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> |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 24 | #include <linux/kprobes.h> |
Ingo Molnar | 2d8b820 | 2008-02-23 16:55:50 +0100 | [diff] [blame] | 25 | #include <linux/ftrace.h> |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 26 | #include <linux/sysctl.h> |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 27 | #include <linux/ctype.h> |
Ingo Molnar | 2d8b820 | 2008-02-23 16:55:50 +0100 | [diff] [blame] | 28 | #include <linux/hash.h> |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 29 | #include <linux/list.h> |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 30 | |
Abhishek Sagar | 395a59d | 2008-06-21 23:47:27 +0530 | [diff] [blame] | 31 | #include <asm/ftrace.h> |
| 32 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 33 | #include "trace.h" |
| 34 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 35 | /* ftrace_enabled is a method to turn ftrace on or off */ |
| 36 | int ftrace_enabled __read_mostly; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 37 | static int last_ftrace_enabled; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 38 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 39 | /* |
| 40 | * ftrace_disabled is set when an anomaly is discovered. |
| 41 | * ftrace_disabled is much stronger than ftrace_enabled. |
| 42 | */ |
| 43 | static int ftrace_disabled __read_mostly; |
| 44 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 45 | static DEFINE_SPINLOCK(ftrace_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 46 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
| 47 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 48 | static struct ftrace_ops ftrace_list_end __read_mostly = |
| 49 | { |
| 50 | .func = ftrace_stub, |
| 51 | }; |
| 52 | |
| 53 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; |
| 54 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
| 55 | |
Ingo Molnar | f225293 | 2008-05-22 10:37:48 +0200 | [diff] [blame] | 56 | static 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] | 57 | { |
| 58 | struct ftrace_ops *op = ftrace_list; |
| 59 | |
| 60 | /* in case someone actually ports this to alpha! */ |
| 61 | read_barrier_depends(); |
| 62 | |
| 63 | while (op != &ftrace_list_end) { |
| 64 | /* silly alpha */ |
| 65 | read_barrier_depends(); |
| 66 | op->func(ip, parent_ip); |
| 67 | op = op->next; |
| 68 | }; |
| 69 | } |
| 70 | |
| 71 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 72 | * clear_ftrace_function - reset the ftrace function |
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 | * This NULLs the ftrace function and in essence stops |
| 75 | * tracing. There may be lag |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 76 | */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 77 | void clear_ftrace_function(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 78 | { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 79 | ftrace_trace_function = ftrace_stub; |
| 80 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 81 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 82 | static int __register_ftrace_function(struct ftrace_ops *ops) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 83 | { |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 84 | /* should not be called from interrupt context */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 85 | spin_lock(&ftrace_lock); |
| 86 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 87 | ops->next = ftrace_list; |
| 88 | /* |
| 89 | * We are entering ops into the ftrace_list but another |
| 90 | * CPU might be walking that list. We need to make sure |
| 91 | * the ops->next pointer is valid before another CPU sees |
| 92 | * the ops pointer included into the ftrace_list. |
| 93 | */ |
| 94 | smp_wmb(); |
| 95 | ftrace_list = ops; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 96 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 97 | if (ftrace_enabled) { |
| 98 | /* |
| 99 | * For one func, simply call it directly. |
| 100 | * For more than one func, call the chain. |
| 101 | */ |
| 102 | if (ops->next == &ftrace_list_end) |
| 103 | ftrace_trace_function = ops->func; |
| 104 | else |
| 105 | ftrace_trace_function = ftrace_list_func; |
| 106 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 107 | |
| 108 | spin_unlock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 113 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 114 | { |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 115 | struct ftrace_ops **p; |
| 116 | int ret = 0; |
| 117 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 118 | /* should not be called from interrupt context */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 119 | spin_lock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 120 | |
| 121 | /* |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 122 | * If we are removing the last function, then simply point |
| 123 | * to the ftrace_stub. |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 124 | */ |
| 125 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { |
| 126 | ftrace_trace_function = ftrace_stub; |
| 127 | ftrace_list = &ftrace_list_end; |
| 128 | goto out; |
| 129 | } |
| 130 | |
| 131 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) |
| 132 | if (*p == ops) |
| 133 | break; |
| 134 | |
| 135 | if (*p != ops) { |
| 136 | ret = -1; |
| 137 | goto out; |
| 138 | } |
| 139 | |
| 140 | *p = (*p)->next; |
| 141 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 142 | if (ftrace_enabled) { |
| 143 | /* If we only have one func left, then call that directly */ |
| 144 | if (ftrace_list == &ftrace_list_end || |
| 145 | ftrace_list->next == &ftrace_list_end) |
| 146 | ftrace_trace_function = ftrace_list->func; |
| 147 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 148 | |
| 149 | out: |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 150 | spin_unlock(&ftrace_lock); |
| 151 | |
| 152 | return ret; |
| 153 | } |
| 154 | |
| 155 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 156 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 157 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
| 158 | /* |
| 159 | * The hash lock is only needed when the recording of the mcount |
| 160 | * callers are dynamic. That is, by the caller themselves and |
| 161 | * not recorded via the compilation. |
| 162 | */ |
| 163 | static DEFINE_SPINLOCK(ftrace_hash_lock); |
| 164 | #define ftrace_hash_lock(flags) spin_lock_irqsave(ftrace_hash_lock, flags) |
| 165 | #define ftrace_hash_unlock(flags) spin_lock_irqsave(ftrace_hash_lock, flags) |
| 166 | #else |
| 167 | /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ |
| 168 | #define ftrace_hash_lock(flags) do { (void)flags; } while (0) |
| 169 | #define ftrace_hash_unlock(flags) do { } while(0) |
| 170 | #endif |
| 171 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 172 | static struct task_struct *ftraced_task; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 173 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 174 | enum { |
| 175 | FTRACE_ENABLE_CALLS = (1 << 0), |
| 176 | FTRACE_DISABLE_CALLS = (1 << 1), |
| 177 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), |
| 178 | FTRACE_ENABLE_MCOUNT = (1 << 3), |
| 179 | FTRACE_DISABLE_MCOUNT = (1 << 4), |
| 180 | }; |
| 181 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 182 | static int ftrace_filtered; |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 183 | static int tracing_on; |
| 184 | static int frozen_record_count; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 185 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 186 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
| 187 | |
| 188 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); |
| 189 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 190 | static DEFINE_MUTEX(ftraced_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 191 | static DEFINE_MUTEX(ftrace_regex_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 192 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 193 | struct ftrace_page { |
| 194 | struct ftrace_page *next; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 195 | unsigned long index; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 196 | struct dyn_ftrace records[]; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 197 | }; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 198 | |
| 199 | #define ENTRIES_PER_PAGE \ |
| 200 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) |
| 201 | |
| 202 | /* estimate from running different kernels */ |
| 203 | #define NR_TO_INIT 10000 |
| 204 | |
| 205 | static struct ftrace_page *ftrace_pages_start; |
| 206 | static struct ftrace_page *ftrace_pages; |
| 207 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 208 | static int ftraced_trigger; |
| 209 | static int ftraced_suspend; |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 210 | static int ftraced_stop; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 211 | |
| 212 | static int ftrace_record_suspend; |
| 213 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 214 | static struct dyn_ftrace *ftrace_free_records; |
| 215 | |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 216 | |
| 217 | #ifdef CONFIG_KPROBES |
| 218 | static inline void freeze_record(struct dyn_ftrace *rec) |
| 219 | { |
| 220 | if (!(rec->flags & FTRACE_FL_FROZEN)) { |
