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> |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 28 | #include <linux/list.h> |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 29 | |
Abhishek Sagar | 395a59d | 2008-06-21 23:47:27 +0530 | [diff] [blame] | 30 | #include <asm/ftrace.h> |
| 31 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 32 | #include "trace.h" |
| 33 | |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame] | 34 | #define FTRACE_WARN_ON(cond) \ |
| 35 | do { \ |
| 36 | if (WARN_ON(cond)) \ |
| 37 | ftrace_kill(); \ |
| 38 | } while (0) |
| 39 | |
| 40 | #define FTRACE_WARN_ON_ONCE(cond) \ |
| 41 | do { \ |
| 42 | if (WARN_ON_ONCE(cond)) \ |
| 43 | ftrace_kill(); \ |
| 44 | } while (0) |
| 45 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 46 | /* ftrace_enabled is a method to turn ftrace on or off */ |
| 47 | int ftrace_enabled __read_mostly; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 48 | static int last_ftrace_enabled; |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 49 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 50 | /* ftrace_pid_trace >= 0 will only trace threads with this pid */ |
| 51 | static int ftrace_pid_trace = -1; |
| 52 | |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 53 | /* Quick disabling of function tracer. */ |
| 54 | int function_trace_stop; |
| 55 | |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 56 | /* By default, current tracing type is normal tracing. */ |
| 57 | enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER; |
| 58 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 59 | /* |
| 60 | * ftrace_disabled is set when an anomaly is discovered. |
| 61 | * ftrace_disabled is much stronger than ftrace_enabled. |
| 62 | */ |
| 63 | static int ftrace_disabled __read_mostly; |
| 64 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 65 | static DEFINE_SPINLOCK(ftrace_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 66 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 67 | static DEFINE_MUTEX(ftrace_start_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 68 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 69 | static struct ftrace_ops ftrace_list_end __read_mostly = |
| 70 | { |
| 71 | .func = ftrace_stub, |
| 72 | }; |
| 73 | |
| 74 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; |
| 75 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 76 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 77 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 78 | |
Ingo Molnar | f225293 | 2008-05-22 10:37:48 +0200 | [diff] [blame] | 79 | 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] | 80 | { |
| 81 | struct ftrace_ops *op = ftrace_list; |
| 82 | |
| 83 | /* in case someone actually ports this to alpha! */ |
| 84 | read_barrier_depends(); |
| 85 | |
| 86 | while (op != &ftrace_list_end) { |
| 87 | /* silly alpha */ |
| 88 | read_barrier_depends(); |
| 89 | op->func(ip, parent_ip); |
| 90 | op = op->next; |
| 91 | }; |
| 92 | } |
| 93 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 94 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
| 95 | { |
| 96 | if (current->pid != ftrace_pid_trace) |
| 97 | return; |
| 98 | |
| 99 | ftrace_pid_function(ip, parent_ip); |
| 100 | } |
| 101 | |
| 102 | static void set_ftrace_pid_function(ftrace_func_t func) |
| 103 | { |
| 104 | /* do not set ftrace_pid_function to itself! */ |
| 105 | if (func != ftrace_pid_func) |
| 106 | ftrace_pid_function = func; |
| 107 | } |
| 108 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 109 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 110 | * clear_ftrace_function - reset the ftrace function |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 111 | * |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 112 | * This NULLs the ftrace function and in essence stops |
| 113 | * tracing. There may be lag |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 114 | */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 115 | void clear_ftrace_function(void) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 116 | { |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 117 | ftrace_trace_function = ftrace_stub; |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 118 | __ftrace_trace_function = ftrace_stub; |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 119 | ftrace_pid_function = ftrace_stub; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 120 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 121 | |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 122 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 123 | /* |
| 124 | * For those archs that do not test ftrace_trace_stop in their |
| 125 | * mcount call site, we need to do it from C. |
| 126 | */ |
| 127 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) |
| 128 | { |
| 129 | if (function_trace_stop) |
| 130 | return; |
| 131 | |
| 132 | __ftrace_trace_function(ip, parent_ip); |
| 133 | } |
| 134 | #endif |
| 135 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 136 | static int __register_ftrace_function(struct ftrace_ops *ops) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 137 | { |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 138 | /* should not be called from interrupt context */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 139 | spin_lock(&ftrace_lock); |
| 140 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 141 | ops->next = ftrace_list; |
| 142 | /* |
| 143 | * We are entering ops into the ftrace_list but another |
| 144 | * CPU might be walking that list. We need to make sure |
| 145 | * the ops->next pointer is valid before another CPU sees |
| 146 | * the ops pointer included into the ftrace_list. |
| 147 | */ |
| 148 | smp_wmb(); |
| 149 | ftrace_list = ops; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 150 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 151 | if (ftrace_enabled) { |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 152 | ftrace_func_t func; |
| 153 | |
| 154 | if (ops->next == &ftrace_list_end) |
| 155 | func = ops->func; |
| 156 | else |
| 157 | func = ftrace_list_func; |
| 158 | |
| 159 | if (ftrace_pid_trace >= 0) { |
| 160 | set_ftrace_pid_function(func); |
| 161 | func = ftrace_pid_func; |
| 162 | } |
| 163 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 164 | /* |
| 165 | * For one func, simply call it directly. |
| 166 | * For more than one func, call the chain. |
| 167 | */ |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 168 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 169 | ftrace_trace_function = func; |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 170 | #else |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 171 | __ftrace_trace_function = func; |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 172 | ftrace_trace_function = ftrace_test_stop_func; |
| 173 | #endif |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 174 | } |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 175 | |
| 176 | spin_unlock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 177 | |
| 178 | return 0; |
| 179 | } |
| 180 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 181 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 182 | { |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 183 | struct ftrace_ops **p; |
| 184 | int ret = 0; |
| 185 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 186 | /* should not be called from interrupt context */ |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 187 | spin_lock(&ftrace_lock); |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 188 | |
| 189 | /* |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 190 | * If we are removing the last function, then simply point |
| 191 | * to the ftrace_stub. |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 192 | */ |
| 193 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { |
| 194 | ftrace_trace_function = ftrace_stub; |
| 195 | ftrace_list = &ftrace_list_end; |
