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authorVineet Gupta <vgupta@synopsys.com>2013-07-10 18:03:45 +0400
committerVineet Gupta <vgupta@synopsys.com>2015-02-27 07:45:00 +0300
commit3a51d50f426cbb65add424baebe511dcf5ac45cc (patch)
treeae5b585e83bd9d4198c8e1307baeb1d9fbad02ac /arch/arc
parentc517d838eb7d07bbe9507871fab3931deccff539 (diff)
downloadlinux-3a51d50f426cbb65add424baebe511dcf5ac45cc.tar.xz
ARC: Make arc_unwind_core accessible externally
The arc unwinder can also be used for perf callchains. Signed-off-by: Mischa Jonker <mjonker@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/include/asm/stacktrace.h37
-rw-r--r--arch/arc/kernel/stacktrace.c15
2 files changed, 51 insertions, 1 deletions
diff --git a/arch/arc/include/asm/stacktrace.h b/arch/arc/include/asm/stacktrace.h
new file mode 100644
index 000000000000..b29b6064ea14
--- /dev/null
+++ b/arch/arc/include/asm/stacktrace.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_STACKTRACE_H
+#define __ASM_STACKTRACE_H
+
+#include <linux/sched.h>
+
+/**
+ * arc_unwind_core - Unwind the kernel mode stack for an execution context
+ * @tsk: NULL for current task, specific task otherwise
+ * @regs: pt_regs used to seed the unwinder {SP, FP, BLINK, PC}
+ * If NULL, use pt_regs of @tsk (if !NULL) otherwise
+ * use the current values of {SP, FP, BLINK, PC}
+ * @consumer_fn: Callback invoked for each frame unwound
+ * Returns 0 to continue unwinding, -1 to stop
+ * @arg: Arg to callback
+ *
+ * Returns the address of first function in stack
+ *
+ * Semantics:
+ * - synchronous unwinding (e.g. dump_stack): @tsk NULL, @regs NULL
+ * - Asynchronous unwinding of sleeping task: @tsk !NULL, @regs NULL
+ * - Asynchronous unwinding of intr/excp etc: @tsk !NULL, @regs !NULL
+ */
+notrace noinline unsigned int arc_unwind_core(
+ struct task_struct *tsk, struct pt_regs *regs,
+ int (*consumer_fn) (unsigned int, void *),
+ void *arg);
+
+#endif /* __ASM_STACKTRACE_H */
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c
index 9ce47cfe2303..6492507a3d74 100644
--- a/arch/arc/kernel/stacktrace.c
+++ b/arch/arc/kernel/stacktrace.c
@@ -43,6 +43,10 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
struct pt_regs *regs,
struct unwind_frame_info *frame_info)
{
+ /*
+ * synchronous unwinding (e.g. dump_stack)
+ * - uses current values of SP and friends
+ */
if (tsk == NULL && regs == NULL) {
unsigned long fp, sp, blink, ret;
frame_info->task = current;
@@ -61,6 +65,11 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
frame_info->regs.r63 = ret;
frame_info->call_frame = 0;
} else if (regs == NULL) {
+ /*
+ * Asynchronous unwinding of sleeping task
+ * - Gets SP etc from task's pt_regs (saved bottom of kernel
+ * mode stack of task)
+ */
frame_info->task = tsk;
@@ -83,6 +92,10 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
frame_info->call_frame = 0;
} else {
+ /*
+ * Asynchronous unwinding of intr/exception
+ * - Just uses the pt_regs passed
+ */
frame_info->task = tsk;
frame_info->regs.r27 = regs->fp;
@@ -95,7 +108,7 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
#endif
-static noinline unsigned int
+notrace noinline unsigned int
arc_unwind_core(struct task_struct *tsk, struct pt_regs *regs,
int (*consumer_fn) (unsigned int, void *), void *arg)
{