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 | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 35 | #define FTRACE_WARN_ON(cond) \ |
| 36 | do { \ |
| 37 | if (WARN_ON(cond)) \ |
| 38 | ftrace_kill(); \ |
| 39 | } while (0) |
| 40 | |
| 41 | #define FTRACE_WARN_ON_ONCE(cond) \ |
| 42 | do { \ |
| 43 | if (WARN_ON_ONCE(cond)) \ |
| 44 | ftrace_kill(); \ |
| 45 | } while (0) |
| 46 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 47 | /* ftrace_enabled is a method to turn ftrace on or off */ |
| 48 | int ftrace_enabled __read_mostly; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 49 | static int last_ftrace_enabled; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 50 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 51 | /* |
| 52 | * ftrace_disabled is set when an anomaly is discovered. |
| 53 | * ftrace_disabled is much stronger than ftrace_enabled. |
| 54 | */ |
| 55 | static int ftrace_disabled __read_mostly; |
| 56 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 57 | static DEFINE_SPINLOCK(ftrace_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 58 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
| 59 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 60 | static struct ftrace_ops ftrace_list_end __read_mostly = |
| 61 | { |
| 62 | .func = ftrace_stub, |
| 63 | }; |
| 64 | |
| 65 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; |
| 66 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
| 67 | |
Ingo Molnar | f225293 | 2008-05-22 10:37:48 +0200 | [diff] [blame] | 68 | 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] | 69 | { |
| 70 | struct ftrace_ops *op = ftrace_list; |
| 71 | |
| 72 | /* in case someone actually ports this to alpha! */ |
| 73 | read_barrier_depends(); |
| 74 | |
| 75 | while (op != &ftrace_list_end) { |
| 76 | /* silly alpha */ |
| 77 | read_barrier_depends(); |
| 78 | op->func(ip, parent_ip); |
| 79 | op = op->next; |
| 80 | }; |
| 81 | } |
| 82 | |
| 83 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 84 | * clear_ftrace_function - reset the ftrace function |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 85 | * |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 86 | * This NULLs the ftrace function and in essence stops |
| 87 | * tracing. There may be lag |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 88 | */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 89 | void clear_ftrace_function(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 90 | { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 91 | ftrace_trace_function = ftrace_stub; |
| 92 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 93 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 94 | static int __register_ftrace_function(struct ftrace_ops *ops) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 95 | { |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 96 | /* should not be called from interrupt context */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 97 | spin_lock(&ftrace_lock); |
| 98 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 99 | ops->next = ftrace_list; |
| 100 | /* |
| 101 | * We are entering ops into the ftrace_list but another |
| 102 | * CPU might be walking that list. We need to make sure |
| 103 | * the ops->next pointer is valid before another CPU sees |
| 104 | * the ops pointer included into the ftrace_list. |
| 105 | */ |
| 106 | smp_wmb(); |
| 107 | ftrace_list = ops; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 108 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 109 | if (ftrace_enabled) { |
| 110 | /* |
| 111 | * For one func, simply call it directly. |
| 112 | * For more than one func, call the chain. |
| 113 | */ |
| 114 | if (ops->next == &ftrace_list_end) |
| 115 | ftrace_trace_function = ops->func; |
| 116 | else |
| 117 | ftrace_trace_function = ftrace_list_func; |
| 118 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 119 | |
| 120 | spin_unlock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 121 | |
| 122 | return 0; |
| 123 | } |
| 124 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 125 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 126 | { |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 127 | struct ftrace_ops **p; |
| 128 | int ret = 0; |
| 129 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 130 | /* should not be called from interrupt context */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 131 | spin_lock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 132 | |
| 133 | /* |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 134 | * If we are removing the last function, then simply point |
| 135 | * to the ftrace_stub. |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 136 | */ |
| 137 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { |
| 138 | ftrace_trace_function = ftrace_stub; |
| 139 | ftrace_list = &ftrace_list_end; |
| 140 | goto out; |
| 141 | } |
| 142 | |
| 143 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) |
| 144 | if (*p == ops) |
| 145 | break; |
| 146 | |
| 147 | if (*p != ops) { |
| 148 | ret = -1; |
| 149 | goto out; |
| 150 | } |
| 151 | |
| 152 | *p = (*p)->next; |
| 153 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 154 | if (ftrace_enabled) { |
| 155 | /* If we only have one func left, then call that directly */ |
| 156 | if (ftrace_list == &ftrace_list_end || |
| 157 | ftrace_list->next == &ftrace_list_end) |
| 158 | ftrace_trace_function = ftrace_list->func; |
| 159 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 160 | |
| 161 | out: |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 162 | spin_unlock(&ftrace_lock); |
| 163 | |
| 164 | return ret; |
| 165 | } |
| 166 | |
| 167 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 168 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 169 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
| 170 | /* |
| 171 | * The hash lock is only needed when the recording of the mcount |
| 172 | * callers are dynamic. That is, by the caller themselves and |
| 173 | * not recorded via the compilation. |
| 174 | */ |
| 175 | static DEFINE_SPINLOCK(ftrace_hash_lock); |
Stephen Rothwell | 2d7da80 | 2008-08-25 13:08:44 +1000 | [diff] [blame] | 176 | #define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) |
Steven Rostedt | 644f991 | 2008-09-06 01:06:04 -0400 | [diff] [blame] | 177 | #define ftrace_hash_unlock(flags) \ |
| 178 | spin_unlock_irqrestore(&ftrace_hash_lock, flags) |
Steven Rostedt | bd95b88 | 2008-10-16 09:31:27 -0400 | [diff] [blame] | 179 | static void ftrace_release_hash(unsigned long start, unsigned long end); |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 180 | #else |
| 181 | /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ |
Ingo Molnar | ac8825e | 2008-08-25 08:12:04 +0200 | [diff] [blame] | 182 | #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 183 | #define ftrace_hash_unlock(flags) do { } while(0) |
Steven Rostedt | bd95b88 | 2008-10-16 09:31:27 -0400 | [diff] [blame] | 184 | static inline void ftrace_release_hash(unsigned long start, unsigned long end) |
| 185 | { |
| 186 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 187 | #endif |
| 188 | |
Steven Noonan | 71c67d5 | 2008-09-20 01:00:37 -0700 | [diff] [blame] | 189 | /* |
| 190 | * Since MCOUNT_ADDR may point to mcount itself, we do not want |
| 191 | * to get it confused by reading a reference in the code as we |
| 192 | * are parsing on objcopy output of text. Use a variable for |
| 193 | * it instead. |
| 194 | */ |
| 195 | static unsigned long mcount_addr = MCOUNT_ADDR; |
| 196 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 197 | static struct task_struct *ftraced_task; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 198 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 199 | enum { |
| 200 | FTRACE_ENABLE_CALLS = (1 << 0), |
| 201 | FTRACE_DISABLE_CALLS = (1 << 1), |
| 202 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), |
| 203 | FTRACE_ENABLE_MCOUNT = (1 << 3), |
| 204 | FTRACE_DISABLE_MCOUNT = (1 << 4), |
| 205 | }; |
| 206 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 207 | static int ftrace_filtered; |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 208 | static int tracing_on; |
| 209 | static int frozen_record_count; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 210 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 211 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
| 212 | |
| 213 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); |
| 214 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 215 | static DEFINE_MUTEX(ftraced_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 216 | static DEFINE_MUTEX(ftrace_regex_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 217 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 218 | struct ftrace_page { |
| 219 | struct ftrace_page *next; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 220 | unsigned long index; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 221 | struct dyn_ftrace records[]; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 222 | }; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 223 | |
| 224 | #define ENTRIES_PER_PAGE \ |
| 225 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) |
| 226 | |
| 227 | /* estimate from running different kernels */ |
| 228 | #define NR_TO_INIT 10000 |
| 229 | |
| 230 | static struct ftrace_page *ftrace_pages_start; |
| 231 | static struct ftrace_page *ftrace_pages; |
| 232 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 233 | static int ftraced_trigger; |
| 234 | static int ftraced_suspend; |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 235 | static int ftraced_stop; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 236 | |
