[PATCH v4 2/9] arm64: stacktrace: simplify unwind_next_common()

[Mark Rutland]

Currently unwind_next_common() takes a pointer to a stack_info which is
only ever used within unwind_next_common().

Make it a local variable and simplify callers.

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

Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Reviewed-by: Kalesh Singh <kaleshsingh at google.com>
Reviewed-by: Madhavan T. Venkataraman <madvenka at linux.microsoft.com>
Reviewed-by: Mark Brown <broonie at kernel.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Fuad Tabba <tabba at google.com>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Will Deacon <will at kernel.org>
---
 arch/arm64/include/asm/stacktrace/common.h | 12 ++++++------
 arch/arm64/kernel/stacktrace.c             |  3 +--
 arch/arm64/kvm/hyp/nvhe/stacktrace.c       |  4 +---
 arch/arm64/kvm/stacktrace.c                |  4 +---
 4 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
index b8b20ef5aa5db..0fbae7c78b70d 100644
--- a/arch/arm64/include/asm/stacktrace/common.h
+++ b/arch/arm64/include/asm/stacktrace/common.h
@@ -146,27 +146,27 @@ typedef bool (*on_accessible_stack_fn)(const struct task_struct *tsk,
 				       struct stack_info *info);
 
 static inline int unwind_next_common(struct unwind_state *state,
-				     struct stack_info *info,
 				     on_accessible_stack_fn accessible,
 				     stack_trace_translate_fp_fn translate_fp)
 {
+	struct stack_info info;
 	unsigned long fp = state->fp, kern_fp = fp;
 	struct task_struct *tsk = state->task;
 
 	if (fp & 0x7)
 		return -EINVAL;
 
-	if (!accessible(tsk, fp, 16, info))
+	if (!accessible(tsk, fp, 16, &info))
 		return -EINVAL;
 
-	if (test_bit(info->type, state->stacks_done))
+	if (test_bit(info.type, state->stacks_done))
 		return -EINVAL;
 
 	/*
 	 * If fp is not from the current address space perform the necessary
 	 * translation before dereferencing it to get the next fp.
 	 */
-	if (translate_fp && !translate_fp(&kern_fp, info->type))
+	if (translate_fp && !translate_fp(&kern_fp, info.type))
 		return -EINVAL;
 
 	/*
@@ -183,7 +183,7 @@ static inline int unwind_next_common(struct unwind_state *state,
 	 * stack to another, it's never valid to unwind back to that first
 	 * stack.
 	 */
-	if (info->type == state->prev_type) {
+	if (info.type == state->prev_type) {
 		if (fp <= state->prev_fp)
 			return -EINVAL;
 	} else {
@@ -197,7 +197,7 @@ static inline int unwind_next_common(struct unwind_state *state,
 	state->fp = READ_ONCE(*(unsigned long *)(kern_fp));
 	state->pc = READ_ONCE(*(unsigned long *)(kern_fp + 8));
 	state->prev_fp = fp;
-	state->prev_type = info->type;
+	state->prev_type = info.type;
 
 	return 0;
 }
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index ce190ee18a201..056fb045d0e0c 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -103,14 +103,13 @@ static int notrace unwind_next(struct unwind_state *state)
 {
 	struct task_struct *tsk = state->task;
 	unsigned long fp = state->fp;
-	struct stack_info info;
 	int err;
 
 	/* Final frame; nothing to unwind */
 	if (fp == (unsigned long)task_pt_regs(tsk)->stackframe)
 		return -ENOENT;
 
-	err = unwind_next_common(state, &info, on_accessible_stack, NULL);
+	err = unwind_next_common(state, on_accessible_stack, NULL);
 	if (err)
 		return err;
 
diff --git a/arch/arm64/kvm/hyp/nvhe/stacktrace.c b/arch/arm64/kvm/hyp/nvhe/stacktrace.c
index 58f645ad66bcb..50a1fa6b5c044 100644
--- a/arch/arm64/kvm/hyp/nvhe/stacktrace.c
+++ b/arch/arm64/kvm/hyp/nvhe/stacktrace.c
@@ -71,9 +71,7 @@ static bool on_accessible_stack(const struct task_struct *tsk,
 
 static int unwind_next(struct unwind_state *state)
 {
-	struct stack_info info;
-
-	return unwind_next_common(state, &info, on_accessible_stack, NULL);
+	return unwind_next_common(state, on_accessible_stack, NULL);
 }
 
 static void notrace unwind(struct unwind_state *state,
diff --git a/arch/arm64/kvm/stacktrace.c b/arch/arm64/kvm/stacktrace.c
index 949d19d603fba..b9cf551d9d31d 100644
--- a/arch/arm64/kvm/stacktrace.c
+++ b/arch/arm64/kvm/stacktrace.c
@@ -97,9 +97,7 @@ static bool on_accessible_stack(const struct task_struct *tsk,
 
 static int unwind_next(struct unwind_state *state)
 {
-	struct stack_info info;
-
-	return unwind_next_common(state, &info, on_accessible_stack,
+	return unwind_next_common(state, on_accessible_stack,
 				  kvm_nvhe_stack_kern_va);
 }
 
-- 
2.30.2