| 196 | goto out; |
| 197 | } |
| 198 | |
| 199 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) |
| 200 | if (*p == ops) |
| 201 | break; |
| 202 | |
| 203 | if (*p != ops) { |
| 204 | ret = -1; |
| 205 | goto out; |
| 206 | } |
| 207 | |
| 208 | *p = (*p)->next; |
| 209 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 210 | if (ftrace_enabled) { |
| 211 | /* If we only have one func left, then call that directly */ |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 212 | if (ftrace_list->next == &ftrace_list_end) { |
| 213 | ftrace_func_t func = ftrace_list->func; |
| 214 | |
| 215 | if (ftrace_pid_trace >= 0) { |
| 216 | set_ftrace_pid_function(func); |
| 217 | func = ftrace_pid_func; |
| 218 | } |
| 219 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 220 | ftrace_trace_function = func; |
| 221 | #else |
| 222 | __ftrace_trace_function = func; |
| 223 | #endif |
| 224 | } |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 225 | } |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 226 | |
| 227 | out: |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 228 | spin_unlock(&ftrace_lock); |
| 229 | |
| 230 | return ret; |
| 231 | } |
| 232 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 233 | static void ftrace_update_pid_func(void) |
| 234 | { |
| 235 | ftrace_func_t func; |
| 236 | |
| 237 | /* should not be called from interrupt context */ |
| 238 | spin_lock(&ftrace_lock); |
| 239 | |
| 240 | if (ftrace_trace_function == ftrace_stub) |
| 241 | goto out; |
| 242 | |
| 243 | func = ftrace_trace_function; |
| 244 | |
| 245 | if (ftrace_pid_trace >= 0) { |
| 246 | set_ftrace_pid_function(func); |
| 247 | func = ftrace_pid_func; |
| 248 | } else { |
| 249 | if (func != ftrace_pid_func) |
| 250 | goto out; |
| 251 | |
| 252 | set_ftrace_pid_function(func); |
| 253 | } |
| 254 | |
| 255 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 256 | ftrace_trace_function = func; |
| 257 | #else |
| 258 | __ftrace_trace_function = func; |
| 259 | #endif |
| 260 | |
| 261 | out: |
| 262 | spin_unlock(&ftrace_lock); |
| 263 | } |
| 264 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 265 | #ifdef CONFIG_DYNAMIC_FTRACE |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 266 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 267 | # error Dynamic ftrace depends on MCOUNT_RECORD |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 268 | #endif |
| 269 | |
Steven Noonan | 71c67d5 | 2008-09-20 01:00:37 -0700 | [diff] [blame] | 270 | /* |
| 271 | * Since MCOUNT_ADDR may point to mcount itself, we do not want |
| 272 | * to get it confused by reading a reference in the code as we |
| 273 | * are parsing on objcopy output of text. Use a variable for |
| 274 | * it instead. |
| 275 | */ |
| 276 | static unsigned long mcount_addr = MCOUNT_ADDR; |
| 277 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 278 | enum { |
| 279 | FTRACE_ENABLE_CALLS = (1 << 0), |
| 280 | FTRACE_DISABLE_CALLS = (1 << 1), |
| 281 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), |
| 282 | FTRACE_ENABLE_MCOUNT = (1 << 3), |
| 283 | FTRACE_DISABLE_MCOUNT = (1 << 4), |
| 284 | }; |
| 285 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 286 | static int ftrace_filtered; |
| 287 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 288 | static LIST_HEAD(ftrace_new_addrs); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 289 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 290 | static DEFINE_MUTEX(ftrace_regex_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 291 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 292 | struct ftrace_page { |
| 293 | struct ftrace_page *next; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 294 | unsigned long index; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 295 | struct dyn_ftrace records[]; |
David Miller | aa5e5ce | 2008-05-13 22:06:56 -0700 | [diff] [blame] | 296 | }; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 297 | |
| 298 | #define ENTRIES_PER_PAGE \ |
| 299 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) |
| 300 | |
| 301 | /* estimate from running different kernels */ |
| 302 | #define NR_TO_INIT 10000 |
| 303 | |
| 304 | static struct ftrace_page *ftrace_pages_start; |
| 305 | static struct ftrace_page *ftrace_pages; |
| 306 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 307 | static struct dyn_ftrace *ftrace_free_records; |
| 308 | |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 309 | |
| 310 | #ifdef CONFIG_KPROBES |
Ingo Molnar | f17845e | 2008-10-24 12:47:10 +0200 | [diff] [blame] | 311 | |
| 312 | static int frozen_record_count; |
| 313 | |
Abhishek Sagar | ecea656 | 2008-06-21 23:47:53 +0530 | [diff] [blame] | 314 | static inline void freeze_record(struct dyn_ftrace *rec) |
| 315 | { |
| 316 | if (!(rec->flags & FTRACE_FL_FROZEN)) { |
| 317 | rec->flags |= FTRACE_FL_FROZEN; |
| 318 | frozen_record_count++; |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | static inline void unfreeze_record(struct dyn_ftrace *rec) |
| 323 | { |
| 324 | if (rec->flags & FTRACE_FL_FROZEN) { |
| 325 | rec->flags &= ~FTRACE_FL_FROZEN; |
| 326 | frozen_record_count--; |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | static inline int record_frozen(struct dyn_ftrace *rec) |
| 331 | { |
| 332 | return rec->flags & FTRACE_FL_FROZEN; |
| 333 | } |
| 334 | #else |
| 335 | # define freeze_record(rec) ({ 0; }) |
| 336 | # define unfreeze_record(rec) ({ 0; }) |
| 337 | # define record_frozen(rec) ({ 0; }) |
| 338 | #endif /* CONFIG_KPROBES */ |
| 339 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 340 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 341 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 342 | rec->ip = (unsigned long)ftrace_free_records; |
| 343 | ftrace_free_records = rec; |
| 344 | rec->flags |= FTRACE_FL_FREE; |
| 345 | } |
| 346 | |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 347 | void ftrace_release(void *start, unsigned long size) |
| 348 | { |
| 349 | struct dyn_ftrace *rec; |
| 350 | struct ftrace_page *pg; |
| 351 | unsigned long s = (unsigned long)start; |
| 352 | unsigned long e = s + size; |
| 353 | int i; |
| 354 | |
Steven Rostedt | 00fd61a | 2008-08-15 21:40:04 -0400 | [diff] [blame] | 355 | if (ftrace_disabled || !start) |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 356 | return; |
| 357 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 358 | /* should not be called from interrupt context */ |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 359 | spin_lock(&ftrace_lock); |
| 360 | |
| 361 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 362 | for (i = 0; i < pg->index; i++) { |
| 363 | rec = &pg->records[i]; |
| 364 | |
| 365 | if ((rec->ip >= s) && (rec->ip < e)) |
| 366 | ftrace_free_rec(rec); |
| 367 | } |
| 368 | } |
| 369 | spin_unlock(&ftrace_lock); |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 370 | } |
| 371 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 372 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 373 | { |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 374 | struct dyn_ftrace *rec; |
| 375 | |
| 376 | /* First check for freed records */ |
| 377 | if (ftrace_free_records) { |
| 378 | rec = ftrace_free_records; |
| 379 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 380 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
Steven Rostedt | 6912896e | 2008-10-23 09:33:03 -0400 | [diff] [blame] | 381 | FTRACE_WARN_ON_ONCE(1); |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 382 | ftrace_free_records = NULL; |
| 383 | return NULL; |
| 384 | } |
| 385 | |
| 386 | ftrace_free_records = (void *)rec->ip; |
| 387 | memset(rec, 0, sizeof(*rec)); |
| 388 | return rec; |
| 389 | } |
| 390 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 391 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 392 | if (!ftrace_pages->next) { |
| 393 | /* allocate another page */ |
| 394 | ftrace_pages->next = |
| 395 | (void *)get_zeroed_page(GFP_KERNEL); |