| 237 | static int ftrace_record_suspend; |
| 238 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 239 | static struct dyn_ftrace *ftrace_free_records; |
| 240 | |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 241 | |
| 242 | #ifdef CONFIG_KPROBES |
| 243 | static inline void freeze_record(struct dyn_ftrace *rec) |
| 244 | { |
| 245 | if (!(rec->flags & FTRACE_FL_FROZEN)) { |
| 246 | rec->flags |= FTRACE_FL_FROZEN; |
| 247 | frozen_record_count++; |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | static inline void unfreeze_record(struct dyn_ftrace *rec) |
| 252 | { |
| 253 | if (rec->flags & FTRACE_FL_FROZEN) { |
| 254 | rec->flags &= ~FTRACE_FL_FROZEN; |
| 255 | frozen_record_count--; |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | static inline int record_frozen(struct dyn_ftrace *rec) |
| 260 | { |
| 261 | return rec->flags & FTRACE_FL_FROZEN; |
| 262 | } |
| 263 | #else |
| 264 | # define freeze_record(rec) ({ 0; }) |
| 265 | # define unfreeze_record(rec) ({ 0; }) |
| 266 | # define record_frozen(rec) ({ 0; }) |
| 267 | #endif /* CONFIG_KPROBES */ |
| 268 | |
| 269 | int skip_trace(unsigned long ip) |
| 270 | { |
| 271 | unsigned long fl; |
| 272 | struct dyn_ftrace *rec; |
| 273 | struct hlist_node *t; |
| 274 | struct hlist_head *head; |
| 275 | |
| 276 | if (frozen_record_count == 0) |
| 277 | return 0; |
| 278 | |
| 279 | head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; |
| 280 | hlist_for_each_entry_rcu(rec, t, head, node) { |
| 281 | if (rec->ip == ip) { |
| 282 | if (record_frozen(rec)) { |
| 283 | if (rec->flags & FTRACE_FL_FAILED) |
| 284 | return 1; |
| 285 | |
| 286 | if (!(rec->flags & FTRACE_FL_CONVERTED)) |
| 287 | return 1; |
| 288 | |
| 289 | if (!tracing_on || !ftrace_enabled) |
| 290 | return 1; |
| 291 | |
| 292 | if (ftrace_filtered) { |
| 293 | fl = rec->flags & (FTRACE_FL_FILTER | |
| 294 | FTRACE_FL_NOTRACE); |
| 295 | if (!fl || (fl & FTRACE_FL_NOTRACE)) |
| 296 | return 1; |
| 297 | } |
| 298 | } |
| 299 | break; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | return 0; |
| 304 | } |
| 305 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 306 | static inline int |
Ingo Molnar | 9ff9cdb | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 307 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 308 | { |
| 309 | struct dyn_ftrace *p; |
| 310 | struct hlist_node *t; |
| 311 | int found = 0; |
| 312 | |
Abhishek Sagar | ffdaa35 | 2008-05-24 23:45:02 +0530 | [diff] [blame] | 313 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 314 | if (p->ip == ip) { |
| 315 | found = 1; |
| 316 | break; |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | return found; |
| 321 | } |
| 322 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 323 | static inline void |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 324 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
| 325 | { |
Abhishek Sagar | ffdaa35 | 2008-05-24 23:45:02 +0530 | [diff] [blame] | 326 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 327 | } |
| 328 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 329 | /* called from kstop_machine */ |
| 330 | static inline void ftrace_del_hash(struct dyn_ftrace *node) |
| 331 | { |
| 332 | hlist_del(&node->node); |
| 333 | } |
| 334 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 335 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 336 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 337 | rec->ip = (unsigned long)ftrace_free_records; |
| 338 | ftrace_free_records = rec; |
| 339 | rec->flags |= FTRACE_FL_FREE; |
| 340 | } |
| 341 | |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 342 | void ftrace_release(void *start, unsigned long size) |
| 343 | { |
| 344 | struct dyn_ftrace *rec; |
| 345 | struct ftrace_page *pg; |
| 346 | unsigned long s = (unsigned long)start; |
| 347 | unsigned long e = s + size; |
| 348 | int i; |
| 349 | |
Steven Rostedt | 00fd61a | 2008-08-15 21:40:04 -0400 | [diff] [blame] | 350 | if (ftrace_disabled || !start) |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 351 | return; |
| 352 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 353 | /* should not be called from interrupt context */ |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 354 | spin_lock(&ftrace_lock); |
| 355 | |
| 356 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 357 | for (i = 0; i < pg->index; i++) { |
| 358 | rec = &pg->records[i]; |
| 359 | |
| 360 | if ((rec->ip >= s) && (rec->ip < e)) |
| 361 | ftrace_free_rec(rec); |
| 362 | } |
| 363 | } |
| 364 | spin_unlock(&ftrace_lock); |
| 365 | |
Steven Rostedt | bd95b88 | 2008-10-16 09:31:27 -0400 | [diff] [blame] | 366 | ftrace_release_hash(s, e); |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 367 | } |
| 368 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 369 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 370 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 371 | struct dyn_ftrace *rec; |
| 372 | |
| 373 | /* First check for freed records */ |
| 374 | if (ftrace_free_records) { |
| 375 | rec = ftrace_free_records; |
| 376 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 377 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 378 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 379 | ftrace_free_records = NULL; |
| 380 | return NULL; |
| 381 | } |
| 382 | |
| 383 | ftrace_free_records = (void *)rec->ip; |
| 384 | memset(rec, 0, sizeof(*rec)); |
| 385 | return rec; |
| 386 | } |
| 387 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 388 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
| 389 | if (!ftrace_pages->next) |
| 390 | return NULL; |
| 391 | ftrace_pages = ftrace_pages->next; |
| 392 | } |
| 393 | |
| 394 | return &ftrace_pages->records[ftrace_pages->index++]; |
| 395 | } |
| 396 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 397 | static void |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 398 | ftrace_record_ip(unsigned long ip) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 399 | { |
| 400 | struct dyn_ftrace *node; |
| 401 | unsigned long flags; |
| 402 | unsigned long key; |
| 403 | int resched; |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 404 | int cpu; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 405 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 406 | if (!ftrace_enabled || ftrace_disabled) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 407 | return; |
| 408 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 409 | resched = need_resched(); |
| 410 | preempt_disable_notrace(); |
| 411 | |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 412 | /* |
| 413 | * We simply need to protect against recursion. |
| 414 | * Use the the raw version of smp_processor_id and not |
| 415 | * __get_cpu_var which can call debug hooks that can |
| 416 | * cause a recursive crash here. |
| 417 | */ |
| 418 | cpu = raw_smp_processor_id(); |
| 419 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; |
| 420 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 421 | goto out; |
| 422 | |
| 423 | if (unlikely(ftrace_record_suspend)) |
| 424 | goto out; |
| 425 | |
| 426 | key = hash_long(ip, FTRACE_HASHBITS); |
| 427 | |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 428 | FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 429 | |
| 430 | if (ftrace_ip_in_hash(ip, key)) |
| 431 | goto out; |
| 432 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 433 | ftrace_hash_lock(flags); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 434 | |
| 435 | /* This ip may have hit the hash before the lock */ |
| 436 | if (ftrace_ip_in_hash(ip, key)) |
| 437 | goto out_unlock; |
| 438 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 439 | node = ftrace_alloc_dyn_node(ip); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 440 | if (!node) |
| 441 | goto out_unlock; |
| 442 | |
| 443 | node->ip = ip; |
| 444 | |
| 445 | ftrace_add_hash(node, key); |
| 446 | |
| 447 | ftraced_trigger = 1; |
| 448 | |
| 449 | out_unlock: |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 450 | ftrace_hash_unlock(flags); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 451 | out: |
Steven Rostedt | 2bb6f8d | 2008-05-12 21:21:02 +0200 | [diff] [blame] | 452 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 453 | |
| 454 | /* prevent recursion with scheduler */ |
| 455 | if (resched) |
| 456 | preempt_enable_no_resched_notrace(); |
| 457 | else |
| 458 | preempt_enable_notrace(); |
| 459 | } |
| 460 | |
Steven Rostedt | caf8cde | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 461 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 462 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 463 | static int |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 464 | __ftrace_replace_code(struct dyn_ftrace *rec, |
| 465 | unsigned char *old, unsigned char *new, int enable) |
| 466 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 467 | unsigned long ip, fl; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 468 | |
| 469 | ip = rec->ip; |
| 470 | |
| 471 | if (ftrace_filtered && enable) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 472 | /* |
| 473 | * If filtering is on: |
| 474 | * |
| 475 | * If this record is set to be filtered and |
| 476 | * is enabled then do nothing. |
| 477 | * |
| 478 | * If this record is set to be filtered and |
| 479 | * it is not enabled, enable it. |
| 480 | * |
| 481 | * If this record is not set to be filtered |
| 482 | * and it is not enabled do nothing. |
| 483 | * |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 484 | * If this record is set not to trace then |
| 485 | * do nothing. |
| 486 | * |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 487 | * If this record is set not to trace and |
| 488 | * it is enabled then disable it. |
