[PATCH 6.1 091/127] arm64/fpsimd: Clear SME state in the target task when setting the VL

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Mark Brown <broonie@xxxxxxxxxx>

commit c9bb40b7f786662e33d71afe236442b0b61f0446 upstream.

When setting SME vector lengths we clear TIF_SME to reenable SME traps,
doing a reallocation of the backing storage on next use. We do this using
clear_thread_flag() which operates on the current thread, meaning that when
setting the vector length via ptrace we may both not force traps for the
target task and force a spurious flush of any SME state that the tracing
task may have.

Clear the flag in the target task.

Fixes: e12310a0d30f ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Reported-by: David Spickett <David.Spickett@xxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-tif-sme-v1-1-88312fd6fbfd@xxxxxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/arm64/kernel/fpsimd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -864,7 +864,7 @@ int vec_set_vector_length(struct task_st
 			 */
 			task->thread.svcr &= ~(SVCR_SM_MASK |
 					       SVCR_ZA_MASK);
-			clear_thread_flag(TIF_SME);
+			clear_tsk_thread_flag(task, TIF_SME);
 			free_sme = true;
 		}
 	}





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux