1 files changed, 63 insertions, 65 deletions

diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 180d951d3624..08378fea3a11 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -84,14 +84,17 @@ static long save_v_state(struct pt_regs *regs, void __user **sc_vec)
 	datap = state + 1;
 
 	/* datap is designed to be 16 byte aligned for better performance */
-	WARN_ON(unlikely(!IS_ALIGNED((unsigned long)datap, 16)));
+	WARN_ON(!IS_ALIGNED((unsigned long)datap, 16));
+
+	get_cpu_vector_context();
+	riscv_v_vstate_save(&current->thread.vstate, regs);
+	put_cpu_vector_context();
 
-	riscv_v_vstate_save(current, regs);
 	/* Copy everything of vstate but datap. */
 	err = __copy_to_user(&state->v_state, &current->thread.vstate,
 			     offsetof(struct __riscv_v_ext_state, datap));
 	/* Copy the pointer datap itself. */
-	err |= __put_user(datap, &state->v_state.datap);
+	err |= __put_user((__force void *)datap, &state->v_state.datap);
 	/* Copy the whole vector content to user space datap. */
 	err |= __copy_to_user(datap, current->thread.vstate.datap, riscv_v_vsize);
 	/* Copy magic to the user space after saving  all vector conetext */
@@ -116,6 +119,13 @@ static long __restore_v_state(struct pt_regs *regs, void __user *sc_vec)
 	struct __sc_riscv_v_state __user *state = sc_vec;
 	void __user *datap;
 
+	/*
+	 * Mark the vstate as clean prior performing the actual copy,
+	 * to avoid getting the vstate incorrectly clobbered by the
+	 *  discarded vector state.
+	 */
+	riscv_v_vstate_set_restore(current, regs);
+
 	/* Copy everything of __sc_riscv_v_state except datap. */
 	err = __copy_from_user(&current->thread.vstate, &state->v_state,
 			       offsetof(struct __riscv_v_ext_state, datap));
@@ -130,13 +140,7 @@ static long __restore_v_state(struct pt_regs *regs, void __user *sc_vec)
 	 * Copy the whole vector content from user space datap. Use
 	 * copy_from_user to prevent information leak.
 	 */
-	err = copy_from_user(current->thread.vstate.datap, datap, riscv_v_vsize);
-	if (unlikely(err))
-		return err;
-
-	riscv_v_vstate_restore(current, regs);
-
-	return err;
+	return copy_from_user(current->thread.vstate.datap, datap, riscv_v_vsize);
 }
 #else
 #define save_v_state(task, regs) (0)
@@ -185,7 +189,7 @@ static long restore_sigcontext(struct pt_regs *regs,
 
 			return 0;
 		case RISCV_V_MAGIC:
-			if (!has_vector() || !riscv_v_vstate_query(regs) ||
+			if (!(has_vector() || has_xtheadvector()) || !riscv_v_vstate_query(regs) ||
 			    size != riscv_v_sc_size)
 				return -EINVAL;
 
@@ -207,16 +211,10 @@ static size_t get_rt_frame_size(bool cal_all)
 
 	frame_size = sizeof(*frame);
 
-	if (has_vector()) {
+	if (has_vector() || has_xtheadvector()) {
 		if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
 			total_context_size += riscv_v_sc_size;
 	}
-	/*
-	 * Preserved a __riscv_ctx_hdr for END signal context header if an
-	 * extension uses __riscv_extra_ext_header
-	 */
-	if (total_context_size)
-		total_context_size += sizeof(struct __riscv_ctx_hdr);
 
 	frame_size += total_context_size;
 
@@ -280,7 +278,7 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
 	if (has_fpu())
 		err |= save_fp_state(regs, &sc->sc_fpregs);
 	/* Save the vector state. */
-	if (has_vector() && riscv_v_vstate_query(regs))
+	if ((has_vector() || has_xtheadvector()) && riscv_v_vstate_query(regs))
 		err |= save_v_state(regs, (void __user **)&sc_ext_ptr);
 	/* Write zero to fp-reserved space and check it on restore_sigcontext */
 	err |= __put_user(0, &sc->sc_extdesc.reserved);
@@ -311,13 +309,6 @@ static inline void __user *get_sigframe(struct ksignal *ksig,
 	/* Align the stack frame. */
 	sp &= ~0xfUL;
 
