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authorIngo Molnar <mingo@elte.hu>2011-07-04 06:27:28 -0400
committerIngo Molnar <mingo@elte.hu>2011-07-04 06:27:28 -0400
commit9f8b6a6cf0ee78de87ebe1e87f54bec1c1741ef7 (patch)
tree083e4b99c53ea1bd3efb35286ebeb5a335fd555e
parent729aa21ab85b5d24f3c2b1e581d71c2333f46628 (diff)
parenta406ab6d77ea86ba7c713276f30ed7058ca64e31 (diff)
Merge branch 'core' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core
-rw-r--r--arch/mips/include/asm/stacktrace.h4
-rw-r--r--arch/mips/kernel/process.c19
-rw-r--r--arch/mips/oprofile/Makefile2
-rw-r--r--arch/mips/oprofile/backtrace.c175
-rw-r--r--arch/mips/oprofile/common.c1
-rw-r--r--arch/mips/oprofile/op_impl.h2
-rw-r--r--arch/x86/oprofile/backtrace.c56
-rw-r--r--arch/x86/oprofile/nmi_int.c14
8 files changed, 254 insertions, 19 deletions
diff --git a/arch/mips/include/asm/stacktrace.h b/arch/mips/include/asm/stacktrace.h
index 0bf82818aa53..780ee2c2a2ac 100644
--- a/arch/mips/include/asm/stacktrace.h
+++ b/arch/mips/include/asm/stacktrace.h
@@ -7,6 +7,10 @@
7extern int raw_show_trace; 7extern int raw_show_trace;
8extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, 8extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
9 unsigned long pc, unsigned long *ra); 9 unsigned long pc, unsigned long *ra);
10extern unsigned long unwind_stack_by_address(unsigned long stack_page,
11 unsigned long *sp,
12 unsigned long pc,
13 unsigned long *ra);
10#else 14#else
11#define raw_show_trace 1 15#define raw_show_trace 1
12static inline unsigned long unwind_stack(struct task_struct *task, 16static inline unsigned long unwind_stack(struct task_struct *task,
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index d2112d3cf115..c28fbe6107bc 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -373,18 +373,18 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
373 373
374 374
375#ifdef CONFIG_KALLSYMS 375#ifdef CONFIG_KALLSYMS
376/* used by show_backtrace() */ 376/* generic stack unwinding function */
377unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, 377unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
378 unsigned long pc, unsigned long *ra) 378 unsigned long *sp,
379 unsigned long pc,
380 unsigned long *ra)
379{ 381{
380 unsigned long stack_page;
381 struct mips_frame_info info; 382 struct mips_frame_info info;
382 unsigned long size, ofs; 383 unsigned long size, ofs;
383 int leaf; 384 int leaf;
384 extern void ret_from_irq(void); 385 extern void ret_from_irq(void);
385 extern void ret_from_exception(void); 386 extern void ret_from_exception(void);
386 387
387 stack_page = (unsigned long)task_stack_page(task);
388 if (!stack_page) 388 if (!stack_page)
389 return 0; 389 return 0;
390 390
@@ -443,6 +443,15 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
443 *ra = 0; 443 *ra = 0;
444 return __kernel_text_address(pc) ? pc : 0; 444 return __kernel_text_address(pc) ? pc : 0;
445} 445}
446EXPORT_SYMBOL(unwind_stack_by_address);
447
448/* used by show_backtrace() */
449unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
450 unsigned long pc, unsigned long *ra)
451{
452 unsigned long stack_page = (unsigned long)task_stack_page(task);
453 return unwind_stack_by_address(stack_page, sp, pc, ra);
454}
446#endif 455#endif
447 456
448/* 457/*
diff --git a/arch/mips/oprofile/Makefile b/arch/mips/oprofile/Makefile
index 4b9d7044e26c..29f2f13eb31c 100644
--- a/arch/mips/oprofile/Makefile
+++ b/arch/mips/oprofile/Makefile
@@ -8,7 +8,7 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
8 oprofilefs.o oprofile_stats.o \ 8 oprofilefs.o oprofile_stats.o \
9 timer_int.o ) 9 timer_int.o )
10 10
11oprofile-y := $(DRIVER_OBJS) common.o 11oprofile-y := $(DRIVER_OBJS) common.o backtrace.o
12 12
13oprofile-$(CONFIG_CPU_MIPS32) += op_model_mipsxx.o 13oprofile-$(CONFIG_CPU_MIPS32) += op_model_mipsxx.o
