diff --git a/arch/arc/boot/dts/haps_hs.dts b/arch/arc/boot/dts/haps_hs.dts
index 60d578e2781ff93b332aad1dfe4998fabe8dfe91..76ad527a084708af0da79f3a83708e4532710125 100644
--- a/arch/arc/boot/dts/haps_hs.dts
+++ b/arch/arc/boot/dts/haps_hs.dts
@@ -16,7 +16,7 @@ / {
 	memory {
 		device_type = "memory";
 		/* CONFIG_LINUX_RAM_BASE needs to match low mem start */
-		reg = <0x0 0x80000000 0x0 0x20000000	/* 512 MB low mem */
+		reg = <0x0 0x80000000 0x0 0x40000000	/* 1 GB low mem */
 		       0x1 0x00000000 0x0 0x40000000>;	/* 1 GB highmem */
 	};
 
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index a78d8f745a6787604108070286ad1f32db6008c4..fdbe06c98895ea34d306e780021f06b6ffa14214 100644
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -96,7 +96,7 @@ stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs,
 			     sizeof(sf->uc.uc_mcontext.regs.scratch));
 	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
 
-	return err;
+	return err ? -EFAULT : 0;
 }
 
 static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
@@ -110,7 +110,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
 				&(sf->uc.uc_mcontext.regs.scratch),
 				sizeof(sf->uc.uc_mcontext.regs.scratch));
 	if (err)
-		return err;
+		return -EFAULT;
 
 	set_current_blocked(&set);
 	regs->bta	= uregs.scratch.bta;
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 74ad4256022e4b80ac9b2937a1e86471197d1909..47bab67f8649b53f0fffddca05ea5d87983ec37d 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -187,25 +187,26 @@ static void init_unwind_table(struct unwind_table *table, const char *name,
 			      const void *table_start, unsigned long table_size,
 			      const u8 *header_start, unsigned long header_size)
 {
-	const u8 *ptr = header_start + 4;
-	const u8 *end = header_start + header_size;
-
 	table->core.pc = (unsigned long)core_start;
 	table->core.range = core_size;
 	table->init.pc = (unsigned long)init_start;
 	table->init.range = init_size;
 	table->address = table_start;
 	table->size = table_size;
-
-	/* See if the linker provided table looks valid. */
-	if (header_size <= 4
-	    || header_start[0] != 1
-	    || (void *)read_pointer(&ptr, end, header_start[1]) != table_start
-	    || header_start[2] == DW_EH_PE_omit
-	    || read_pointer(&ptr, end, header_start[2]) <= 0
-	    || header_start[3] == DW_EH_PE_omit)
-		header_start = NULL;
-
+	/* To avoid the pointer addition with NULL pointer.*/
+	if (header_start != NULL) {
+		const u8 *ptr = header_start + 4;
+		const u8 *end = header_start + header_size;
+		/* See if the linker provided table looks valid. */
+		if (header_size <= 4
+		|| header_start[0] != 1
+		|| (void *)read_pointer(&ptr, end, header_start[1])
+				!= table_start
+		|| header_start[2] == DW_EH_PE_omit
+		|| read_pointer(&ptr, end, header_start[2]) <= 0
+		|| header_start[3] == DW_EH_PE_omit)
+			header_start = NULL;
+	}
 	table->hdrsz = header_size;
 	smp_wmb();
 	table->header = header_start;