Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Infrastructure for profiling code inserted by 'gcc -pg'. |
| 3 | * |
| 4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> |
| 5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> |
| 6 | * |
| 7 | * Originally ported from the -rt patch by: |
| 8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> |
| 9 | * |
| 10 | * Based on code in the latency_tracer, that is: |
| 11 | * |
| 12 | * Copyright (C) 2004-2006 Ingo Molnar |
| 13 | * Copyright (C) 2004 William Lee Irwin III |
| 14 | */ |
| 15 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 16 | #include <linux/stop_machine.h> |
| 17 | #include <linux/clocksource.h> |
| 18 | #include <linux/kallsyms.h> |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 19 | #include <linux/seq_file.h> |
| 20 | #include <linux/debugfs.h> |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 21 | #include <linux/hardirq.h> |
Ingo Molnar | 2d8b820 | 2008-02-23 16:55:50 +0100 | [diff] [blame] | 22 | #include <linux/kthread.h> |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 23 | #include <linux/uaccess.h> |
Ingo Molnar | 2d8b820 | 2008-02-23 16:55:50 +0100 | [diff] [blame] | 24 | #include <linux/ftrace.h> |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 25 | #include <linux/sysctl.h> |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 26 | #include <linux/ctype.h> |
Ingo Molnar | 2d8b820 | 2008-02-23 16:55:50 +0100 | [diff] [blame] | 27 | #include <linux/hash.h> |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 28 | #include <linux/list.h> |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 29 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 30 | #include "trace.h" |
| 31 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 32 | /* ftrace_enabled is a method to turn ftrace on or off */ |
| 33 | int ftrace_enabled __read_mostly; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 34 | static int last_ftrace_enabled; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 35 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 36 | /* |
| 37 | * ftrace_disabled is set when an anomaly is discovered. |
| 38 | * ftrace_disabled is much stronger than ftrace_enabled. |
| 39 | */ |
| 40 | static int ftrace_disabled __read_mostly; |
| 41 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 42 | static DEFINE_SPINLOCK(ftrace_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 43 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
| 44 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 45 | static struct ftrace_ops ftrace_list_end __read_mostly = |
| 46 | { |
| 47 | .func = ftrace_stub, |
| 48 | }; |
| 49 | |
| 50 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; |
| 51 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
| 52 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 53 | void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 54 | { |
| 55 | struct ftrace_ops *op = ftrace_list; |
| 56 | |
| 57 | /* in case someone actually ports this to alpha! */ |
| 58 | read_barrier_depends(); |
| 59 | |
| 60 | while (op != &ftrace_list_end) { |
| 61 | /* silly alpha */ |
| 62 | read_barrier_depends(); |
| 63 | op->func(ip, parent_ip); |
| 64 | op = op->next; |
| 65 | }; |
| 66 | } |
| 67 | |
| 68 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 69 | * clear_ftrace_function - reset the ftrace function |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 70 | * |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 71 | * This NULLs the ftrace function and in essence stops |
| 72 | * tracing. There may be lag |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 73 | */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 74 | void clear_ftrace_function(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 75 | { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 76 | ftrace_trace_function = ftrace_stub; |
| 77 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 78 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 79 | static int __register_ftrace_function(struct ftrace_ops *ops) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 80 | { |
| 81 | /* Should never be called by interrupts */ |
| 82 | spin_lock(&ftrace_lock); |
| 83 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 84 | ops->next = ftrace_list; |
| 85 | /* |
| 86 | * We are entering ops into the ftrace_list but another |
| 87 | * CPU might be walking that list. We need to make sure |
| 88 | * the ops->next pointer is valid before another CPU sees |
| 89 | * the ops pointer included into the ftrace_list. |
| 90 | */ |
| 91 | smp_wmb(); |
| 92 | ftrace_list = ops; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 93 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 94 | if (ftrace_enabled) { |
| 95 | /* |
| 96 | * For one func, simply call it directly. |
| 97 | * For more than one func, call the chain. |
| 98 | */ |
| 99 | if (ops->next == &ftrace_list_end) |
| 100 | ftrace_trace_function = ops->func; |
| 101 | else |
| 102 | ftrace_trace_function = ftrace_list_func; |
| 103 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 104 | |
| 105 | spin_unlock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 106 | |
| 107 | return 0; |
| 108 | } |
| 109 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 110 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 111 | { |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 112 | struct ftrace_ops **p; |
| 113 | int ret = 0; |
| 114 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 115 | spin_lock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 116 | |
| 117 | /* |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 118 | * If we are removing the last function, then simply point |
| 119 | * to the ftrace_stub. |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 120 | */ |
| 121 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { |
| 122 | ftrace_trace_function = ftrace_stub; |
| 123 | ftrace_list = &ftrace_list_end; |
| 124 | goto out; |
| 125 | } |
| 126 | |
| 127 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) |
| 128 | if (*p == ops) |
| 129 | break; |
| 130 | |
| 131 | if (*p != ops) { |
| 132 | ret = -1; |
| 133 | goto out; |
| 134 | } |
| 135 | |
| 136 | *p = (*p)->next; |
| 137 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 138 | if (ftrace_enabled) { |
| 139 | /* If we only have one func left, then call that directly */ |
| 140 | if (ftrace_list == &ftrace_list_end || |
| 141 | ftrace_list->next == &ftrace_list_end) |
| 142 | ftrace_trace_function = ftrace_list->func; |
| 143 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 144 | |
| 145 | out: |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 146 | spin_unlock(&ftrace_lock); |
| 147 | |
| 148 | return ret; |
| 149 | } |
| 150 | |
| 151 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 152 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 153 | static struct task_struct *ftraced_task; |
| 154 | static DECLARE_WAIT_QUEUE_HEAD(ftraced_waiters); |
| 155 | static unsigned long ftraced_iteration_counter; |
| 156 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 157 | enum { |
| 158 | FTRACE_ENABLE_CALLS = (1 << 0), |
| 159 | FTRACE_DISABLE_CALLS = (1 << 1), |
| 160 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), |
| 161 | FTRACE_ENABLE_MCOUNT = (1 << 3), |
| 162 | FTRACE_DISABLE_MCOUNT = (1 << 4), |
| 163 | }; |
| 164 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 165 | static int ftrace_filtered; |
| 166 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 167 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