| 489 | * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 490 | * If this record is not set to be filtered and |
| 491 | * it is enabled, disable it. |
| 492 | */ |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 493 | |
| 494 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | |
| 495 | FTRACE_FL_ENABLED); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 496 | |
| 497 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 498 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
| 499 | !fl || (fl == FTRACE_FL_NOTRACE)) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 500 | return 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 501 | |
| 502 | /* |
| 503 | * If it is enabled disable it, |
| 504 | * otherwise enable it! |
| 505 | */ |
Abhishek Sagar | a4500b8 | 2008-06-14 11:59:39 +0530 | [diff] [blame] | 506 | if (fl & FTRACE_FL_ENABLED) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 507 | /* swap new and old */ |
| 508 | new = old; |
| 509 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
| 510 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 511 | } else { |
| 512 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
| 513 | rec->flags |= FTRACE_FL_ENABLED; |
| 514 | } |
| 515 | } else { |
| 516 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 517 | if (enable) { |
| 518 | /* |
| 519 | * If this record is set not to trace and is |
| 520 | * not enabled, do nothing. |
| 521 | */ |
| 522 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); |
| 523 | if (fl == FTRACE_FL_NOTRACE) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 524 | return 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 525 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 526 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 527 | } else |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 528 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
| 529 | |
| 530 | if (enable) { |
| 531 | if (rec->flags & FTRACE_FL_ENABLED) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 532 | return 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 533 | rec->flags |= FTRACE_FL_ENABLED; |
| 534 | } else { |
| 535 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 536 | return 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 537 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 538 | } |
| 539 | } |
| 540 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 541 | return ftrace_modify_code(ip, old, new); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 542 | } |
| 543 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 544 | static void ftrace_replace_code(int enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 545 | { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 546 | int i, failed; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 547 | unsigned char *new = NULL, *old = NULL; |
| 548 | struct dyn_ftrace *rec; |
| 549 | struct ftrace_page *pg; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 550 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 551 | if (enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 552 | old = ftrace_nop_replace(); |
| 553 | else |
| 554 | new = ftrace_nop_replace(); |
| 555 | |
| 556 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 557 | for (i = 0; i < pg->index; i++) { |
| 558 | rec = &pg->records[i]; |
| 559 | |
| 560 | /* don't modify code that has already faulted */ |
| 561 | if (rec->flags & FTRACE_FL_FAILED) |
| 562 | continue; |
| 563 | |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 564 | /* ignore updates to this record's mcount site */ |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 565 | if (get_kprobe((void *)rec->ip)) { |
| 566 | freeze_record(rec); |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 567 | continue; |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 568 | } else { |
| 569 | unfreeze_record(rec); |
| 570 | } |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 571 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 572 | failed = __ftrace_replace_code(rec, old, new, enable); |
| 573 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
| 574 | rec->flags |= FTRACE_FL_FAILED; |
| 575 | if ((system_state == SYSTEM_BOOTING) || |
Abhishek Sagar | 34078a5 | 2008-06-03 08:33:41 +0530 | [diff] [blame] | 576 | !core_kernel_text(rec->ip)) { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 577 | ftrace_del_hash(rec); |
| 578 | ftrace_free_rec(rec); |
| 579 | } |
| 580 | } |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 581 | } |
| 582 | } |
| 583 | } |
| 584 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 585 | static void ftrace_shutdown_replenish(void) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 586 | { |
| 587 | if (ftrace_pages->next) |
| 588 | return; |
| 589 | |
| 590 | /* allocate another page */ |
| 591 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 592 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 593 | |
Steven Rostedt | 05736a4 | 2008-09-22 14:55:47 -0700 | [diff] [blame] | 594 | static void print_ip_ins(const char *fmt, unsigned char *p) |
| 595 | { |
| 596 | int i; |
| 597 | |
| 598 | printk(KERN_CONT "%s", fmt); |
| 599 | |
| 600 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) |
| 601 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); |
| 602 | } |
| 603 | |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 604 | static int |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 605 | ftrace_code_disable(struct dyn_ftrace *rec) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 606 | { |
| 607 | unsigned long ip; |
| 608 | unsigned char *nop, *call; |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 609 | int ret; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 610 | |
| 611 | ip = rec->ip; |
| 612 | |
| 613 | nop = ftrace_nop_replace(); |
Steven Rostedt | 3b47bfc | 2008-08-27 23:24:15 -0400 | [diff] [blame] | 614 | call = ftrace_call_replace(ip, mcount_addr); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 615 | |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 616 | ret = ftrace_modify_code(ip, call, nop); |
| 617 | if (ret) { |
| 618 | switch (ret) { |
| 619 | case -EFAULT: |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 620 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 05736a4 | 2008-09-22 14:55:47 -0700 | [diff] [blame] | 621 | pr_info("ftrace faulted on modifying "); |
| 622 | print_ip_sym(ip); |
| 623 | break; |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 624 | case -EINVAL: |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 625 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 05736a4 | 2008-09-22 14:55:47 -0700 | [diff] [blame] | 626 | pr_info("ftrace failed to modify "); |
| 627 | print_ip_sym(ip); |
| 628 | print_ip_ins(" expected: ", call); |
| 629 | print_ip_ins(" actual: ", (unsigned char *)ip); |
| 630 | print_ip_ins(" replace: ", nop); |
| 631 | printk(KERN_CONT "\n"); |
| 632 | break; |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 633 | case -EPERM: |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 634 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 635 | pr_info("ftrace faulted on writing "); |
| 636 | print_ip_sym(ip); |
| 637 | break; |
| 638 | default: |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 639 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 640 | pr_info("ftrace faulted on unknown error "); |
| 641 | print_ip_sym(ip); |
Steven Rostedt | 05736a4 | 2008-09-22 14:55:47 -0700 | [diff] [blame] | 642 | } |
| 643 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 644 | rec->flags |= FTRACE_FL_FAILED; |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 645 | return 0; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 646 | } |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 647 | return 1; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 648 | } |
| 649 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 650 | static int __ftrace_update_code(void *ignore); |
| 651 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 652 | static int __ftrace_modify_code(void *data) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 653 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 654 | unsigned long addr; |
| 655 | int *command = data; |
| 656 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 657 | if (*command & FTRACE_ENABLE_CALLS) { |
| 658 | /* |
| 659 | * Update any recorded ips now that we have the |
| 660 | * machine stopped |
| 661 | */ |
| 662 | __ftrace_update_code(NULL); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 663 | ftrace_replace_code(1); |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 664 | tracing_on = 1; |
| 665 | } else if (*command & FTRACE_DISABLE_CALLS) { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 666 | ftrace_replace_code(0); |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 667 | tracing_on = 0; |
| 668 | } |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 669 | |
| 670 | if (*command & FTRACE_UPDATE_TRACE_FUNC) |
| 671 | ftrace_update_ftrace_func(ftrace_trace_function); |
| 672 | |
| 673 | if (*command & FTRACE_ENABLE_MCOUNT) { |
| 674 | addr = (unsigned long)ftrace_record_ip; |
| 675 | ftrace_mcount_set(&addr); |
| 676 | } else if (*command & FTRACE_DISABLE_MCOUNT) { |
| 677 | addr = (unsigned long)ftrace_stub; |
| 678 | ftrace_mcount_set(&addr); |
| 679 | } |
| 680 | |
| 681 | return 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 682 | } |
| 683 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 684 | static void ftrace_run_update_code(int command) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 685 | { |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 686 | stop_machine(__ftrace_modify_code, &command, NULL); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 687 | } |
