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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2007-04-28 04:59:37 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-04-28 04:59:37 -0400
commitf16fb1ecc5a1cb2f7cc595179d1fe55e711e599f (patch)
tree6fae06d1edc3cd1235149c4e68058120e00ef4a8 /arch/arm
parented519dede3d705e1c0012acd5b8de4074aa30fa4 (diff)
[ARM] Add stacktrace support and make oprofile use it
Add support for stacktrace. Use the new stacktrace code with oprofile instead of it's version; there's no point having multiple versions of stacktracing in the kernel. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/Kconfig8
-rw-r--r--arch/arm/kernel/Makefile4
-rw-r--r--arch/arm/kernel/stacktrace.c73
-rw-r--r--arch/arm/kernel/stacktrace.h9
-rw-r--r--arch/arm/oprofile/backtrace.c69
5 files changed, 109 insertions, 54 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e7baca29f3fb..e25a197af6e8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -67,6 +67,14 @@ config GENERIC_HARDIRQS
67 bool 67 bool
68 default y 68 default y
69 69
70config STACKTRACE_SUPPORT
71 bool
72 default y
73
74config LOCKDEP_SUPPORT
75 bool
76 default y
77
70config TRACE_IRQFLAGS_SUPPORT 78config TRACE_IRQFLAGS_SUPPORT
71 bool 79 bool
72 default y 80 default y
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index bb28087bf818..593b56509f4f 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -7,8 +7,8 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
7# Object file lists. 7# Object file lists.
8 8
9obj-y := compat.o entry-armv.o entry-common.o irq.o \ 9obj-y := compat.o entry-armv.o entry-common.o irq.o \
10 process.o ptrace.o semaphore.o setup.o signal.o sys_arm.o \ 10 process.o ptrace.o semaphore.o setup.o signal.o \
11 time.o traps.o 11 sys_arm.o stacktrace.o time.o traps.o
12 12
13obj-$(CONFIG_ISA_DMA_API) += dma.o 13obj-$(CONFIG_ISA_DMA_API) += dma.o
14obj-$(CONFIG_ARCH_ACORN) += ecard.o 14obj-$(CONFIG_ARCH_ACORN) += ecard.o
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
new file mode 100644
index 000000000000..77ef35efaa8d
--- /dev/null
+++ b/arch/arm/kernel/stacktrace.c
@@ -0,0 +1,73 @@
1#include <linux/sched.h>
2#include <linux/stacktrace.h>
3
4#include "stacktrace.h"
5
6int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high,
7 int (*fn)(struct stackframe *, void *), void *data)
8{
9 struct stackframe *frame;
10
11 do {
12 /*
13 * Check current frame pointer is within bounds
14 */
15 if ((fp - 12) < low || fp + 4 >= high)
16 break;
17
18 frame = (struct stackframe *)(fp - 12);
19
20 if (fn(frame, data))
21 break;
22
23 /*
24 * Update the low bound - the next frame must always
25 * be at a higher address than the current frame.
