arm64: stacktrace: rename stackframe to unwind_state

Rename "struct stackframe" to "struct unwind_state" for consistency and
better naming. Accordingly, rename variable/argument "frame" to "state".

There should be no functional change as a result of this patch.

Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Kalesh Singh <kaleshsingh@google.com> for the series.
Link: https://lore.kernel.org/r/20220413145910.3060139-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: madvenka786

arch/arm64/kernel/stacktrace.c

@@ -39,7 +39,7 @@
  *               associated with the most recently encountered replacement lr
  *               value.
  */
-struct stackframe {
+struct unwind_state {
 	unsigned long fp;
 	unsigned long pc;
 	DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
@@ -50,13 +50,13 @@ struct stackframe {
 #endif
 };
 
-static notrace void unwind_init(struct stackframe *frame, unsigned long fp,
+static notrace void unwind_init(struct unwind_state *state, unsigned long fp,
 				unsigned long pc)
 {
-	frame->fp = fp;
-	frame->pc = pc;
+	state->fp = fp;
+	state->pc = pc;
 #ifdef CONFIG_KRETPROBES
-	frame->kr_cur = NULL;
+	state->kr_cur = NULL;
 #endif
 
 	/*
@@ -68,9 +68,9 @@ static notrace void unwind_init(struct stackframe *frame, unsigned long fp,
 	 * prev_fp value won't be used, but we set it to 0 such that it is
 	 * definitely not an accessible stack address.
 	 */
-	bitmap_zero(frame->stacks_done, __NR_STACK_TYPES);
-	frame->prev_fp = 0;
-	frame->prev_type = STACK_TYPE_UNKNOWN;
+	bitmap_zero(state->stacks_done, __NR_STACK_TYPES);
+	state->prev_fp = 0;
+	state->prev_type = STACK_TYPE_UNKNOWN;
 }
 NOKPROBE_SYMBOL(unwind_init);
 
@@ -82,9 +82,9 @@ NOKPROBE_SYMBOL(unwind_init);
  * and the location (but not the fp value) of B.
  */
 static int notrace unwind_next(struct task_struct *tsk,
-			       struct stackframe *frame)
+			       struct unwind_state *state)
 {
-	unsigned long fp = frame->fp;
+	unsigned long fp = state->fp;
 	struct stack_info info;
 
 	/* Final frame; nothing to unwind */
@@ -97,7 +97,7 @@ static int notrace unwind_next(struct task_struct *tsk,
 	if (!on_accessible_stack(tsk, fp, 16, &info))
 		return -EINVAL;
 
-	if (test_bit(info.type, frame->stacks_done))
+	if (test_bit(info.type, state->stacks_done))
 		return -EINVAL;
 
 	/*
@@ -113,60 +113,60 @@ static int notrace unwind_next(struct task_struct *tsk,
 	 * stack to another, it's never valid to unwind back to that first
 	 * stack.
 	 */
-	if (info.type == frame->prev_type) {
-		if (fp <= frame->prev_fp)
+	if (info.type == state->prev_type) {
+		if (fp <= state->prev_fp)
 			return -EINVAL;
 	} else {
-		set_bit(frame->prev_type, frame->stacks_done);
+		set_bit(state->prev_type, state->stacks_done);
 	}
 
 	/*
 	 * Record this frame record's values and location. The prev_fp and
 	 * prev_type are only meaningful to the next unwind_next() invocation.
 	 */
-	frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
-	frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
-	frame->prev_fp = fp;
-	frame->prev_type = info.type;
+	state->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
+	state->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
+	state->prev_fp = fp;
+	state->prev_type = info.type;
 
-	frame->pc = ptrauth_strip_insn_pac(frame->pc);
+	state->pc = ptrauth_strip_insn_pac(state->pc);
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	if (tsk->ret_stack &&
-		(frame->pc == (unsigned long)return_to_handler)) {
+		(state->pc == (unsigned long)return_to_handler)) {
 		unsigned long orig_pc;
 		/*
 		 * This is a case where function graph tracer has
 		 * modified a return address (LR) in a stack frame
 		 * to hook a function return.
 		 * So replace it to an original value.
 		 */
-		orig_pc = ftrace_graph_ret_addr(tsk, NULL, frame->pc,
-						(void *)frame->fp);
-		if (WARN_ON_ONCE(frame->pc == orig_pc))
+		orig_pc = ftrace_graph_ret_addr(tsk, NULL, state->pc,
+						(void *)state->fp);
+		if (WARN_ON_ONCE(state->pc == orig_pc))
 			return -EINVAL;
-		frame->pc = orig_pc;
+		state->pc = orig_pc;
 	}
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 #ifdef CONFIG_KRETPROBES
-	if (is_kretprobe_trampoline(frame->pc))
-		frame->pc = kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr_cur);
+	if (is_kretprobe_trampoline(state->pc))
+		state->pc = kretprobe_find_ret_addr(tsk, (void *)state->fp, &state->kr_cur);
 #endif
 
 	return 0;
 }
 NOKPROBE_SYMBOL(unwind_next);
 
 static void notrace unwind(struct task_struct *tsk,
-			   struct stackframe *frame,
+			   struct unwind_state *state,
 			   bool (*fn)(void *, unsigned long), void *data)
 {
 	while (1) {
 		int ret;
 
-		if (!fn(data, frame->pc))
+		if (!fn(data, state->pc))
 			break;
-		ret = unwind_next(tsk, frame);
+		ret = unwind_next(tsk, state);
 		if (ret < 0)
 			break;
 	}
@@ -210,17 +210,17 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
 			      void *cookie, struct task_struct *task,
 			      struct pt_regs *regs)
 {
-	struct stackframe frame;
+	struct unwind_state state;
 
 	if (regs)
-		unwind_init(&frame, regs->regs[29], regs->pc);
+		unwind_init(&state, regs->regs[29], regs->pc);
 	else if (task == current)
-		unwind_init(&frame,
+		unwind_init(&state,
 				(unsigned long)__builtin_frame_address(1),
 				(unsigned long)__builtin_return_address(0));
 	else
-		unwind_init(&frame, thread_saved_fp(task),
+		unwind_init(&state, thread_saved_fp(task),
 				thread_saved_pc(task));
 
-	unwind(task, &frame, consume_entry, cookie);
+	unwind(task, &state, consume_entry, cookie);
 }