| 396 | if (!ftrace_pages->next) |
| 397 | return NULL; |
| 398 | } |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 399 | ftrace_pages = ftrace_pages->next; |
| 400 | } |
| 401 | |
| 402 | return &ftrace_pages->records[ftrace_pages->index++]; |
| 403 | } |
| 404 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 405 | static struct dyn_ftrace * |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 406 | ftrace_record_ip(unsigned long ip) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 407 | { |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 408 | struct dyn_ftrace *rec; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 409 | |
Steven Rostedt | f3c7ac4 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 410 | if (ftrace_disabled) |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 411 | return NULL; |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 412 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 413 | rec = ftrace_alloc_dyn_node(ip); |
| 414 | if (!rec) |
| 415 | return NULL; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 416 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 417 | rec->ip = ip; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 418 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 419 | list_add(&rec->list, &ftrace_new_addrs); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 420 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 421 | return rec; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 422 | } |
| 423 | |
Steven Rostedt | 05736a4 | 2008-09-22 14:55:47 -0700 | [diff] [blame] | 424 | static void print_ip_ins(const char *fmt, unsigned char *p) |
| 425 | { |
| 426 | int i; |
| 427 | |
| 428 | printk(KERN_CONT "%s", fmt); |
| 429 | |
| 430 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) |
| 431 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); |
| 432 | } |
| 433 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 434 | static void ftrace_bug(int failed, unsigned long ip) |
Steven Rostedt | b17e8a3 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 435 | { |
| 436 | switch (failed) { |
| 437 | case -EFAULT: |
| 438 | FTRACE_WARN_ON_ONCE(1); |
| 439 | pr_info("ftrace faulted on modifying "); |
| 440 | print_ip_sym(ip); |
| 441 | break; |
| 442 | case -EINVAL: |
| 443 | FTRACE_WARN_ON_ONCE(1); |
| 444 | pr_info("ftrace failed to modify "); |
| 445 | print_ip_sym(ip); |
Steven Rostedt | b17e8a3 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 446 | print_ip_ins(" actual: ", (unsigned char *)ip); |
Steven Rostedt | b17e8a3 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 447 | printk(KERN_CONT "\n"); |
| 448 | break; |
| 449 | case -EPERM: |
| 450 | FTRACE_WARN_ON_ONCE(1); |
| 451 | pr_info("ftrace faulted on writing "); |
| 452 | print_ip_sym(ip); |
| 453 | break; |
| 454 | default: |
| 455 | FTRACE_WARN_ON_ONCE(1); |
| 456 | pr_info("ftrace faulted on unknown error "); |
| 457 | print_ip_sym(ip); |
| 458 | } |
| 459 | } |
| 460 | |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 461 | |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 462 | static int |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 463 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 464 | { |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 465 | unsigned long ip, fl; |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 466 | unsigned long ftrace_addr; |
| 467 | |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 468 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 469 | if (ftrace_tracing_type == FTRACE_TYPE_ENTER) |
| 470 | ftrace_addr = (unsigned long)ftrace_caller; |
| 471 | else |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 472 | ftrace_addr = (unsigned long)ftrace_graph_caller; |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 473 | #else |
| 474 | ftrace_addr = (unsigned long)ftrace_caller; |
| 475 | #endif |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 476 | |
| 477 | ip = rec->ip; |
| 478 | |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 479 | /* |
| 480 | * If this record is not to be traced and |
| 481 | * it is not enabled then do nothing. |
| 482 | * |
| 483 | * If this record is not to be traced and |
| 484 | * it is enabled then disabled it. |
| 485 | * |
| 486 | */ |
| 487 | if (rec->flags & FTRACE_FL_NOTRACE) { |
| 488 | if (rec->flags & FTRACE_FL_ENABLED) |
| 489 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 490 | else |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 491 | return 0; |
| 492 | |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 493 | } else if (ftrace_filtered && enable) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 494 | /* |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 495 | * Filtering is on: |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 496 | */ |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 497 | |
| 498 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
| 499 | |
| 500 | /* Record is filtered and enabled, do nothing */ |
| 501 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) |
| 502 | return 0; |
| 503 | |
| 504 | /* Record is not filtered and is not enabled do nothing */ |
| 505 | if (!fl) |
| 506 | return 0; |
| 507 | |
| 508 | /* Record is not filtered but enabled, disable it */ |
| 509 | if (fl == FTRACE_FL_ENABLED) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 510 | rec->flags &= ~FTRACE_FL_ENABLED; |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 511 | else |
| 512 | /* Otherwise record is filtered but not enabled, enable it */ |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 513 | rec->flags |= FTRACE_FL_ENABLED; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 514 | } else { |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 515 | /* Disable or not filtered */ |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 516 | |
| 517 | if (enable) { |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 518 | /* if record is enabled, do nothing */ |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 519 | if (rec->flags & FTRACE_FL_ENABLED) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 520 | return 0; |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 521 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 522 | rec->flags |= FTRACE_FL_ENABLED; |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 523 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 524 | } else { |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 525 | |
| 526 | /* if record is not enabled do nothing */ |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 527 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
| 528 | return 0; |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 529 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 530 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 531 | } |
| 532 | } |
| 533 | |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 534 | if (rec->flags & FTRACE_FL_ENABLED) |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 535 | return ftrace_make_call(rec, ftrace_addr); |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 536 | else |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 537 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 538 | } |
| 539 | |
| 540 | static void ftrace_replace_code(int enable) |
| 541 | { |
| 542 | int i, failed; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 543 | struct dyn_ftrace *rec; |
| 544 | struct ftrace_page *pg; |
| 545 | |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 546 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| 547 | for (i = 0; i < pg->index; i++) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 548 | rec = &pg->records[i]; |
| 549 | |
Steven Rostedt | 918c115 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 550 | /* |
| 551 | * Skip over free records and records that have |
| 552 | * failed. |
| 553 | */ |
| 554 | if (rec->flags & FTRACE_FL_FREE || |