-	/*
-	 * Fail if the size of the altstack is not large enough for the
-	 * sigframe construction.
-	 */
-	if (current->sas_ss_size && sp < current->sas_ss_sp)
-		return (void __user __force *)-1UL;
-
 	return (void __user *)sp;
 }
 
@@ -391,30 +382,6 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 	sigset_t *oldset = sigmask_to_save();
 	int ret;
 
-	/* Are we from a system call? */
-	if (regs->cause == EXC_SYSCALL) {
-		/* Avoid additional syscall restarting via ret_from_exception */
-		regs->cause = -1UL;
-		/* If so, check system call restarting.. */
-		switch (regs->a0) {
-		case -ERESTART_RESTARTBLOCK:
-		case -ERESTARTNOHAND:
-			regs->a0 = -EINTR;
-			break;
-
-		case -ERESTARTSYS:
-			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
-				regs->a0 = -EINTR;
-				break;
-			}
-			fallthrough;
-		case -ERESTARTNOINTR:
-                        regs->a0 = regs->orig_a0;
-			regs->epc -= 0x4;
-			break;
-		}
-	}
-
 	rseq_signal_deliver(ksig, regs);
 
 	/* Set up the stack frame */
@@ -428,36 +395,67 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 
 void arch_do_signal_or_restart(struct pt_regs *regs)
 {
+	unsigned long continue_addr = 0, restart_addr = 0;
+	int retval = 0;
 	struct ksignal ksig;
+	bool syscall = (regs->cause == EXC_SYSCALL);
 
-	if (get_signal(&ksig)) {
-		/* Actually deliver the signal */
-		handle_signal(&ksig, regs);
-		return;
-	}
+	/* If we were from a system call, check for system call restarting */
+	if (syscall) {
+		continue_addr = regs->epc;
+		restart_addr = continue_addr - 4;
+		retval = regs->a0;
 
-	/* Did we come from a system call? */
-	if (regs->cause == EXC_SYSCALL) {
 		/* Avoid additional syscall restarting via ret_from_exception */
 		regs->cause = -1UL;
 
-		/* Restart the system call - no handlers present */
-		switch (regs->a0) {
+		/*
+		 * Prepare for system call restart. We do this here so that a
+		 * debugger will see the already changed PC.
+		 */
+		switch (retval) {
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
-                        regs->a0 = regs->orig_a0;
-			regs->epc -= 0x4;
-			break;
 		case -ERESTART_RESTARTBLOCK:
-                        regs->a0 = regs->orig_a0;
-			regs->a7 = __NR_restart_syscall;
-			regs->epc -= 0x4;
+			regs->a0 = regs->orig_a0;
+			regs->epc = restart_addr;
 			break;
 		}
 	}
 
 	/*
+	 * Get the signal to deliver. When running under ptrace, at this point
+	 * the debugger may change all of our registers.
+	 */
+	if (get_signal(&ksig)) {
+		/*
+		 * Depending on the signal settings, we may need to revert the
+		 * decision to restart the system call, but skip this if a
+		 * debugger has chosen to restart at a different PC.
+		 */
+		if (regs->epc == restart_addr &&
+		    (retval == -ERESTARTNOHAND ||
+		     retval == -ERESTART_RESTARTBLOCK ||
+		     (retval == -ERESTARTSYS &&
+		      !(ksig.ka.sa.sa_flags & SA_RESTART)))) {
+			regs->a0 = -EINTR;
+			regs->epc = continue_addr;
+		}
+
+		/* Actually deliver the signal */
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/*
+	 * Handle restarting a different system call. As above, if a debugger
+	 * has chosen to restart at a different PC, ignore the restart.
+	 */
+	if (syscall && regs->epc == restart_addr && retval == -ERESTART_RESTARTBLOCK)
+		regs->a7 = __NR_restart_syscall;
+
+	/*
 	 * If there is no signal to deliver, we just put the saved
 	 * sigmask back.
 	 */