Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 871c739..091c115 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -50,7 +50,7 @@
 		ret = do_ni_syscall(regs, scno);
 	}
 
-	regs->regs[0] = ret;
+	syscall_set_return_value(current, regs, 0, ret);
 }
 
 static inline bool has_syscall_work(unsigned long flags)
@@ -99,13 +99,13 @@
 	regs->syscallno = scno;
 
 	cortex_a76_erratum_1463225_svc_handler();
+	user_exit_irqoff();
 	local_daif_restore(DAIF_PROCCTX);
-	user_exit();
 
 	if (has_syscall_work(flags)) {
 		/* set default errno for user-issued syscall(-1) */
 		if (scno == NO_SYSCALL)
-			regs->regs[0] = -ENOSYS;
+			syscall_set_return_value(current, regs, -ENOSYS, 0);
 		scno = syscall_trace_enter(regs);
 		if (scno == NO_SYSCALL)
 			goto trace_exit;
@@ -121,7 +121,7 @@
 	if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) {
 		local_daif_mask();
 		flags = current_thread_info()->flags;
-		if (!has_syscall_work(flags)) {
+		if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP)) {
 			/*
 			 * We're off to userspace, where interrupts are
 			 * always enabled after we restore the flags from