14oprofile-$(CONFIG_CPU_MIPS64) += op_model_mipsxx.o 14oprofile-$(CONFIG_CPU_MIPS64) += op_model_mipsxx.o
diff --git a/arch/mips/oprofile/backtrace.c b/arch/mips/oprofile/backtrace.c
new file mode 100644
index 000000000000..6854ed5097d2
--- /dev/null
+++ b/arch/mips/oprofile/backtrace.c
@@ -0,0 +1,175 @@
1#include <linux/oprofile.h>
2#include <linux/sched.h>
3#include <linux/mm.h>
4#include <linux/uaccess.h>
5#include <asm/ptrace.h>
6#include <asm/stacktrace.h>
7#include <linux/stacktrace.h>
8#include <linux/kernel.h>
9#include <asm/sections.h>
10#include <asm/inst.h>
11
12struct stackframe {
13 unsigned long sp;
14 unsigned long pc;
15 unsigned long ra;
16};
17
18static inline int get_mem(unsigned long addr, unsigned long *result)
19{
20 unsigned long *address = (unsigned long *) addr;
21 if (!access_ok(VERIFY_READ, addr, sizeof(unsigned long)))
22 return -1;
23 if (__copy_from_user_inatomic(result, address, sizeof(unsigned long)))
24 return -3;
25 return 0;
26}
27
28/*
29 * These two instruction helpers were taken from process.c
30 */
31static inline int is_ra_save_ins(union mips_instruction *ip)
32{
33 /* sw / sd $ra, offset($sp) */
34 return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op)
35 && ip->i_format.rs == 29 && ip->i_format.rt == 31;
36}
37
38static inline int is_sp_move_ins(union mips_instruction *ip)
39{
40 /* addiu/daddiu sp,sp,-imm */
41 if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
42 return 0;
43 if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
44 return 1;
45 return 0;
46}
47
48/*
49 * Looks for specific instructions that mark the end of a function.
50 * This usually means we ran into the code area of the previous function.
51 */
52static inline int is_end_of_function_marker(union mips_instruction *ip)
53{
54 /* jr ra */
55 if (ip->r_format.func == jr_op && ip->r_format.rs == 31)
56 return 1;
57 /* lui gp */
58 if (ip->i_format.opcode == lui_op && ip->i_format.rt == 28)
59 return 1;
60 return 0;
61}
62
63/*
64 * TODO for userspace stack unwinding:
65 * - handle cases where the stack is adjusted inside a function
66 * (generally doesn't happen)
67 * - find optimal value for max_instr_check
68 * - try to find a way to handle leaf functions
69 */
70
71static inline int unwind_user_frame(struct stackframe *old_frame,
72 const unsigned int max_instr_check)
73{
74 struct stackframe new_frame = *old_frame;
75 off_t ra_offset = 0;
76 size_t stack_size = 0;
77 unsigned long addr;
78
79 if (old_frame->pc == 0 || old_frame->sp == 0 || old_frame->ra == 0)
80 return -9;
81
82 for (addr = new_frame.pc; (addr + max_instr_check > new_frame.pc)
83 && (!ra_offset || !stack_size); --addr) {
84 union mips_instruction ip;
85
86 if (get_mem(addr, (unsigned long *) &ip))
87 return -11;
88
89 if (is_sp_move_ins(&ip)) {
90 int stack_adjustment = ip.i_format.simmediate;
91 if (stack_adjustment > 0)
92 /* This marks the end of the previous function,
93 which means we overran. */
94 break;
95 stack_size = (unsigned) stack_adjustment;
96 } else if (is_ra_save_ins(&ip)) {
97 int ra_slot = ip.i_format.simmediate;
98 if (ra_slot < 0)
99 /* This shouldn't happen. */
100 break;
101 ra_offset = ra_slot;
102 } else if (is_end_of_function_marker(&ip))
103 break;
104 }
105
106 if (!ra_offset || !stack_size)
107 return -1;
108
109 if (ra_offset) {
110 new_frame.ra = old_frame->sp + ra_offset;
111 if (get_mem(new_frame.ra, &(new_frame.ra)))
112 return -13;
113 }
114
115 if (stack_size) {
116 new_frame.sp = old_frame->sp + stack_size;
117 if (get_mem(new_frame.sp, &(new_frame.sp)))
118 return -14;
119 }
120
121 if (new_frame.sp > old_frame->sp)
122 return -2;
123
124 new_frame.pc = old_frame->ra;
125 *old_frame = new_frame;
126
127 return 0;
128}
129