| 221 | rec->flags |= FTRACE_FL_FROZEN; |
| 222 | frozen_record_count++; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | static inline void unfreeze_record(struct dyn_ftrace *rec) |
| 227 | { |
| 228 | if (rec->flags & FTRACE_FL_FROZEN) { |
| 229 | rec->flags &= ~FTRACE_FL_FROZEN; |
| 230 | frozen_record_count--; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | static inline int record_frozen(struct dyn_ftrace *rec) |
| 235 | { |
| 236 | return rec->flags & FTRACE_FL_FROZEN; |
| 237 | } |
| 238 | #else |
| 239 | # define freeze_record(rec) ({ 0; }) |
| 240 | # define unfreeze_record(rec) ({ 0; }) |
| 241 | # define record_frozen(rec) ({ 0; }) |
| 242 | #endif /* CONFIG_KPROBES */ |
| 243 | |
| 244 | int skip_trace(unsigned long ip) |
| 245 | { |
| 246 | unsigned long fl; |
| 247 | struct dyn_ftrace *rec; |
| 248 | struct hlist_node *t; |
| 249 | struct hlist_head *head; |
| 250 | |
| 251 | if (frozen_record_count == 0) |
| 252 | return 0; |
| 253 | |
| 254 | head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; |
| 255 | hlist_for_each_entry_rcu(rec, t, head, node) { |
| 256 | if (rec->ip == ip) { |
| 257 | if (record_frozen(rec)) { |
| 258 | if (rec->flags & FTRACE_FL_FAILED) |
| 259 | return 1; |
| 260 | |
| 261 | if (!(rec->flags & FTRACE_FL_CONVERTED)) |
| 262 | return 1; |
| 263 | |
| 264 | if (!tracing_on || !ftrace_enabled) |
| 265 | return 1; |
| 266 | |
| 267 | if (ftrace_filtered) { |
| 268 | fl = rec->flags & (FTRACE_FL_FILTER | |
| 269 | FTRACE_FL_NOTRACE); |
| 270 | if (!fl || (fl & FTRACE_FL_NOTRACE)) |
| 271 | return 1; |
| 272 | } |
| 273 | } |
| 274 | break; |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | return 0; |
| 279 | } |
| 280 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 281 | static inline int |
Ingo Molnar | 9ff9cdb | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 282 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 283 | { |
| 284 | struct dyn_ftrace *p; |
| 285 | struct hlist_node *t; |
| 286 | int found = 0; |
| 287 | |
Abhishek Sagar | ffdaa35 | 2008-05-24 23:45:02 +0530 | [diff] [blame] | 288 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 289 | if (p->ip == ip) { |
| 290 | found = 1; |
| 291 | break; |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | return found; |
| 296 | } |
| 297 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 298 | static inline void |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 299 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
| 300 | { |
Abhishek Sagar | ffdaa35 | 2008-05-24 23:45:02 +0530 | [diff] [blame] | 301 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 302 | } |
| 303 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 304 | /* called from kstop_machine */ |
| 305 | static inline void ftrace_del_hash(struct dyn_ftrace *node) |
| 306 | { |
| 307 | hlist_del(&node->node); |
| 308 | } |
| 309 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 310 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 311 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 312 | rec->ip = (unsigned long)ftrace_free_records; |
| 313 | ftrace_free_records = rec; |
| 314 | rec->flags |= FTRACE_FL_FREE; |
| 315 | } |
| 316 | |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 317 | void ftrace_release(void *start, unsigned long size) |
| 318 | { |
| 319 | struct dyn_ftrace *rec; |
| 320 | struct ftrace_page *pg; |
| 321 | unsigned long s = (unsigned long)start; |
| 322 | unsigned long e = s + size; |
| 323 | int i; |
| 324 | |
Steven Rostedt | 00fd61a | 2008-08-15 21:40:04 -0400 | [diff] [blame] | 325 | if (ftrace_disabled || !start) |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 326 | return; |
| 327 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 328 | /* should not be called from interrupt context */ |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 329 | spin_lock(&ftrace_lock); |
| 330 | |
| 331 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 332 | for (i = 0; i < pg->index; i++) { |
| 333 | rec = &pg->records[i]; |
| 334 | |
| 335 | if ((rec->ip >= s) && (rec->ip < e)) |
| 336 | ftrace_free_rec(rec); |
| 337 | } |
| 338 | } |
| 339 | spin_unlock(&ftrace_lock); |
| 340 | |
| 341 | } |
| 342 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 343 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 344 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 345 | struct dyn_ftrace *rec; |
| 346 | |
| 347 | /* First check for freed records */ |
| 348 | if (ftrace_free_records) { |
| 349 | rec = ftrace_free_records; |
| 350 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 351 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
| 352 | WARN_ON_ONCE(1); |
| 353 | ftrace_free_records = NULL; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 354 | ftrace_disabled = 1; |
| 355 | ftrace_enabled = 0; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 356 | return NULL; |
| 357 | } |
| 358 | |
| 359 | ftrace_free_records = (void *)rec->ip; |
| 360 | memset(rec, 0, sizeof(*rec)); |
| 361 | return rec; |
| 362 | } |
| 363 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 364 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
| 365 | if (!ftrace_pages->next) |
| 366 | return NULL; |
| 367 | ftrace_pages = ftrace_pages->next; |
| 368 | } |
| 369 | |
| 370 | return &ftrace_pages->records[ftrace_pages->index++]; |
| 371 | } |
| 372 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 373 | static void |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 374 | ftrace_record_ip(unsigned long ip) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 375 | { |
| 376 | struct dyn_ftrace *node; |
| 377 | unsigned long flags; |
| 378 | unsigned long key; |
| 379 | int resched; |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 380 | int cpu; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 381 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 382 | if (!ftrace_enabled || ftrace_disabled) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 383 | return; |
| 384 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 385 | resched = need_resched(); |
| 386 | preempt_disable_notrace(); |
| 387 | |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 388 | /* |
| 389 | * We simply need to protect against recursion. |
| 390 | * Use the the raw version of smp_processor_id and not |
| 391 | * __get_cpu_var which can call debug hooks that can |
| 392 | * cause a recursive crash here. |
| 393 | */ |
| 394 | cpu = raw_smp_processor_id(); |
| 395 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; |
| 396 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 397 | goto out; |
| 398 | |
| 399 | if (unlikely(ftrace_record_suspend)) |
| 400 | goto out; |
| 401 | |
| 402 | key = hash_long(ip, FTRACE_HASHBITS); |
| 403 | |
| 404 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); |
| 405 | |
| 406 | if (ftrace_ip_in_hash(ip, key)) |
| 407 | goto out; |
| 408 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 409 | ftrace_hash_lock(flags); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 410 | |
| 411 | /* This ip may have hit the hash before the lock */ |
| 412 | if (ftrace_ip_in_hash(ip, key)) |
| 413 | goto out_unlock; |
| 414 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 415 | node = ftrace_alloc_dyn_node(ip); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 416 | if (!node) |
| 417 | goto out_unlock; |
| 418 | |
| 419 | node->ip = ip; |
| 420 | |
| 421 | ftrace_add_hash(node, key); |
| 422 | |
| 423 | ftraced_trigger = 1; |
| 424 | |
| 425 | out_unlock: |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 426 | ftrace_hash_unlock(flags); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 427 | out: |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 428 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 429 | |
| 430 | /* prevent recursion with scheduler */ |
| 431 | if (resched) |
| 432 | preempt_enable_no_resched_notrace(); |
| 433 | else |
| 434 | preempt_enable_notrace(); |
| 435 | } |
| 436 | |
Steven Rostedt | caf8cde | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 437 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 438 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 439 | static int |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 440 | __ftrace_replace_code(struct dyn_ftrace *rec, |
| 441 | unsigned char *old, unsigned char *new, int enable) |
| 442 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 443 | unsigned long ip, fl; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 444 | |
| 445 | ip = rec->ip; |
| 446 | |
| 447 | if (ftrace_filtered && enable) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 448 | /* |
| 449 | * If filtering is on: |
| 450 | * |
| 451 | * If this record is set to be filtered and |
| 452 | * is enabled then do nothing. |
| 453 | * |
| 454 | * If this record is set to be filtered and |
| 455 | * it is not enabled, enable it. |
| 456 | * |
| 457 | * If this record is not set to be filtered |
| 458 | * and it is not enabled do nothing. |
| 459 | * |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 460 | * If this record is set not to trace then |
| 461 | * do nothing. |
| 462 | * |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 463 | * If this record is set not to trace and |
| 464 | * it is enabled then disable it. |
| 465 | * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 466 | * If this record is not set to be filtered and |
