summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--arch/avr32/oprofile/Makefile2
-rw-r--r--arch/avr32/oprofile/backtrace.c81
-rw-r--r--arch/avr32/oprofile/op_model_avr32.c4
3 files changed, 86 insertions, 1 deletions
diff --git a/arch/avr32/oprofile/Makefile b/arch/avr32/oprofile/Makefile
index 1fe81c3..e0eb520 100644
--- a/arch/avr32/oprofile/Makefile
+++ b/arch/avr32/oprofile/Makefile
@@ -5,4 +5,4 @@ oprofile-y := $(addprefix ../../../drivers/oprofile/, \
event_buffer.o oprofile_files.o \
oprofilefs.o oprofile_stats.o \
timer_int.o)
-oprofile-y += op_model_avr32.o
+oprofile-y += op_model_avr32.o backtrace.o
diff --git a/arch/avr32/oprofile/backtrace.c b/arch/avr32/oprofile/backtrace.c
new file mode 100644
index 0000000..75d9ad6
--- /dev/null
+++ b/arch/avr32/oprofile/backtrace.c
@@ -0,0 +1,81 @@
+/*
+ * AVR32 specific backtracing code for oprofile
+ *
+ * Copyright 2008 Weinmann GmbH
+ *
+ * Author: Nikolaus Voss <n.voss@weinmann.de>
+ *
+ * Based on i386 oprofile backtrace code by John Levon and David Smith
+ *
+ * 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.
+ *
+ */
+
+#include <linux/oprofile.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+
+/* The first two words of each frame on the stack look like this if we have
+ * frame pointers */
+struct frame_head {
+ unsigned long lr;
+ struct frame_head *fp;
+};
+
+/* copied from arch/avr32/kernel/process.c */
+static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
+{
+ return (p > (unsigned long)tinfo)
+ && (p < (unsigned long)tinfo + THREAD_SIZE - 3);
+}
+
+/* copied from arch/x86/oprofile/backtrace.c */
+static struct frame_head *dump_user_backtrace(struct frame_head *head)
+{
+ struct frame_head bufhead[2];
+
+ /* Also check accessibility of one struct frame_head beyond */
+ if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
+ return NULL;
+ if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
+ return NULL;
+
+ oprofile_add_trace(bufhead[0].lr);
+
+ /* frame pointers should strictly progress back up the stack
+ * (towards higher addresses) */
+ if (bufhead[0].fp <= head)
+ return NULL;
+
+ return bufhead[0].fp;
+}
+
+void avr32_backtrace(struct pt_regs * const regs, unsigned int depth)
+{
+ /* Get first frame pointer */
+ struct frame_head *head = (struct frame_head *)(regs->r7);
+
+ if (!user_mode(regs)) {
+#ifdef CONFIG_FRAME_POINTER
+ /*
+ * Traverse the kernel stack from frame to frame up to
+ * "depth" steps.
+ */
+ while (depth-- && valid_stack_ptr(task_thread_info(current),
+ (unsigned long)head)) {
+ oprofile_add_trace(head->lr);
+ if (head->fp <= head)
+ break;
+ head = head->fp;
+ }
+#endif
+ } else {
+ /* Assume we have frame pointers in user mode process */
+ while (depth-- && head)
+ head = dump_user_backtrace(head);
+ }
+}
+
+
diff --git a/arch/avr32/oprofile/op_model_avr32.c b/arch/avr32/oprofile/op_model_avr32.c
index df42325..a3e9b3c 100644
--- a/arch/avr32/oprofile/op_model_avr32.c
+++ b/arch/avr32/oprofile/op_model_avr32.c
@@ -22,6 +22,8 @@
#define AVR32_PERFCTR_IRQ_GROUP 0
#define AVR32_PERFCTR_IRQ_LINE 1
+void avr32_backtrace(struct pt_regs * const regs, unsigned int depth);
+
enum { PCCNT, PCNT0, PCNT1, NR_counter };
struct avr32_perf_counter {
@@ -223,6 +225,8 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
memcpy(ops, &avr32_perf_counter_ops,
sizeof(struct oprofile_operations));
+ ops->backtrace = avr32_backtrace;
+
printk(KERN_INFO "oprofile: using AVR32 performance monitoring.\n");
return 0;