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authorSoeren Sandmann Pedersen <sandmann@redhat.com>2010-11-05 05:59:39 -0400
committerFrederic Weisbecker <fweisbec@gmail.com>2010-11-18 08:37:34 -0500
commit9c0729dc8062bed96189bd14ac6d4920f3958743 (patch)
treeea124a706d49b52e04257df13f3aeb980d6000cd
parent3985c7ce85039adacdf882904ca096f091d39346 (diff)
x86: Eliminate bp argument from the stack tracing routines
The various stack tracing routines take a 'bp' argument in which the caller is supposed to provide the base pointer to use, or 0 if doesn't have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not defined, this means all callers in principle should either always pass 0, or be conditional on CONFIG_FRAME_POINTER. However, there are only really three use cases for stack tracing: (a) Trace the current task, including IRQ stack if any (b) Trace the current task, but skip IRQ stack (c) Trace some other task In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just be 0. If it _is_ defined, then - in case (a) bp should be gotten directly from the CPU's register, so the caller should pass NULL for regs, - in case (b) the caller should should pass the IRQ registers to dump_trace(), - in case (c) bp should be gotten from the top of the task's stack, so the caller should pass NULL for regs. Hence, the bp argument is not necessary because the combination of task and regs is sufficient to determine an appropriate value for bp. This patch introduces a new inline function stack_frame(task, regs) that computes the desired bp. This function is then called from the two versions of dump_stack(). Signed-off-by: Soren Sandmann <ssp@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@infradead.org>, Cc: Frederic Weisbecker <fweisbec@gmail.com>, Cc: Arnaldo Carvalho de Melo <acme@redhat.com>, LKML-Reference: <m3oc9rop28.fsf@dhcp-100-3-82.bos.redhat.com>> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
-rw-r--r--arch/x86/include/asm/kdebug.h2
-rw-r--r--arch/x86/include/asm/stacktrace.h33
-rw-r--r--arch/x86/kernel/cpu/perf_event.c2
-rw-r--r--arch/x86/kernel/dumpstack.c12
-rw-r--r--arch/x86/kernel/dumpstack_32.c25
-rw-r--r--arch/x86/kernel/dumpstack_64.c24
-rw-r--r--arch/x86/kernel/process.c3
-rw-r--r--arch/x86/kernel/stacktrace.c8
-rw-r--r--arch/x86/mm/kmemcheck/error.c2
-rw-r--r--arch/x86/oprofile/backtrace.c2
-rw-r--r--include/linux/stacktrace.h4
11 files changed, 62 insertions, 55 deletions
diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
index 5bdfca86581b..f23eb2528464 100644
--- a/arch/x86/include/asm/kdebug.h
+++ b/arch/x86/include/asm/kdebug.h
@@ -28,7 +28,7 @@ extern void die(const char *, struct pt_regs *,long);
28extern int __must_check __die(const char *, struct pt_regs *, long); 28extern int __must_check __die(const char *, struct pt_regs *, long);
29extern void show_registers(struct pt_regs *regs); 29extern void show_registers(struct pt_regs *regs);
30extern void show_trace(struct task_struct *t, struct pt_regs *regs, 30extern void show_trace(struct task_struct *t, struct pt_regs *regs,
31 unsigned long *sp, unsigned long bp); 31 unsigned long *sp);
32extern void __show_regs(struct pt_regs *regs, int all); 32extern void __show_regs(struct pt_regs *regs, int all);
33extern void show_regs(struct pt_regs *regs); 33extern void show_regs(struct pt_regs *regs);
34extern unsigned long oops_begin(void); 34extern unsigned long oops_begin(void);
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 2b16a2ad23dc..52b5c7ed3608 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -7,6 +7,7 @@
7#define _ASM_X86_STACKTRACE_H 7#define _ASM_X86_STACKTRACE_H
8 8
9#include <linux/uaccess.h> 9#include <linux/uaccess.h>
10#include <linux/ptrace.h>
10 11
11extern int kstack_depth_to_print; 12extern int kstack_depth_to_print;
12 13
@@ -46,7 +47,7 @@ struct stacktrace_ops {
46}; 47};
47 48
48void dump_trace(struct task_struct *tsk, struct pt_regs *regs, 49void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
49 unsigned long *stack, unsigned long bp, 50 unsigned long *stack,
50 const struct stacktrace_ops *ops, void *data); 51 const struct stacktrace_ops *ops, void *data);
51 52
52#ifdef CONFIG_X86_32 53#ifdef CONFIG_X86_32
@@ -57,13 +58,39 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
57#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :) 58#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