| 467 | * it is enabled, disable it. |
| 468 | */ |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 469 | |
| 470 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | |
| 471 | FTRACE_FL_ENABLED); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 472 | |
| 473 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 474 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
| 475 | !fl || (fl == FTRACE_FL_NOTRACE)) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 476 | return 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 477 | |
| 478 | /* |
| 479 | * If it is enabled disable it, |
| 480 | * otherwise enable it! |
| 481 | */ |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 482 | if (fl & FTRACE_FL_ENABLED) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 483 | /* swap new and old */ |
| 484 | new = old; |
| 485 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
| 486 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 487 | } else { |
| 488 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
| 489 | rec->flags |= FTRACE_FL_ENABLED; |
| 490 | } |
| 491 | } else { |
| 492 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 493 | if (enable) { |
| 494 | /* |
| 495 | * If this record is set not to trace and is |
| 496 | * not enabled, do nothing. |
| 497 | */ |
| 498 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); |
| 499 | if (fl == FTRACE_FL_NOTRACE) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 500 | return 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 501 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 502 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 503 | } else |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 504 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
| 505 | |
| 506 | if (enable) { |
| 507 | if (rec->flags & FTRACE_FL_ENABLED) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 508 | return 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 509 | rec->flags |= FTRACE_FL_ENABLED; |
| 510 | } else { |
| 511 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 512 | return 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 513 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 514 | } |
| 515 | } |
| 516 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 517 | return ftrace_modify_code(ip, old, new); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 518 | } |
| 519 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 520 | static void ftrace_replace_code(int enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 521 | { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 522 | int i, failed; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 523 | unsigned char *new = NULL, *old = NULL; |
| 524 | struct dyn_ftrace *rec; |
| 525 | struct ftrace_page *pg; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 526 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 527 | if (enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 528 | old = ftrace_nop_replace(); |
| 529 | else |
| 530 | new = ftrace_nop_replace(); |
| 531 | |
| 532 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 533 | for (i = 0; i < pg->index; i++) { |
| 534 | rec = &pg->records[i]; |
| 535 | |
| 536 | /* don't modify code that has already faulted */ |
| 537 | if (rec->flags & FTRACE_FL_FAILED) |
| 538 | continue; |
| 539 | |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 540 | /* ignore updates to this record's mcount site */ |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 541 | if (get_kprobe((void *)rec->ip)) { |
| 542 | freeze_record(rec); |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 543 | continue; |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 544 | } else { |
| 545 | unfreeze_record(rec); |
| 546 | } |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 547 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 548 | failed = __ftrace_replace_code(rec, old, new, enable); |
| 549 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
| 550 | rec->flags |= FTRACE_FL_FAILED; |
| 551 | if ((system_state == SYSTEM_BOOTING) || |
Abhishek Sagar | 34078a5 | 2008-06-03 08:33:41 +0530 | [diff] [blame] | 552 | !core_kernel_text(rec->ip)) { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 553 | ftrace_del_hash(rec); |
| 554 | ftrace_free_rec(rec); |
| 555 | } |
| 556 | } |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 557 | } |
| 558 | } |
| 559 | } |
| 560 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 561 | static void ftrace_shutdown_replenish(void) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 562 | { |
| 563 | if (ftrace_pages->next) |
| 564 | return; |
| 565 | |
| 566 | /* allocate another page */ |
| 567 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 568 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 569 | |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 570 | static int |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 571 | ftrace_code_disable(struct dyn_ftrace *rec) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 572 | { |
| 573 | unsigned long ip; |
| 574 | unsigned char *nop, *call; |
| 575 | int failed; |
| 576 | |
| 577 | ip = rec->ip; |
| 578 | |
| 579 | nop = ftrace_nop_replace(); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 580 | call = ftrace_call_replace(ip, MCOUNT_ADDR); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 581 | |
| 582 | failed = ftrace_modify_code(ip, call, nop); |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 583 | if (failed) { |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 584 | rec->flags |= FTRACE_FL_FAILED; |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 585 | return 0; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 586 | } |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 587 | return 1; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 588 | } |
| 589 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 590 | static int __ftrace_update_code(void *ignore); |
| 591 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 592 | static int __ftrace_modify_code(void *data) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 593 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 594 | unsigned long addr; |
| 595 | int *command = data; |
| 596 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 597 | if (*command & FTRACE_ENABLE_CALLS) { |
| 598 | /* |
| 599 | * Update any recorded ips now that we have the |
| 600 | * machine stopped |
| 601 | */ |
| 602 | __ftrace_update_code(NULL); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 603 | ftrace_replace_code(1); |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 604 | tracing_on = 1; |
| 605 | } else if (*command & FTRACE_DISABLE_CALLS) { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 606 | ftrace_replace_code(0); |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 607 | tracing_on = 0; |
| 608 | } |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 609 | |
| 610 | if (*command & FTRACE_UPDATE_TRACE_FUNC) |
| 611 | ftrace_update_ftrace_func(ftrace_trace_function); |
| 612 | |
| 613 | if (*command & FTRACE_ENABLE_MCOUNT) { |
| 614 | addr = (unsigned long)ftrace_record_ip; |
| 615 | ftrace_mcount_set(&addr); |
| 616 | } else if (*command & FTRACE_DISABLE_MCOUNT) { |
| 617 | addr = (unsigned long)ftrace_stub; |
| 618 | ftrace_mcount_set(&addr); |
| 619 | } |
| 620 | |
| 621 | return 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 622 | } |
| 623 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 624 | static void ftrace_run_update_code(int command) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 625 | { |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 626 | stop_machine(__ftrace_modify_code, &command, NULL); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 627 | } |
| 628 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 629 | void ftrace_disable_daemon(void) |
| 630 | { |
| 631 | /* Stop the daemon from calling kstop_machine */ |
| 632 | mutex_lock(&ftraced_lock); |
| 633 | ftraced_stop = 1; |
| 634 | mutex_unlock(&ftraced_lock); |
| 635 | |
| 636 | ftrace_force_update(); |
| 637 | } |
| 638 | |
| 639 | void ftrace_enable_daemon(void) |
| 640 | { |
| 641 | mutex_lock(&ftraced_lock); |
| 642 | ftraced_stop = 0; |
| 643 | mutex_unlock(&ftraced_lock); |
| 644 | |
| 645 | ftrace_force_update(); |
| 646 | } |
| 647 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 648 | static ftrace_func_t saved_ftrace_func; |
| 649 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 650 | static void ftrace_startup(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 651 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 652 | int command = 0; |
| 653 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 654 | if (unlikely(ftrace_disabled)) |
| 655 | return; |
| 656 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 657 | mutex_lock(&ftraced_lock); |
| 658 | ftraced_suspend++; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 659 | if (ftraced_suspend == 1) |
| 660 | command |= FTRACE_ENABLE_CALLS; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 661 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 662 | if (saved_ftrace_func != ftrace_trace_function) { |
| 663 | saved_ftrace_func = ftrace_trace_function; |
| 664 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 665 | } |
| 666 | |