| 168 | |
| 169 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); |
| 170 | |
| 171 | static DEFINE_SPINLOCK(ftrace_shutdown_lock); |
| 172 | static DEFINE_MUTEX(ftraced_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 173 | static DEFINE_MUTEX(ftrace_regex_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 174 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 175 | struct ftrace_page { |
| 176 | struct ftrace_page *next; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 177 | unsigned long index; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 178 | struct dyn_ftrace records[]; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 179 | }; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 180 | |
| 181 | #define ENTRIES_PER_PAGE \ |
| 182 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) |
| 183 | |
| 184 | /* estimate from running different kernels */ |
| 185 | #define NR_TO_INIT 10000 |
| 186 | |
| 187 | static struct ftrace_page *ftrace_pages_start; |
| 188 | static struct ftrace_page *ftrace_pages; |
| 189 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 190 | static int ftraced_trigger; |
| 191 | static int ftraced_suspend; |
| 192 | |
| 193 | static int ftrace_record_suspend; |
| 194 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 195 | static struct dyn_ftrace *ftrace_free_records; |
| 196 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 197 | static inline int |
Ingo Molnar | 9ff9cdb | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 198 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 199 | { |
| 200 | struct dyn_ftrace *p; |
| 201 | struct hlist_node *t; |
| 202 | int found = 0; |
| 203 | |
Abhishek Sagar | ffdaa35 | 2008-05-24 23:45:02 +0530 | [diff] [blame] | 204 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 205 | if (p->ip == ip) { |
| 206 | found = 1; |
| 207 | break; |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | return found; |
| 212 | } |
| 213 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 214 | static inline void |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 215 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
| 216 | { |
Abhishek Sagar | ffdaa35 | 2008-05-24 23:45:02 +0530 | [diff] [blame] | 217 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 218 | } |
| 219 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 220 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 221 | { |
| 222 | /* no locking, only called from kstop_machine */ |
| 223 | |
| 224 | rec->ip = (unsigned long)ftrace_free_records; |
| 225 | ftrace_free_records = rec; |
| 226 | rec->flags |= FTRACE_FL_FREE; |
| 227 | } |
| 228 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 229 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 230 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 231 | struct dyn_ftrace *rec; |
| 232 | |
| 233 | /* First check for freed records */ |
| 234 | if (ftrace_free_records) { |
| 235 | rec = ftrace_free_records; |
| 236 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 237 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
| 238 | WARN_ON_ONCE(1); |
| 239 | ftrace_free_records = NULL; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 240 | ftrace_disabled = 1; |
| 241 | ftrace_enabled = 0; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 242 | return NULL; |
| 243 | } |
| 244 | |
| 245 | ftrace_free_records = (void *)rec->ip; |
| 246 | memset(rec, 0, sizeof(*rec)); |
| 247 | return rec; |
| 248 | } |
| 249 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 250 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
| 251 | if (!ftrace_pages->next) |
| 252 | return NULL; |
| 253 | ftrace_pages = ftrace_pages->next; |
| 254 | } |
| 255 | |
| 256 | return &ftrace_pages->records[ftrace_pages->index++]; |
| 257 | } |
| 258 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 259 | static void |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 260 | ftrace_record_ip(unsigned long ip) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 261 | { |
| 262 | struct dyn_ftrace *node; |
| 263 | unsigned long flags; |
| 264 | unsigned long key; |
| 265 | int resched; |
| 266 | int atomic; |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 267 | int cpu; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 268 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 269 | if (!ftrace_enabled || ftrace_disabled) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 270 | return; |
| 271 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 272 | resched = need_resched(); |
| 273 | preempt_disable_notrace(); |
| 274 | |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 275 | /* |
| 276 | * We simply need to protect against recursion. |
| 277 | * Use the the raw version of smp_processor_id and not |
| 278 | * __get_cpu_var which can call debug hooks that can |
| 279 | * cause a recursive crash here. |
| 280 | */ |
| 281 | cpu = raw_smp_processor_id(); |
| 282 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; |
| 283 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 284 | goto out; |
| 285 | |
| 286 | if (unlikely(ftrace_record_suspend)) |
| 287 | goto out; |
| 288 | |
| 289 | key = hash_long(ip, FTRACE_HASHBITS); |
| 290 | |
| 291 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); |
| 292 | |
| 293 | if (ftrace_ip_in_hash(ip, key)) |
| 294 | goto out; |
| 295 | |
| 296 | atomic = irqs_disabled(); |
| 297 | |
| 298 | spin_lock_irqsave(&ftrace_shutdown_lock, flags); |
| 299 | |
| 300 | /* This ip may have hit the hash before the lock */ |
| 301 | if (ftrace_ip_in_hash(ip, key)) |
| 302 | goto out_unlock; |
| 303 | |
| 304 | /* |
| 305 | * There's a slight race that the ftraced will update the |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 306 | * hash and reset here. If it is already converted, skip it. |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 307 | */ |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 308 | if (ftrace_ip_converted(ip)) |
| 309 | goto out_unlock; |
| 310 | |
| 311 | node = ftrace_alloc_dyn_node(ip); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 312 | if (!node) |
| 313 | goto out_unlock; |
| 314 | |
| 315 | node->ip = ip; |
| 316 | |
| 317 | ftrace_add_hash(node, key); |
| 318 | |
| 319 | ftraced_trigger = 1; |
| 320 | |
| 321 | out_unlock: |
| 322 | spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); |
| 323 | out: |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 324 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 325 | |
| 326 | /* prevent recursion with scheduler */ |
| 327 | if (resched) |
| 328 | preempt_enable_no_resched_notrace(); |
| 329 | else |
| 330 | preempt_enable_notrace(); |
| 331 | } |
| 332 | |
Steven Rostedt | caf8cde | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 333 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
| 334 | #define MCOUNT_ADDR ((long)(mcount)) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 335 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 336 | static void |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 337 | __ftrace_replace_code(struct dyn_ftrace *rec, |
| 338 | unsigned char *old, unsigned char *new, int enable) |
| 339 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 340 | unsigned long ip, fl; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 341 | int failed; |
| 342 | |
| 343 | ip = rec->ip; |
| 344 | |
| 345 | if (ftrace_filtered && enable) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 346 | /* |
| 347 | * If filtering is on: |
| 348 | * |
