diff options
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 28 | ||||
| -rw-r--r-- | arch/arm64/kernel/signal.c | 66 |
3 files changed, 12 insertions, 83 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 1a18f851b614..b7adb2c72204 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -76,7 +76,6 @@ extern void fpsimd_load_state(struct user_fpsimd_state *state); extern void fpsimd_thread_switch(struct task_struct *next); extern void fpsimd_flush_thread(void); -extern void fpsimd_signal_preserve_current_state(void); extern void fpsimd_preserve_current_state(void); extern void fpsimd_restore_current_state(void); extern void fpsimd_update_current_state(struct user_fpsimd_state const *state); diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index ea07c4577f17..b0874402f7ec 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1663,18 +1663,6 @@ void fpsimd_preserve_current_state(void) } /* - * Like fpsimd_preserve_current_state(), but ensure that - * current->thread.uw.fpsimd_state is updated so that it can be copied to - * the signal frame. - */ -void fpsimd_signal_preserve_current_state(void) -{ - fpsimd_preserve_current_state(); - if (current->thread.fp_type == FP_STATE_SVE) - sve_to_fpsimd(current); -} - -/* * Associate current's FPSIMD context with this cpu * The caller must have ownership of the cpu FPSIMD context before calling * this function. @@ -1766,30 +1754,14 @@ void fpsimd_restore_current_state(void) put_cpu_fpsimd_context(); } -/* - * Load an updated userland FPSIMD state for 'current' from memory and set the - * flag that indicates that the FPSIMD register contents are the most recent - * FPSIMD state of 'current'. This is used by the signal code to restore the - * register state when returning from a signal handler in FPSIMD only cases, - * any SVE context will be discarded. - */ void fpsimd_update_current_state(struct user_fpsimd_state const *state) { if (WARN_ON(!system_supports_fpsimd())) return; - get_cpu_fpsimd_context(); - current->thread.uw.fpsimd_state = *state; if (current->thread.fp_type == FP_STATE_SVE) fpsimd_to_sve(current); - - task_fpsimd_load(); - fpsimd_bind_task_to_cpu(); - - clear_thread_flag(TIF_FOREIGN_FPSTATE); - - put_cpu_fpsimd_context(); } /* diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index a7c37afb4ebe..0de9c452c6c0 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -250,6 +250,8 @@ static int preserve_fpsimd_context(struct fpsimd_context __user *ctx) ¤t->thread.uw.fpsimd_state; int err; + sve_sync_to_fpsimd(current); + /* copy the FP and status/control registers */ err = __copy_to_user(ctx->vregs, fpsimd->vregs, sizeof(fpsimd->vregs)); __put_user_error(fpsimd->fpsr, &ctx->fpsr, err); @@ -291,8 +293,6 @@ static int preserve_fpmr_context(struct fpmr_context __user *ctx) { int err = 0; - current->thread.uw.fpmr = read_sysreg_s(SYS_FPMR); - __put_user_error(FPMR_MAGIC, &ctx->head.magic, err); __put_user_error(sizeof(*ctx), &ctx->head.size, err); __put_user_error(current->thread.uw.fpmr, &ctx->fpmr, err); @@ -310,7 +310,7 @@ static int restore_fpmr_context(struct user_ctxs *user) __get_user_error(fpmr, &user->fpmr->fpmr, err); if (!err) - write_sysreg_s(fpmr, SYS_FPMR); + current->thread.uw.fpmr = fpmr; return err; } @@ -372,11 +372,6 @@ static int preserve_sve_context(struct sve_context __user *ctx) err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved)); if (vq) { - /* - * This assumes that the SVE state has already been saved to - * the task struct by calling the function - * fpsimd_signal_preserve_current_state(). - */ err |= __copy_to_user((char __user *)ctx + SVE_SIG_REGS_OFFSET, current->thread.sve_state, SVE_SIG_REGS_SIZE(vq)); @@ -432,16 +427,6 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user) if (user->sve_size < SVE_SIG_CONTEXT_SIZE(vq)) return -EINVAL; - /* - * Careful: we are about __copy_from_user() directly into - * thread.sve_state with preemption enabled, so protection is - * needed to prevent a racing context switch from writing stale - * registers back over the new data. - */ - - fpsimd_flush_task_state(current); - /* From now, fpsimd_thread_switch() won't touch thread.sve_state */ - sve_alloc(current, true); if (!current->thread.sve_state) { clear_thread_flag(TIF_SVE); @@ -541,11 +526,6 @@ static int preserve_za_context(struct za_context __user *ctx) err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved)); if (vq) { - /* - * This assumes that the ZA state has already been saved to - * the task struct by calling the function - * fpsimd_signal_preserve_current_state(). - */ err |= __copy_to_user((char __user *)ctx + ZA_SIG_REGS_OFFSET, current->thread.sme_state, ZA_SIG_REGS_SIZE(vq)); @@ -580,16 +560,6 @@ static int restore_za_context(struct user_ctxs *user) if (user->za_size < ZA_SIG_CONTEXT_SIZE(vq)) return -EINVAL; - /* - * Careful: we are about __copy_from_user() directly into - * thread.sme_state with preemption enabled, so protection is - * needed to prevent a racing context switch from writing stale - * registers back over the new data. - */ - - fpsimd_flush_task_state(current); - /* From now, fpsimd_thread_switch() won't touch thread.sve_state */ - sme_alloc(current, true); if (!current->thread.sme_state) { current->thread.svcr &= ~SVCR_ZA_MASK; @@ -627,11 +597,6 @@ static int preserve_zt_context(struct zt_context __user *ctx) BUILD_BUG_ON(sizeof(ctx->__reserved) != sizeof(reserved)); err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved)); - /* - * This assumes that the ZT state has already been saved to - * the task struct by calling the function - * fpsimd_signal_preserve_current_state(). - */ err |= __copy_to_user((char __user *)ctx + ZT_SIG_REGS_OFFSET, thread_zt_state(¤t->thread), ZT_SIG_REGS_SIZE(1)); @@ -657,16 +622,6 @@ static int restore_zt_context(struct user_ctxs *user) if (nregs != 1) return -EINVAL; - /* - * Careful: we are about __copy_from_user() directly into - * thread.zt_state with preemption enabled, so protection is - * needed to prevent a racing context switch from writing stale - * registers back over the new data. - */ - - fpsimd_flush_task_state(current); - /* From now, fpsimd_thread_switch() won't touch ZT in thread state */ - err = __copy_from_user(thread_zt_state(¤t->thread), (char __user const *)user->zt + ZT_SIG_REGS_OFFSET, @@ -1017,6 +972,8 @@ static int restore_sigframe(struct pt_regs *regs, */ forget_syscall(regs); + fpsimd_save_and_flush_current_state(); + err |= !valid_user_regs(®s->user_regs, current); if (err == 0) err = parse_user_sigframe(&user, sf); @@ -1510,8 +1467,11 @@ static int setup_return(struct pt_regs *regs, struct ksignal *ksig, /* * If we were in streaming mode the saved register * state was SVE but we will exit SM and use the - * FPSIMD register state - flush the saved FPSIMD - * register state in case it gets loaded. + * FPSIMD register state. + * + * TODO: decide if this should behave as SMSTOP (e.g. reset + * FPSR + FPMR), or whether this should only clear the scalable + * registers + ZA state. */ if (current->thread.svcr & SVCR_SM_MASK) { memset(¤t->thread.uw.fpsimd_state, 0, @@ -1519,9 +1479,7 @@ static int setup_return(struct pt_regs *regs, struct ksignal *ksig, current->thread.fp_type = FP_STATE_FPSIMD; } - current->thread.svcr &= ~(SVCR_ZA_MASK | - SVCR_SM_MASK); - sme_smstop(); + current->thread.svcr &= ~(SVCR_ZA_MASK | SVCR_SM_MASK); } return 0; @@ -1535,7 +1493,7 @@ static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set, struct user_access_state ua_state; int err = 0; - fpsimd_signal_preserve_current_state(); + fpsimd_save_and_flush_current_state(); if (get_sigframe(&user, ksig, regs)) return 1; |