| 667 | if (!command || !ftrace_enabled) |
| 668 | goto out; |
| 669 | |
| 670 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 671 | out: |
| 672 | mutex_unlock(&ftraced_lock); |
| 673 | } |
| 674 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 675 | static void ftrace_shutdown(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 676 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 677 | int command = 0; |
| 678 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 679 | if (unlikely(ftrace_disabled)) |
| 680 | return; |
| 681 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 682 | mutex_lock(&ftraced_lock); |
| 683 | ftraced_suspend--; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 684 | if (!ftraced_suspend) |
| 685 | command |= FTRACE_DISABLE_CALLS; |
| 686 | |
| 687 | if (saved_ftrace_func != ftrace_trace_function) { |
| 688 | saved_ftrace_func = ftrace_trace_function; |
| 689 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 690 | } |
| 691 | |
| 692 | if (!command || !ftrace_enabled) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 693 | goto out; |
| 694 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 695 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 696 | out: |
| 697 | mutex_unlock(&ftraced_lock); |
| 698 | } |
| 699 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 700 | static void ftrace_startup_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 701 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 702 | int command = FTRACE_ENABLE_MCOUNT; |
| 703 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 704 | if (unlikely(ftrace_disabled)) |
| 705 | return; |
| 706 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 707 | mutex_lock(&ftraced_lock); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 708 | /* Force update next time */ |
| 709 | saved_ftrace_func = NULL; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 710 | /* ftraced_suspend is true if we want ftrace running */ |
| 711 | if (ftraced_suspend) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 712 | command |= FTRACE_ENABLE_CALLS; |
| 713 | |
| 714 | ftrace_run_update_code(command); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 715 | mutex_unlock(&ftraced_lock); |
| 716 | } |
| 717 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 718 | static void ftrace_shutdown_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 719 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 720 | int command = FTRACE_DISABLE_MCOUNT; |
| 721 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 722 | if (unlikely(ftrace_disabled)) |
| 723 | return; |
| 724 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 725 | mutex_lock(&ftraced_lock); |
| 726 | /* ftraced_suspend is true if ftrace is running */ |
| 727 | if (ftraced_suspend) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 728 | command |= FTRACE_DISABLE_CALLS; |
| 729 | |
| 730 | ftrace_run_update_code(command); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 731 | mutex_unlock(&ftraced_lock); |
| 732 | } |
| 733 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 734 | static cycle_t ftrace_update_time; |
| 735 | static unsigned long ftrace_update_cnt; |
| 736 | unsigned long ftrace_update_tot_cnt; |
| 737 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 738 | static int __ftrace_update_code(void *ignore) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 739 | { |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 740 | int i, save_ftrace_enabled; |
| 741 | cycle_t start, stop; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 742 | struct dyn_ftrace *p; |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 743 | struct hlist_node *t, *n; |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 744 | struct hlist_head *head, temp_list; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 745 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 746 | /* Don't be recording funcs now */ |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 747 | ftrace_record_suspend++; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 748 | save_ftrace_enabled = ftrace_enabled; |
| 749 | ftrace_enabled = 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 750 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 751 | start = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 752 | ftrace_update_cnt = 0; |
| 753 | |
| 754 | /* No locks needed, the machine is stopped! */ |
| 755 | for (i = 0; i < FTRACE_HASHSIZE; i++) { |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 756 | INIT_HLIST_HEAD(&temp_list); |
| 757 | head = &ftrace_hash[i]; |
| 758 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 759 | /* all CPUS are stopped, we are safe to modify code */ |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 760 | hlist_for_each_entry_safe(p, t, n, head, node) { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 761 | /* Skip over failed records which have not been |
| 762 | * freed. */ |
| 763 | if (p->flags & FTRACE_FL_FAILED) |
| 764 | continue; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 765 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 766 | /* Unconverted records are always at the head of the |
| 767 | * hash bucket. Once we encounter a converted record, |
| 768 | * simply skip over to the next bucket. Saves ftraced |
| 769 | * some processor cycles (ftrace does its bid for |
| 770 | * global warming :-p ). */ |
| 771 | if (p->flags & (FTRACE_FL_CONVERTED)) |
| 772 | break; |
| 773 | |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 774 | /* Ignore updates to this record's mcount site. |
| 775 | * Reintroduce this record at the head of this |
| 776 | * bucket to attempt to "convert" it again if |
| 777 | * the kprobe on it is unregistered before the |
| 778 | * next run. */ |
| 779 | if (get_kprobe((void *)p->ip)) { |
| 780 | ftrace_del_hash(p); |
| 781 | INIT_HLIST_NODE(&p->node); |
| 782 | hlist_add_head(&p->node, &temp_list); |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 783 | freeze_record(p); |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 784 | continue; |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 785 | } else { |
| 786 | unfreeze_record(p); |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 787 | } |
| 788 | |
| 789 | /* convert record (i.e, patch mcount-call with NOP) */ |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 790 | if (ftrace_code_disable(p)) { |
| 791 | p->flags |= FTRACE_FL_CONVERTED; |
| 792 | ftrace_update_cnt++; |
| 793 | } else { |
| 794 | if ((system_state == SYSTEM_BOOTING) || |
Abhishek Sagar | 34078a5 | 2008-06-03 08:33:41 +0530 | [diff] [blame] | 795 | !core_kernel_text(p->ip)) { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 796 | ftrace_del_hash(p); |
| 797 | ftrace_free_rec(p); |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 798 | } |
| 799 | } |
| 800 | } |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 801 | |
| 802 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { |
| 803 | hlist_del(&p->node); |
| 804 | INIT_HLIST_NODE(&p->node); |
| 805 | hlist_add_head(&p->node, head); |
| 806 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 807 | } |
| 808 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 809 | stop = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 810 | ftrace_update_time = stop - start; |
| 811 | ftrace_update_tot_cnt += ftrace_update_cnt; |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 812 | ftraced_trigger = 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 813 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 814 | ftrace_enabled = save_ftrace_enabled; |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 815 | ftrace_record_suspend--; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 816 | |
| 817 | return 0; |
| 818 | } |
| 819 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 820 | static int ftrace_update_code(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 821 | { |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 822 | if (unlikely(ftrace_disabled) || |
| 823 | !ftrace_enabled || !ftraced_trigger) |
| 824 | return 0; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 825 | |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 826 | stop_machine(__ftrace_update_code, NULL, NULL); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 827 | |
| 828 | return 1; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 829 | } |
| 830 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 831 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 832 | { |
| 833 | struct ftrace_page *pg; |
| 834 | int cnt; |
| 835 | int i; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 836 | |
| 837 | /* allocate a few pages */ |
| 838 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); |
| 839 | if (!ftrace_pages_start) |
| 840 | return -1; |
| 841 | |
| 842 | /* |
| 843 | * Allocate a few more pages. |
| 844 | * |
| 845 | * TODO: have some parser search vmlinux before |
| 846 | * final linking to find all calls to ftrace. |
| 847 | * Then we can: |
| 848 | * a) know how many pages to allocate. |
| 849 | * and/or |
| 850 | * b) set up the table then. |
| 851 | * |
| 852 | * The dynamic code is still necessary for |
| 853 | * modules. |
| 854 | */ |
| 855 | |
| 856 | pg = ftrace_pages = ftrace_pages_start; |
| 857 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 858 | cnt = num_to_init / ENTRIES_PER_PAGE; |