| 688 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 689 | void ftrace_disable_daemon(void) |
| 690 | { |
| 691 | /* Stop the daemon from calling kstop_machine */ |
| 692 | mutex_lock(&ftraced_lock); |
| 693 | ftraced_stop = 1; |
| 694 | mutex_unlock(&ftraced_lock); |
| 695 | |
| 696 | ftrace_force_update(); |
| 697 | } |
| 698 | |
| 699 | void ftrace_enable_daemon(void) |
| 700 | { |
| 701 | mutex_lock(&ftraced_lock); |
| 702 | ftraced_stop = 0; |
| 703 | mutex_unlock(&ftraced_lock); |
| 704 | |
| 705 | ftrace_force_update(); |
| 706 | } |
| 707 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 708 | static ftrace_func_t saved_ftrace_func; |
| 709 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 710 | static void ftrace_startup(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 711 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 712 | int command = 0; |
| 713 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 714 | if (unlikely(ftrace_disabled)) |
| 715 | return; |
| 716 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 717 | mutex_lock(&ftraced_lock); |
| 718 | ftraced_suspend++; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 719 | if (ftraced_suspend == 1) |
| 720 | command |= FTRACE_ENABLE_CALLS; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 721 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 722 | if (saved_ftrace_func != ftrace_trace_function) { |
| 723 | saved_ftrace_func = ftrace_trace_function; |
| 724 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 725 | } |
| 726 | |
| 727 | if (!command || !ftrace_enabled) |
| 728 | goto out; |
| 729 | |
| 730 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 731 | out: |
| 732 | mutex_unlock(&ftraced_lock); |
| 733 | } |
| 734 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 735 | static void ftrace_shutdown(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 736 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 737 | int command = 0; |
| 738 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 739 | if (unlikely(ftrace_disabled)) |
| 740 | return; |
| 741 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 742 | mutex_lock(&ftraced_lock); |
| 743 | ftraced_suspend--; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 744 | if (!ftraced_suspend) |
| 745 | command |= FTRACE_DISABLE_CALLS; |
| 746 | |
| 747 | if (saved_ftrace_func != ftrace_trace_function) { |
| 748 | saved_ftrace_func = ftrace_trace_function; |
| 749 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 750 | } |
| 751 | |
| 752 | if (!command || !ftrace_enabled) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 753 | goto out; |
| 754 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 755 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 756 | out: |
| 757 | mutex_unlock(&ftraced_lock); |
| 758 | } |
| 759 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 760 | static void ftrace_startup_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 761 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 762 | int command = FTRACE_ENABLE_MCOUNT; |
| 763 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 764 | if (unlikely(ftrace_disabled)) |
| 765 | return; |
| 766 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 767 | mutex_lock(&ftraced_lock); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 768 | /* Force update next time */ |
| 769 | saved_ftrace_func = NULL; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 770 | /* ftraced_suspend is true if we want ftrace running */ |
| 771 | if (ftraced_suspend) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 772 | command |= FTRACE_ENABLE_CALLS; |
| 773 | |
| 774 | ftrace_run_update_code(command); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 775 | mutex_unlock(&ftraced_lock); |
| 776 | } |
| 777 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 778 | static void ftrace_shutdown_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 779 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 780 | int command = FTRACE_DISABLE_MCOUNT; |
| 781 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 782 | if (unlikely(ftrace_disabled)) |
| 783 | return; |
| 784 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 785 | mutex_lock(&ftraced_lock); |
| 786 | /* ftraced_suspend is true if ftrace is running */ |
| 787 | if (ftraced_suspend) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 788 | command |= FTRACE_DISABLE_CALLS; |
| 789 | |
| 790 | ftrace_run_update_code(command); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 791 | mutex_unlock(&ftraced_lock); |
| 792 | } |
| 793 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 794 | static cycle_t ftrace_update_time; |
| 795 | static unsigned long ftrace_update_cnt; |
| 796 | unsigned long ftrace_update_tot_cnt; |
| 797 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 798 | static int __ftrace_update_code(void *ignore) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 799 | { |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 800 | int i, save_ftrace_enabled; |
| 801 | cycle_t start, stop; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 802 | struct dyn_ftrace *p; |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 803 | struct hlist_node *t, *n; |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 804 | struct hlist_head *head, temp_list; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 805 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 806 | /* Don't be recording funcs now */ |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 807 | ftrace_record_suspend++; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 808 | save_ftrace_enabled = ftrace_enabled; |
| 809 | ftrace_enabled = 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 810 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 811 | start = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 812 | ftrace_update_cnt = 0; |
| 813 | |
| 814 | /* No locks needed, the machine is stopped! */ |
| 815 | for (i = 0; i < FTRACE_HASHSIZE; i++) { |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 816 | INIT_HLIST_HEAD(&temp_list); |
| 817 | head = &ftrace_hash[i]; |
| 818 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 819 | /* all CPUS are stopped, we are safe to modify code */ |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 820 | hlist_for_each_entry_safe(p, t, n, head, node) { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 821 | /* Skip over failed records which have not been |
| 822 | * freed. */ |
| 823 | if (p->flags & FTRACE_FL_FAILED) |
| 824 | continue; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 825 | |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 826 | /* Unconverted records are always at the head of the |
| 827 | * hash bucket. Once we encounter a converted record, |
| 828 | * simply skip over to the next bucket. Saves ftraced |
| 829 | * some processor cycles (ftrace does its bid for |
| 830 | * global warming :-p ). */ |
| 831 | if (p->flags & (FTRACE_FL_CONVERTED)) |
| 832 | break; |
| 833 | |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 834 | /* Ignore updates to this record's mcount site. |
| 835 | * Reintroduce this record at the head of this |
| 836 | * bucket to attempt to "convert" it again if |
| 837 | * the kprobe on it is unregistered before the |
| 838 | * next run. */ |
| 839 | if (get_kprobe((void *)p->ip)) { |
| 840 | ftrace_del_hash(p); |
| 841 | INIT_HLIST_NODE(&p->node); |
| 842 | hlist_add_head(&p->node, &temp_list); |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 843 | freeze_record(p); |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 844 | continue; |
Abhishek Sagar | 98a05ed | 2008-06-26 22:51:51 +0530 | [diff] [blame] | 845 | } else { |
| 846 | unfreeze_record(p); |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 847 | } |
| 848 | |
| 849 | /* convert record (i.e, patch mcount-call with NOP) */ |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 850 | if (ftrace_code_disable(p)) { |
| 851 | p->flags |= FTRACE_FL_CONVERTED; |
| 852 | ftrace_update_cnt++; |
| 853 | } else { |
| 854 | if ((system_state == SYSTEM_BOOTING) || |
Abhishek Sagar | 34078a5 | 2008-06-03 08:33:41 +0530 | [diff] [blame] | 855 | !core_kernel_text(p->ip)) { |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 856 | ftrace_del_hash(p); |
| 857 | ftrace_free_rec(p); |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 858 | } |
| 859 | } |
| 860 | } |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 861 | |
| 862 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { |
| 863 | hlist_del(&p->node); |
| 864 | INIT_HLIST_NODE(&p->node); |
| 865 | hlist_add_head(&p->node, head); |
| 866 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 867 | } |
| 868 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 869 | stop = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 870 | ftrace_update_time = stop - start; |
| 871 | ftrace_update_tot_cnt += ftrace_update_cnt; |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 872 | ftraced_trigger = 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 873 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 874 | ftrace_enabled = save_ftrace_enabled; |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 875 | ftrace_record_suspend--; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 876 | |
| 877 | return 0; |
| 878 | } |
| 879 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 880 | static int ftrace_update_code(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 881 | { |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 882 | if (unlikely(ftrace_disabled) || |
| 883 | !ftrace_enabled || !ftraced_trigger) |
