From: Mark Brown <broonie@xxxxxxxxxx> 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@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-3-49df214bfb3e@xxxxxxxxxx Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -835,7 +835,8 @@ 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));