diff mbox series

[v9,06/11] arm64: Make profile_pc() use arch_stack_walk()

Message ID 20211015023413.16614-9-madvenka@linux.microsoft.com (mailing list archive)
State New, archived
Headers show
Series arm64: Reorganize the unwinder and implement stack trace reliability checks | expand

Commit Message

Madhavan T. Venkataraman Oct. 15, 2021, 2:34 a.m. UTC 
From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>

Currently, profile_pc() in ARM64 code walks the stack using
start_backtrace() and unwind_frame(). Make it use arch_stack_walk()
instead. This makes maintenance easier.

Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
---
 arch/arm64/kernel/time.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index eebbc8d7123e..671b3038a772 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -32,22 +32,26 @@ 
 #include <asm/stacktrace.h>
 #include <asm/paravirt.h>
 
+static bool profile_pc_cb(void *arg, unsigned long pc)
+{
+	unsigned long *prof_pc = arg;
+
+	if (in_lock_functions(pc))
+		return true;
+	*prof_pc = pc;
+	return false;
+}
+
 unsigned long profile_pc(struct pt_regs *regs)
 {
-	struct stackframe frame;
+	unsigned long prof_pc = 0;
 
 	if (!in_lock_functions(regs->pc))
 		return regs->pc;
 
-	start_backtrace(&frame, regs->regs[29], regs->pc);
-
-	do {
-		int ret = unwind_frame(NULL, &frame);
-		if (ret < 0)
-			return 0;
-	} while (in_lock_functions(frame.pc));
+	arch_stack_walk(profile_pc_cb, &prof_pc, current, regs);
 
-	return frame.pc;
+	return prof_pc;
 }
 EXPORT_SYMBOL(profile_pc);