| 884 | return 0; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 885 | |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 886 | stop_machine(__ftrace_update_code, NULL, NULL); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 887 | |
| 888 | return 1; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 889 | } |
| 890 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 891 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 892 | { |
| 893 | struct ftrace_page *pg; |
| 894 | int cnt; |
| 895 | int i; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 896 | |
| 897 | /* allocate a few pages */ |
| 898 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); |
| 899 | if (!ftrace_pages_start) |
| 900 | return -1; |
| 901 | |
| 902 | /* |
| 903 | * Allocate a few more pages. |
| 904 | * |
| 905 | * TODO: have some parser search vmlinux before |
| 906 | * final linking to find all calls to ftrace. |
| 907 | * Then we can: |
| 908 | * a) know how many pages to allocate. |
| 909 | * and/or |
| 910 | * b) set up the table then. |
| 911 | * |
| 912 | * The dynamic code is still necessary for |
| 913 | * modules. |
| 914 | */ |
| 915 | |
| 916 | pg = ftrace_pages = ftrace_pages_start; |
| 917 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 918 | cnt = num_to_init / ENTRIES_PER_PAGE; |
| 919 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", |
| 920 | num_to_init, cnt); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 921 | |
| 922 | for (i = 0; i < cnt; i++) { |
| 923 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 924 | |
| 925 | /* If we fail, we'll try later anyway */ |
| 926 | if (!pg->next) |
| 927 | break; |
| 928 | |
| 929 | pg = pg->next; |
| 930 | } |
| 931 | |
| 932 | return 0; |
| 933 | } |
| 934 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 935 | enum { |
| 936 | FTRACE_ITER_FILTER = (1 << 0), |
| 937 | FTRACE_ITER_CONT = (1 << 1), |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 938 | FTRACE_ITER_NOTRACE = (1 << 2), |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 939 | FTRACE_ITER_FAILURES = (1 << 3), |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 940 | }; |
| 941 | |
| 942 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| 943 | |
| 944 | struct ftrace_iterator { |
| 945 | loff_t pos; |
| 946 | struct ftrace_page *pg; |
| 947 | unsigned idx; |
| 948 | unsigned flags; |
| 949 | unsigned char buffer[FTRACE_BUFF_MAX+1]; |
| 950 | unsigned buffer_idx; |
| 951 | unsigned filtered; |
| 952 | }; |
| 953 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 954 | static void * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 955 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 956 | { |
| 957 | struct ftrace_iterator *iter = m->private; |
| 958 | struct dyn_ftrace *rec = NULL; |
| 959 | |
| 960 | (*pos)++; |
| 961 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 962 | /* should not be called from interrupt context */ |
| 963 | spin_lock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 964 | retry: |
| 965 | if (iter->idx >= iter->pg->index) { |
| 966 | if (iter->pg->next) { |
| 967 | iter->pg = iter->pg->next; |
| 968 | iter->idx = 0; |
| 969 | goto retry; |
| 970 | } |
| 971 | } else { |
| 972 | rec = &iter->pg->records[iter->idx++]; |
Steven Rostedt | a9fdda3 | 2008-08-14 22:47:17 -0400 | [diff] [blame] | 973 | if ((rec->flags & FTRACE_FL_FREE) || |
| 974 | |
| 975 | (!(iter->flags & FTRACE_ITER_FAILURES) && |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 976 | (rec->flags & FTRACE_FL_FAILED)) || |
| 977 | |
| 978 | ((iter->flags & FTRACE_ITER_FAILURES) && |
Steven Rostedt | a9fdda3 | 2008-08-14 22:47:17 -0400 | [diff] [blame] | 979 | !(rec->flags & FTRACE_FL_FAILED)) || |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 980 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 981 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
| 982 | !(rec->flags & FTRACE_FL_NOTRACE))) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 983 | rec = NULL; |
| 984 | goto retry; |
| 985 | } |
| 986 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 987 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 988 | |
| 989 | iter->pos = *pos; |
| 990 | |
| 991 | return rec; |
| 992 | } |
| 993 | |
| 994 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 995 | { |
| 996 | struct ftrace_iterator *iter = m->private; |
| 997 | void *p = NULL; |
| 998 | loff_t l = -1; |
| 999 | |
| 1000 | if (*pos != iter->pos) { |
| 1001 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) |
| 1002 | ; |
| 1003 | } else { |
| 1004 | l = *pos; |
| 1005 | p = t_next(m, p, &l); |
| 1006 | } |
| 1007 | |
| 1008 | return p; |
| 1009 | } |
| 1010 | |
| 1011 | static void t_stop(struct seq_file *m, void *p) |
| 1012 | { |
| 1013 | } |
| 1014 | |
| 1015 | static int t_show(struct seq_file *m, void *v) |
| 1016 | { |
| 1017 | struct dyn_ftrace *rec = v; |
| 1018 | char str[KSYM_SYMBOL_LEN]; |
| 1019 | |
| 1020 | if (!rec) |
| 1021 | return 0; |
| 1022 | |
| 1023 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1024 | |
| 1025 | seq_printf(m, "%s\n", str); |
| 1026 | |
| 1027 | return 0; |
| 1028 | } |
| 1029 | |
| 1030 | static struct seq_operations show_ftrace_seq_ops = { |
| 1031 | .start = t_start, |
| 1032 | .next = t_next, |
| 1033 | .stop = t_stop, |
| 1034 | .show = t_show, |
| 1035 | }; |
| 1036 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1037 | static int |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1038 | ftrace_avail_open(struct inode *inode, struct file *file) |
| 1039 | { |
| 1040 | struct ftrace_iterator *iter; |
| 1041 | int ret; |
| 1042 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1043 | if (unlikely(ftrace_disabled)) |
| 1044 | return -ENODEV; |
| 1045 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1046 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 1047 | if (!iter) |
| 1048 | return -ENOMEM; |
| 1049 | |
| 1050 | iter->pg = ftrace_pages_start; |
| 1051 | iter->pos = -1; |
| 1052 | |
| 1053 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 1054 | if (!ret) { |
| 1055 | struct seq_file *m = file->private_data; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 1056 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1057 | m->private = iter; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 1058 | } else { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1059 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 1060 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1061 | |
| 1062 | return ret; |
| 1063 | } |
| 1064 | |
| 1065 | int ftrace_avail_release(struct inode *inode, struct file *file) |
| 1066 | { |
| 1067 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1068 | struct ftrace_iterator *iter = m->private; |
| 1069 | |
| 1070 | seq_release(inode, file); |
| 1071 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 1072 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1073 | return 0; |
| 1074 | } |
| 1075 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1076 | static int |
| 1077 | ftrace_failures_open(struct inode *inode, struct file *file) |
| 1078 | { |
| 1079 | int ret; |
| 1080 | struct seq_file *m; |
| 1081 | struct ftrace_iterator *iter; |
| 1082 | |
| 1083 | ret = ftrace_avail_open(inode, file); |
| 1084 | if (!ret) { |
| 1085 | m = (struct seq_file *)file->private_data; |
| 1086 | iter = (struct ftrace_iterator *)m->private; |
| 1087 | iter->flags = FTRACE_ITER_FAILURES; |
| 1088 | } |
| 1089 | |
| 1090 | return ret; |
| 1091 | } |
| 1092 | |
| 1093 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1094 | static void ftrace_filter_reset(int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1095 | { |
| 1096 | struct ftrace_page *pg; |
| 1097 | struct dyn_ftrace *rec; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1098 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1099 | unsigned i; |
| 1100 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1101 | /* should not be called from interrupt context */ |
| 1102 | spin_lock(&ftrace_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1103 | if (enable) |
| 1104 | ftrace_filtered = 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1105 | pg = ftrace_pages_start; |
| 1106 | while (pg) { |
| 1107 | for (i = 0; i < pg->index; i++) { |
| 1108 | rec = &pg->records[i]; |
| 1109 | if (rec->flags & FTRACE_FL_FAILED) |
| 1110 | continue; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1111 | rec->flags &= ~type; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1112 | } |
| 1113 | pg = pg->next; |
| 1114 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1115 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1116 | } |
| 1117 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1118 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1119 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1120 | { |
| 1121 | struct ftrace_iterator *iter; |
| 1122 | int ret = 0; |
| 1123 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1124 | if (unlikely(ftrace_disabled)) |
| 1125 | return -ENODEV; |
| 1126 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1127 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 1128 | if (!iter) |
| 1129 | return -ENOMEM; |
| 1130 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1131 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1132 | if ((file->f_mode & FMODE_WRITE) && |
| 1133 | !(file->f_flags & O_APPEND)) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1134 | ftrace_filter_reset(enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1135 | |
| 1136 | if (file->f_mode & FMODE_READ) { |
| 1137 | iter->pg = ftrace_pages_start; |
| 1138 | iter->pos = -1; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1139 | iter->flags = enable ? FTRACE_ITER_FILTER : |