| 349 | * If this record is set to be filtered and |
| 350 | * is enabled then do nothing. |
| 351 | * |
| 352 | * If this record is set to be filtered and |
| 353 | * it is not enabled, enable it. |
| 354 | * |
| 355 | * If this record is not set to be filtered |
| 356 | * and it is not enabled do nothing. |
| 357 | * |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 358 | * If this record is set not to trace then |
| 359 | * do nothing. |
| 360 | * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 361 | * If this record is not set to be filtered and |
| 362 | * it is enabled, disable it. |
| 363 | */ |
| 364 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
| 365 | |
| 366 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 367 | (fl == 0) || (rec->flags & FTRACE_FL_NOTRACE)) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 368 | return; |
| 369 | |
| 370 | /* |
| 371 | * If it is enabled disable it, |
| 372 | * otherwise enable it! |
| 373 | */ |
| 374 | if (fl == FTRACE_FL_ENABLED) { |
| 375 | /* swap new and old */ |
| 376 | new = old; |
| 377 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
| 378 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 379 | } else { |
| 380 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
| 381 | rec->flags |= FTRACE_FL_ENABLED; |
| 382 | } |
| 383 | } else { |
| 384 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 385 | if (enable) { |
| 386 | /* |
| 387 | * If this record is set not to trace and is |
| 388 | * not enabled, do nothing. |
| 389 | */ |
| 390 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); |
| 391 | if (fl == FTRACE_FL_NOTRACE) |
| 392 | return; |
| 393 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 394 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 395 | } else |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 396 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
| 397 | |
| 398 | if (enable) { |
| 399 | if (rec->flags & FTRACE_FL_ENABLED) |
| 400 | return; |
| 401 | rec->flags |= FTRACE_FL_ENABLED; |
| 402 | } else { |
| 403 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
| 404 | return; |
| 405 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 406 | } |
| 407 | } |
| 408 | |
| 409 | failed = ftrace_modify_code(ip, old, new); |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 410 | if (failed) { |
| 411 | unsigned long key; |
| 412 | /* It is possible that the function hasn't been converted yet */ |
| 413 | key = hash_long(ip, FTRACE_HASHBITS); |
| 414 | if (!ftrace_ip_in_hash(ip, key)) { |
| 415 | rec->flags |= FTRACE_FL_FAILED; |
| 416 | ftrace_free_rec(rec); |
| 417 | } |
| 418 | |
| 419 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 420 | } |
| 421 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 422 | static void ftrace_replace_code(int enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 423 | { |
| 424 | unsigned char *new = NULL, *old = NULL; |
| 425 | struct dyn_ftrace *rec; |
| 426 | struct ftrace_page *pg; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 427 | int i; |
| 428 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 429 | if (enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 430 | old = ftrace_nop_replace(); |
| 431 | else |
| 432 | new = ftrace_nop_replace(); |
| 433 | |
| 434 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 435 | for (i = 0; i < pg->index; i++) { |
| 436 | rec = &pg->records[i]; |
| 437 | |
| 438 | /* don't modify code that has already faulted */ |
| 439 | if (rec->flags & FTRACE_FL_FAILED) |
| 440 | continue; |
| 441 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 442 | __ftrace_replace_code(rec, old, new, enable); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 443 | } |
| 444 | } |
| 445 | } |
| 446 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 447 | static void ftrace_shutdown_replenish(void) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 448 | { |
| 449 | if (ftrace_pages->next) |
| 450 | return; |
| 451 | |
| 452 | /* allocate another page */ |
| 453 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 454 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 455 | |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame^] | 456 | static int |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 457 | ftrace_code_disable(struct dyn_ftrace *rec) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 458 | { |
| 459 | unsigned long ip; |
| 460 | unsigned char *nop, *call; |
| 461 | int failed; |
| 462 | |
| 463 | ip = rec->ip; |
| 464 | |
| 465 | nop = ftrace_nop_replace(); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 466 | call = ftrace_call_replace(ip, MCOUNT_ADDR); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 467 | |
| 468 | failed = ftrace_modify_code(ip, call, nop); |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 469 | if (failed) { |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 470 | rec->flags |= FTRACE_FL_FAILED; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 471 | ftrace_free_rec(rec); |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame^] | 472 | return 0; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 473 | } |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame^] | 474 | return 1; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 475 | } |
| 476 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 477 | static int __ftrace_modify_code(void *data) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 478 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 479 | unsigned long addr; |
| 480 | int *command = data; |
| 481 | |
| 482 | if (*command & FTRACE_ENABLE_CALLS) |
| 483 | ftrace_replace_code(1); |
| 484 | else if (*command & FTRACE_DISABLE_CALLS) |
| 485 | ftrace_replace_code(0); |
| 486 | |
| 487 | if (*command & FTRACE_UPDATE_TRACE_FUNC) |
| 488 | ftrace_update_ftrace_func(ftrace_trace_function); |
| 489 | |
| 490 | if (*command & FTRACE_ENABLE_MCOUNT) { |
| 491 | addr = (unsigned long)ftrace_record_ip; |
| 492 | ftrace_mcount_set(&addr); |
| 493 | } else if (*command & FTRACE_DISABLE_MCOUNT) { |
| 494 | addr = (unsigned long)ftrace_stub; |
| 495 | ftrace_mcount_set(&addr); |
| 496 | } |
| 497 | |
| 498 | return 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 499 | } |
| 500 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 501 | static void ftrace_run_update_code(int command) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 502 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 503 | stop_machine_run(__ftrace_modify_code, &command, NR_CPUS); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 504 | } |
| 505 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 506 | static ftrace_func_t saved_ftrace_func; |
| 507 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 508 | static void ftrace_startup(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 509 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 510 | int command = 0; |
| 511 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 512 | if (unlikely(ftrace_disabled)) |
| 513 | return; |
| 514 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 515 | mutex_lock(&ftraced_lock); |
| 516 | ftraced_suspend++; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 517 | if (ftraced_suspend == 1) |
| 518 | command |= FTRACE_ENABLE_CALLS; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 519 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 520 | if (saved_ftrace_func != ftrace_trace_function) { |
| 521 | saved_ftrace_func = ftrace_trace_function; |
| 522 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 523 | } |
