diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
index c5534facf9416fefbec606ad8f320f023f662ce7..3c60f37e48ab51998db2c5870fe2df4427949b37 100644
--- a/arch/arm64/include/asm/ftrace.h
+++ b/arch/arm64/include/asm/ftrace.h
@@ -28,6 +28,8 @@ struct dyn_arch_ftrace {
extern unsigned long ftrace_graph_call;
+extern void return_to_handler(void);
+
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
/*
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 6fb61c5090b49bb07ca0e7e841f7a32f1b7bdb79..801a16dbbdf622d5239cf61be4f67eccab5c1e09 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -22,6 +22,9 @@ struct stackframe {
unsigned long fp;
unsigned long sp;
unsigned long pc;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ unsigned int graph;
+#endif
};
extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 797220da912b77c2bb4a795324d190ec77c83d62..ff4665462a025d4ec2655ca30d49732a63194e53 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -164,6 +164,9 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry,
frame.fp = regs->regs[29];
frame.sp = regs->sp;
frame.pc = regs->pc;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ frame.graph = current->curr_ret_stack;
+#endif
walk_stackframe(current, &frame, callchain_trace, entry);
}
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 98bf5461d4b6e2b802d516b5f21531905c61d864..88d742ba19d50590561c741ff3a1d48ba49c0ce3 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -344,6 +344,9 @@ unsigned long get_wchan(struct task_struct *p)
frame.fp = thread_saved_fp(p);
frame.sp = thread_saved_sp(p);
frame.pc = thread_saved_pc(p);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ frame.graph = p->curr_ret_stack;
+#endif
stack_page = (unsigned long)task_stack_page(p);
do {
if (frame.sp < stack_page ||
diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index 07b37ac05be44f4608fcb539c29bfe0c4763f309..1718706fde83604f78d81d850bf8827705338f1a 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -43,6 +43,9 @@ void *return_address(unsigned int level)
frame.fp = (unsigned long)__builtin_frame_address(0);
frame.sp = current_stack_pointer;
frame.pc = (unsigned long)return_address; /* dummy */
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ frame.graph = current->curr_ret_stack;
+#endif
walk_stackframe(current, &frame, save_return_addr, &data);
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index f7ee597ec8838b4a561e2876fb1d329c609f0b92..4fad9787ab46ed04bf36873e8f7f7eb724beb262 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -17,6 +17,7 @@
*/
#include <linux/kernel.h>
#include <linux/export.h>
+#include <linux/ftrace.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
@@ -66,6 +67,19 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
frame->fp = *(unsigned long *)(fp);
frame->pc = *(unsigned long *)(fp + 8);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (tsk && tsk->ret_stack &&
+ (frame->pc == (unsigned long)return_to_handler)) {
+ /*
+ * 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.
+ */
+ frame->pc = tsk->ret_stack[frame->graph--].ret;
+ }
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
/*
* Check whether we are going to walk through from interrupt stack
* to task stack.
@@ -158,6 +172,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
frame.sp = current_stack_pointer;
frame.pc = (unsigned long)save_stack_trace_tsk;
}
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ frame.graph = tsk->curr_ret_stack;
+#endif
walk_stackframe(tsk, &frame, save_trace, &data);
if (trace->nr_entries < trace->max_entries)
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index 6e5c521f123ac5a833b862763408acfd815be9d2..59779699a1a40ef3a1940aa0d878c16164ea5398 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -52,6 +52,9 @@ unsigned long profile_pc(struct pt_regs *regs)
frame.fp = regs->regs[29];
frame.sp = regs->sp;
frame.pc = regs->pc;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ frame.graph = -1; /* no task info */
+#endif
do {
int ret = unwind_frame(NULL, &frame);
if (ret < 0)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 937008523fa5d516381d272b44805b65f2f83048..bdc293f6adc43b347c85272d4868a3975f67fe72 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -147,17 +147,14 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
struct stackframe frame;
unsigned long irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
+ int skip;
pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
if (!tsk)
tsk = current;
- if (regs) {
- frame.fp = regs->regs[29];
- frame.sp = regs->sp;
- frame.pc = regs->pc;
- } else if (tsk == current) {
+ if (tsk == current) {
frame.fp = (unsigned long)__builtin_frame_address(0);
frame.sp = current_stack_pointer;
frame.pc = (unsigned long)dump_backtrace;
@@ -169,14 +166,31 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
frame.sp = thread_saved_sp(tsk);
frame.pc = thread_saved_pc(tsk);
}
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ frame.graph = tsk->curr_ret_stack;
+#endif
+ skip = !!regs;
pr_emerg("Call trace:\n");
while (1) {
unsigned long where = frame.pc;
unsigned long stack;
int ret;
- dump_backtrace_entry(where);
+ /* skip until specified stack frame */
+ if (!skip) {
+ dump_backtrace_entry(where);
+ } else if (frame.fp == regs->regs[29]) {
+ skip = 0;
+ /*
+ * Mostly, this is the case where this function is
+ * called in panic/abort. As exception handler's
+ * stack frame does not contain the corresponding pc
+ * at which an exception has taken place, use regs->pc
+ * instead.
+ */
+ dump_backtrace_entry(regs->pc);
+ }
ret = unwind_frame(tsk, &frame);
if (ret < 0)
break;