| 555 | rec->flags & FTRACE_FL_FAILED) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 556 | continue; |
| 557 | |
| 558 | /* ignore updates to this record's mcount site */ |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 559 | if (get_kprobe((void *)rec->ip)) { |
| 560 | freeze_record(rec); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 561 | continue; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 562 | } else { |
| 563 | unfreeze_record(rec); |
| 564 | } |
| 565 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 566 | failed = __ftrace_replace_code(rec, enable); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 567 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
| 568 | rec->flags |= FTRACE_FL_FAILED; |
| 569 | if ((system_state == SYSTEM_BOOTING) || |
| 570 | !core_kernel_text(rec->ip)) { |
| 571 | ftrace_free_rec(rec); |
Steven Rostedt | b17e8a3 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 572 | } else |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 573 | ftrace_bug(failed, rec->ip); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 574 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 575 | } |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 576 | } |
| 577 | } |
| 578 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 579 | static int |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 580 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 581 | { |
| 582 | unsigned long ip; |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 583 | int ret; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 584 | |
| 585 | ip = rec->ip; |
| 586 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 587 | ret = ftrace_make_nop(mod, rec, mcount_addr); |
Steven Rostedt | 593eb8a | 2008-10-23 09:32:59 -0400 | [diff] [blame] | 588 | if (ret) { |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 589 | ftrace_bug(ret, ip); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 590 | rec->flags |= FTRACE_FL_FAILED; |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 591 | return 0; |
Steven Rostedt | 37ad508 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 592 | } |
Abhishek Sagar | 492a7ea5 | 2008-05-25 00:10:04 +0530 | [diff] [blame] | 593 | return 1; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 594 | } |
| 595 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 596 | static int __ftrace_modify_code(void *data) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 597 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 598 | int *command = data; |
| 599 | |
Steven Rostedt | a358324 | 2008-11-11 15:01:42 -0500 | [diff] [blame] | 600 | if (*command & FTRACE_ENABLE_CALLS) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 601 | ftrace_replace_code(1); |
Steven Rostedt | a358324 | 2008-11-11 15:01:42 -0500 | [diff] [blame] | 602 | else if (*command & FTRACE_DISABLE_CALLS) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 603 | ftrace_replace_code(0); |
| 604 | |
| 605 | if (*command & FTRACE_UPDATE_TRACE_FUNC) |
| 606 | ftrace_update_ftrace_func(ftrace_trace_function); |
| 607 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 608 | return 0; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 609 | } |
| 610 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 611 | static void ftrace_run_update_code(int command) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 612 | { |
Rusty Russell | 784e2d7 | 2008-07-28 12:16:31 -0500 | [diff] [blame] | 613 | stop_machine(__ftrace_modify_code, &command, NULL); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 614 | } |
| 615 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 616 | static ftrace_func_t saved_ftrace_func; |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 617 | static int ftrace_start_up; |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 618 | |
| 619 | static void ftrace_startup_enable(int command) |
| 620 | { |
| 621 | if (saved_ftrace_func != ftrace_trace_function) { |
| 622 | saved_ftrace_func = ftrace_trace_function; |
| 623 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 624 | } |
| 625 | |
| 626 | if (!command || !ftrace_enabled) |
| 627 | return; |
| 628 | |
| 629 | ftrace_run_update_code(command); |
| 630 | } |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 631 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 632 | static void ftrace_startup(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 633 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 634 | int command = 0; |
| 635 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 636 | if (unlikely(ftrace_disabled)) |
| 637 | return; |
| 638 | |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 639 | mutex_lock(&ftrace_start_lock); |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 640 | ftrace_start_up++; |
Steven Rostedt | 982c350 | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 641 | command |= FTRACE_ENABLE_CALLS; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 642 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 643 | ftrace_startup_enable(command); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 644 | |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 645 | mutex_unlock(&ftrace_start_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 646 | } |
| 647 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 648 | static void ftrace_shutdown(void) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 649 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 650 | int command = 0; |
| 651 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 652 | if (unlikely(ftrace_disabled)) |
| 653 | return; |
| 654 | |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 655 | mutex_lock(&ftrace_start_lock); |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 656 | ftrace_start_up--; |
| 657 | if (!ftrace_start_up) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 658 | command |= FTRACE_DISABLE_CALLS; |
| 659 | |
| 660 | if (saved_ftrace_func != ftrace_trace_function) { |
| 661 | saved_ftrace_func = ftrace_trace_function; |
| 662 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 663 | } |
| 664 | |
| 665 | if (!command || !ftrace_enabled) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 666 | goto out; |
| 667 | |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 668 | ftrace_run_update_code(command); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 669 | out: |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 670 | mutex_unlock(&ftrace_start_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 671 | } |
| 672 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 673 | static void ftrace_startup_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 674 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 675 | int command = FTRACE_ENABLE_MCOUNT; |
| 676 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 677 | if (unlikely(ftrace_disabled)) |
| 678 | return; |
| 679 | |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 680 | mutex_lock(&ftrace_start_lock); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 681 | /* Force update next time */ |
| 682 | saved_ftrace_func = NULL; |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 683 | /* ftrace_start_up is true if we want ftrace running */ |
| 684 | if (ftrace_start_up) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 685 | command |= FTRACE_ENABLE_CALLS; |
| 686 | |
| 687 | ftrace_run_update_code(command); |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 688 | mutex_unlock(&ftrace_start_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 689 | } |
| 690 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 691 | static void ftrace_shutdown_sysctl(void) |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 692 | { |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 693 | int command = FTRACE_DISABLE_MCOUNT; |
| 694 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 695 | if (unlikely(ftrace_disabled)) |
| 696 | return; |