| 524 | |
| 525 | if (!command || !ftrace_enabled) |
| 526 | goto out; |
| 527 | |
| 528 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 529 | out: |
| 530 | mutex_unlock(&ftraced_lock); |
| 531 | } |
| 532 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 533 | static void ftrace_shutdown(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 534 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 535 | int command = 0; |
| 536 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 537 | if (unlikely(ftrace_disabled)) |
| 538 | return; |
| 539 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 540 | mutex_lock(&ftraced_lock); |
| 541 | ftraced_suspend--; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 542 | if (!ftraced_suspend) |
| 543 | command |= FTRACE_DISABLE_CALLS; |
| 544 | |
| 545 | if (saved_ftrace_func != ftrace_trace_function) { |
| 546 | saved_ftrace_func = ftrace_trace_function; |
| 547 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 548 | } |
| 549 | |
| 550 | if (!command || !ftrace_enabled) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 551 | goto out; |
| 552 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 553 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 554 | out: |
| 555 | mutex_unlock(&ftraced_lock); |
| 556 | } |
| 557 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 558 | static void ftrace_startup_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 559 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 560 | int command = FTRACE_ENABLE_MCOUNT; |
| 561 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 562 | if (unlikely(ftrace_disabled)) |
| 563 | return; |
| 564 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 565 | mutex_lock(&ftraced_lock); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 566 | /* Force update next time */ |
| 567 | saved_ftrace_func = NULL; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 568 | /* ftraced_suspend is true if we want ftrace running */ |
| 569 | if (ftraced_suspend) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 570 | command |= FTRACE_ENABLE_CALLS; |
| 571 | |
| 572 | ftrace_run_update_code(command); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 573 | mutex_unlock(&ftraced_lock); |
| 574 | } |
| 575 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 576 | static void ftrace_shutdown_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 577 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 578 | int command = FTRACE_DISABLE_MCOUNT; |
| 579 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 580 | if (unlikely(ftrace_disabled)) |
| 581 | return; |
| 582 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 583 | mutex_lock(&ftraced_lock); |
| 584 | /* ftraced_suspend is true if ftrace is running */ |
| 585 | if (ftraced_suspend) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 586 | command |= FTRACE_DISABLE_CALLS; |
| 587 | |
| 588 | ftrace_run_update_code(command); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 589 | mutex_unlock(&ftraced_lock); |
| 590 | } |
| 591 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 592 | static cycle_t ftrace_update_time; |
| 593 | static unsigned long ftrace_update_cnt; |
| 594 | unsigned long ftrace_update_tot_cnt; |
| 595 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 596 | static int __ftrace_update_code(void *ignore) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 597 | { |
| 598 | struct dyn_ftrace *p; |
| 599 | struct hlist_head head; |
| 600 | struct hlist_node *t; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 601 | int save_ftrace_enabled; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 602 | cycle_t start, stop; |
| 603 | int i; |
| 604 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 605 | /* Don't be recording funcs now */ |
| 606 | save_ftrace_enabled = ftrace_enabled; |
| 607 | ftrace_enabled = 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 608 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 609 | start = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 610 | ftrace_update_cnt = 0; |
| 611 | |
| 612 | /* No locks needed, the machine is stopped! */ |
| 613 | for (i = 0; i < FTRACE_HASHSIZE; i++) { |
| 614 | if (hlist_empty(&ftrace_hash[i])) |
| 615 | continue; |
| 616 | |
| 617 | head = ftrace_hash[i]; |
| 618 | INIT_HLIST_HEAD(&ftrace_hash[i]); |
| 619 | |
| 620 | /* all CPUS are stopped, we are safe to modify code */ |
| 621 | hlist_for_each_entry(p, t, &head, node) { |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame^] | 622 | if (ftrace_code_disable(p)) |
| 623 | ftrace_update_cnt++; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 624 | } |
| 625 | |
| 626 | } |
| 627 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 628 | stop = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 629 | ftrace_update_time = stop - start; |
| 630 | ftrace_update_tot_cnt += ftrace_update_cnt; |
| 631 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 632 | ftrace_enabled = save_ftrace_enabled; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 633 | |
| 634 | return 0; |
| 635 | } |
| 636 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 637 | static void ftrace_update_code(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 638 | { |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 639 | if (unlikely(ftrace_disabled)) |
| 640 | return; |
| 641 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 642 | stop_machine_run(__ftrace_update_code, NULL, NR_CPUS); |
| 643 | } |
| 644 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 645 | static int ftraced(void *ignore) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 646 | { |
| 647 | unsigned long usecs; |
| 648 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 649 | while (!kthread_should_stop()) { |
| 650 | |
Steven Rostedt | 07a267c | 2008-05-12 21:20:55 +0200 | [diff] [blame] | 651 | set_current_state(TASK_INTERRUPTIBLE); |
| 652 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 653 | /* check once a second */ |
| 654 | schedule_timeout(HZ); |
| 655 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 656 | if (unlikely(ftrace_disabled)) |
| 657 | continue; |
| 658 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 659 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 660 | mutex_lock(&ftraced_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 661 | if (ftrace_enabled && ftraced_trigger && !ftraced_suspend) { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 662 | ftrace_record_suspend++; |
| 663 | ftrace_update_code(); |
| 664 | usecs = nsecs_to_usecs(ftrace_update_time); |
| 665 | if (ftrace_update_tot_cnt > 100000) { |
| 666 | ftrace_update_tot_cnt = 0; |
| 667 | pr_info("hm, dftrace overflow: %lu change%s" |
| 668 | " (%lu total) in %lu usec%s\n", |
| 669 | ftrace_update_cnt, |
| 670 | ftrace_update_cnt != 1 ? "s" : "", |
| 671 | ftrace_update_tot_cnt, |
| 672 | usecs, usecs != 1 ? "s" : ""); |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 673 | ftrace_disabled = 1; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 674 | WARN_ON_ONCE(1); |
| 675 | } |
| 676 | ftraced_trigger = 0; |
| 677 | ftrace_record_suspend--; |
| 678 | } |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 679 | ftraced_iteration_counter++; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 680 | mutex_unlock(&ftraced_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 681 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 682 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 683 | wake_up_interruptible(&ftraced_waiters); |