| 1140 | FTRACE_ITER_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1141 | |
| 1142 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 1143 | if (!ret) { |
| 1144 | struct seq_file *m = file->private_data; |
| 1145 | m->private = iter; |
| 1146 | } else |
| 1147 | kfree(iter); |
| 1148 | } else |
| 1149 | file->private_data = iter; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1150 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1151 | |
| 1152 | return ret; |
| 1153 | } |
| 1154 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1155 | static int |
| 1156 | ftrace_filter_open(struct inode *inode, struct file *file) |
| 1157 | { |
| 1158 | return ftrace_regex_open(inode, file, 1); |
| 1159 | } |
| 1160 | |
| 1161 | static int |
| 1162 | ftrace_notrace_open(struct inode *inode, struct file *file) |
| 1163 | { |
| 1164 | return ftrace_regex_open(inode, file, 0); |
| 1165 | } |
| 1166 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1167 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1168 | ftrace_regex_read(struct file *file, char __user *ubuf, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1169 | size_t cnt, loff_t *ppos) |
| 1170 | { |
| 1171 | if (file->f_mode & FMODE_READ) |
| 1172 | return seq_read(file, ubuf, cnt, ppos); |
| 1173 | else |
| 1174 | return -EPERM; |
| 1175 | } |
| 1176 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1177 | static loff_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1178 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1179 | { |
| 1180 | loff_t ret; |
| 1181 | |
| 1182 | if (file->f_mode & FMODE_READ) |
| 1183 | ret = seq_lseek(file, offset, origin); |
| 1184 | else |
| 1185 | file->f_pos = ret = 1; |
| 1186 | |
| 1187 | return ret; |
| 1188 | } |
| 1189 | |
| 1190 | enum { |
| 1191 | MATCH_FULL, |
| 1192 | MATCH_FRONT_ONLY, |
| 1193 | MATCH_MIDDLE_ONLY, |
| 1194 | MATCH_END_ONLY, |
| 1195 | }; |
| 1196 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1197 | static void |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1198 | ftrace_match(unsigned char *buff, int len, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1199 | { |
| 1200 | char str[KSYM_SYMBOL_LEN]; |
| 1201 | char *search = NULL; |
| 1202 | struct ftrace_page *pg; |
| 1203 | struct dyn_ftrace *rec; |
| 1204 | int type = MATCH_FULL; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1205 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1206 | unsigned i, match = 0, search_len = 0; |
| 1207 | |
| 1208 | for (i = 0; i < len; i++) { |
| 1209 | if (buff[i] == '*') { |
| 1210 | if (!i) { |
| 1211 | search = buff + i + 1; |
| 1212 | type = MATCH_END_ONLY; |
| 1213 | search_len = len - (i + 1); |
| 1214 | } else { |
| 1215 | if (type == MATCH_END_ONLY) { |
| 1216 | type = MATCH_MIDDLE_ONLY; |
| 1217 | } else { |
| 1218 | match = i; |
| 1219 | type = MATCH_FRONT_ONLY; |
| 1220 | } |
| 1221 | buff[i] = 0; |
| 1222 | break; |
| 1223 | } |
| 1224 | } |
| 1225 | } |
| 1226 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1227 | /* should not be called from interrupt context */ |
| 1228 | spin_lock(&ftrace_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1229 | if (enable) |
| 1230 | ftrace_filtered = 1; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1231 | pg = ftrace_pages_start; |
| 1232 | while (pg) { |
| 1233 | for (i = 0; i < pg->index; i++) { |
| 1234 | int matched = 0; |
| 1235 | char *ptr; |
| 1236 | |
| 1237 | rec = &pg->records[i]; |
| 1238 | if (rec->flags & FTRACE_FL_FAILED) |
| 1239 | continue; |
| 1240 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1241 | switch (type) { |
| 1242 | case MATCH_FULL: |
| 1243 | if (strcmp(str, buff) == 0) |
| 1244 | matched = 1; |
| 1245 | break; |
| 1246 | case MATCH_FRONT_ONLY: |
| 1247 | if (memcmp(str, buff, match) == 0) |
| 1248 | matched = 1; |
| 1249 | break; |
| 1250 | case MATCH_MIDDLE_ONLY: |
| 1251 | if (strstr(str, search)) |
| 1252 | matched = 1; |
| 1253 | break; |
| 1254 | case MATCH_END_ONLY: |
| 1255 | ptr = strstr(str, search); |
| 1256 | if (ptr && (ptr[search_len] == 0)) |
| 1257 | matched = 1; |
| 1258 | break; |
| 1259 | } |
| 1260 | if (matched) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1261 | rec->flags |= flag; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1262 | } |
| 1263 | pg = pg->next; |
| 1264 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1265 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1266 | } |
| 1267 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1268 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1269 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
| 1270 | size_t cnt, loff_t *ppos, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1271 | { |
| 1272 | struct ftrace_iterator *iter; |
| 1273 | char ch; |
| 1274 | size_t read = 0; |
| 1275 | ssize_t ret; |
| 1276 | |
| 1277 | if (!cnt || cnt < 0) |
| 1278 | return 0; |
| 1279 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1280 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1281 | |
| 1282 | if (file->f_mode & FMODE_READ) { |
| 1283 | struct seq_file *m = file->private_data; |
| 1284 | iter = m->private; |
| 1285 | } else |
| 1286 | iter = file->private_data; |
| 1287 | |
| 1288 | if (!*ppos) { |
| 1289 | iter->flags &= ~FTRACE_ITER_CONT; |
| 1290 | iter->buffer_idx = 0; |
| 1291 | } |
| 1292 | |
| 1293 | ret = get_user(ch, ubuf++); |
| 1294 | if (ret) |
| 1295 | goto out; |
| 1296 | read++; |
| 1297 | cnt--; |
| 1298 | |
| 1299 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { |
| 1300 | /* skip white space */ |
| 1301 | while (cnt && isspace(ch)) { |
| 1302 | ret = get_user(ch, ubuf++); |
| 1303 | if (ret) |
| 1304 | goto out; |
| 1305 | read++; |
| 1306 | cnt--; |
| 1307 | } |
| 1308 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1309 | if (isspace(ch)) { |
| 1310 | file->f_pos += read; |
| 1311 | ret = read; |
| 1312 | goto out; |
| 1313 | } |
| 1314 | |
| 1315 | iter->buffer_idx = 0; |
| 1316 | } |
| 1317 | |
| 1318 | while (cnt && !isspace(ch)) { |
| 1319 | if (iter->buffer_idx < FTRACE_BUFF_MAX) |
| 1320 | iter->buffer[iter->buffer_idx++] = ch; |
| 1321 | else { |
| 1322 | ret = -EINVAL; |
| 1323 | goto out; |
| 1324 | } |
| 1325 | ret = get_user(ch, ubuf++); |
| 1326 | if (ret) |
| 1327 | goto out; |
| 1328 | read++; |
| 1329 | cnt--; |
| 1330 | } |
| 1331 | |
| 1332 | if (isspace(ch)) { |
| 1333 | iter->filtered++; |
| 1334 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1335 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1336 | iter->buffer_idx = 0; |
| 1337 | } else |
| 1338 | iter->flags |= FTRACE_ITER_CONT; |
| 1339 | |
| 1340 | |
| 1341 | file->f_pos += read; |
| 1342 | |
| 1343 | ret = read; |
| 1344 | out: |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1345 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1346 | |
| 1347 | return ret; |
| 1348 | } |
| 1349 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1350 | static ssize_t |
| 1351 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
| 1352 | size_t cnt, loff_t *ppos) |
| 1353 | { |
| 1354 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
| 1355 | } |
| 1356 | |
| 1357 | static ssize_t |
| 1358 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
| 1359 | size_t cnt, loff_t *ppos) |
| 1360 | { |
| 1361 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
| 1362 | } |
| 1363 | |
| 1364 | static void |
| 1365 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) |
| 1366 | { |
| 1367 | if (unlikely(ftrace_disabled)) |
| 1368 | return; |
| 1369 | |
| 1370 | mutex_lock(&ftrace_regex_lock); |
| 1371 | if (reset) |
| 1372 | ftrace_filter_reset(enable); |
| 1373 | if (buf) |
| 1374 | ftrace_match(buf, len, enable); |
| 1375 | mutex_unlock(&ftrace_regex_lock); |
| 1376 | } |
| 1377 | |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1378 | /** |
| 1379 | * ftrace_set_filter - set a function to filter on in ftrace |
| 1380 | * @buf - the string that holds the function filter text. |
| 1381 | * @len - the length of the string. |
| 1382 | * @reset - non zero to reset all filters before applying this filter. |
| 1383 | * |
| 1384 | * Filters denote which functions should be enabled when tracing is enabled. |
| 1385 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| 1386 | */ |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1387 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1388 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1389 | ftrace_set_regex(buf, len, reset, 1); |
| 1390 | } |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1391 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1392 | /** |
| 1393 | * ftrace_set_notrace - set a function to not trace in ftrace |
| 1394 | * @buf - the string that holds the function notrace text. |
| 1395 | * @len - the length of the string. |
| 1396 | * @reset - non zero to reset all filters before applying this filter. |
| 1397 | * |
| 1398 | * Notrace Filters denote which functions should not be enabled when tracing |
| 1399 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| 1400 | * for tracing. |
| 1401 | */ |
| 1402 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) |
| 1403 | { |
| 1404 | ftrace_set_regex(buf, len, reset, 0); |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1405 | } |
| 1406 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1407 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1408 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1409 | { |
| 1410 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1411 | struct ftrace_iterator *iter; |
| 1412 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1413 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1414 | if (file->f_mode & FMODE_READ) { |
| 1415 | iter = m->private; |
| 1416 | |
| 1417 | seq_release(inode, file); |
| 1418 | } else |
