arm64: pass a task parameter to unwind_frame()
Function graph tracer modifies a return address (LR) in a stack frame
to hook a function's return. This will result in many useless entries
(return_to_handler) showing up in a call stack list.
We will fix this problem in a later patch ("arm64: ftrace: fix a stack
tracer's output under function graph tracer"). But since real return
addresses are saved in ret_stack[] array in struct task_struct,
unwind functions need to be notified of, in addition to a stack pointer
address, which task is being traced in order to find out real return
addresses.
This patch extends unwind functions' interfaces by adding an extra
argument of a pointer to task_struct.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 7318f6d..6fb61c5 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -16,14 +16,16 @@
#ifndef __ASM_STACKTRACE_H
#define __ASM_STACKTRACE_H
+struct task_struct;
+
struct stackframe {
unsigned long fp;
unsigned long sp;
unsigned long pc;
};
-extern int unwind_frame(struct stackframe *frame);
-extern void walk_stackframe(struct stackframe *frame,
+extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
+extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data);
#endif /* __ASM_STACKTRACE_H */
diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 3aa7483..797220d 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -165,7 +165,7 @@
frame.sp = regs->sp;
frame.pc = regs->pc;
- walk_stackframe(&frame, callchain_trace, entry);
+ walk_stackframe(current, &frame, callchain_trace, entry);
}
unsigned long perf_instruction_pointer(struct pt_regs *regs)
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index f75b540..98bf546 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -348,7 +348,7 @@
do {
if (frame.sp < stack_page ||
frame.sp >= stack_page + THREAD_SIZE ||
- unwind_frame(&frame))
+ unwind_frame(p, &frame))
return 0;
if (!in_sched_functions(frame.pc))
return frame.pc;
diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index 6c4fd28..07b37ac 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -44,7 +44,7 @@
frame.sp = current_stack_pointer;
frame.pc = (unsigned long)return_address; /* dummy */
- walk_stackframe(&frame, save_return_addr, &data);
+ walk_stackframe(current, &frame, save_return_addr, &data);
if (!data.level)
return data.addr;
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index b9fd3a8..f7ee597 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -36,7 +36,7 @@
* ldp x29, x30, [sp]
* add sp, sp, #0x10
*/
-int notrace unwind_frame(struct stackframe *frame)
+int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
{
unsigned long high, low;
unsigned long fp = frame->fp;
@@ -99,7 +99,7 @@
return 0;
}
-void notrace walk_stackframe(struct stackframe *frame,
+void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data)
{
while (1) {
@@ -107,7 +107,7 @@
if (fn(frame, data))
break;
- ret = unwind_frame(frame);
+ ret = unwind_frame(tsk, frame);
if (ret < 0)
break;
}
@@ -159,7 +159,7 @@
frame.pc = (unsigned long)save_stack_trace_tsk;
}
- walk_stackframe(&frame, save_trace, &data);
+ walk_stackframe(tsk, &frame, save_trace, &data);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index 13339b6..6e5c521 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -53,7 +53,7 @@
frame.sp = regs->sp;
frame.pc = regs->pc;
do {
- int ret = unwind_frame(&frame);
+ int ret = unwind_frame(NULL, &frame);
if (ret < 0)
return 0;
} while (in_lock_functions(frame.pc));
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 8a00845..9370085 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -177,7 +177,7 @@
int ret;
dump_backtrace_entry(where);
- ret = unwind_frame(&frame);
+ ret = unwind_frame(tsk, &frame);
if (ret < 0)
break;
stack = frame.sp;