| 684 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 685 | ftrace_shutdown_replenish(); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 686 | } |
| 687 | __set_current_state(TASK_RUNNING); |
| 688 | return 0; |
| 689 | } |
| 690 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 691 | static int __init ftrace_dyn_table_alloc(void) |
| 692 | { |
| 693 | struct ftrace_page *pg; |
| 694 | int cnt; |
| 695 | int i; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 696 | |
| 697 | /* allocate a few pages */ |
| 698 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); |
| 699 | if (!ftrace_pages_start) |
| 700 | return -1; |
| 701 | |
| 702 | /* |
| 703 | * Allocate a few more pages. |
| 704 | * |
| 705 | * TODO: have some parser search vmlinux before |
| 706 | * final linking to find all calls to ftrace. |
| 707 | * Then we can: |
| 708 | * a) know how many pages to allocate. |
| 709 | * and/or |
| 710 | * b) set up the table then. |
| 711 | * |
| 712 | * The dynamic code is still necessary for |
| 713 | * modules. |
| 714 | */ |
| 715 | |
| 716 | pg = ftrace_pages = ftrace_pages_start; |
| 717 | |
| 718 | cnt = NR_TO_INIT / ENTRIES_PER_PAGE; |
| 719 | |
| 720 | for (i = 0; i < cnt; i++) { |
| 721 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 722 | |
| 723 | /* If we fail, we'll try later anyway */ |
| 724 | if (!pg->next) |
| 725 | break; |
| 726 | |
| 727 | pg = pg->next; |
| 728 | } |
| 729 | |
| 730 | return 0; |
| 731 | } |
| 732 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 733 | enum { |
| 734 | FTRACE_ITER_FILTER = (1 << 0), |
| 735 | FTRACE_ITER_CONT = (1 << 1), |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 736 | FTRACE_ITER_NOTRACE = (1 << 2), |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 737 | }; |
| 738 | |
| 739 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| 740 | |
| 741 | struct ftrace_iterator { |
| 742 | loff_t pos; |
| 743 | struct ftrace_page *pg; |
| 744 | unsigned idx; |
| 745 | unsigned flags; |
| 746 | unsigned char buffer[FTRACE_BUFF_MAX+1]; |
| 747 | unsigned buffer_idx; |
| 748 | unsigned filtered; |
| 749 | }; |
| 750 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 751 | static void * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 752 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 753 | { |
| 754 | struct ftrace_iterator *iter = m->private; |
| 755 | struct dyn_ftrace *rec = NULL; |
| 756 | |
| 757 | (*pos)++; |
| 758 | |
| 759 | retry: |
| 760 | if (iter->idx >= iter->pg->index) { |
| 761 | if (iter->pg->next) { |
| 762 | iter->pg = iter->pg->next; |
| 763 | iter->idx = 0; |
| 764 | goto retry; |
| 765 | } |
| 766 | } else { |
| 767 | rec = &iter->pg->records[iter->idx++]; |
| 768 | if ((rec->flags & FTRACE_FL_FAILED) || |
| 769 | ((iter->flags & FTRACE_ITER_FILTER) && |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 770 | !(rec->flags & FTRACE_FL_FILTER)) || |
| 771 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
| 772 | !(rec->flags & FTRACE_FL_NOTRACE))) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 773 | rec = NULL; |
| 774 | goto retry; |
| 775 | } |
| 776 | } |
| 777 | |
| 778 | iter->pos = *pos; |
| 779 | |
| 780 | return rec; |
| 781 | } |
| 782 | |
| 783 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 784 | { |
| 785 | struct ftrace_iterator *iter = m->private; |
| 786 | void *p = NULL; |
| 787 | loff_t l = -1; |
| 788 | |
| 789 | if (*pos != iter->pos) { |
| 790 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) |
| 791 | ; |
| 792 | } else { |
| 793 | l = *pos; |
| 794 | p = t_next(m, p, &l); |
| 795 | } |
| 796 | |
| 797 | return p; |
| 798 | } |
| 799 | |
| 800 | static void t_stop(struct seq_file *m, void *p) |
| 801 | { |
| 802 | } |
| 803 | |
| 804 | static int t_show(struct seq_file *m, void *v) |
| 805 | { |
| 806 | struct dyn_ftrace *rec = v; |
| 807 | char str[KSYM_SYMBOL_LEN]; |
| 808 | |
| 809 | if (!rec) |
| 810 | return 0; |
| 811 | |
| 812 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 813 | |
| 814 | seq_printf(m, "%s\n", str); |
| 815 | |
| 816 | return 0; |
| 817 | } |
| 818 | |
| 819 | static struct seq_operations show_ftrace_seq_ops = { |
| 820 | .start = t_start, |
| 821 | .next = t_next, |
| 822 | .stop = t_stop, |
| 823 | .show = t_show, |
| 824 | }; |
| 825 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 826 | static int |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 827 | ftrace_avail_open(struct inode *inode, struct file *file) |
| 828 | { |
| 829 | struct ftrace_iterator *iter; |
| 830 | int ret; |
| 831 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 832 | if (unlikely(ftrace_disabled)) |
| 833 | return -ENODEV; |
| 834 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 835 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 836 | if (!iter) |
| 837 | return -ENOMEM; |
| 838 | |
| 839 | iter->pg = ftrace_pages_start; |
| 840 | iter->pos = -1; |
| 841 | |
| 842 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 843 | if (!ret) { |
| 844 | struct seq_file *m = file->private_data; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 845 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 846 | m->private = iter; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 847 | } else { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 848 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 849 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 850 | |
| 851 | return ret; |
| 852 | } |
| 853 | |
| 854 | int ftrace_avail_release(struct inode *inode, struct file *file) |
| 855 | { |
| 856 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 857 | struct ftrace_iterator *iter = m->private; |
| 858 | |
| 859 | seq_release(inode, file); |
| 860 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 861 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 862 | return 0; |
| 863 | } |
| 864 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 865 | static void ftrace_filter_reset(int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 866 | { |
| 867 | struct ftrace_page *pg; |
| 868 | struct dyn_ftrace *rec; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 869 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 870 | unsigned i; |
| 871 | |
| 872 | /* keep kstop machine from running */ |
| 873 | preempt_disable(); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 874 | if (enable) |
| 875 | ftrace_filtered = 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 876 | pg = ftrace_pages_start; |
| 877 | while (pg) { |
| 878 | for (i = 0; i < pg->index; i++) { |
| 879 | rec = &pg->records[i]; |
| 880 | if (rec->flags & FTRACE_FL_FAILED) |
| 881 | continue; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 882 | rec->flags &= ~type; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 883 | } |
| 884 | pg = pg->next; |
| 885 | } |
| 886 | preempt_enable(); |
| 887 | } |
| 888 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 889 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 890 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 891 | { |
| 892 | struct ftrace_iterator *iter; |
| 893 | int ret = 0; |
| 894 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 895 | if (unlikely(ftrace_disabled)) |
| 896 | return -ENODEV; |
| 897 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 898 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 899 | if (!iter) |
| 900 | return -ENOMEM; |
| 901 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 902 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 903 | if ((file->f_mode & FMODE_WRITE) && |
