh Poimboeuf wrote: > On Tue, Dec 15, 2020 at 03:54:08PM +0100, Peter Zijlstra wrote: > > The problem is that a single instance of unwind information (ORC) must > > capture and correctly unwind all alternatives. Since the trivially > > correct mandate is

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-15 Thread Josh Poimboeuf
On Tue, Dec 15, 2020 at 03:54:08PM +0100, Peter Zijlstra wrote: > The problem is that a single instance of unwind information (ORC) must > capture and correctly unwind all alternatives. Since the trivially > correct mandate is out, implement the straight forward brute-force > approach: > > 1)

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-15 Thread Jürgen Groß
On 15.12.20 15:54, Peter Zijlstra wrote: On Tue, Dec 15, 2020 at 03:18:34PM +0100, Peter Zijlstra wrote: Ah, I was waiting for Josh to have an opinion (and then sorta forgot about the whole thing again). Let me refresh and provide at least a Changelog. How's this then? Thanks, will add it

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-15 Thread Peter Zijlstra
On Tue, Dec 15, 2020 at 03:18:34PM +0100, Peter Zijlstra wrote: > Ah, I was waiting for Josh to have an opinion (and then sorta forgot > about the whole thing again). Let me refresh and provide at least a > Changelog. How's this then? --- Subject: objtool: Alternatives vs ORC, the hard way From:

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-15 Thread Peter Zijlstra
On Tue, Dec 15, 2020 at 12:42:45PM +0100, Jürgen Groß wrote: > Peter, > > On 23.11.20 14:43, Peter Zijlstra wrote: > > On Fri, Nov 20, 2020 at 01:53:42PM +0100, Peter Zijlstra wrote: > > > On Fri, Nov 20, 2020 at 12:46:18PM +0100, Juergen Gross wrote: > > > > 30 files changed, 325

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-12-15 Thread Jürgen Groß
Peter, On 23.11.20 14:43, Peter Zijlstra wrote: On Fri, Nov 20, 2020 at 01:53:42PM +0100, Peter Zijlstra wrote: On Fri, Nov 20, 2020 at 12:46:18PM +0100, Juergen Gross wrote: 30 files changed, 325 insertions(+), 598 deletions(-) Much awesome ! I'll try and get that objtool thing sorted.

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-11-23 Thread Peter Zijlstra
On Fri, Nov 20, 2020 at 01:53:42PM +0100, Peter Zijlstra wrote: > On Fri, Nov 20, 2020 at 12:46:18PM +0100, Juergen Gross wrote: > > 30 files changed, 325 insertions(+), 598 deletions(-) > > Much awesome ! I'll try and get that objtool thing sorted. This seems to work for me. It isn't 100%

Re: [PATCH v2 00/12] x86: major paravirt cleanup

2020-11-20 Thread Peter Zijlstra
On Fri, Nov 20, 2020 at 12:46:18PM +0100, Juergen Gross wrote: > 30 files changed, 325 insertions(+), 598 deletions(-) Much awesome ! I'll try and get that objtool thing sorted.

[PATCH v2 00/12] x86: major paravirt cleanup

2020-11-20 Thread Juergen Gross
This is a major cleanup of the paravirt infrastructure aiming at eliminating all custom code patching via paravirt patching. This is achieved by using ALTERNATIVE instead, leading to the ability to give objtool access to the patched in instructions. In order to remove most of the 32-bit special