[PATCH 6.1 090/127] arm64/fpsimd: Sync and zero pad FPSIMD state for streaming SVE

Greg Kroah-Hartman
2023-08-09T10:55:24Z

From: Mark Brown <broonie@kernel.org>

commit 69af56ae56a48a2522aad906c4461c6c7c092737 upstream.

We have a function sve_sync_from_fpsimd_zeropad() which is used by the
ptrace code to update the SVE state when the user writes to the the
FPSIMD register set. Currently this checks that the task has SVE
enabled but this will miss updates for tasks which have streaming SVE
enabled if SVE has not been enabled for the thread, also do the
conversion if the task has streaming SVE enabled.

Fixes: e12310a0d30f ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-3-49df214bfb3e@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/kernel/fpsimd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -791,7 +791,8 @@ void sve_sync_from_fpsimd_zeropad(struct
void *sst = task->thread.sve_state;
struct user_fpsimd_state const *fst = &task->thread.uw.fpsimd_state;

- if (!test_tsk_thread_flag(task, TIF_SVE))
+ if (!test_tsk_thread_flag(task, TIF_SVE) &&
+ !thread_sm_enabled(&task->thread))
return;

vq = sve_vq_from_vl(thread_get_cur_vl(&task->thread));