| 904 | !(file->f_flags & O_APPEND)) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 905 | ftrace_filter_reset(enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 906 | |
| 907 | if (file->f_mode & FMODE_READ) { |
| 908 | iter->pg = ftrace_pages_start; |
| 909 | iter->pos = -1; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 910 | iter->flags = enable ? FTRACE_ITER_FILTER : |
| 911 | FTRACE_ITER_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 912 | |
| 913 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 914 | if (!ret) { |
| 915 | struct seq_file *m = file->private_data; |
| 916 | m->private = iter; |
| 917 | } else |
| 918 | kfree(iter); |
| 919 | } else |
| 920 | file->private_data = iter; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 921 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 922 | |
| 923 | return ret; |
| 924 | } |
| 925 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 926 | static int |
| 927 | ftrace_filter_open(struct inode *inode, struct file *file) |
| 928 | { |
| 929 | return ftrace_regex_open(inode, file, 1); |
| 930 | } |
| 931 | |
| 932 | static int |
| 933 | ftrace_notrace_open(struct inode *inode, struct file *file) |
| 934 | { |
| 935 | return ftrace_regex_open(inode, file, 0); |
| 936 | } |
| 937 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 938 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 939 | ftrace_regex_read(struct file *file, char __user *ubuf, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 940 | size_t cnt, loff_t *ppos) |
| 941 | { |
| 942 | if (file->f_mode & FMODE_READ) |
| 943 | return seq_read(file, ubuf, cnt, ppos); |
| 944 | else |
| 945 | return -EPERM; |
| 946 | } |
| 947 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 948 | static loff_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 949 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 950 | { |
| 951 | loff_t ret; |
| 952 | |
| 953 | if (file->f_mode & FMODE_READ) |
| 954 | ret = seq_lseek(file, offset, origin); |
| 955 | else |
| 956 | file->f_pos = ret = 1; |
| 957 | |
| 958 | return ret; |
| 959 | } |
| 960 | |
| 961 | enum { |
| 962 | MATCH_FULL, |
| 963 | MATCH_FRONT_ONLY, |
| 964 | MATCH_MIDDLE_ONLY, |
| 965 | MATCH_END_ONLY, |
| 966 | }; |
| 967 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 968 | static void |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 969 | ftrace_match(unsigned char *buff, int len, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 970 | { |
| 971 | char str[KSYM_SYMBOL_LEN]; |
| 972 | char *search = NULL; |
| 973 | struct ftrace_page *pg; |
| 974 | struct dyn_ftrace *rec; |
| 975 | int type = MATCH_FULL; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 976 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 977 | unsigned i, match = 0, search_len = 0; |
| 978 | |
| 979 | for (i = 0; i < len; i++) { |
| 980 | if (buff[i] == '*') { |
| 981 | if (!i) { |
| 982 | search = buff + i + 1; |
| 983 | type = MATCH_END_ONLY; |
| 984 | search_len = len - (i + 1); |
| 985 | } else { |
| 986 | if (type == MATCH_END_ONLY) { |
| 987 | type = MATCH_MIDDLE_ONLY; |
| 988 | } else { |
| 989 | match = i; |
| 990 | type = MATCH_FRONT_ONLY; |
| 991 | } |
| 992 | buff[i] = 0; |
| 993 | break; |
| 994 | } |
| 995 | } |
| 996 | } |
| 997 | |
| 998 | /* keep kstop machine from running */ |
| 999 | preempt_disable(); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1000 | if (enable) |
| 1001 | ftrace_filtered = 1; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1002 | pg = ftrace_pages_start; |
| 1003 | while (pg) { |
| 1004 | for (i = 0; i < pg->index; i++) { |
| 1005 | int matched = 0; |
| 1006 | char *ptr; |
| 1007 | |
| 1008 | rec = &pg->records[i]; |
| 1009 | if (rec->flags & FTRACE_FL_FAILED) |
| 1010 | continue; |
| 1011 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1012 | switch (type) { |
| 1013 | case MATCH_FULL: |
| 1014 | if (strcmp(str, buff) == 0) |
| 1015 | matched = 1; |
| 1016 | break; |
| 1017 | case MATCH_FRONT_ONLY: |
| 1018 | if (memcmp(str, buff, match) == 0) |
| 1019 | matched = 1; |
| 1020 | break; |
| 1021 | case MATCH_MIDDLE_ONLY: |
| 1022 | if (strstr(str, search)) |
| 1023 | matched = 1; |
| 1024 | break; |
| 1025 | case MATCH_END_ONLY: |
| 1026 | ptr = strstr(str, search); |
| 1027 | if (ptr && (ptr[search_len] == 0)) |
| 1028 | matched = 1; |
| 1029 | break; |
| 1030 | } |
| 1031 | if (matched) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1032 | rec->flags |= flag; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1033 | } |
| 1034 | pg = pg->next; |
| 1035 | } |
| 1036 | preempt_enable(); |
| 1037 | } |
| 1038 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1039 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1040 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
| 1041 | size_t cnt, loff_t *ppos, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1042 | { |
| 1043 | struct ftrace_iterator *iter; |
| 1044 | char ch; |
| 1045 | size_t read = 0; |
| 1046 | ssize_t ret; |
| 1047 | |
| 1048 | if (!cnt || cnt < 0) |
| 1049 | return 0; |
| 1050 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1051 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1052 | |
| 1053 | if (file->f_mode & FMODE_READ) { |
| 1054 | struct seq_file *m = file->private_data; |
| 1055 | iter = m->private; |
| 1056 | } else |
| 1057 | iter = file->private_data; |
| 1058 | |
| 1059 | if (!*ppos) { |
| 1060 | iter->flags &= ~FTRACE_ITER_CONT; |
| 1061 | iter->buffer_idx = 0; |
| 1062 | } |
| 1063 | |
| 1064 | ret = get_user(ch, ubuf++); |
| 1065 | if (ret) |
| 1066 | goto out; |
| 1067 | read++; |
| 1068 | cnt--; |
| 1069 | |
| 1070 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { |
| 1071 | /* skip white space */ |
| 1072 | while (cnt && isspace(ch)) { |
| 1073 | ret = get_user(ch, ubuf++); |
| 1074 | if (ret) |
| 1075 | goto out; |
| 1076 | read++; |
| 1077 | cnt--; |
| 1078 | } |
| 1079 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1080 | if (isspace(ch)) { |
| 1081 | file->f_pos += read; |
| 1082 | ret = read; |
| 1083 | goto out; |
| 1084 | } |
| 1085 | |
| 1086 | iter->buffer_idx = 0; |
| 1087 | } |
| 1088 | |
| 1089 | while (cnt && !isspace(ch)) { |
| 1090 | if (iter->buffer_idx < FTRACE_BUFF_MAX) |
| 1091 | iter->buffer[iter->buffer_idx++] = ch; |
| 1092 | else { |
| 1093 | ret = -EINVAL; |
| 1094 | goto out; |
| 1095 | } |
| 1096 | ret = get_user(ch, ubuf++); |
| 1097 | if (ret) |
| 1098 | goto out; |
| 1099 | read++; |
| 1100 | cnt--; |
| 1101 | } |
| 1102 | |
| 1103 | if (isspace(ch)) { |
| 1104 | iter->filtered++; |
| 1105 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1106 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1107 | iter->buffer_idx = 0; |
| 1108 | } else |
| 1109 | iter->flags |= FTRACE_ITER_CONT; |
| 1110 | |
| 1111 | |
| 1112 | file->f_pos += read; |
| 1113 | |
| 1114 | ret = read; |
| 1115 | out: |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1116 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1117 | |
| 1118 | return ret; |
| 1119 | } |
| 1120 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1121 | static ssize_t |
| 1122 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
| 1123 | size_t cnt, loff_t *ppos) |
| 1124 | { |
| 1125 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
| 1126 | } |
| 1127 | |
| 1128 | static ssize_t |
| 1129 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
| 1130 | size_t cnt, loff_t *ppos) |
| 1131 | { |
| 1132 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
| 1133 | } |
| 1134 | |
| 1135 | static void |