| 859 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", |
| 860 | num_to_init, cnt); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 861 | |
| 862 | for (i = 0; i < cnt; i++) { |
| 863 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 864 | |
| 865 | /* If we fail, we'll try later anyway */ |
| 866 | if (!pg->next) |
| 867 | break; |
| 868 | |
| 869 | pg = pg->next; |
| 870 | } |
| 871 | |
| 872 | return 0; |
| 873 | } |
| 874 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 875 | enum { |
| 876 | FTRACE_ITER_FILTER = (1 << 0), |
| 877 | FTRACE_ITER_CONT = (1 << 1), |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 878 | FTRACE_ITER_NOTRACE = (1 << 2), |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 879 | FTRACE_ITER_FAILURES = (1 << 3), |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 880 | }; |
| 881 | |
| 882 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| 883 | |
| 884 | struct ftrace_iterator { |
| 885 | loff_t pos; |
| 886 | struct ftrace_page *pg; |
| 887 | unsigned idx; |
| 888 | unsigned flags; |
| 889 | unsigned char buffer[FTRACE_BUFF_MAX+1]; |
| 890 | unsigned buffer_idx; |
| 891 | unsigned filtered; |
| 892 | }; |
| 893 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 894 | static void * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 895 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 896 | { |
| 897 | struct ftrace_iterator *iter = m->private; |
| 898 | struct dyn_ftrace *rec = NULL; |
| 899 | |
| 900 | (*pos)++; |
| 901 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 902 | /* should not be called from interrupt context */ |
| 903 | spin_lock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 904 | retry: |
| 905 | if (iter->idx >= iter->pg->index) { |
| 906 | if (iter->pg->next) { |
| 907 | iter->pg = iter->pg->next; |
| 908 | iter->idx = 0; |
| 909 | goto retry; |
| 910 | } |
| 911 | } else { |
| 912 | rec = &iter->pg->records[iter->idx++]; |
Steven Rostedt | a9fdda3 | 2008-08-14 22:47:17 -0400 | [diff] [blame] | 913 | if ((rec->flags & FTRACE_FL_FREE) || |
| 914 | |
| 915 | (!(iter->flags & FTRACE_ITER_FAILURES) && |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 916 | (rec->flags & FTRACE_FL_FAILED)) || |
| 917 | |
| 918 | ((iter->flags & FTRACE_ITER_FAILURES) && |
Steven Rostedt | a9fdda3 | 2008-08-14 22:47:17 -0400 | [diff] [blame] | 919 | !(rec->flags & FTRACE_FL_FAILED)) || |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 920 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 921 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
| 922 | !(rec->flags & FTRACE_FL_NOTRACE))) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 923 | rec = NULL; |
| 924 | goto retry; |
| 925 | } |
| 926 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 927 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 928 | |
| 929 | iter->pos = *pos; |
| 930 | |
| 931 | return rec; |
| 932 | } |
| 933 | |
| 934 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 935 | { |
| 936 | struct ftrace_iterator *iter = m->private; |
| 937 | void *p = NULL; |
| 938 | loff_t l = -1; |
| 939 | |
| 940 | if (*pos != iter->pos) { |
| 941 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) |
| 942 | ; |
| 943 | } else { |
| 944 | l = *pos; |
| 945 | p = t_next(m, p, &l); |
| 946 | } |
| 947 | |
| 948 | return p; |
| 949 | } |
| 950 | |
| 951 | static void t_stop(struct seq_file *m, void *p) |
| 952 | { |
| 953 | } |
| 954 | |
| 955 | static int t_show(struct seq_file *m, void *v) |
| 956 | { |
| 957 | struct dyn_ftrace *rec = v; |
| 958 | char str[KSYM_SYMBOL_LEN]; |
| 959 | |
| 960 | if (!rec) |
| 961 | return 0; |
| 962 | |
| 963 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 964 | |
| 965 | seq_printf(m, "%s\n", str); |
| 966 | |
| 967 | return 0; |
| 968 | } |
| 969 | |
| 970 | static struct seq_operations show_ftrace_seq_ops = { |
| 971 | .start = t_start, |
| 972 | .next = t_next, |
| 973 | .stop = t_stop, |
| 974 | .show = t_show, |
| 975 | }; |
| 976 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 977 | static int |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 978 | ftrace_avail_open(struct inode *inode, struct file *file) |
| 979 | { |
| 980 | struct ftrace_iterator *iter; |
| 981 | int ret; |
| 982 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 983 | if (unlikely(ftrace_disabled)) |
| 984 | return -ENODEV; |
| 985 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 986 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 987 | if (!iter) |
| 988 | return -ENOMEM; |
| 989 | |
| 990 | iter->pg = ftrace_pages_start; |
| 991 | iter->pos = -1; |
| 992 | |
| 993 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 994 | if (!ret) { |
| 995 | struct seq_file *m = file->private_data; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 996 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 997 | m->private = iter; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 998 | } else { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 999 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 1000 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1001 | |
| 1002 | return ret; |
| 1003 | } |
| 1004 | |
| 1005 | int ftrace_avail_release(struct inode *inode, struct file *file) |
| 1006 | { |
| 1007 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1008 | struct ftrace_iterator *iter = m->private; |
| 1009 | |
| 1010 | seq_release(inode, file); |
| 1011 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 1012 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1013 | return 0; |
| 1014 | } |
| 1015 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1016 | static int |
| 1017 | ftrace_failures_open(struct inode *inode, struct file *file) |
| 1018 | { |
| 1019 | int ret; |
| 1020 | struct seq_file *m; |
| 1021 | struct ftrace_iterator *iter; |
| 1022 | |
| 1023 | ret = ftrace_avail_open(inode, file); |
| 1024 | if (!ret) { |
| 1025 | m = (struct seq_file *)file->private_data; |
| 1026 | iter = (struct ftrace_iterator *)m->private; |
| 1027 | iter->flags = FTRACE_ITER_FAILURES; |
| 1028 | } |
| 1029 | |
| 1030 | return ret; |
| 1031 | } |
| 1032 | |
| 1033 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1034 | static void ftrace_filter_reset(int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1035 | { |
| 1036 | struct ftrace_page *pg; |
| 1037 | struct dyn_ftrace *rec; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1038 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1039 | unsigned i; |
| 1040 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 1041 | /* should not be called from interrupt context */ |
| 1042 | spin_lock(&ftrace_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1043 | if (enable) |
| 1044 | ftrace_filtered = 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1045 | pg = ftrace_pages_start; |
| 1046 | while (pg) { |
| 1047 | for (i = 0; i < pg->index; i++) { |
| 1048 | rec = &pg->records[i]; |
| 1049 | if (rec->flags & FTRACE_FL_FAILED) |
| 1050 | continue; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1051 | rec->flags &= ~type; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1052 | } |
| 1053 | pg = pg->next; |
| 1054 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 1055 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1056 | } |
| 1057 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1058 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1059 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1060 | { |
| 1061 | struct ftrace_iterator *iter; |
| 1062 | int ret = 0; |
| 1063 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1064 | if (unlikely(ftrace_disabled)) |
| 1065 | return -ENODEV; |
| 1066 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1067 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 1068 | if (!iter) |
| 1069 | return -ENOMEM; |
| 1070 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1071 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1072 | if ((file->f_mode & FMODE_WRITE) && |
| 1073 | !(file->f_flags & O_APPEND)) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1074 | ftrace_filter_reset(enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1075 | |
| 1076 | if (file->f_mode & FMODE_READ) { |
| 1077 | iter->pg = ftrace_pages_start; |
| 1078 | iter->pos = -1; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1079 | iter->flags = enable ? FTRACE_ITER_FILTER : |
| 1080 | FTRACE_ITER_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1081 | |
| 1082 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 1083 | if (!ret) { |
| 1084 | struct seq_file *m = file->private_data; |
| 1085 | m->private = iter; |
| 1086 | } else |
| 1087 | kfree(iter); |
| 1088 | } else |
| 1089 | file->private_data = iter; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1090 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1091 | |
| 1092 | return ret; |
| 1093 | } |
| 1094 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1095 | static int |
| 1096 | ftrace_filter_open(struct inode *inode, struct file *file) |
| 1097 | { |
| 1098 | return ftrace_regex_open(inode, file, 1); |
| 1099 | } |
| 1100 | |
| 1101 | static int |
| 1102 | ftrace_notrace_open(struct inode *inode, struct file *file) |
| 1103 | { |
| 1104 | return ftrace_regex_open(inode, file, 0); |
| 1105 | } |