130static inline void do_user_backtrace(unsigned long low_addr,
131 struct stackframe *frame,
132 unsigned int depth)
133{
134 const unsigned int max_instr_check = 512;
135 const unsigned long high_addr = low_addr + THREAD_SIZE;
136
137 while (depth-- && !unwind_user_frame(frame, max_instr_check)) {
138 oprofile_add_trace(frame->ra);
139 if (frame->sp < low_addr || frame->sp > high_addr)
140 break;
141 }
142}
143
144#ifndef CONFIG_KALLSYMS
145static inline void do_kernel_backtrace(unsigned long low_addr,
146 struct stackframe *frame,
147 unsigned int depth) { }
148#else
149static inline void do_kernel_backtrace(unsigned long low_addr,
150 struct stackframe *frame,
151 unsigned int depth)
152{
153 while (depth-- && frame->pc) {
154 frame->pc = unwind_stack_by_address(low_addr,
155 &(frame->sp),
156 frame->pc,
157 &(frame->ra));
158 oprofile_add_trace(frame->ra);
159 }
160}
161#endif
162
163void notrace op_mips_backtrace(struct pt_regs *const regs, unsigned int depth)
164{
165 struct stackframe frame = { .sp = regs->regs[29],
166 .pc = regs->cp0_epc,
167 .ra = regs->regs[31] };
168 const int userspace = user_mode(regs);
169 const unsigned long low_addr = ALIGN(frame.sp, THREAD_SIZE);
170
171 if (userspace)
172 do_user_backtrace(low_addr, &frame, depth);
173 else
174 do_kernel_backtrace(low_addr, &frame, depth);
175}
diff --git a/arch/mips/oprofile/common.c b/arch/mips/oprofile/common.c
index f9eb1aba6345..d1f2d4c52d42 100644
--- a/arch/mips/oprofile/common.c
+++ b/arch/mips/oprofile/common.c
@@ -115,6 +115,7 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
115 ops->start = op_mips_start; 115 ops->start = op_mips_start;
116 ops->stop = op_mips_stop; 116 ops->stop = op_mips_stop;
117 ops->cpu_type = lmodel->cpu_type; 117 ops->cpu_type = lmodel->cpu_type;
118 ops->backtrace = op_mips_backtrace;
118 119
119 printk(KERN_INFO "oprofile: using %s performance monitoring.\n", 120 printk(KERN_INFO "oprofile: using %s performance monitoring.\n",
120 lmodel->cpu_type); 121 lmodel->cpu_type);
diff --git a/arch/mips/oprofile/op_impl.h b/arch/mips/oprofile/op_impl.h
index f04b54fb37d1..7c2da27ece04 100644
--- a/arch/mips/oprofile/op_impl.h
+++ b/arch/mips/oprofile/op_impl.h
@@ -36,4 +36,6 @@ struct op_mips_model {
36 unsigned char num_counters; 36 unsigned char num_counters;
37}; 37};
38 38
39void op_mips_backtrace(struct pt_regs * const regs, unsigned int depth);
40
39#endif 41#endif
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index a5b64ab4cd6e..32f78eb46744 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -11,10 +11,12 @@
11#include <linux/oprofile.h> 11#include <linux/oprofile.h>
12#include <linux/sched.h> 12#include <linux/sched.h>
13#include <linux/mm.h> 13#include <linux/mm.h>
14#include <linux/compat.h>
15#include <linux/highmem.h>
16
14#include <asm/ptrace.h> 17#include <asm/ptrace.h>
15#include <asm/uaccess.h> 18#include <asm/uaccess.h>
16#include <asm/stacktrace.h> 19#include <asm/stacktrace.h>
17#include <linux/compat.h>
18 20
19static int backtrace_stack(void *data, char *name) 21static int backtrace_stack(void *data, char *name)
20{ 22{
@@ -36,17 +38,53 @@ static struct stacktrace_ops backtrace_ops = {
36 .walk_stack = print_context_stack, 38 .walk_stack = print_context_stack,
37}; 39};
38 40
41/* from arch/x86/kernel/cpu/perf_event.c: */
42
43/*
44 * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
45 */
46static unsigned long
47copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
48{
49 unsigned long offset, addr = (unsigned long)from;
50 unsigned long size, len = 0;
51 struct page *page;
52 void *map;
53 int ret;
54
55 do {
56 ret = __get_user_pages_fast(addr, 1, 0, &page);
57 if (!ret)
58 break;
59
60 offset = addr & (PAGE_SIZE - 1);
61 size = min(PAGE_SIZE - offset, n - len);
62
63 map = kmap_atomic(page);
64 memcpy(to, map+offset, size);
