Re: [PATCH 6.1] arm64/sve: Discard stale CPU state when handling SVE traps

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Found matching upstream commit: 751ecf6afd6568adc98f2a6052315552c0483d18


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: 51d11ea0250d)
6.1.y | Not found

Note: The patch differs from the upstream commit:
---
1:  751ecf6afd656 ! 1:  b773f808e9357 arm64/sve: Discard stale CPU state when handling SVE traps
    @@ Commit message
         Reviewed-by: Mark Rutland <mark.rutland@arm.com>
         Link: https://lore.kernel.org/r/20241030-arm64-fpsimd-foreign-flush-v1-1-bd7bd66905a2@kernel.org
         Signed-off-by: Will Deacon <will@kernel.org>
    +    [Backported to 6.1 -- broonie]
    +    (cherry picked from commit 751ecf6afd6568adc98f2a6052315552c0483d18)
     
      ## arch/arm64/kernel/fpsimd.c ##
     @@ arch/arm64/kernel/fpsimd.c: static void sve_init_regs(void)
    + 		fpsimd_bind_task_to_cpu();
      	} else {
      		fpsimd_to_sve(current);
    - 		current->thread.fp_type = FP_STATE_SVE;
     +		fpsimd_flush_task_state(current);
      	}
      }
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |