| Message ID | 20240130-arm64-sve-signal-regs-v2-1-9fc6f9502782@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] arm64/signal: Don't assume that TIF_SVE means we saved SVE state | expand |
On Tue, 30 Jan 2024 15:43:53 +0000, Mark Brown wrote: > When we are in a syscall we will only save the FPSIMD subset even though > the task still has access to the full register set, and on context switch > we will only remove TIF_SVE when loading the register state. This means > that the signal handling code should not assume that TIF_SVE means that > the register state is stored in SVE format, it should instead check the > format that was recorded during save. > > [...] Applied to arm64 (for-next/fixes), thanks! [1/1] arm64/signal: Don't assume that TIF_SVE means we saved SVE state https://git.kernel.org/arm64/c/61da7c8e2a60 Cheers,
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index a5dc6f764195..25ceaee6b025 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1635,7 +1635,7 @@ void fpsimd_preserve_current_state(void) void fpsimd_signal_preserve_current_state(void) { fpsimd_preserve_current_state(); - if (test_thread_flag(TIF_SVE)) + if (current->thread.fp_type == FP_STATE_SVE) sve_to_fpsimd(current); } diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 0e8beb3349ea..425b1bc17a3f 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -242,7 +242,7 @@ static int preserve_sve_context(struct sve_context __user *ctx) vl = task_get_sme_vl(current); vq = sve_vq_from_vl(vl); flags |= SVE_SIG_FLAG_SM; - } else if (test_thread_flag(TIF_SVE)) { + } else if (current->thread.fp_type == FP_STATE_SVE) { vq = sve_vq_from_vl(vl); } @@ -878,7 +878,7 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, if (system_supports_sve() || system_supports_sme()) { unsigned int vq = 0; - if (add_all || test_thread_flag(TIF_SVE) || + if (add_all || current->thread.fp_type == FP_STATE_SVE || thread_sm_enabled(¤t->thread)) { int vl = max(sve_max_vl(), sme_max_vl());
When we are in a syscall we will only save the FPSIMD subset even though the task still has access to the full register set, and on context switch we will only remove TIF_SVE when loading the register state. This means that the signal handling code should not assume that TIF_SVE means that the register state is stored in SVE format, it should instead check the format that was recorded during save. Fixes: 8c845e273104 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch") Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org --- Changes in v2: - Rebase onto v6.8-rc2. - Link to v1: https://lore.kernel.org/r/20240119-arm64-sve-signal-regs-v1-1-b9fd61b0289a@kernel.org --- arch/arm64/kernel/fpsimd.c | 2 +- arch/arm64/kernel/signal.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) --- base-commit: 41bccc98fb7931d63d03f326a746ac4d429c1dd3 change-id: 20240118-arm64-sve-signal-regs-5711e0d10425 Best regards,