58#endif 59#endif
59 60
61#ifdef CONFIG_FRAME_POINTER
62static inline unsigned long
63stack_frame(struct task_struct *task, struct pt_regs *regs)
64{
65 unsigned long bp;
66
67 if (regs)
68 return regs->bp;
69
70 if (task == current) {
71 /* Grab bp right from our regs */
72 get_bp(bp);
73 return bp;
74 }
75
76 /* bp is the last reg pushed by switch_to */
77 return *(unsigned long *)task->thread.sp;
78}
79#else
80static inline unsigned long
81stack_frame(struct task_struct *task, struct pt_regs *regs)
82{
83 return 0;
84}
85#endif
86
60extern void 87extern void
61show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, 88show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
62 unsigned long *stack, unsigned long bp, char *log_lvl); 89 unsigned long *stack, char *log_lvl);
63 90
64extern void 91extern void
65show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, 92show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
66 unsigned long *sp, unsigned long bp, char *log_lvl); 93 unsigned long *sp, char *log_lvl);
67 94
68extern unsigned int code_bytes; 95extern unsigned int code_bytes;
69 96
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index ed6310183efb..461a85dcaba4 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1666,7 +1666,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
1666 1666
1667 perf_callchain_store(entry, regs->ip); 1667 perf_callchain_store(entry, regs->ip);
1668 1668
1669 dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry); 1669 dump_trace(NULL, regs, NULL, &backtrace_ops, entry);
1670} 1670}
1671 1671
1672#ifdef CONFIG_COMPAT 1672#ifdef CONFIG_COMPAT
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 6e8752c1bd52..8474c998cbd4 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -175,21 +175,21 @@ static const struct stacktrace_ops print_trace_ops = {
175 175
176void 176void
177show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, 177show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
178 unsigned long *stack, unsigned long bp, char *log_lvl) 178 unsigned long *stack, char *log_lvl)
179{ 179{
180 printk("%sCall Trace:\n", log_lvl); 180 printk("%sCall Trace:\n", log_lvl);
181 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl); 181 dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
182} 182}
183 183
184void show_trace(struct task_struct *task, struct pt_regs *regs, 184void show_trace(struct task_struct *task, struct pt_regs *regs,
185 unsigned long *stack, unsigned long bp) 185 unsigned long *stack)
186{ 186{
187 show_trace_log_lvl(task, regs, stack, bp, ""); 187 show_trace_log_lvl(task, regs, stack, "");
188} 188}
189 189
190void show_stack(struct task_struct *task, unsigned long *sp) 190void show_stack(struct task_struct *task, unsigned long *sp)
191{ 191{
192 show_stack_log_lvl(task, NULL, sp, 0, ""); 192 show_stack_log_lvl(task, NULL, sp, "");
193} 193}
194 194
195/* 195/*
@@ -210,7 +210,7 @@ void dump_stack(void)
210 init_utsname()->release, 210 init_utsname()->release,
211 (int)strcspn(init_utsname()->version, " "), 211 (int)strcspn(init_utsname()->version, " "),
212 init_utsname()->version); 212 init_utsname()->version);
213 show_trace(NULL, NULL, &stack, bp); 213 show_trace(NULL, NULL, &stack);
214} 214}
215EXPORT_SYMBOL(dump_stack); 215EXPORT_SYMBOL(dump_stack);
216 216
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 1bc7f75a5bda..74cc1eda384b 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -17,11 +17,12 @@
17#include <asm/stacktrace.h> 17#include <asm/stacktrace.h>
18 18
19 19
20void dump_trace(struct task_struct *task, struct pt_regs *regs, 20void dump_trace(struct task_struct *task,
21 unsigned long *stack, unsigned long bp, 21 struct pt_regs *regs, unsigned long *stack,
22 const struct stacktrace_ops *ops, void *data) 22 const struct stacktrace_ops *ops, void *data)
23{ 23{
24 int graph = 0; 24 int graph = 0;
25 unsigned long bp;
25 26
26 if (!task) 27 if (!task)
27 task = current; 28 task = current;
@@ -34,18 +35,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
34 stack = (unsigned long *)task->thread.sp; 35 stack = (unsigned long *)task->thread.sp;
35 } 36 }
36 37
37#ifdef CONFIG_FRAME_POINTER 38 bp = stack_frame(task, regs);
38 if (!bp) {
39 if (task == current) {
40 /* Grab bp right from our regs */
41 get_bp(bp);
42 } else {
43 /* bp is the last reg pushed by switch_to */