| 697 | |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 698 | mutex_lock(&ftrace_start_lock); |
Steven Rostedt | 60a7ecf | 2008-11-05 16:05:44 -0500 | [diff] [blame] | 699 | /* ftrace_start_up is true if ftrace is running */ |
| 700 | if (ftrace_start_up) |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 701 | command |= FTRACE_DISABLE_CALLS; |
| 702 | |
| 703 | ftrace_run_update_code(command); |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 704 | mutex_unlock(&ftrace_start_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 705 | } |
| 706 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 707 | static cycle_t ftrace_update_time; |
| 708 | static unsigned long ftrace_update_cnt; |
| 709 | unsigned long ftrace_update_tot_cnt; |
| 710 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 711 | static int ftrace_update_code(struct module *mod) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 712 | { |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 713 | struct dyn_ftrace *p, *t; |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 714 | cycle_t start, stop; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 715 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 716 | start = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 717 | ftrace_update_cnt = 0; |
| 718 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 719 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
Abhishek Sagar | f22f9a8 | 2008-06-21 23:50:29 +0530 | [diff] [blame] | 720 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 721 | /* If something went wrong, bail without enabling anything */ |
| 722 | if (unlikely(ftrace_disabled)) |
| 723 | return -1; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 724 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 725 | list_del_init(&p->list); |
Abhishek Sagar | 0eb9670 | 2008-06-01 21:47:30 +0530 | [diff] [blame] | 726 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 727 | /* convert record (i.e, patch mcount-call with NOP) */ |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 728 | if (ftrace_code_disable(mod, p)) { |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 729 | p->flags |= FTRACE_FL_CONVERTED; |
| 730 | ftrace_update_cnt++; |
| 731 | } else |
| 732 | ftrace_free_rec(p); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 733 | } |
| 734 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 735 | stop = ftrace_now(raw_smp_processor_id()); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 736 | ftrace_update_time = stop - start; |
| 737 | ftrace_update_tot_cnt += ftrace_update_cnt; |
| 738 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 739 | return 0; |
| 740 | } |
| 741 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 742 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 743 | { |
| 744 | struct ftrace_page *pg; |
| 745 | int cnt; |
| 746 | int i; |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 747 | |
| 748 | /* allocate a few pages */ |
| 749 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); |
| 750 | if (!ftrace_pages_start) |
| 751 | return -1; |
| 752 | |
| 753 | /* |
| 754 | * Allocate a few more pages. |
| 755 | * |
| 756 | * TODO: have some parser search vmlinux before |
| 757 | * final linking to find all calls to ftrace. |
| 758 | * Then we can: |
| 759 | * a) know how many pages to allocate. |
| 760 | * and/or |
| 761 | * b) set up the table then. |
| 762 | * |
| 763 | * The dynamic code is still necessary for |
| 764 | * modules. |
| 765 | */ |
| 766 | |
| 767 | pg = ftrace_pages = ftrace_pages_start; |
| 768 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 769 | cnt = num_to_init / ENTRIES_PER_PAGE; |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 770 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 771 | num_to_init, cnt + 1); |
Steven Rostedt | 3c1720f | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 772 | |
| 773 | for (i = 0; i < cnt; i++) { |
| 774 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 775 | |
| 776 | /* If we fail, we'll try later anyway */ |
| 777 | if (!pg->next) |
| 778 | break; |
| 779 | |
| 780 | pg = pg->next; |
| 781 | } |
| 782 | |
| 783 | return 0; |
| 784 | } |
| 785 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 786 | enum { |
| 787 | FTRACE_ITER_FILTER = (1 << 0), |
| 788 | FTRACE_ITER_CONT = (1 << 1), |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 789 | FTRACE_ITER_NOTRACE = (1 << 2), |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 790 | FTRACE_ITER_FAILURES = (1 << 3), |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 791 | }; |
| 792 | |
| 793 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| 794 | |
| 795 | struct ftrace_iterator { |
| 796 | loff_t pos; |
| 797 | struct ftrace_page *pg; |
| 798 | unsigned idx; |
| 799 | unsigned flags; |
| 800 | unsigned char buffer[FTRACE_BUFF_MAX+1]; |
| 801 | unsigned buffer_idx; |
| 802 | unsigned filtered; |
| 803 | }; |
| 804 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 805 | static void * |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 806 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 807 | { |
| 808 | struct ftrace_iterator *iter = m->private; |
| 809 | struct dyn_ftrace *rec = NULL; |
| 810 | |
| 811 | (*pos)++; |
| 812 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 813 | /* should not be called from interrupt context */ |
| 814 | spin_lock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 815 | retry: |
| 816 | if (iter->idx >= iter->pg->index) { |
| 817 | if (iter->pg->next) { |
| 818 | iter->pg = iter->pg->next; |
| 819 | iter->idx = 0; |
| 820 | goto retry; |
| 821 | } |
| 822 | } else { |
| 823 | rec = &iter->pg->records[iter->idx++]; |
Steven Rostedt | a9fdda3 | 2008-08-14 22:47:17 -0400 | [diff] [blame] | 824 | if ((rec->flags & FTRACE_FL_FREE) || |
| 825 | |
| 826 | (!(iter->flags & FTRACE_ITER_FAILURES) && |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 827 | (rec->flags & FTRACE_FL_FAILED)) || |
| 828 | |
| 829 | ((iter->flags & FTRACE_ITER_FAILURES) && |
Steven Rostedt | a9fdda3 | 2008-08-14 22:47:17 -0400 | [diff] [blame] | 830 | !(rec->flags & FTRACE_FL_FAILED)) || |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 831 | |
Steven Rostedt | 0183fb1 | 2008-11-07 22:36:02 -0500 | [diff] [blame] | 832 | ((iter->flags & FTRACE_ITER_FILTER) && |
| 833 | !(rec->flags & FTRACE_FL_FILTER)) || |
| 834 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 835 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
| 836 | !(rec->flags & FTRACE_FL_NOTRACE))) { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 837 | rec = NULL; |
| 838 | goto retry; |
| 839 | } |
| 840 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 841 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 842 | |
| 843 | iter->pos = *pos; |
| 844 | |
| 845 | return rec; |
| 846 | } |
| 847 | |
| 848 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 849 | { |
| 850 | struct ftrace_iterator *iter = m->private; |
| 851 | void *p = NULL; |
| 852 | loff_t l = -1; |
| 853 | |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 854 | if (*pos > iter->pos) |
| 855 | *pos = iter->pos; |
| 856 | |
| 857 | l = *pos; |
| 858 | p = t_next(m, p, &l); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 859 | |
| 860 | return p; |
| 861 | } |
| 862 | |
| 863 | static void t_stop(struct seq_file *m, void *p) |
| 864 | { |
| 865 | } |
| 866 | |
| 867 | static int t_show(struct seq_file *m, void *v) |
| 868 | { |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 869 | struct ftrace_iterator *iter = m->private; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 870 | struct dyn_ftrace *rec = v; |
| 871 | char str[KSYM_SYMBOL_LEN]; |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 872 | int ret = 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 873 | |
| 874 | if (!rec) |
| 875 | return 0; |
| 876 | |
| 877 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 878 | |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 879 | ret = seq_printf(m, "%s\n", str); |