| 1419 | iter = file->private_data; |
| 1420 | |
| 1421 | if (iter->buffer_idx) { |
| 1422 | iter->filtered++; |
| 1423 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1424 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1425 | } |
| 1426 | |
| 1427 | mutex_lock(&ftrace_sysctl_lock); |
| 1428 | mutex_lock(&ftraced_lock); |
| 1429 | if (iter->filtered && ftraced_suspend && ftrace_enabled) |
| 1430 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
| 1431 | mutex_unlock(&ftraced_lock); |
| 1432 | mutex_unlock(&ftrace_sysctl_lock); |
| 1433 | |
| 1434 | kfree(iter); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1435 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1436 | return 0; |
| 1437 | } |
| 1438 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1439 | static int |
| 1440 | ftrace_filter_release(struct inode *inode, struct file *file) |
| 1441 | { |
| 1442 | return ftrace_regex_release(inode, file, 1); |
| 1443 | } |
| 1444 | |
| 1445 | static int |
| 1446 | ftrace_notrace_release(struct inode *inode, struct file *file) |
| 1447 | { |
| 1448 | return ftrace_regex_release(inode, file, 0); |
| 1449 | } |
| 1450 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1451 | static ssize_t |
| 1452 | ftraced_read(struct file *filp, char __user *ubuf, |
| 1453 | size_t cnt, loff_t *ppos) |
| 1454 | { |
| 1455 | /* don't worry about races */ |
| 1456 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; |
| 1457 | int r = strlen(buf); |
| 1458 | |
| 1459 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 1460 | } |
| 1461 | |
| 1462 | static ssize_t |
| 1463 | ftraced_write(struct file *filp, const char __user *ubuf, |
| 1464 | size_t cnt, loff_t *ppos) |
| 1465 | { |
| 1466 | char buf[64]; |
| 1467 | long val; |
| 1468 | int ret; |
| 1469 | |
| 1470 | if (cnt >= sizeof(buf)) |
| 1471 | return -EINVAL; |
| 1472 | |
| 1473 | if (copy_from_user(&buf, ubuf, cnt)) |
| 1474 | return -EFAULT; |
| 1475 | |
| 1476 | if (strncmp(buf, "enable", 6) == 0) |
| 1477 | val = 1; |
| 1478 | else if (strncmp(buf, "disable", 7) == 0) |
| 1479 | val = 0; |
| 1480 | else { |
| 1481 | buf[cnt] = 0; |
| 1482 | |
| 1483 | ret = strict_strtoul(buf, 10, &val); |
| 1484 | if (ret < 0) |
| 1485 | return ret; |
| 1486 | |
| 1487 | val = !!val; |
| 1488 | } |
| 1489 | |
| 1490 | if (val) |
| 1491 | ftrace_enable_daemon(); |
| 1492 | else |
| 1493 | ftrace_disable_daemon(); |
| 1494 | |
| 1495 | filp->f_pos += cnt; |
| 1496 | |
| 1497 | return cnt; |
| 1498 | } |
| 1499 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1500 | static struct file_operations ftrace_avail_fops = { |
| 1501 | .open = ftrace_avail_open, |
| 1502 | .read = seq_read, |
| 1503 | .llseek = seq_lseek, |
| 1504 | .release = ftrace_avail_release, |
| 1505 | }; |
| 1506 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1507 | static struct file_operations ftrace_failures_fops = { |
| 1508 | .open = ftrace_failures_open, |
| 1509 | .read = seq_read, |
| 1510 | .llseek = seq_lseek, |
| 1511 | .release = ftrace_avail_release, |
| 1512 | }; |
| 1513 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1514 | static struct file_operations ftrace_filter_fops = { |
| 1515 | .open = ftrace_filter_open, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1516 | .read = ftrace_regex_read, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1517 | .write = ftrace_filter_write, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1518 | .llseek = ftrace_regex_lseek, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1519 | .release = ftrace_filter_release, |
| 1520 | }; |
| 1521 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1522 | static struct file_operations ftrace_notrace_fops = { |
| 1523 | .open = ftrace_notrace_open, |
| 1524 | .read = ftrace_regex_read, |
| 1525 | .write = ftrace_notrace_write, |
| 1526 | .llseek = ftrace_regex_lseek, |
| 1527 | .release = ftrace_notrace_release, |
| 1528 | }; |
| 1529 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1530 | static struct file_operations ftraced_fops = { |
| 1531 | .open = tracing_open_generic, |
| 1532 | .read = ftraced_read, |
| 1533 | .write = ftraced_write, |
| 1534 | }; |
| 1535 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1536 | /** |
| 1537 | * ftrace_force_update - force an update to all recording ftrace functions |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1538 | */ |
| 1539 | int ftrace_force_update(void) |
| 1540 | { |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1541 | int ret = 0; |
| 1542 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1543 | if (unlikely(ftrace_disabled)) |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1544 | return -ENODEV; |
| 1545 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1546 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1547 | mutex_lock(&ftraced_lock); |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1548 | |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1549 | /* |
| 1550 | * If ftraced_trigger is not set, then there is nothing |
| 1551 | * to update. |
| 1552 | */ |
| 1553 | if (ftraced_trigger && !ftrace_update_code()) |
| 1554 | ret = -EBUSY; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1555 | |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1556 | mutex_unlock(&ftraced_lock); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1557 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1558 | |
| 1559 | return ret; |
| 1560 | } |
| 1561 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1562 | static __init int ftrace_init_debugfs(void) |
| 1563 | { |
| 1564 | struct dentry *d_tracer; |
| 1565 | struct dentry *entry; |
| 1566 | |
| 1567 | d_tracer = tracing_init_dentry(); |
| 1568 | |
| 1569 | entry = debugfs_create_file("available_filter_functions", 0444, |
| 1570 | d_tracer, NULL, &ftrace_avail_fops); |
| 1571 | if (!entry) |
| 1572 | pr_warning("Could not create debugfs " |
| 1573 | "'available_filter_functions' entry\n"); |
| 1574 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1575 | entry = debugfs_create_file("failures", 0444, |
| 1576 | d_tracer, NULL, &ftrace_failures_fops); |
| 1577 | if (!entry) |
| 1578 | pr_warning("Could not create debugfs 'failures' entry\n"); |
| 1579 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1580 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
| 1581 | NULL, &ftrace_filter_fops); |
| 1582 | if (!entry) |
| 1583 | pr_warning("Could not create debugfs " |
| 1584 | "'set_ftrace_filter' entry\n"); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1585 | |
| 1586 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, |
| 1587 | NULL, &ftrace_notrace_fops); |
| 1588 | if (!entry) |
| 1589 | pr_warning("Could not create debugfs " |
| 1590 | "'set_ftrace_notrace' entry\n"); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1591 | |
| 1592 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, |
| 1593 | NULL, &ftraced_fops); |
| 1594 | if (!entry) |
| 1595 | pr_warning("Could not create debugfs " |
| 1596 | "'ftraced_enabled' entry\n"); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1597 | return 0; |
| 1598 | } |
| 1599 | |
| 1600 | fs_initcall(ftrace_init_debugfs); |
| 1601 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1602 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
| 1603 | static int ftrace_convert_nops(unsigned long *start, |
| 1604 | unsigned long *end) |
| 1605 | { |
| 1606 | unsigned long *p; |
| 1607 | unsigned long addr; |
| 1608 | unsigned long flags; |
| 1609 | |
| 1610 | p = start; |
| 1611 | while (p < end) { |
| 1612 | addr = ftrace_call_adjust(*p++); |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1613 | /* should not be called from interrupt context */ |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1614 | spin_lock(&ftrace_lock); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1615 | ftrace_record_ip(addr); |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1616 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1617 | ftrace_shutdown_replenish(); |
| 1618 | } |
| 1619 | |
| 1620 | /* p is ignored */ |
| 1621 | local_irq_save(flags); |
| 1622 | __ftrace_update_code(p); |
| 1623 | local_irq_restore(flags); |
| 1624 | |
| 1625 | return 0; |
| 1626 | } |
| 1627 | |
Steven Rostedt | 90d595f | 2008-08-14 15:45:09 -0400 | [diff] [blame] | 1628 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
| 1629 | { |
Steven Rostedt | 00fd61a | 2008-08-15 21:40:04 -0400 | [diff] [blame] | 1630 | if (ftrace_disabled || start == end) |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1631 | return; |
Steven Rostedt | 90d595f | 2008-08-14 15:45:09 -0400 | [diff] [blame] | 1632 | ftrace_convert_nops(start, end); |
| 1633 | } |
| 1634 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1635 | extern unsigned long __start_mcount_loc[]; |
| 1636 | extern unsigned long __stop_mcount_loc[]; |
| 1637 | |
| 1638 | void __init ftrace_init(void) |
| 1639 | { |
| 1640 | unsigned long count, addr, flags; |
| 1641 | int ret; |
| 1642 | |
| 1643 | /* Keep the ftrace pointer to the stub */ |
| 1644 | addr = (unsigned long)ftrace_stub; |
| 1645 | |
| 1646 | local_irq_save(flags); |
| 1647 | ftrace_dyn_arch_init(&addr); |
| 1648 | local_irq_restore(flags); |
| 1649 | |
| 1650 | /* ftrace_dyn_arch_init places the return code in addr */ |
| 1651 | if (addr) |
| 1652 | goto failed; |
| 1653 | |
| 1654 | count = __stop_mcount_loc - __start_mcount_loc; |
| 1655 | |
| 1656 | ret = ftrace_dyn_table_alloc(count); |
| 1657 | if (ret) |
| 1658 | goto failed; |
| 1659 | |
| 1660 | last_ftrace_enabled = ftrace_enabled = 1; |
| 1661 | |
| 1662 | ret = ftrace_convert_nops(__start_mcount_loc, |
| 1663 | __stop_mcount_loc); |
| 1664 | |
| 1665 | return; |
| 1666 | failed: |
| 1667 | ftrace_disabled = 1; |
| 1668 | } |
| 1669 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ |
Steven Rostedt | bd95b88 | 2008-10-16 09:31:27 -0400 | [diff] [blame] | 1670 | |
| 1671 | static void ftrace_release_hash(unsigned long start, unsigned long end) |
| 1672 | { |
| 1673 | struct dyn_ftrace *rec; |
| 1674 | struct hlist_node *t, *n; |
| 1675 | struct hlist_head *head, temp_list; |
| 1676 | unsigned long flags; |
| 1677 | int i, cpu; |
| 1678 | |
| 1679 | preempt_disable_notrace(); |
| 1680 | |
| 1681 | /* disable incase we call something that calls mcount */ |
| 1682 | cpu = raw_smp_processor_id(); |
| 1683 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; |
| 1684 | |
| 1685 | ftrace_hash_lock(flags); |
| 1686 | |
| 1687 | for (i = 0; i < FTRACE_HASHSIZE; i++) { |
| 1688 | INIT_HLIST_HEAD(&temp_list); |
| 1689 | head = &ftrace_hash[i]; |
| 1690 | |
| 1691 | /* all CPUS are stopped, we are safe to modify code */ |
| 1692 | hlist_for_each_entry_safe(rec, t, n, head, node) { |
| 1693 | if (rec->flags & FTRACE_FL_FREE) |
| 1694 | continue; |
| 1695 | |
| 1696 | if ((rec->ip >= start) && (rec->ip < end)) |
| 1697 | ftrace_free_rec(rec); |
| 1698 | } |
| 1699 | } |
| 1700 | |
| 1701 | ftrace_hash_unlock(flags); |
| 1702 | |
| 1703 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
| 1704 | preempt_enable_notrace(); |
| 1705 | |
| 1706 | } |
| 1707 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1708 | static int ftraced(void *ignore) |
| 1709 | { |
| 1710 | unsigned long usecs; |
| 1711 | |
| 1712 | while (!kthread_should_stop()) { |
| 1713 | |
| 1714 | set_current_state(TASK_INTERRUPTIBLE); |
| 1715 | |
| 1716 | /* check once a second */ |
| 1717 | schedule_timeout(HZ); |
| 1718 | |
| 1719 | if (unlikely(ftrace_disabled)) |
| 1720 | continue; |
| 1721 | |
| 1722 | mutex_lock(&ftrace_sysctl_lock); |
| 1723 | mutex_lock(&ftraced_lock); |
| 1724 | if (!ftraced_suspend && !ftraced_stop && |
| 1725 | ftrace_update_code()) { |
| 1726 | usecs = nsecs_to_usecs(ftrace_update_time); |
| 1727 | if (ftrace_update_tot_cnt > 100000) { |
| 1728 | ftrace_update_tot_cnt = 0; |
| 1729 | pr_info("hm, dftrace overflow: %lu change%s" |
| 1730 | " (%lu total) in %lu usec%s\n", |
| 1731 | ftrace_update_cnt, |
| 1732 | ftrace_update_cnt != 1 ? "s" : "", |
| 1733 | ftrace_update_tot_cnt, |
| 1734 | usecs, usecs != 1 ? "s" : ""); |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame^] | 1735 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1736 | } |
| 1737 | } |
| 1738 | mutex_unlock(&ftraced_lock); |
| 1739 | mutex_unlock(&ftrace_sysctl_lock); |
| 1740 | |
| 1741 | ftrace_shutdown_replenish(); |
| 1742 | } |
| 1743 | __set_current_state(TASK_RUNNING); |
| 1744 | return 0; |
| 1745 | } |
| 1746 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1747 | static int __init ftrace_dynamic_init(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1748 | { |
| 1749 | struct task_struct *p; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1750 | unsigned long addr; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1751 | int ret; |
| 1752 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1753 | addr = (unsigned long)ftrace_record_ip; |
Ingo Molnar | 9ff9cdb | 2008-05-12 21:20:50 +0200 | [diff] [blame] | 1754 | |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 1755 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1756 | |
| 1757 | /* ftrace_dyn_arch_init places the return code in addr */ |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1758 | if (addr) { |
| 1759 | ret = (int)addr; |
| 1760 | goto failed; |
| 1761 | } |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1762 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1763 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1764 | if (ret) |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1765 | goto failed; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1766 | |
| 1767 | p = kthread_run(ftraced, NULL, "ftraced"); |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1768 | if (IS_ERR(p)) { |
| 1769 | ret = -1; |
| 1770 | goto failed; |
| 1771 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1772 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1773 | last_ftrace_enabled = ftrace_enabled = 1; |
Steven Rostedt | e1c08bd | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 1774 | ftraced_task = p; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1775 | |
| 1776 | return 0; |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1777 | |
| 1778 | failed: |
| 1779 | ftrace_disabled = 1; |
| 1780 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1781 | } |
| 1782 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1783 | core_initcall(ftrace_dynamic_init); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1784 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
| 1785 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1786 | #else |
Ingo Molnar | c7aafc5 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1787 | # define ftrace_startup() do { } while (0) |
| 1788 | # define ftrace_shutdown() do { } while (0) |
| 1789 | # define ftrace_startup_sysctl() do { } while (0) |
| 1790 | # define ftrace_shutdown_sysctl() do { } while (0) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1791 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 1792 | |
| 1793 | /** |
Steven Rostedt | 81adbdc | 2008-10-23 09:33:02 -0400 | [diff] [blame] | 1794 | * ftrace_kill - kill ftrace |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1795 | * |
| 1796 | * This function should be used by panic code. It stops ftrace |
| 1797 | * but in a not so nice way. If you need to simply kill ftrace |
| 1798 | * from a non-atomic section, use ftrace_kill. |
| 1799 | */ |
Steven Rostedt | 81adbdc | 2008-10-23 09:33:02 -0400 | [diff] [blame] | 1800 | void ftrace_kill(void) |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1801 | { |
| 1802 | ftrace_disabled = 1; |
| 1803 | ftrace_enabled = 0; |
Ingo Molnar | b2613e3 | 2008-07-11 16:44:27 +0200 | [diff] [blame] | 1804 | #ifdef CONFIG_DYNAMIC_FTRACE |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1805 | ftraced_suspend = -1; |
Ingo Molnar | b2613e3 | 2008-07-11 16:44:27 +0200 | [diff] [blame] | 1806 | #endif |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1807 | clear_ftrace_function(); |
| 1808 | } |
| 1809 | |
| 1810 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1811 | * register_ftrace_function - register a function for profiling |
| 1812 | * @ops - ops structure that holds the function for profiling. |
| 1813 | * |
| 1814 | * Register a function to be called by all functions in the |
| 1815 | * kernel. |
| 1816 | * |
| 1817 | * Note: @ops->func and all the functions it calls must be labeled |
| 1818 | * with "notrace", otherwise it will go into a |
| 1819 | * recursive loop. |
| 1820 | */ |
| 1821 | int register_ftrace_function(struct ftrace_ops *ops) |
| 1822 | { |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1823 | int ret; |
| 1824 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1825 | if (unlikely(ftrace_disabled)) |
| 1826 | return -1; |
| 1827 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1828 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1829 | ret = __register_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1830 | ftrace_startup(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1831 | mutex_unlock(&ftrace_sysctl_lock); |
| 1832 | |
| 1833 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1834 | } |
| 1835 | |
| 1836 | /** |
| 1837 | * unregister_ftrace_function - unresgister a function for profiling. |
| 1838 | * @ops - ops structure that holds the function to unregister |
| 1839 | * |
| 1840 | * Unregister a function that was added to be called by ftrace profiling. |
| 1841 | */ |
| 1842 | int unregister_ftrace_function(struct ftrace_ops *ops) |
| 1843 | { |
| 1844 | int ret; |
| 1845 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1846 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1847 | ret = __unregister_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1848 | ftrace_shutdown(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1849 | mutex_unlock(&ftrace_sysctl_lock); |
| 1850 | |
| 1851 | return ret; |
| 1852 | } |
| 1853 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1854 | int |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1855 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1856 | struct file *file, void __user *buffer, size_t *lenp, |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1857 | loff_t *ppos) |
| 1858 | { |
| 1859 | int ret; |
| 1860 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1861 | if (unlikely(ftrace_disabled)) |
| 1862 | return -ENODEV; |
| 1863 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1864 | mutex_lock(&ftrace_sysctl_lock); |
| 1865 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1866 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1867 | |
| 1868 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) |
| 1869 | goto out; |
| 1870 | |
| 1871 | last_ftrace_enabled = ftrace_enabled; |
| 1872 | |
| 1873 | if (ftrace_enabled) { |
| 1874 | |
| 1875 | ftrace_startup_sysctl(); |
| 1876 | |
| 1877 | /* we are starting ftrace again */ |
| 1878 | if (ftrace_list != &ftrace_list_end) { |
| 1879 | if (ftrace_list->next == &ftrace_list_end) |
| 1880 | ftrace_trace_function = ftrace_list->func; |
| 1881 | else |
| 1882 | ftrace_trace_function = ftrace_list_func; |
| 1883 | } |
| 1884 | |
| 1885 | } else { |
| 1886 | /* stopping ftrace calls (just send to ftrace_stub) */ |
| 1887 | ftrace_trace_function = ftrace_stub; |
| 1888 | |
| 1889 | ftrace_shutdown_sysctl(); |
| 1890 | } |
| 1891 | |
| 1892 | out: |
| 1893 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1894 | return ret; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1895 | } |