44 bp = *(unsigned long *) task->thread.sp;
45 }
46 }
47#endif
48
49 for (;;) { 39 for (;;) {
50 struct thread_info *context; 40 struct thread_info *context;
51 41
@@ -65,7 +55,7 @@ EXPORT_SYMBOL(dump_trace);
65 55
66void 56void
67show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, 57show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
68 unsigned long *sp, unsigned long bp, char *log_lvl) 58 unsigned long *sp, char *log_lvl)
69{ 59{
70 unsigned long *stack; 60 unsigned long *stack;
71 int i; 61 int i;
@@ -87,7 +77,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
87 touch_nmi_watchdog(); 77 touch_nmi_watchdog();
88 } 78 }
89 printk(KERN_CONT "\n"); 79 printk(KERN_CONT "\n");
90 show_trace_log_lvl(task, regs, sp, bp, log_lvl); 80 show_trace_log_lvl(task, regs, sp, log_lvl);
91} 81}
92 82
93 83
@@ -112,8 +102,7 @@ void show_registers(struct pt_regs *regs)
112 u8 *ip; 102 u8 *ip;
113 103
114 printk(KERN_EMERG "Stack:\n"); 104 printk(KERN_EMERG "Stack:\n");
115 show_stack_log_lvl(NULL, regs, &regs->sp, 105 show_stack_log_lvl(NULL, regs, &regs->sp, KERN_EMERG);
116 0, KERN_EMERG);
117 106
118 printk(KERN_EMERG "Code: "); 107 printk(KERN_EMERG "Code: ");
119 108
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 6a340485249a..64101335de19 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -139,8 +139,8 @@ fixup_bp_irq_link(unsigned long bp, unsigned long *stack,
139 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack 139 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
140 */ 140 */
141 141
142void dump_trace(struct task_struct *task, struct pt_regs *regs, 142void dump_trace(struct task_struct *task,
143 unsigned long *stack, unsigned long bp, 143 struct pt_regs *regs, unsigned long *stack,
144 const struct stacktrace_ops *ops, void *data) 144 const struct stacktrace_ops *ops, void *data)
145{ 145{
146 const unsigned cpu = get_cpu(); 146 const unsigned cpu = get_cpu();
@@ -149,6 +149,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
149 unsigned used = 0; 149 unsigned used = 0;
150 struct thread_info *tinfo; 150 struct thread_info *tinfo;
151 int graph = 0; 151 int graph = 0;
152 unsigned long bp;
152 153
153 if (!task) 154 if (!task)
154 task = current; 155 task = current;
@@ -160,18 +161,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
160 stack = (unsigned long *)task->thread.sp; 161 stack = (unsigned long *)task->thread.sp;
161 } 162 }
162 163
163#ifdef CONFIG_FRAME_POINTER 164 bp = stack_frame(task, regs);
164 if (!bp) {
165 if (task == current) {
166 /* Grab bp right from our regs */
167 get_bp(bp);
168 } else {
169 /* bp is the last reg pushed by switch_to */
170 bp = *(unsigned long *) task->thread.sp;
171 }
172 }
173#endif
174
175 /* 165 /*
176 * Print function call entries in all stacks, starting at the 166 * Print function call entries in all stacks, starting at the
177 * current stack address. If the stacks consist of nested 167 * current stack address. If the stacks consist of nested
@@ -235,7 +225,7 @@ EXPORT_SYMBOL(dump_trace);
235 225
236void 226void
237show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, 227show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
238 unsigned long *sp, unsigned long bp, char *log_lvl) 228 unsigned long *sp, char *log_lvl)
239{ 229{
240 unsigned long *irq_stack_end; 230 unsigned long *irq_stack_end;
241 unsigned long *irq_stack; 231 unsigned long *irq_stack;
@@ -279,7 +269,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
279 preempt_enable(); 269 preempt_enable();
280 270
281 printk(KERN_CONT "\n"); 271 printk(KERN_CONT "\n");
282 show_trace_log_lvl(task, regs, sp, bp, log_lvl); 272 show_trace_log_lvl(task, regs, sp, log_lvl);
283} 273}
284 274
285void show_registers(struct pt_regs *regs) 275void show_registers(struct pt_regs *regs)
@@ -308,7 +298,7 @@ void show_registers(struct pt_regs *regs)
308 298
309 printk(KERN_EMERG "Stack:\n"); 299 printk(KERN_EMERG "Stack:\n");
310 show_stack_log_lvl(NULL, regs, (unsigned long *)sp, 300 show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
311 regs->bp, KERN_EMERG); 301 KERN_EMERG);
312 302
313 printk(KERN_EMERG "Code: "); 303 printk(KERN_EMERG "Code: ");
314 304
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 57d1868a86aa..96ed1aac543a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -91,8 +91,7 @@ void exit_thread(void)
