diff options
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 8 | ||||
| -rw-r--r-- | arch/arm64/kernel/syscall.c | 19 |
2 files changed, 12 insertions, 15 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 7cb2d89ead83..a66b8640a0a4 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -481,7 +481,13 @@ static void fpsimd_save(void) if (test_thread_flag(TIF_FOREIGN_FPSTATE)) return; - if ((last->to_save == FP_STATE_CURRENT && test_thread_flag(TIF_SVE)) || + /* + * If a task is in a syscall the ABI allows us to only + * preserve the state shared with FPSIMD so don't bother + * saving the full SVE state in that case. + */ + if ((last->to_save == FP_STATE_CURRENT && test_thread_flag(TIF_SVE) && + !in_syscall(current_pt_regs())) || last->to_save == FP_STATE_SVE) { save_sve_regs = true; save_ffr = true; diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index d72e8f23422d..a5de47e3df2b 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -183,21 +183,12 @@ static inline void fp_user_discard(void) if (!system_supports_sve()) return; - /* - * If SME is not active then disable SVE, the registers will - * be cleared when userspace next attempts to access them and - * we do not need to track the SVE register state until then. - */ - clear_thread_flag(TIF_SVE); + if (test_thread_flag(TIF_SVE)) { + unsigned int sve_vq_minus_one; - /* - * task_fpsimd_load() won't be called to update CPACR_EL1 in - * ret_to_user unless TIF_FOREIGN_FPSTATE is still set, which only - * happens if a context switch or kernel_neon_begin() or context - * modification (sigreturn, ptrace) intervenes. - * So, ensure that CPACR_EL1 is already correct for the fast-path case. - */ - sve_user_disable(); + sve_vq_minus_one = sve_vq_from_vl(task_get_sve_vl(current)) - 1; + sve_flush_live(true, sve_vq_minus_one); + } } void do_el0_svc(struct pt_regs *regs) |