| 1136 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) |
| 1137 | { |
| 1138 | if (unlikely(ftrace_disabled)) |
| 1139 | return; |
| 1140 | |
| 1141 | mutex_lock(&ftrace_regex_lock); |
| 1142 | if (reset) |
| 1143 | ftrace_filter_reset(enable); |
| 1144 | if (buf) |
| 1145 | ftrace_match(buf, len, enable); |
| 1146 | mutex_unlock(&ftrace_regex_lock); |
| 1147 | } |
| 1148 | |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1149 | /** |
| 1150 | * ftrace_set_filter - set a function to filter on in ftrace |
| 1151 | * @buf - the string that holds the function filter text. |
| 1152 | * @len - the length of the string. |
| 1153 | * @reset - non zero to reset all filters before applying this filter. |
| 1154 | * |
| 1155 | * Filters denote which functions should be enabled when tracing is enabled. |
| 1156 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| 1157 | */ |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1158 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1159 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1160 | ftrace_set_regex(buf, len, reset, 1); |
| 1161 | } |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1162 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1163 | /** |
| 1164 | * ftrace_set_notrace - set a function to not trace in ftrace |
| 1165 | * @buf - the string that holds the function notrace text. |
| 1166 | * @len - the length of the string. |
| 1167 | * @reset - non zero to reset all filters before applying this filter. |
| 1168 | * |
| 1169 | * Notrace Filters denote which functions should not be enabled when tracing |
| 1170 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| 1171 | * for tracing. |
| 1172 | */ |
| 1173 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) |
| 1174 | { |
| 1175 | ftrace_set_regex(buf, len, reset, 0); |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1176 | } |
| 1177 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1178 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1179 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1180 | { |
| 1181 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1182 | struct ftrace_iterator *iter; |
| 1183 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1184 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1185 | if (file->f_mode & FMODE_READ) { |
| 1186 | iter = m->private; |
| 1187 | |
| 1188 | seq_release(inode, file); |
| 1189 | } else |
| 1190 | iter = file->private_data; |
| 1191 | |
| 1192 | if (iter->buffer_idx) { |
| 1193 | iter->filtered++; |
| 1194 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1195 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1196 | } |
| 1197 | |
| 1198 | mutex_lock(&ftrace_sysctl_lock); |
| 1199 | mutex_lock(&ftraced_lock); |
| 1200 | if (iter->filtered && ftraced_suspend && ftrace_enabled) |
| 1201 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
| 1202 | mutex_unlock(&ftraced_lock); |
| 1203 | mutex_unlock(&ftrace_sysctl_lock); |
| 1204 | |
| 1205 | kfree(iter); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1206 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1207 | return 0; |
| 1208 | } |
| 1209 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1210 | static int |
| 1211 | ftrace_filter_release(struct inode *inode, struct file *file) |
| 1212 | { |
| 1213 | return ftrace_regex_release(inode, file, 1); |
| 1214 | } |
| 1215 | |
| 1216 | static int |
| 1217 | ftrace_notrace_release(struct inode *inode, struct file *file) |
| 1218 | { |
| 1219 | return ftrace_regex_release(inode, file, 0); |
| 1220 | } |
| 1221 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1222 | static struct file_operations ftrace_avail_fops = { |
| 1223 | .open = ftrace_avail_open, |
| 1224 | .read = seq_read, |
| 1225 | .llseek = seq_lseek, |
| 1226 | .release = ftrace_avail_release, |
| 1227 | }; |
| 1228 | |
| 1229 | static struct file_operations ftrace_filter_fops = { |
| 1230 | .open = ftrace_filter_open, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1231 | .read = ftrace_regex_read, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1232 | .write = ftrace_filter_write, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1233 | .llseek = ftrace_regex_lseek, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1234 | .release = ftrace_filter_release, |
| 1235 | }; |
| 1236 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1237 | static struct file_operations ftrace_notrace_fops = { |
| 1238 | .open = ftrace_notrace_open, |
| 1239 | .read = ftrace_regex_read, |
| 1240 | .write = ftrace_notrace_write, |
| 1241 | .llseek = ftrace_regex_lseek, |
| 1242 | .release = ftrace_notrace_release, |
| 1243 | }; |
| 1244 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1245 | /** |
| 1246 | * ftrace_force_update - force an update to all recording ftrace functions |
| 1247 | * |
| 1248 | * The ftrace dynamic update daemon only wakes up once a second. |
| 1249 | * There may be cases where an update needs to be done immediately |
| 1250 | * for tests or internal kernel tracing to begin. This function |
| 1251 | * wakes the daemon to do an update and will not return until the |
| 1252 | * update is complete. |
| 1253 | */ |
| 1254 | int ftrace_force_update(void) |
| 1255 | { |
| 1256 | unsigned long last_counter; |
| 1257 | DECLARE_WAITQUEUE(wait, current); |
| 1258 | int ret = 0; |
| 1259 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1260 | if (unlikely(ftrace_disabled)) |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1261 | return -ENODEV; |
| 1262 | |
| 1263 | mutex_lock(&ftraced_lock); |
| 1264 | last_counter = ftraced_iteration_counter; |
| 1265 | |
| 1266 | set_current_state(TASK_INTERRUPTIBLE); |
| 1267 | add_wait_queue(&ftraced_waiters, &wait); |
| 1268 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1269 | if (unlikely(!ftraced_task)) { |
| 1270 | ret = -ENODEV; |
| 1271 | goto out; |
| 1272 | } |
| 1273 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1274 | do { |
| 1275 | mutex_unlock(&ftraced_lock); |
| 1276 | wake_up_process(ftraced_task); |
| 1277 | schedule(); |
| 1278 | mutex_lock(&ftraced_lock); |
| 1279 | if (signal_pending(current)) { |
| 1280 | ret = -EINTR; |
| 1281 | break; |
| 1282 | } |
| 1283 | set_current_state(TASK_INTERRUPTIBLE); |
| 1284 | } while (last_counter == ftraced_iteration_counter); |
| 1285 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1286 | out: |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1287 | mutex_unlock(&ftraced_lock); |
| 1288 | remove_wait_queue(&ftraced_waiters, &wait); |
| 1289 | set_current_state(TASK_RUNNING); |
| 1290 | |
| 1291 | return ret; |
| 1292 | } |
| 1293 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1294 | static void ftrace_force_shutdown(void) |
| 1295 | { |
| 1296 | struct task_struct *task; |
| 1297 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; |
| 1298 | |
| 1299 | mutex_lock(&ftraced_lock); |
| 1300 | task = ftraced_task; |
| 1301 | ftraced_task = NULL; |
| 1302 | ftraced_suspend = -1; |
| 1303 | ftrace_run_update_code(command); |
| 1304 | mutex_unlock(&ftraced_lock); |
| 1305 | |
| 1306 | if (task) |
| 1307 | kthread_stop(task); |
| 1308 | } |
| 1309 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1310 | static __init int ftrace_init_debugfs(void) |
| 1311 | { |
| 1312 | struct dentry *d_tracer; |
| 1313 | struct dentry *entry; |
| 1314 | |
| 1315 | d_tracer = tracing_init_dentry(); |
| 1316 | |
| 1317 | entry = debugfs_create_file("available_filter_functions", 0444, |
| 1318 | d_tracer, NULL, &ftrace_avail_fops); |
| 1319 | if (!entry) |
| 1320 | pr_warning("Could not create debugfs " |
