[PATCH v4 7/9] arm64: stacktrace: remove stack type from fp translator

[Mark Rutland]

In subsequent patches we'll remove the stack_type enum, and move the FP
translation logic out of the raw FP unwind code.

In preparation for doing so, this patch removes the type parameter from
the FP translation callback, and modifies kvm_nvhe_stack_kern_va() to
determine the relevant stack directly.

So that kvm_nvhe_stack_kern_va() can use the stackinfo_*() helpers,
these are moved earlier in the file, but are not modified in any way.

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 |  6 +-
 arch/arm64/kvm/stacktrace.c                | 82 +++++++++++++---------
 2 files changed, 49 insertions(+), 39 deletions(-)

diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
index 3c3bda34bb872..2f972441f572e 100644
--- a/arch/arm64/include/asm/stacktrace/common.h
+++ b/arch/arm64/include/asm/stacktrace/common.h
@@ -113,14 +113,12 @@ static inline void unwind_init_common(struct unwind_state *state,
  * pointer to a kernel address.
  *
  * @fp:   the frame pointer to be updated to its kernel address.
- * @type: the stack type associated with frame pointer @fp
  *
  * Return: true if the VA can be translated, false otherwise.
  *
  * Upon success @fp is updated to the corresponding kernel virtual address.
  */
-typedef bool (*stack_trace_translate_fp_fn)(unsigned long *fp,
-					    enum stack_type type);
+typedef bool (*stack_trace_translate_fp_fn)(unsigned long *fp);
 
 /**
  * typedef on_accessible_stack_fn() - Check whether a stack range is on any of
@@ -172,7 +170,7 @@ unwind_next_frame_record(struct unwind_state *state,
 	 * 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))
 		return -EINVAL;
 
 	/*
diff --git a/arch/arm64/kvm/stacktrace.c b/arch/arm64/kvm/stacktrace.c
index 26927344a2632..7658c5db47c1d 100644
--- a/arch/arm64/kvm/stacktrace.c
+++ b/arch/arm64/kvm/stacktrace.c
@@ -21,6 +21,34 @@
 
 #include <asm/stacktrace/nvhe.h>
 
+static struct stack_info stackinfo_get_overflow(void)
+{
+	struct kvm_nvhe_stacktrace_info *stacktrace_info
+				= this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+	unsigned long low = (unsigned long)stacktrace_info->overflow_stack_base;
+	unsigned long high = low + OVERFLOW_STACK_SIZE;
+
+	return (struct stack_info) {
+		.low = low,
+		.high = high,
+		.type = STACK_TYPE_OVERFLOW,
+	};
+}
+
+static struct stack_info stackinfo_get_hyp(void)
+{
+	struct kvm_nvhe_stacktrace_info *stacktrace_info
+				= this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+	unsigned long low = (unsigned long)stacktrace_info->stack_base;
+	unsigned long high = low + PAGE_SIZE;
+
+	return (struct stack_info) {
+		.low = low,
+		.high = high,
+		.type = STACK_TYPE_HYP,
+	};
+}
+
 /*
  * kvm_nvhe_stack_kern_va - Convert KVM nVHE HYP stack addresses to a kernel VAs
  *
@@ -34,27 +62,31 @@
  * Returns true on success and updates @addr to its corresponding kernel VA;
  * otherwise returns false.
  */
-static bool kvm_nvhe_stack_kern_va(unsigned long *addr,
-				   enum stack_type type)
+static bool kvm_nvhe_stack_kern_va(unsigned long *addr, unsigned long size)
 {
 	struct kvm_nvhe_stacktrace_info *stacktrace_info;
 	unsigned long hyp_base, kern_base, hyp_offset;
+	struct stack_info stack;
 
 	stacktrace_info = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
 
-	switch (type) {
-	case STACK_TYPE_HYP:
+	stack = stackinfo_get_hyp();
+	if (stackinfo_on_stack(&stack, *addr, size)) {
 		kern_base = (unsigned long)*this_cpu_ptr(&kvm_arm_hyp_stack_page);
 		hyp_base = (unsigned long)stacktrace_info->stack_base;
-		break;
-	case STACK_TYPE_OVERFLOW:
+		goto found;
+	}
+
+	stack = stackinfo_get_overflow();
+	if (stackinfo_on_stack(&stack, *addr, size)) {
 		kern_base = (unsigned long)this_cpu_ptr_nvhe_sym(overflow_stack);
 		hyp_base = (unsigned long)stacktrace_info->overflow_stack_base;
-		break;
-	default:
-		return false;
+		goto found;
 	}
 
+	return false;
+
+found:
 	hyp_offset = *addr - hyp_base;
 
 	*addr = kern_base + hyp_offset;
@@ -62,32 +94,12 @@ static bool kvm_nvhe_stack_kern_va(unsigned long *addr,
 	return true;
 }
 
-static struct stack_info stackinfo_get_overflow(void)
-{
-	struct kvm_nvhe_stacktrace_info *stacktrace_info
-				= this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
-	unsigned long low = (unsigned long)stacktrace_info->overflow_stack_base;
-	unsigned long high = low + OVERFLOW_STACK_SIZE;
-
-	return (struct stack_info) {
-		.low = low,
-		.high = high,
-		.type = STACK_TYPE_OVERFLOW,
-	};
-}
-
-static struct stack_info stackinfo_get_hyp(void)
+/*
+ * Convert a KVN nVHE HYP frame record address to a kernel VA
+ */
+static bool kvm_nvhe_stack_kern_record_va(unsigned long *addr)
 {
-	struct kvm_nvhe_stacktrace_info *stacktrace_info
-				= this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
-	unsigned long low = (unsigned long)stacktrace_info->stack_base;
-	unsigned long high = low + PAGE_SIZE;
-
-	return (struct stack_info) {
-		.low = low,
-		.high = high,
-		.type = STACK_TYPE_HYP,
-	};
+	return kvm_nvhe_stack_kern_va(addr, 16);
 }
 
 static bool on_accessible_stack(const struct task_struct *tsk,
@@ -115,7 +127,7 @@ static bool on_accessible_stack(const struct task_struct *tsk,
 static int unwind_next(struct unwind_state *state)
 {
 	return unwind_next_frame_record(state, on_accessible_stack,
-					kvm_nvhe_stack_kern_va);
+					kvm_nvhe_stack_kern_record_va);
 }
 
 static void unwind(struct unwind_state *state,
-- 
2.30.2