| 880 | if (ret < 0) { |
| 881 | iter->pos--; |
| 882 | iter->idx--; |
| 883 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 884 | |
| 885 | return 0; |
| 886 | } |
| 887 | |
| 888 | static struct seq_operations show_ftrace_seq_ops = { |
| 889 | .start = t_start, |
| 890 | .next = t_next, |
| 891 | .stop = t_stop, |
| 892 | .show = t_show, |
| 893 | }; |
| 894 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 895 | static int |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 896 | ftrace_avail_open(struct inode *inode, struct file *file) |
| 897 | { |
| 898 | struct ftrace_iterator *iter; |
| 899 | int ret; |
| 900 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 901 | if (unlikely(ftrace_disabled)) |
| 902 | return -ENODEV; |
| 903 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 904 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 905 | if (!iter) |
| 906 | return -ENOMEM; |
| 907 | |
| 908 | iter->pg = ftrace_pages_start; |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 909 | iter->pos = 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 910 | |
| 911 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 912 | if (!ret) { |
| 913 | struct seq_file *m = file->private_data; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 914 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 915 | m->private = iter; |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 916 | } else { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 917 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 918 | } |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 919 | |
| 920 | return ret; |
| 921 | } |
| 922 | |
| 923 | int ftrace_avail_release(struct inode *inode, struct file *file) |
| 924 | { |
| 925 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 926 | struct ftrace_iterator *iter = m->private; |
| 927 | |
| 928 | seq_release(inode, file); |
| 929 | kfree(iter); |
Ingo Molnar | 4bf39a9 | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 930 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 931 | return 0; |
| 932 | } |
| 933 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 934 | static int |
| 935 | ftrace_failures_open(struct inode *inode, struct file *file) |
| 936 | { |
| 937 | int ret; |
| 938 | struct seq_file *m; |
| 939 | struct ftrace_iterator *iter; |
| 940 | |
| 941 | ret = ftrace_avail_open(inode, file); |
| 942 | if (!ret) { |
| 943 | m = (struct seq_file *)file->private_data; |
| 944 | iter = (struct ftrace_iterator *)m->private; |
| 945 | iter->flags = FTRACE_ITER_FAILURES; |
| 946 | } |
| 947 | |
| 948 | return ret; |
| 949 | } |
| 950 | |
| 951 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 952 | static void ftrace_filter_reset(int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 953 | { |
| 954 | struct ftrace_page *pg; |
| 955 | struct dyn_ftrace *rec; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 956 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 957 | unsigned i; |
| 958 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 959 | /* should not be called from interrupt context */ |
| 960 | spin_lock(&ftrace_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 961 | if (enable) |
| 962 | ftrace_filtered = 0; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 963 | pg = ftrace_pages_start; |
| 964 | while (pg) { |
| 965 | for (i = 0; i < pg->index; i++) { |
| 966 | rec = &pg->records[i]; |
| 967 | if (rec->flags & FTRACE_FL_FAILED) |
| 968 | continue; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 969 | rec->flags &= ~type; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 970 | } |
| 971 | pg = pg->next; |
| 972 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 973 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 974 | } |
| 975 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 976 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 977 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 978 | { |
| 979 | struct ftrace_iterator *iter; |
| 980 | int ret = 0; |
| 981 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 982 | if (unlikely(ftrace_disabled)) |
| 983 | return -ENODEV; |
| 984 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 985 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 986 | if (!iter) |
| 987 | return -ENOMEM; |
| 988 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 989 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 990 | if ((file->f_mode & FMODE_WRITE) && |
| 991 | !(file->f_flags & O_APPEND)) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 992 | ftrace_filter_reset(enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 993 | |
| 994 | if (file->f_mode & FMODE_READ) { |
| 995 | iter->pg = ftrace_pages_start; |
walimis | 5821e1b | 2008-11-15 15:19:06 +0800 | [diff] [blame] | 996 | iter->pos = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 997 | iter->flags = enable ? FTRACE_ITER_FILTER : |
| 998 | FTRACE_ITER_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 999 | |
| 1000 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 1001 | if (!ret) { |
| 1002 | struct seq_file *m = file->private_data; |
| 1003 | m->private = iter; |
| 1004 | } else |
| 1005 | kfree(iter); |
| 1006 | } else |
| 1007 | file->private_data = iter; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1008 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1009 | |
| 1010 | return ret; |
| 1011 | } |
| 1012 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1013 | static int |
| 1014 | ftrace_filter_open(struct inode *inode, struct file *file) |
| 1015 | { |
| 1016 | return ftrace_regex_open(inode, file, 1); |
| 1017 | } |
| 1018 | |
| 1019 | static int |
| 1020 | ftrace_notrace_open(struct inode *inode, struct file *file) |
| 1021 | { |
| 1022 | return ftrace_regex_open(inode, file, 0); |
| 1023 | } |
| 1024 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1025 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1026 | ftrace_regex_read(struct file *file, char __user *ubuf, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1027 | size_t cnt, loff_t *ppos) |
| 1028 | { |
| 1029 | if (file->f_mode & FMODE_READ) |
| 1030 | return seq_read(file, ubuf, cnt, ppos); |
| 1031 | else |
| 1032 | return -EPERM; |
| 1033 | } |
| 1034 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1035 | static loff_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1036 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1037 | { |
| 1038 | loff_t ret; |
| 1039 | |
| 1040 | if (file->f_mode & FMODE_READ) |
| 1041 | ret = seq_lseek(file, offset, origin); |
| 1042 | else |
| 1043 | file->f_pos = ret = 1; |
| 1044 | |
| 1045 | return ret; |
| 1046 | } |
| 1047 | |
| 1048 | enum { |
| 1049 | MATCH_FULL, |
| 1050 | MATCH_FRONT_ONLY, |
| 1051 | MATCH_MIDDLE_ONLY, |
| 1052 | MATCH_END_ONLY, |
| 1053 | }; |
| 1054 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1055 | static void |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1056 | ftrace_match(unsigned char *buff, int len, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1057 | { |
| 1058 | char str[KSYM_SYMBOL_LEN]; |
| 1059 | char *search = NULL; |
| 1060 | struct ftrace_page *pg; |
| 1061 | struct dyn_ftrace *rec; |
| 1062 | int type = MATCH_FULL; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1063 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1064 | unsigned i, match = 0, search_len = 0; |
| 1065 | |
| 1066 | for (i = 0; i < len; i++) { |
| 1067 | if (buff[i] == '*') { |
| 1068 | if (!i) { |
| 1069 | search = buff + i + 1; |
| 1070 | type = MATCH_END_ONLY; |
| 1071 | search_len = len - (i + 1); |
| 1072 | } else { |
| 1073 | if (type == MATCH_END_ONLY) { |
| 1074 | type = MATCH_MIDDLE_ONLY; |
| 1075 | } else { |
| 1076 | match = i; |
| 1077 | type = MATCH_FRONT_ONLY; |
| 1078 | } |
| 1079 | buff[i] = 0; |
| 1080 | break; |
| 1081 | } |
| 1082 | } |
| 1083 | } |
| 1084 | |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1085 | /* should not be called from interrupt context */ |