| 1321 | "'available_filter_functions' entry\n"); |
| 1322 | |
| 1323 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
| 1324 | NULL, &ftrace_filter_fops); |
| 1325 | if (!entry) |
| 1326 | pr_warning("Could not create debugfs " |
| 1327 | "'set_ftrace_filter' entry\n"); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1328 | |
| 1329 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, |
| 1330 | NULL, &ftrace_notrace_fops); |
| 1331 | if (!entry) |
| 1332 | pr_warning("Could not create debugfs " |
| 1333 | "'set_ftrace_notrace' entry\n"); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1334 | return 0; |
| 1335 | } |
| 1336 | |
| 1337 | fs_initcall(ftrace_init_debugfs); |
| 1338 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1339 | static int __init ftrace_dynamic_init(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1340 | { |
| 1341 | struct task_struct *p; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1342 | unsigned long addr; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1343 | int ret; |
| 1344 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1345 | addr = (unsigned long)ftrace_record_ip; |
Ingo Molnar | 9ff9cdb | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 1346 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1347 | stop_machine_run(ftrace_dyn_arch_init, &addr, NR_CPUS); |
| 1348 | |
| 1349 | /* ftrace_dyn_arch_init places the return code in addr */ |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1350 | if (addr) { |
| 1351 | ret = (int)addr; |
| 1352 | goto failed; |
| 1353 | } |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1354 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1355 | ret = ftrace_dyn_table_alloc(); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1356 | if (ret) |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1357 | goto failed; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1358 | |
| 1359 | p = kthread_run(ftraced, NULL, "ftraced"); |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1360 | if (IS_ERR(p)) { |
| 1361 | ret = -1; |
| 1362 | goto failed; |
| 1363 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1364 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1365 | last_ftrace_enabled = ftrace_enabled = 1; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1366 | ftraced_task = p; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1367 | |
| 1368 | return 0; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1369 | |
| 1370 | failed: |
| 1371 | ftrace_disabled = 1; |
| 1372 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1373 | } |
| 1374 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1375 | core_initcall(ftrace_dynamic_init); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1376 | #else |
Ingo Molnar | c7aafc5 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1377 | # define ftrace_startup() do { } while (0) |
| 1378 | # define ftrace_shutdown() do { } while (0) |
| 1379 | # define ftrace_startup_sysctl() do { } while (0) |
| 1380 | # define ftrace_shutdown_sysctl() do { } while (0) |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1381 | # define ftrace_force_shutdown() do { } while (0) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1382 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 1383 | |
| 1384 | /** |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1385 | * ftrace_kill - totally shutdown ftrace |
| 1386 | * |
| 1387 | * This is a safety measure. If something was detected that seems |
| 1388 | * wrong, calling this function will keep ftrace from doing |
| 1389 | * any more modifications, and updates. |
| 1390 | * used when something went wrong. |
| 1391 | */ |
| 1392 | void ftrace_kill(void) |
| 1393 | { |
| 1394 | mutex_lock(&ftrace_sysctl_lock); |
| 1395 | ftrace_disabled = 1; |
| 1396 | ftrace_enabled = 0; |
| 1397 | |
| 1398 | clear_ftrace_function(); |
| 1399 | mutex_unlock(&ftrace_sysctl_lock); |
| 1400 | |
| 1401 | /* Try to totally disable ftrace */ |
| 1402 | ftrace_force_shutdown(); |
| 1403 | } |
| 1404 | |
| 1405 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1406 | * register_ftrace_function - register a function for profiling |
| 1407 | * @ops - ops structure that holds the function for profiling. |
| 1408 | * |
| 1409 | * Register a function to be called by all functions in the |
| 1410 | * kernel. |
| 1411 | * |
| 1412 | * Note: @ops->func and all the functions it calls must be labeled |
| 1413 | * with "notrace", otherwise it will go into a |
| 1414 | * recursive loop. |
| 1415 | */ |
| 1416 | int register_ftrace_function(struct ftrace_ops *ops) |
| 1417 | { |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1418 | int ret; |
| 1419 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1420 | if (unlikely(ftrace_disabled)) |
| 1421 | return -1; |
| 1422 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1423 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1424 | ret = __register_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1425 | ftrace_startup(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1426 | mutex_unlock(&ftrace_sysctl_lock); |
| 1427 | |
| 1428 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1429 | } |
| 1430 | |
| 1431 | /** |
| 1432 | * unregister_ftrace_function - unresgister a function for profiling. |
| 1433 | * @ops - ops structure that holds the function to unregister |
| 1434 | * |
| 1435 | * Unregister a function that was added to be called by ftrace profiling. |
| 1436 | */ |
| 1437 | int unregister_ftrace_function(struct ftrace_ops *ops) |
| 1438 | { |
| 1439 | int ret; |
| 1440 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1441 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1442 | ret = __unregister_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1443 | ftrace_shutdown(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1444 | mutex_unlock(&ftrace_sysctl_lock); |
| 1445 | |
| 1446 | return ret; |
| 1447 | } |
| 1448 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1449 | int |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1450 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1451 | struct file *file, void __user *buffer, size_t *lenp, |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1452 | loff_t *ppos) |
| 1453 | { |
| 1454 | int ret; |
| 1455 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1456 | if (unlikely(ftrace_disabled)) |
| 1457 | return -ENODEV; |
| 1458 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1459 | mutex_lock(&ftrace_sysctl_lock); |
| 1460 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1461 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1462 | |
| 1463 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) |
| 1464 | goto out; |
| 1465 | |
| 1466 | last_ftrace_enabled = ftrace_enabled; |
| 1467 | |
| 1468 | if (ftrace_enabled) { |
| 1469 | |
| 1470 | ftrace_startup_sysctl(); |
| 1471 | |
| 1472 | /* we are starting ftrace again */ |
| 1473 | if (ftrace_list != &ftrace_list_end) { |
| 1474 | if (ftrace_list->next == &ftrace_list_end) |
| 1475 | ftrace_trace_function = ftrace_list->func; |
| 1476 | else |
| 1477 | ftrace_trace_function = ftrace_list_func; |
| 1478 | } |
| 1479 | |
| 1480 | } else { |
| 1481 | /* stopping ftrace calls (just send to ftrace_stub) */ |
| 1482 | ftrace_trace_function = ftrace_stub; |
| 1483 | |
| 1484 | ftrace_shutdown_sysctl(); |
| 1485 | } |
| 1486 | |
| 1487 | out: |
| 1488 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1489 | return ret; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1490 | } |