91void show_regs(struct pt_regs *regs) 91void show_regs(struct pt_regs *regs)
92{ 92{
93 show_registers(regs); 93 show_registers(regs);
94 show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs), 94 show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs));
95 regs->bp);
96} 95}
97 96
98void show_regs_common(void) 97void show_regs_common(void)
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index b53c525368a7..938c8e10a19a 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -73,22 +73,22 @@ static const struct stacktrace_ops save_stack_ops_nosched = {
73 */ 73 */
74void save_stack_trace(struct stack_trace *trace) 74void save_stack_trace(struct stack_trace *trace)
75{ 75{
76 dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace); 76 dump_trace(current, NULL, NULL, &save_stack_ops, trace);
77 if (trace->nr_entries < trace->max_entries) 77 if (trace->nr_entries < trace->max_entries)
78 trace->entries[trace->nr_entries++] = ULONG_MAX; 78 trace->entries[trace->nr_entries++] = ULONG_MAX;
79} 79}
80EXPORT_SYMBOL_GPL(save_stack_trace); 80EXPORT_SYMBOL_GPL(save_stack_trace);
81 81
82void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp) 82void save_stack_trace_regs(struct stack_trace *trace, struct pt_regs *regs)
83{ 83{
84 dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace); 84 dump_trace(current, regs, NULL, &save_stack_ops, trace);
85 if (trace->nr_entries < trace->max_entries) 85 if (trace->nr_entries < trace->max_entries)
86 trace->entries[trace->nr_entries++] = ULONG_MAX; 86 trace->entries[trace->nr_entries++] = ULONG_MAX;
87} 87}
88 88
89void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 89void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
90{ 90{
91 dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace); 91 dump_trace(tsk, NULL, NULL, &save_stack_ops_nosched, trace);
92 if (trace->nr_entries < trace->max_entries) 92 if (trace->nr_entries < trace->max_entries)
93 trace->entries[trace->nr_entries++] = ULONG_MAX; 93 trace->entries[trace->nr_entries++] = ULONG_MAX;
94} 94}
diff --git a/arch/x86/mm/kmemcheck/error.c b/arch/x86/mm/kmemcheck/error.c
index af3b6c8a436f..704a37cedddb 100644
--- a/arch/x86/mm/kmemcheck/error.c
+++ b/arch/x86/mm/kmemcheck/error.c
@@ -185,7 +185,7 @@ void kmemcheck_error_save(enum kmemcheck_shadow state,
185 e->trace.entries = e->trace_entries; 185 e->trace.entries = e->trace_entries;
186 e->trace.max_entries = ARRAY_SIZE(e->trace_entries); 186 e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
187 e->trace.skip = 0; 187 e->trace.skip = 0;
188 save_stack_trace_bp(&e->trace, regs->bp); 188 save_stack_trace_regs(&e->trace, regs);
189 189
190 /* Round address down to nearest 16 bytes */ 190 /* Round address down to nearest 16 bytes */
191 shadow_copy = kmemcheck_shadow_lookup(address 191 shadow_copy = kmemcheck_shadow_lookup(address
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index 2d49d4e19a36..72cbec14d783 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -126,7 +126,7 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
126 if (!user_mode_vm(regs)) { 126 if (!user_mode_vm(regs)) {
127 unsigned long stack = kernel_stack_pointer(regs); 127 unsigned long stack = kernel_stack_pointer(regs);
128 if (depth) 128 if (depth)
129 dump_trace(NULL, regs, (unsigned long *)stack, 0, 129 dump_trace(NULL, regs, (unsigned long *)stack,
130 &backtrace_ops, &depth); 130 &backtrace_ops, &depth);
131 return; 131 return;
132 } 132 }
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index 51efbef38fb0..25310f1d7f37 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -2,6 +2,7 @@
2#define __LINUX_STACKTRACE_H 2#define __LINUX_STACKTRACE_H
3 3
4struct task_struct; 4struct task_struct;
5struct pt_regs;
5 6
6#ifdef CONFIG_STACKTRACE 7#ifdef CONFIG_STACKTRACE
7struct task_struct; 8struct task_struct;
@@ -13,7 +14,8 @@ struct stack_trace {
13}; 14};
14 15
15extern void save_stack_trace(struct stack_trace *trace); 16extern void save_stack_trace(struct stack_trace *trace);
16extern void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp); 17extern void save_stack_trace_regs(struct stack_trace *trace,
18 struct pt_regs *regs);
17extern void save_stack_trace_tsk(struct task_struct *tsk, 19extern void save_stack_trace_tsk(struct task_struct *tsk,
18 struct stack_trace *trace); 20 struct stack_trace *trace);
19 21