| 1086 | spin_lock(&ftrace_lock); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1087 | if (enable) |
| 1088 | ftrace_filtered = 1; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1089 | pg = ftrace_pages_start; |
| 1090 | while (pg) { |
| 1091 | for (i = 0; i < pg->index; i++) { |
| 1092 | int matched = 0; |
| 1093 | char *ptr; |
| 1094 | |
| 1095 | rec = &pg->records[i]; |
| 1096 | if (rec->flags & FTRACE_FL_FAILED) |
| 1097 | continue; |
| 1098 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1099 | switch (type) { |
| 1100 | case MATCH_FULL: |
| 1101 | if (strcmp(str, buff) == 0) |
| 1102 | matched = 1; |
| 1103 | break; |
| 1104 | case MATCH_FRONT_ONLY: |
| 1105 | if (memcmp(str, buff, match) == 0) |
| 1106 | matched = 1; |
| 1107 | break; |
| 1108 | case MATCH_MIDDLE_ONLY: |
| 1109 | if (strstr(str, search)) |
| 1110 | matched = 1; |
| 1111 | break; |
| 1112 | case MATCH_END_ONLY: |
| 1113 | ptr = strstr(str, search); |
| 1114 | if (ptr && (ptr[search_len] == 0)) |
| 1115 | matched = 1; |
| 1116 | break; |
| 1117 | } |
| 1118 | if (matched) |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1119 | rec->flags |= flag; |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1120 | } |
| 1121 | pg = pg->next; |
| 1122 | } |
Steven Rostedt | 99ecdc4 | 2008-08-15 21:40:05 -0400 | [diff] [blame] | 1123 | spin_unlock(&ftrace_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1124 | } |
| 1125 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1126 | static ssize_t |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1127 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
| 1128 | size_t cnt, loff_t *ppos, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1129 | { |
| 1130 | struct ftrace_iterator *iter; |
| 1131 | char ch; |
| 1132 | size_t read = 0; |
| 1133 | ssize_t ret; |
| 1134 | |
| 1135 | if (!cnt || cnt < 0) |
| 1136 | return 0; |
| 1137 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1138 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1139 | |
| 1140 | if (file->f_mode & FMODE_READ) { |
| 1141 | struct seq_file *m = file->private_data; |
| 1142 | iter = m->private; |
| 1143 | } else |
| 1144 | iter = file->private_data; |
| 1145 | |
| 1146 | if (!*ppos) { |
| 1147 | iter->flags &= ~FTRACE_ITER_CONT; |
| 1148 | iter->buffer_idx = 0; |
| 1149 | } |
| 1150 | |
| 1151 | ret = get_user(ch, ubuf++); |
| 1152 | if (ret) |
| 1153 | goto out; |
| 1154 | read++; |
| 1155 | cnt--; |
| 1156 | |
| 1157 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { |
| 1158 | /* skip white space */ |
| 1159 | while (cnt && isspace(ch)) { |
| 1160 | ret = get_user(ch, ubuf++); |
| 1161 | if (ret) |
| 1162 | goto out; |
| 1163 | read++; |
| 1164 | cnt--; |
| 1165 | } |
| 1166 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1167 | if (isspace(ch)) { |
| 1168 | file->f_pos += read; |
| 1169 | ret = read; |
| 1170 | goto out; |
| 1171 | } |
| 1172 | |
| 1173 | iter->buffer_idx = 0; |
| 1174 | } |
| 1175 | |
| 1176 | while (cnt && !isspace(ch)) { |
| 1177 | if (iter->buffer_idx < FTRACE_BUFF_MAX) |
| 1178 | iter->buffer[iter->buffer_idx++] = ch; |
| 1179 | else { |
| 1180 | ret = -EINVAL; |
| 1181 | goto out; |
| 1182 | } |
| 1183 | ret = get_user(ch, ubuf++); |
| 1184 | if (ret) |
| 1185 | goto out; |
| 1186 | read++; |
| 1187 | cnt--; |
| 1188 | } |
| 1189 | |
| 1190 | if (isspace(ch)) { |
| 1191 | iter->filtered++; |
| 1192 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1193 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1194 | iter->buffer_idx = 0; |
| 1195 | } else |
| 1196 | iter->flags |= FTRACE_ITER_CONT; |
| 1197 | |
| 1198 | |
| 1199 | file->f_pos += read; |
| 1200 | |
| 1201 | ret = read; |
| 1202 | out: |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1203 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1204 | |
| 1205 | return ret; |
| 1206 | } |
| 1207 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1208 | static ssize_t |
| 1209 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
| 1210 | size_t cnt, loff_t *ppos) |
| 1211 | { |
| 1212 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
| 1213 | } |
| 1214 | |
| 1215 | static ssize_t |
| 1216 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
| 1217 | size_t cnt, loff_t *ppos) |
| 1218 | { |
| 1219 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
| 1220 | } |
| 1221 | |
| 1222 | static void |
| 1223 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) |
| 1224 | { |
| 1225 | if (unlikely(ftrace_disabled)) |
| 1226 | return; |
| 1227 | |
| 1228 | mutex_lock(&ftrace_regex_lock); |
| 1229 | if (reset) |
| 1230 | ftrace_filter_reset(enable); |
| 1231 | if (buf) |
| 1232 | ftrace_match(buf, len, enable); |
| 1233 | mutex_unlock(&ftrace_regex_lock); |
| 1234 | } |
| 1235 | |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1236 | /** |
| 1237 | * ftrace_set_filter - set a function to filter on in ftrace |
| 1238 | * @buf - the string that holds the function filter text. |
| 1239 | * @len - the length of the string. |
| 1240 | * @reset - non zero to reset all filters before applying this filter. |
| 1241 | * |
| 1242 | * Filters denote which functions should be enabled when tracing is enabled. |
| 1243 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| 1244 | */ |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1245 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1246 | { |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1247 | ftrace_set_regex(buf, len, reset, 1); |
| 1248 | } |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1249 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1250 | /** |
| 1251 | * ftrace_set_notrace - set a function to not trace in ftrace |
| 1252 | * @buf - the string that holds the function notrace text. |
| 1253 | * @len - the length of the string. |
| 1254 | * @reset - non zero to reset all filters before applying this filter. |
| 1255 | * |
| 1256 | * Notrace Filters denote which functions should not be enabled when tracing |
| 1257 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| 1258 | * for tracing. |
| 1259 | */ |
| 1260 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) |
| 1261 | { |
| 1262 | ftrace_set_regex(buf, len, reset, 0); |
Steven Rostedt | 77a2b37 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1263 | } |
| 1264 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1265 | static int |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1266 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1267 | { |
| 1268 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1269 | struct ftrace_iterator *iter; |
| 1270 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1271 | mutex_lock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1272 | if (file->f_mode & FMODE_READ) { |
| 1273 | iter = m->private; |
| 1274 | |
| 1275 | seq_release(inode, file); |
| 1276 | } else |
| 1277 | iter = file->private_data; |
| 1278 | |
| 1279 | if (iter->buffer_idx) { |
| 1280 | iter->filtered++; |
| 1281 | iter->buffer[iter->buffer_idx] = 0; |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1282 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1283 | } |
| 1284 | |
| 1285 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 1286 | mutex_lock(&ftrace_start_lock); |
Steven Rostedt | ee02a2e | 2008-11-15 16:31:41 -0500 | [diff] [blame] | 1287 | if (ftrace_start_up && ftrace_enabled) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1288 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
Steven Rostedt | cb7be3b | 2008-10-23 09:33:05 -0400 | [diff] [blame] | 1289 | mutex_unlock(&ftrace_start_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1290 | mutex_unlock(&ftrace_sysctl_lock); |
| 1291 | |
| 1292 | kfree(iter); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1293 | mutex_unlock(&ftrace_regex_lock); |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1294 | return 0; |
| 1295 | } |
| 1296 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1297 | static int |