26 */
27 low = fp + 4;
28 fp = frame->fp;
29 } while (fp);
30
31 return 0;
32}
33
34#ifdef CONFIG_STACKTRACE
35struct stack_trace_data {
36 struct stack_trace *trace;
37 unsigned int skip;
38};
39
40static int save_trace(struct stackframe *frame, void *d)
41{
42 struct stack_trace_data *data = d;
43 struct stack_trace *trace = data->trace;
44
45 if (data->skip) {
46 data->skip--;
47 return 0;
48 }
49
50 trace->entries[trace->nr_entries++] = frame->lr;
51
52 return trace->nr_entries >= trace->max_entries;
53}
54
55void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
56{
57 struct stack_trace_data data;
58 unsigned long fp, base;
59
60 data.trace = trace;
61 data.skip = trace->skip;
62
63 if (task) {
64 base = (unsigned long)task_stack_page(task);
65 fp = 0; /* FIXME */
66 } else {
67 base = (unsigned long)task_stack_page(current);
68 asm("mov %0, fp" : "=r" (fp));
69 }
70
71 walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data);
72}
73#endif
diff --git a/arch/arm/kernel/stacktrace.h b/arch/arm/kernel/stacktrace.h
new file mode 100644
index 000000000000..e9fd20cb5662
--- /dev/null
+++ b/arch/arm/kernel/stacktrace.h
@@ -0,0 +1,9 @@
1struct stackframe {
2 unsigned long fp;
3 unsigned long sp;
4 unsigned long lr;
5 unsigned long pc;
6};
7
8int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high,
9 int (*fn)(struct stackframe *, void *), void *data);
diff --git a/arch/arm/oprofile/backtrace.c b/arch/arm/oprofile/backtrace.c
index 7c22c12618cc..f5ebf30151fa 100644
--- a/arch/arm/oprofile/backtrace.c
+++ b/arch/arm/oprofile/backtrace.c
@@ -19,6 +19,19 @@
19#include <asm/ptrace.h> 19#include <asm/ptrace.h>
20#include <asm/uaccess.h> 20#include <asm/uaccess.h>
21 21
22#include "../kernel/stacktrace.h"
23
24static int report_trace(struct stackframe *frame, void *d)
25{
26 unsigned int *depth = d;
27
28 if (*depth) {
29 oprofile_add_trace(frame->lr);
30 (*depth)--;
31 }
32
33 return *depth == 0;
34}
22 35
23/* 36/*
24 * The registers we're interested in are at the end of the variable 37 * The registers we're interested in are at the end of the variable
@@ -32,21 +45,6 @@ struct frame_tail {
32 unsigned long lr; 45 unsigned long lr;
33} __attribute__((packed)); 46} __attribute__((packed));
34 47
35
36#ifdef CONFIG_FRAME_POINTER
37static struct frame_tail* kernel_backtrace(struct frame_tail *tail)
38{
39 oprofile_add_trace(tail->lr);
40
41 /* frame pointers should strictly progress back up the stack
42 * (towards higher addresses) */
43 if (tail >= tail->fp)
44 return NULL;
45
46 return tail->fp-1;
47}
48#endif
49
50static struct frame_tail* user_backtrace(struct frame_tail *tail) 48static struct frame_tail* user_backtrace(struct frame_tail *tail)
51{ 49{
52 struct frame_tail buftail[2]; 50 struct frame_tail buftail[2];
@@ -67,47 +65,14 @@ static struct frame_tail* user_backtrace(struct frame_tail *tail)
67 return buftail[0].fp-1; 65 return buftail[0].fp-1;
68} 66}
69 67
70/*
71 * | | /\ Higher addresses
72 * | |
73 * --------------- stack base (address of current_thread_info)
74 * | thread info |
75 * . .
76 * | stack |
77 * --------------- saved regs->ARM_fp value if valid (frame_tail address)
78 * . .
79 * --------------- struct pt_regs stored on stack (struct pt_regs *)
80 * | |
81 * . .
82 * | |
83 * --------------- %esp
84 * | |
85 * | | \/ Lower addresses
86 *
87 * Thus, &pt_regs <-> stack base restricts the valid(ish) fp values
88 */
89static int valid_kernel_stack(struct frame_tail *tail, struct pt_regs *regs)
90{
91 unsigned long tailaddr = (unsigned long)tail;
92 unsigned long stack = (unsigned long)regs;
93 unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE;
94
95 return (tailaddr > stack) && (tailaddr < stack_base);
96}
97
98void arm_backtrace(struct pt_regs * const regs, unsigned int depth) 68void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
99{ 69{
100 struct frame_tail *tail; 70 struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
101
102 tail = ((struct frame_tail *) regs->ARM_fp) - 1;
103 71
104 if (!user_mode(regs)) { 72 if (!user_mode(regs)) {
105 73 unsigned long base = ((unsigned long)regs) & ~(THREAD_SIZE - 1);
106#ifdef CONFIG_FRAME_POINTER 74 walk_stackframe(regs->ARM_fp, base, base + THREAD_SIZE,
107 while (depth-- && tail && valid_kernel_stack(tail, regs)) { 75 report_trace, &depth);
108 tail = kernel_backtrace(tail);
109 }
110#endif
111 return; 76 return;
112 } 77 }
113 78