Merge tag 'parisc-for-6.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc fix from Helge Deller:

 - fix crash triggered by unaligned access in parisc unwinder

* tag 'parisc-for-6.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Avoid crash due to unaligned access in unwinder

Author: torvalds

arch/parisc/kernel/unwind.c

@@ -35,6 +35,8 @@
 
 #define KERNEL_START (KERNEL_BINARY_TEXT_START)
 
+#define ALIGNMENT_OK(ptr, type) (((ptr) & (sizeof(type) - 1)) == 0)
+
 extern struct unwind_table_entry __start___unwind[];
 extern struct unwind_table_entry __stop___unwind[];
 
@@ -257,12 +259,15 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
 	if (pc_is_kernel_fn(pc, _switch_to) ||
 	    pc == (unsigned long)&_switch_to_ret) {
 		info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE;
-		info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET);
+		if (ALIGNMENT_OK(info->prev_sp, long))
+			info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET);
+		else
+			info->prev_ip = info->prev_sp = 0;
 		return 1;
 	}
 
 #ifdef CONFIG_IRQSTACKS
-	if (pc == (unsigned long)&_call_on_stack) {
+	if (pc == (unsigned long)&_call_on_stack && ALIGNMENT_OK(info->sp, long)) {
 		info->prev_sp = *(unsigned long *)(info->sp - FRAME_SIZE - REG_SZ);
 		info->prev_ip = *(unsigned long *)(info->sp - FRAME_SIZE - RP_OFFSET);
 		return 1;
@@ -370,8 +375,10 @@ static void unwind_frame_regs(struct unwind_frame_info *info)
 			info->prev_sp = info->sp - frame_size;
 			if (e->Millicode)
 				info->rp = info->r31;
-			else if (rpoffset)
+			else if (rpoffset && ALIGNMENT_OK(info->prev_sp, long))
 				info->rp = *(unsigned long *)(info->prev_sp - rpoffset);
+			else
+				info->rp = 0;
 			info->prev_ip = info->rp;
 			info->rp = 0;
 		}