[v4] x86/alternative: Patch a single alternative location only once

[PATCH v4 0/3] x86/alternative: Patch a single alternative location only once

Posted by Juergen Gross 2 months, 2 weeks ago

Instead of patching a single location potentially multiple times in
case of nested ALTERNATIVE()s, do the patching only after having
evaluated all alt_instr instances for that location.

Changes in V2:
- complete rework (Boris Petkov)

Changes in V3:
- split former V2 patch into 2 by introducing a helper function (Boris Petkov)
- repost the small cleanup patch 1 which was taken before, but has somehow
  vanished from the tip x86/alternative branch (it is still in the tip
  master branch, but I couldn't find it in any other tip branch).

Changes in V4:
- use 3 helpers instead of 1 (Boris Petkov)

Juergen Gross (3):
  x86/alternative: Drop not needed test after call of alt_replace_call()
  x86/alternative: Use helper functions for patching alternatives
  x86/alternative: Patch a single alternative location only once

 arch/x86/kernel/alternative.c | 147 ++++++++++++++++++++--------------
 1 file changed, 87 insertions(+), 60 deletions(-)

-- 
2.51.0

Re: [PATCH v4 0/3] x86/alternative: Patch a single alternative location only once

Posted by Juergen Gross 1 month, 3 weeks ago

Ping?

On 19.11.25 17:04, Juergen Gross wrote:
> Instead of patching a single location potentially multiple times in
> case of nested ALTERNATIVE()s, do the patching only after having
> evaluated all alt_instr instances for that location.
> 
> Changes in V2:
> - complete rework (Boris Petkov)
> 
> Changes in V3:
> - split former V2 patch into 2 by introducing a helper function (Boris Petkov)
> - repost the small cleanup patch 1 which was taken before, but has somehow
>    vanished from the tip x86/alternative branch (it is still in the tip
>    master branch, but I couldn't find it in any other tip branch).
> 
> Changes in V4:
> - use 3 helpers instead of 1 (Boris Petkov)
> 
> Juergen Gross (3):
>    x86/alternative: Drop not needed test after call of alt_replace_call()
>    x86/alternative: Use helper functions for patching alternatives
>    x86/alternative: Patch a single alternative location only once
> 
>   arch/x86/kernel/alternative.c | 147 ++++++++++++++++++++--------------
>   1 file changed, 87 insertions(+), 60 deletions(-)
>

Re: [PATCH v4 0/3] x86/alternative: Patch a single alternative location only once

Posted by Borislav Petkov 1 month, 3 weeks ago

On December 15, 2025 8:25:13 AM UTC, Juergen Gross <jgross@suse.com> wrote:
>Ping?

On vacation. 

Will take a look when I get back.

Thx.

Small device. Typos and formatting crap