| 1106 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1107 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1108 | ftrace_regex_read(struct file *file, char __user *ubuf, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1109 | size_t cnt, loff_t *ppos) |
| 1110 | { |
| 1111 | if (file->f_mode & FMODE_READ) |
| 1112 | return seq_read(file, ubuf, cnt, ppos); |
| 1113 | else |
| 1114 | return -EPERM; |
| 1115 | } |
| 1116 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1117 | static loff_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1118 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1119 | { |
| 1120 | loff_t ret; |
| 1121 | |
| 1122 | if (file->f_mode & FMODE_READ) |
| 1123 | ret = seq_lseek(file, offset, origin); |
| 1124 | else |
| 1125 | file->f_pos = ret = 1; |
| 1126 | |
| 1127 | return ret; |
| 1128 | } |
| 1129 | |
| 1130 | enum { |
| 1131 | MATCH_FULL, |
| 1132 | MATCH_FRONT_ONLY, |
| 1133 | MATCH_MIDDLE_ONLY, |
| 1134 | MATCH_END_ONLY, |
| 1135 | }; |
| 1136 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1137 | static void |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1138 | ftrace_match(unsigned char *buff, int len, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1139 | { |
| 1140 | char str[KSYM_SYMBOL_LEN]; |
| 1141 | char *search = NULL; |
| 1142 | struct ftrace_page *pg; |
| 1143 | struct dyn_ftrace *rec; |
| 1144 | int type = MATCH_FULL; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1145 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1146 | unsigned i, match = 0, search_len = 0; |
| 1147 | |
| 1148 | for (i = 0; i < len; i++) { |
| 1149 | if (buff[i] == '*') { |
| 1150 | if (!i) { |
| 1151 | search = buff + i + 1; |
| 1152 | type = MATCH_END_ONLY; |
| 1153 | search_len = len - (i + 1); |
| 1154 | } else { |
| 1155 | if (type == MATCH_END_ONLY) { |
| 1156 | type = MATCH_MIDDLE_ONLY; |
| 1157 | } else { |
| 1158 | match = i; |
| 1159 | type = MATCH_FRONT_ONLY; |
| 1160 | } |
| 1161 | buff[i] = 0; |
| 1162 | break; |
| 1163 | } |
| 1164 | } |
| 1165 | } |
| 1166 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 1167 | /* should not be called from interrupt context */ |
| 1168 | spin_lock(&ftrace_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1169 | if (enable) |
| 1170 | ftrace_filtered = 1; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1171 | pg = ftrace_pages_start; |
| 1172 | while (pg) { |
| 1173 | for (i = 0; i < pg->index; i++) { |
| 1174 | int matched = 0; |
| 1175 | char *ptr; |
| 1176 | |
| 1177 | rec = &pg->records[i]; |
| 1178 | if (rec->flags & FTRACE_FL_FAILED) |
| 1179 | continue; |
| 1180 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1181 | switch (type) { |
| 1182 | case MATCH_FULL: |
| 1183 | if (strcmp(str, buff) == 0) |
| 1184 | matched = 1; |
| 1185 | break; |
| 1186 | case MATCH_FRONT_ONLY: |
| 1187 | if (memcmp(str, buff, match) == 0) |
| 1188 | matched = 1; |
| 1189 | break; |
| 1190 | case MATCH_MIDDLE_ONLY: |
| 1191 | if (strstr(str, search)) |
| 1192 | matched = 1; |
| 1193 | break; |
| 1194 | case MATCH_END_ONLY: |
| 1195 | ptr = strstr(str, search); |
| 1196 | if (ptr && (ptr[search_len] == 0)) |
| 1197 | matched = 1; |
| 1198 | break; |
| 1199 | } |
| 1200 | if (matched) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1201 | rec->flags |= flag; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1202 | } |
| 1203 | pg = pg->next; |
| 1204 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 1205 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1206 | } |
| 1207 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1208 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1209 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
| 1210 | size_t cnt, loff_t *ppos, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1211 | { |
| 1212 | struct ftrace_iterator *iter; |
| 1213 | char ch; |
| 1214 | size_t read = 0; |
| 1215 | ssize_t ret; |
| 1216 | |
| 1217 | if (!cnt || cnt < 0) |
| 1218 | return 0; |
| 1219 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1220 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1221 | |
| 1222 | if (file->f_mode & FMODE_READ) { |
| 1223 | struct seq_file *m = file->private_data; |
| 1224 | iter = m->private; |
| 1225 | } else |
| 1226 | iter = file->private_data; |
| 1227 | |
| 1228 | if (!*ppos) { |
| 1229 | iter->flags &= ~FTRACE_ITER_CONT; |
| 1230 | iter->buffer_idx = 0; |
| 1231 | } |
| 1232 | |
| 1233 | ret = get_user(ch, ubuf++); |
| 1234 | if (ret) |
| 1235 | goto out; |
| 1236 | read++; |
| 1237 | cnt--; |
| 1238 | |
| 1239 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { |
| 1240 | /* skip white space */ |
| 1241 | while (cnt && isspace(ch)) { |
| 1242 | ret = get_user(ch, ubuf++); |
| 1243 | if (ret) |
| 1244 | goto out; |
| 1245 | read++; |
| 1246 | cnt--; |
| 1247 | } |
| 1248 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1249 | if (isspace(ch)) { |
| 1250 | file->f_pos += read; |
| 1251 | ret = read; |
| 1252 | goto out; |
| 1253 | } |
| 1254 | |
| 1255 | iter->buffer_idx = 0; |
| 1256 | } |
| 1257 | |
| 1258 | while (cnt && !isspace(ch)) { |
| 1259 | if (iter->buffer_idx < FTRACE_BUFF_MAX) |
| 1260 | iter->buffer[iter->buffer_idx++] = ch; |
| 1261 | else { |
| 1262 | ret = -EINVAL; |
| 1263 | goto out; |
| 1264 | } |
| 1265 | ret = get_user(ch, ubuf++); |
| 1266 | if (ret) |
| 1267 | goto out; |
| 1268 | read++; |
| 1269 | cnt--; |
| 1270 | } |
| 1271 | |
| 1272 | if (isspace(ch)) { |
| 1273 | iter->filtered++; |
| 1274 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1275 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1276 | iter->buffer_idx = 0; |
| 1277 | } else |
| 1278 | iter->flags |= FTRACE_ITER_CONT; |
| 1279 | |
| 1280 | |
| 1281 | file->f_pos += read; |
| 1282 | |
| 1283 | ret = read; |
| 1284 | out: |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1285 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1286 | |
| 1287 | return ret; |
| 1288 | } |
| 1289 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1290 | static ssize_t |
| 1291 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
| 1292 | size_t cnt, loff_t *ppos) |
| 1293 | { |
| 1294 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
| 1295 | } |
| 1296 | |
| 1297 | static ssize_t |
| 1298 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
| 1299 | size_t cnt, loff_t *ppos) |
| 1300 | { |
| 1301 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
| 1302 | } |
| 1303 | |
| 1304 | static void |
| 1305 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) |
| 1306 | { |
| 1307 | if (unlikely(ftrace_disabled)) |
| 1308 | return; |
| 1309 | |
| 1310 | mutex_lock(&ftrace_regex_lock); |
| 1311 | if (reset) |
| 1312 | ftrace_filter_reset(enable); |
| 1313 | if (buf) |
| 1314 | ftrace_match(buf, len, enable); |
| 1315 | mutex_unlock(&ftrace_regex_lock); |
| 1316 | } |
| 1317 | |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1318 | /** |
| 1319 | * ftrace_set_filter - set a function to filter on in ftrace |
| 1320 | * @buf - the string that holds the function filter text. |
| 1321 | * @len - the length of the string. |
| 1322 | * @reset - non zero to reset all filters before applying this filter. |
| 1323 | * |
| 1324 | * Filters denote which functions should be enabled when tracing is enabled. |
| 1325 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| 1326 | */ |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1327 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1328 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1329 | ftrace_set_regex(buf, len, reset, 1); |
| 1330 | } |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1331 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1332 | /** |
| 1333 | * ftrace_set_notrace - set a function to not trace in ftrace |
| 1334 | * @buf - the string that holds the function notrace text. |
| 1335 | * @len - the length of the string. |
| 1336 | * @reset - non zero to reset all filters before applying this filter. |
| 1337 | * |
| 1338 | * Notrace Filters denote which functions should not be enabled when tracing |
| 1339 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| 1340 | * for tracing. |
| 1341 | */ |
| 1342 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) |
| 1343 | { |
| 1344 | ftrace_set_regex(buf, len, reset, 0); |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1345 | } |
| 1346 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1347 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1348 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1349 | { |
| 1350 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1351 | struct ftrace_iterator *iter; |
| 1352 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1353 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1354 | if (file->f_mode & FMODE_READ) { |
| 1355 | iter = m->private; |
| 1356 | |
| 1357 | seq_release(inode, file); |
| 1358 | } else |
| 1359 | iter = file->private_data; |
| 1360 | |
| 1361 | if (iter->buffer_idx) { |
| 1362 | iter->filtered++; |
| 1363 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1364 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1365 | } |
| 1366 | |
| 1367 | mutex_lock(&ftrace_sysctl_lock); |
| 1368 | mutex_lock(&ftraced_lock); |
| 1369 | if (iter->filtered && ftraced_suspend && ftrace_enabled) |
| 1370 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
| 1371 | mutex_unlock(&ftraced_lock); |
| 1372 | mutex_unlock(&ftrace_sysctl_lock); |
| 1373 | |