65 kunmap_atomic(map);
66 put_page(page);
67
68 len += size;
69 to += size;
70 addr += size;
71
72 } while (len < n);
73
74 return len;
75}
76
39#ifdef CONFIG_COMPAT 77#ifdef CONFIG_COMPAT
40static struct stack_frame_ia32 * 78static struct stack_frame_ia32 *
41dump_user_backtrace_32(struct stack_frame_ia32 *head) 79dump_user_backtrace_32(struct stack_frame_ia32 *head)
42{ 80{
81 /* Also check accessibility of one struct frame_head beyond: */
43 struct stack_frame_ia32 bufhead[2]; 82 struct stack_frame_ia32 bufhead[2];
44 struct stack_frame_ia32 *fp; 83 struct stack_frame_ia32 *fp;
84 unsigned long bytes;
45 85
46 /* Also check accessibility of one struct frame_head beyond */ 86 bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
47 if (!access_ok(VERIFY_READ, head, sizeof(bufhead))) 87 if (bytes != sizeof(bufhead))
48 return NULL;
49 if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
50 return NULL; 88 return NULL;
51 89
52 fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame); 90 fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
@@ -87,12 +125,12 @@ x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
87 125
88static struct stack_frame *dump_user_backtrace(struct stack_frame *head) 126static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
89{ 127{
128 /* Also check accessibility of one struct frame_head beyond: */
90 struct stack_frame bufhead[2]; 129 struct stack_frame bufhead[2];
130 unsigned long bytes;
91 131
92 /* Also check accessibility of one struct stack_frame beyond */ 132 bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
93 if (!access_ok(VERIFY_READ, head, sizeof(bufhead))) 133 if (bytes != sizeof(bufhead))
94 return NULL;
95 if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
96 return NULL; 134 return NULL;
97 135
98 oprofile_add_trace(bufhead[0].return_address); 136 oprofile_add_trace(bufhead[0].return_address);
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index cf9750004a08..68894fdc034b 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -112,8 +112,10 @@ static void nmi_cpu_start(void *dummy)
112static int nmi_start(void) 112static int nmi_start(void)
113{ 113{
114 get_online_cpus(); 114 get_online_cpus();
115 on_each_cpu(nmi_cpu_start, NULL, 1);
116 ctr_running = 1; 115 ctr_running = 1;
116 /* make ctr_running visible to the nmi handler: */
117 smp_mb();
118 on_each_cpu(nmi_cpu_start, NULL, 1);
117 put_online_cpus(); 119 put_online_cpus();
118 return 0; 120 return 0;
119} 121}
@@ -504,15 +506,18 @@ static int nmi_setup(void)
504 506
505 nmi_enabled = 0; 507 nmi_enabled = 0;
506 ctr_running = 0; 508 ctr_running = 0;
507 barrier(); 509 /* make variables visible to the nmi handler: */
510 smp_mb();
508 err = register_die_notifier(&profile_exceptions_nb); 511 err = register_die_notifier(&profile_exceptions_nb);
509 if (err) 512 if (err)
510 goto fail; 513 goto fail;
511 514
512 get_online_cpus(); 515 get_online_cpus();
513 register_cpu_notifier(&oprofile_cpu_nb); 516 register_cpu_notifier(&oprofile_cpu_nb);
514 on_each_cpu(nmi_cpu_setup, NULL, 1);
515 nmi_enabled = 1; 517 nmi_enabled = 1;
518 /* make nmi_enabled visible to the nmi handler: */
519 smp_mb();
520 on_each_cpu(nmi_cpu_setup, NULL, 1);
516 put_online_cpus(); 521 put_online_cpus();
517 522
518 return 0; 523 return 0;
@@ -531,7 +536,8 @@ static void nmi_shutdown(void)
531 nmi_enabled = 0; 536 nmi_enabled = 0;
532 ctr_running = 0; 537 ctr_running = 0;
533 put_online_cpus(); 538 put_online_cpus();
534 barrier(); 539 /* make variables visible to the nmi handler: */
540 smp_mb();
535 unregister_die_notifier(&profile_exceptions_nb); 541 unregister_die_notifier(&profile_exceptions_nb);
536 msrs = &get_cpu_var(cpu_msrs); 542 msrs = &get_cpu_var(cpu_msrs);
537 model->shutdown(msrs); 543 model->shutdown(msrs);