| 1374 | kfree(iter); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1375 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1376 | return 0; |
| 1377 | } |
| 1378 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1379 | static int |
| 1380 | ftrace_filter_release(struct inode *inode, struct file *file) |
| 1381 | { |
| 1382 | return ftrace_regex_release(inode, file, 1); |
| 1383 | } |
| 1384 | |
| 1385 | static int |
| 1386 | ftrace_notrace_release(struct inode *inode, struct file *file) |
| 1387 | { |
| 1388 | return ftrace_regex_release(inode, file, 0); |
| 1389 | } |
| 1390 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1391 | static ssize_t |
| 1392 | ftraced_read(struct file *filp, char __user *ubuf, |
| 1393 | size_t cnt, loff_t *ppos) |
| 1394 | { |
| 1395 | /* don't worry about races */ |
| 1396 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; |
| 1397 | int r = strlen(buf); |
| 1398 | |
| 1399 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 1400 | } |
| 1401 | |
| 1402 | static ssize_t |
| 1403 | ftraced_write(struct file *filp, const char __user *ubuf, |
| 1404 | size_t cnt, loff_t *ppos) |
| 1405 | { |
| 1406 | char buf[64]; |
| 1407 | long val; |
| 1408 | int ret; |
| 1409 | |
| 1410 | if (cnt >= sizeof(buf)) |
| 1411 | return -EINVAL; |
| 1412 | |
| 1413 | if (copy_from_user(&buf, ubuf, cnt)) |
| 1414 | return -EFAULT; |
| 1415 | |
| 1416 | if (strncmp(buf, "enable", 6) == 0) |
| 1417 | val = 1; |
| 1418 | else if (strncmp(buf, "disable", 7) == 0) |
| 1419 | val = 0; |
| 1420 | else { |
| 1421 | buf[cnt] = 0; |
| 1422 | |
| 1423 | ret = strict_strtoul(buf, 10, &val); |
| 1424 | if (ret < 0) |
| 1425 | return ret; |
| 1426 | |
| 1427 | val = !!val; |
| 1428 | } |
| 1429 | |
| 1430 | if (val) |
| 1431 | ftrace_enable_daemon(); |
| 1432 | else |
| 1433 | ftrace_disable_daemon(); |
| 1434 | |
| 1435 | filp->f_pos += cnt; |
| 1436 | |
| 1437 | return cnt; |
| 1438 | } |
| 1439 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1440 | static struct file_operations ftrace_avail_fops = { |
| 1441 | .open = ftrace_avail_open, |
| 1442 | .read = seq_read, |
| 1443 | .llseek = seq_lseek, |
| 1444 | .release = ftrace_avail_release, |
| 1445 | }; |
| 1446 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1447 | static struct file_operations ftrace_failures_fops = { |
| 1448 | .open = ftrace_failures_open, |
| 1449 | .read = seq_read, |
| 1450 | .llseek = seq_lseek, |
| 1451 | .release = ftrace_avail_release, |
| 1452 | }; |
| 1453 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1454 | static struct file_operations ftrace_filter_fops = { |
| 1455 | .open = ftrace_filter_open, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1456 | .read = ftrace_regex_read, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1457 | .write = ftrace_filter_write, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1458 | .llseek = ftrace_regex_lseek, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1459 | .release = ftrace_filter_release, |
| 1460 | }; |
| 1461 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1462 | static struct file_operations ftrace_notrace_fops = { |
| 1463 | .open = ftrace_notrace_open, |
| 1464 | .read = ftrace_regex_read, |
| 1465 | .write = ftrace_notrace_write, |
| 1466 | .llseek = ftrace_regex_lseek, |
| 1467 | .release = ftrace_notrace_release, |
| 1468 | }; |
| 1469 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1470 | static struct file_operations ftraced_fops = { |
| 1471 | .open = tracing_open_generic, |
| 1472 | .read = ftraced_read, |
| 1473 | .write = ftraced_write, |
| 1474 | }; |
| 1475 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1476 | /** |
| 1477 | * ftrace_force_update - force an update to all recording ftrace functions |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1478 | */ |
| 1479 | int ftrace_force_update(void) |
| 1480 | { |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1481 | int ret = 0; |
| 1482 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1483 | if (unlikely(ftrace_disabled)) |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1484 | return -ENODEV; |
| 1485 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1486 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1487 | mutex_lock(&ftraced_lock); |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1488 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1489 | /* |
| 1490 | * If ftraced_trigger is not set, then there is nothing |
| 1491 | * to update. |
| 1492 | */ |
| 1493 | if (ftraced_trigger && !ftrace_update_code()) |
| 1494 | ret = -EBUSY; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1495 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1496 | mutex_unlock(&ftraced_lock); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1497 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1498 | |
| 1499 | return ret; |
| 1500 | } |
| 1501 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1502 | static void ftrace_force_shutdown(void) |
| 1503 | { |
| 1504 | struct task_struct *task; |
| 1505 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; |
| 1506 | |
| 1507 | mutex_lock(&ftraced_lock); |
| 1508 | task = ftraced_task; |
| 1509 | ftraced_task = NULL; |
| 1510 | ftraced_suspend = -1; |
| 1511 | ftrace_run_update_code(command); |
| 1512 | mutex_unlock(&ftraced_lock); |
| 1513 | |
| 1514 | if (task) |
| 1515 | kthread_stop(task); |
| 1516 | } |
| 1517 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1518 | static __init int ftrace_init_debugfs(void) |
| 1519 | { |
| 1520 | struct dentry *d_tracer; |
| 1521 | struct dentry *entry; |
| 1522 | |
| 1523 | d_tracer = tracing_init_dentry(); |
| 1524 | |
| 1525 | entry = debugfs_create_file("available_filter_functions", 0444, |
| 1526 | d_tracer, NULL, &ftrace_avail_fops); |
| 1527 | if (!entry) |
| 1528 | pr_warning("Could not create debugfs " |
| 1529 | "'available_filter_functions' entry\n"); |
| 1530 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1531 | entry = debugfs_create_file("failures", 0444, |
| 1532 | d_tracer, NULL, &ftrace_failures_fops); |
| 1533 | if (!entry) |
| 1534 | pr_warning("Could not create debugfs 'failures' entry\n"); |
| 1535 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1536 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
| 1537 | NULL, &ftrace_filter_fops); |
| 1538 | if (!entry) |
| 1539 | pr_warning("Could not create debugfs " |
| 1540 | "'set_ftrace_filter' entry\n"); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1541 | |
| 1542 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, |
| 1543 | NULL, &ftrace_notrace_fops); |
| 1544 | if (!entry) |
| 1545 | pr_warning("Could not create debugfs " |
| 1546 | "'set_ftrace_notrace' entry\n"); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1547 | |
| 1548 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, |
| 1549 | NULL, &ftraced_fops); |
| 1550 | if (!entry) |
| 1551 | pr_warning("Could not create debugfs " |
| 1552 | "'ftraced_enabled' entry\n"); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1553 | return 0; |
| 1554 | } |
| 1555 | |
| 1556 | fs_initcall(ftrace_init_debugfs); |
| 1557 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1558 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
| 1559 | static int ftrace_convert_nops(unsigned long *start, |
| 1560 | unsigned long *end) |
| 1561 | { |
| 1562 | unsigned long *p; |
| 1563 | unsigned long addr; |
| 1564 | unsigned long flags; |
| 1565 | |
| 1566 | p = start; |
| 1567 | while (p < end) { |
| 1568 | addr = ftrace_call_adjust(*p++); |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame^] | 1569 | /* should not be called from interrupt context */ |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1570 | spin_lock(&ftrace_lock); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1571 | ftrace_record_ip(addr); |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1572 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1573 | ftrace_shutdown_replenish(); |
| 1574 | } |
| 1575 | |
| 1576 | /* p is ignored */ |
| 1577 | local_irq_save(flags); |
| 1578 | __ftrace_update_code(p); |
| 1579 | local_irq_restore(flags); |
| 1580 | |
| 1581 | return 0; |
| 1582 | } |
| 1583 | |
Steven Rostedt | 90d595f | 2008-08-14 15:45:09 -0400 | [diff] [blame] | 1584 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
| 1585 | { |
Steven Rostedt | 00fd61a | 2008-08-15 21:40:04 -0400 | [diff] [blame] | 1586 | if (ftrace_disabled || start == end) |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1587 | return; |
Steven Rostedt | 90d595f | 2008-08-14 15:45:09 -0400 | [diff] [blame] | 1588 | ftrace_convert_nops(start, end); |
| 1589 | } |
| 1590 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1591 | extern unsigned long __start_mcount_loc[]; |
| 1592 | extern unsigned long __stop_mcount_loc[]; |
| 1593 | |
| 1594 | void __init ftrace_init(void) |
| 1595 | { |
| 1596 | unsigned long count, addr, flags; |
| 1597 | int ret; |
| 1598 | |
| 1599 | /* Keep the ftrace pointer to the stub */ |
| 1600 | addr = (unsigned long)ftrace_stub; |
| 1601 | |
| 1602 | local_irq_save(flags); |
| 1603 | ftrace_dyn_arch_init(&addr); |
| 1604 | local_irq_restore(flags); |
| 1605 | |
| 1606 | /* ftrace_dyn_arch_init places the return code in addr */ |
| 1607 | if (addr) |
| 1608 | goto failed; |
| 1609 | |
| 1610 | count = __stop_mcount_loc - __start_mcount_loc; |
| 1611 | |
| 1612 | ret = ftrace_dyn_table_alloc(count); |
| 1613 | if (ret) |
| 1614 | goto failed; |
| 1615 | |
| 1616 | last_ftrace_enabled = ftrace_enabled = 1; |
| 1617 | |
| 1618 | ret = ftrace_convert_nops(__start_mcount_loc, |
| 1619 | __stop_mcount_loc); |
| 1620 | |
| 1621 | return; |
| 1622 | failed: |
| 1623 | ftrace_disabled = 1; |
| 1624 | } |
| 1625 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ |
| 1626 | static int ftraced(void *ignore) |
| 1627 | { |
| 1628 | unsigned long usecs; |
| 1629 | |
| 1630 | while (!kthread_should_stop()) { |
| 1631 | |
| 1632 | set_current_state(TASK_INTERRUPTIBLE); |
| 1633 | |
| 1634 | /* check once a second */ |
| 1635 | schedule_timeout(HZ); |
| 1636 | |
| 1637 | if (unlikely(ftrace_disabled)) |
| 1638 | continue; |
| 1639 | |
| 1640 | mutex_lock(&ftrace_sysctl_lock); |
| 1641 | mutex_lock(&ftraced_lock); |
| 1642 | if (!ftraced_suspend && !ftraced_stop && |
| 1643 | ftrace_update_code()) { |
| 1644 | usecs = nsecs_to_usecs(ftrace_update_time); |
| 1645 | if (ftrace_update_tot_cnt > 100000) { |
| 1646 | ftrace_update_tot_cnt = 0; |
| 1647 | pr_info("hm, dftrace overflow: %lu change%s" |
| 1648 | " (%lu total) in %lu usec%s\n", |
| 1649 | ftrace_update_cnt, |
| 1650 | ftrace_update_cnt != 1 ? "s" : "", |
| 1651 | ftrace_update_tot_cnt, |
| 1652 | usecs, usecs != 1 ? "s" : ""); |
| 1653 | ftrace_disabled = 1; |
| 1654 | WARN_ON_ONCE(1); |
| 1655 | } |
| 1656 | } |
| 1657 | mutex_unlock(&ftraced_lock); |
| 1658 | mutex_unlock(&ftrace_sysctl_lock); |
| 1659 | |
| 1660 | ftrace_shutdown_replenish(); |
| 1661 | } |
| 1662 | __set_current_state(TASK_RUNNING); |
| 1663 | return 0; |
| 1664 | } |
| 1665 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1666 | static int __init ftrace_dynamic_init(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1667 | { |
| 1668 | struct task_struct *p; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1669 | unsigned long addr; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1670 | int ret; |
| 1671 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1672 | addr = (unsigned long)ftrace_record_ip; |
Ingo Molnar | 9ff9cdb | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 1673 | |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 1674 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1675 | |
| 1676 | /* ftrace_dyn_arch_init places the return code in addr */ |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1677 | if (addr) { |
| 1678 | ret = (int)addr; |
| 1679 | goto failed; |
| 1680 | } |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1681 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1682 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1683 | if (ret) |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1684 | goto failed; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1685 | |
| 1686 | p = kthread_run(ftraced, NULL, "ftraced"); |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1687 | if (IS_ERR(p)) { |
| 1688 | ret = -1; |
| 1689 | goto failed; |
| 1690 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1691 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1692 | last_ftrace_enabled = ftrace_enabled = 1; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1693 | ftraced_task = p; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1694 | |
| 1695 | return 0; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1696 | |
| 1697 | failed: |
| 1698 | ftrace_disabled = 1; |
| 1699 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1700 | } |
| 1701 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1702 | core_initcall(ftrace_dynamic_init); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1703 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
| 1704 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1705 | #else |
Ingo Molnar | c7aafc5 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1706 | # define ftrace_startup() do { } while (0) |
| 1707 | # define ftrace_shutdown() do { } while (0) |
| 1708 | # define ftrace_startup_sysctl() do { } while (0) |
| 1709 | # define ftrace_shutdown_sysctl() do { } while (0) |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1710 | # define ftrace_force_shutdown() do { } while (0) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1711 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 1712 | |
| 1713 | /** |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1714 | * ftrace_kill_atomic - kill ftrace from critical sections |
| 1715 | * |
| 1716 | * This function should be used by panic code. It stops ftrace |
| 1717 | * but in a not so nice way. If you need to simply kill ftrace |
| 1718 | * from a non-atomic section, use ftrace_kill. |
| 1719 | */ |
| 1720 | void ftrace_kill_atomic(void) |
| 1721 | { |
| 1722 | ftrace_disabled = 1; |
| 1723 | ftrace_enabled = 0; |
Ingo Molnar | b2613e3 | 2008-07-11 16:44:27 +0200 | [diff] [blame] | 1724 | #ifdef CONFIG_DYNAMIC_FTRACE |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1725 | ftraced_suspend = -1; |
Ingo Molnar | b2613e3 | 2008-07-11 16:44:27 +0200 | [diff] [blame] | 1726 | #endif |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1727 | clear_ftrace_function(); |
| 1728 | } |
| 1729 | |
| 1730 | /** |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1731 | * ftrace_kill - totally shutdown ftrace |
| 1732 | * |
| 1733 | * This is a safety measure. If something was detected that seems |
| 1734 | * wrong, calling this function will keep ftrace from doing |
| 1735 | * any more modifications, and updates. |
| 1736 | * used when something went wrong. |
| 1737 | */ |
| 1738 | void ftrace_kill(void) |
| 1739 | { |
| 1740 | mutex_lock(&ftrace_sysctl_lock); |
| 1741 | ftrace_disabled = 1; |
| 1742 | ftrace_enabled = 0; |
| 1743 | |
| 1744 | clear_ftrace_function(); |
| 1745 | mutex_unlock(&ftrace_sysctl_lock); |
| 1746 | |
| 1747 | /* Try to totally disable ftrace */ |
| 1748 | ftrace_force_shutdown(); |
| 1749 | } |
| 1750 | |
| 1751 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1752 | * register_ftrace_function - register a function for profiling |
| 1753 | * @ops - ops structure that holds the function for profiling. |
| 1754 | * |
| 1755 | * Register a function to be called by all functions in the |
| 1756 | * kernel. |
| 1757 | * |
| 1758 | * Note: @ops->func and all the functions it calls must be labeled |
| 1759 | * with "notrace", otherwise it will go into a |
| 1760 | * recursive loop. |
| 1761 | */ |
| 1762 | int register_ftrace_function(struct ftrace_ops *ops) |
| 1763 | { |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1764 | int ret; |
| 1765 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1766 | if (unlikely(ftrace_disabled)) |
| 1767 | return -1; |
| 1768 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1769 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1770 | ret = __register_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1771 | ftrace_startup(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1772 | mutex_unlock(&ftrace_sysctl_lock); |
| 1773 | |
| 1774 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1775 | } |
| 1776 | |
| 1777 | /** |
| 1778 | * unregister_ftrace_function - unresgister a function for profiling. |
| 1779 | * @ops - ops structure that holds the function to unregister |
| 1780 | * |
| 1781 | * Unregister a function that was added to be called by ftrace profiling. |
| 1782 | */ |
| 1783 | int unregister_ftrace_function(struct ftrace_ops *ops) |
| 1784 | { |
| 1785 | int ret; |
| 1786 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1787 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1788 | ret = __unregister_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1789 | ftrace_shutdown(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1790 | mutex_unlock(&ftrace_sysctl_lock); |
| 1791 | |
| 1792 | return ret; |
| 1793 | } |
| 1794 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1795 | int |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1796 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1797 | struct file *file, void __user *buffer, size_t *lenp, |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1798 | loff_t *ppos) |
| 1799 | { |
| 1800 | int ret; |
| 1801 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1802 | if (unlikely(ftrace_disabled)) |
| 1803 | return -ENODEV; |
| 1804 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1805 | mutex_lock(&ftrace_sysctl_lock); |
| 1806 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1807 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1808 | |
| 1809 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) |
| 1810 | goto out; |
| 1811 | |
| 1812 | last_ftrace_enabled = ftrace_enabled; |
| 1813 | |
| 1814 | if (ftrace_enabled) { |
| 1815 | |
| 1816 | ftrace_startup_sysctl(); |
| 1817 | |
| 1818 | /* we are starting ftrace again */ |
| 1819 | if (ftrace_list != &ftrace_list_end) { |
| 1820 | if (ftrace_list->next == &ftrace_list_end) |
| 1821 | ftrace_trace_function = ftrace_list->func; |
| 1822 | else |
| 1823 | ftrace_trace_function = ftrace_list_func; |
| 1824 | } |
| 1825 | |
| 1826 | } else { |
| 1827 | /* stopping ftrace calls (just send to ftrace_stub) */ |
| 1828 | ftrace_trace_function = ftrace_stub; |
| 1829 | |
| 1830 | ftrace_shutdown_sysctl(); |
| 1831 | } |
| 1832 | |
| 1833 | out: |
| 1834 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1835 | return ret; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1836 | } |