| 1298 | ftrace_filter_release(struct inode *inode, struct file *file) |
| 1299 | { |
| 1300 | return ftrace_regex_release(inode, file, 1); |
| 1301 | } |
| 1302 | |
| 1303 | static int |
| 1304 | ftrace_notrace_release(struct inode *inode, struct file *file) |
| 1305 | { |
| 1306 | return ftrace_regex_release(inode, file, 0); |
| 1307 | } |
| 1308 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1309 | static struct file_operations ftrace_avail_fops = { |
| 1310 | .open = ftrace_avail_open, |
| 1311 | .read = seq_read, |
| 1312 | .llseek = seq_lseek, |
| 1313 | .release = ftrace_avail_release, |
| 1314 | }; |
| 1315 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1316 | static struct file_operations ftrace_failures_fops = { |
| 1317 | .open = ftrace_failures_open, |
| 1318 | .read = seq_read, |
| 1319 | .llseek = seq_lseek, |
| 1320 | .release = ftrace_avail_release, |
| 1321 | }; |
| 1322 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1323 | static struct file_operations ftrace_filter_fops = { |
| 1324 | .open = ftrace_filter_open, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1325 | .read = ftrace_regex_read, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1326 | .write = ftrace_filter_write, |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1327 | .llseek = ftrace_regex_lseek, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1328 | .release = ftrace_filter_release, |
| 1329 | }; |
| 1330 | |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1331 | static struct file_operations ftrace_notrace_fops = { |
| 1332 | .open = ftrace_notrace_open, |
| 1333 | .read = ftrace_regex_read, |
| 1334 | .write = ftrace_notrace_write, |
| 1335 | .llseek = ftrace_regex_lseek, |
| 1336 | .release = ftrace_notrace_release, |
| 1337 | }; |
| 1338 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 1339 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1340 | { |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1341 | struct dentry *entry; |
| 1342 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1343 | entry = debugfs_create_file("available_filter_functions", 0444, |
| 1344 | d_tracer, NULL, &ftrace_avail_fops); |
| 1345 | if (!entry) |
| 1346 | pr_warning("Could not create debugfs " |
| 1347 | "'available_filter_functions' entry\n"); |
| 1348 | |
Abhishek Sagar | eb9a7bf | 2008-06-01 21:47:54 +0530 | [diff] [blame] | 1349 | entry = debugfs_create_file("failures", 0444, |
| 1350 | d_tracer, NULL, &ftrace_failures_fops); |
| 1351 | if (!entry) |
| 1352 | pr_warning("Could not create debugfs 'failures' entry\n"); |
| 1353 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1354 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
| 1355 | NULL, &ftrace_filter_fops); |
| 1356 | if (!entry) |
| 1357 | pr_warning("Could not create debugfs " |
| 1358 | "'set_ftrace_filter' entry\n"); |
Steven Rostedt | 41c52c0 | 2008-05-22 11:46:33 -0400 | [diff] [blame] | 1359 | |
| 1360 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, |
| 1361 | NULL, &ftrace_notrace_fops); |
| 1362 | if (!entry) |
| 1363 | pr_warning("Could not create debugfs " |
| 1364 | "'set_ftrace_notrace' entry\n"); |
Steven Rostedt | ad90c0e | 2008-05-27 20:48:37 -0400 | [diff] [blame] | 1365 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1366 | return 0; |
| 1367 | } |
| 1368 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 1369 | static int ftrace_convert_nops(struct module *mod, |
| 1370 | unsigned long *start, |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1371 | unsigned long *end) |
| 1372 | { |
| 1373 | unsigned long *p; |
| 1374 | unsigned long addr; |
| 1375 | unsigned long flags; |
| 1376 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 1377 | mutex_lock(&ftrace_start_lock); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1378 | p = start; |
| 1379 | while (p < end) { |
| 1380 | addr = ftrace_call_adjust(*p++); |
Steven Rostedt | 20e5227 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 1381 | /* |
| 1382 | * Some architecture linkers will pad between |
| 1383 | * the different mcount_loc sections of different |
| 1384 | * object files to satisfy alignments. |
| 1385 | * Skip any NULL pointers. |
| 1386 | */ |
| 1387 | if (!addr) |
| 1388 | continue; |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1389 | ftrace_record_ip(addr); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1390 | } |
| 1391 | |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 1392 | /* disable interrupts to prevent kstop machine */ |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1393 | local_irq_save(flags); |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 1394 | ftrace_update_code(mod); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1395 | local_irq_restore(flags); |
Steven Rostedt | 08f5ac90 | 2008-10-23 09:33:07 -0400 | [diff] [blame] | 1396 | mutex_unlock(&ftrace_start_lock); |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1397 | |
| 1398 | return 0; |
| 1399 | } |
| 1400 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 1401 | void ftrace_init_module(struct module *mod, |
| 1402 | unsigned long *start, unsigned long *end) |
Steven Rostedt | 90d595f | 2008-08-14 15:45:09 -0400 | [diff] [blame] | 1403 | { |
Steven Rostedt | 00fd61a | 2008-08-15 21:40:04 -0400 | [diff] [blame] | 1404 | if (ftrace_disabled || start == end) |
Steven Rostedt | fed1939 | 2008-08-14 22:47:19 -0400 | [diff] [blame] | 1405 | return; |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 1406 | ftrace_convert_nops(mod, start, end); |
Steven Rostedt | 90d595f | 2008-08-14 15:45:09 -0400 | [diff] [blame] | 1407 | } |
| 1408 | |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1409 | extern unsigned long __start_mcount_loc[]; |
| 1410 | extern unsigned long __stop_mcount_loc[]; |
| 1411 | |
| 1412 | void __init ftrace_init(void) |
| 1413 | { |
| 1414 | unsigned long count, addr, flags; |
| 1415 | int ret; |
| 1416 | |
| 1417 | /* Keep the ftrace pointer to the stub */ |
| 1418 | addr = (unsigned long)ftrace_stub; |
| 1419 | |
| 1420 | local_irq_save(flags); |
| 1421 | ftrace_dyn_arch_init(&addr); |
| 1422 | local_irq_restore(flags); |
| 1423 | |
| 1424 | /* ftrace_dyn_arch_init places the return code in addr */ |
| 1425 | if (addr) |
| 1426 | goto failed; |
| 1427 | |
| 1428 | count = __stop_mcount_loc - __start_mcount_loc; |
| 1429 | |
| 1430 | ret = ftrace_dyn_table_alloc(count); |
| 1431 | if (ret) |
| 1432 | goto failed; |
| 1433 | |
| 1434 | last_ftrace_enabled = ftrace_enabled = 1; |
| 1435 | |
Steven Rostedt | 31e8890 | 2008-11-14 16:21:19 -0800 | [diff] [blame] | 1436 | ret = ftrace_convert_nops(NULL, |
| 1437 | __start_mcount_loc, |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1438 | __stop_mcount_loc); |
| 1439 | |
| 1440 | return; |
| 1441 | failed: |
| 1442 | ftrace_disabled = 1; |
| 1443 | } |
Steven Rostedt | 68bf21a | 2008-08-14 15:45:08 -0400 | [diff] [blame] | 1444 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1445 | #else |
Frederic Weisbecker | 0b6e4d5 | 2008-10-28 20:17:38 +0100 | [diff] [blame] | 1446 | |
| 1447 | static int __init ftrace_nodyn_init(void) |
| 1448 | { |
| 1449 | ftrace_enabled = 1; |
| 1450 | return 0; |
| 1451 | } |
| 1452 | device_initcall(ftrace_nodyn_init); |
| 1453 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 1454 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
| 1455 | static inline void ftrace_startup_enable(int command) { } |
Ingo Molnar | c7aafc5 | 2008-05-12 21:20:45 +0200 | [diff] [blame] | 1456 | # define ftrace_startup() do { } while (0) |
| 1457 | # define ftrace_shutdown() do { } while (0) |
| 1458 | # define ftrace_startup_sysctl() do { } while (0) |
| 1459 | # define ftrace_shutdown_sysctl() do { } while (0) |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1460 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 1461 | |
Steven Rostedt | df4fc31 | 2008-11-26 00:16:23 -0500 | [diff] [blame^] | 1462 | static ssize_t |
| 1463 | ftrace_pid_read(struct file *file, char __user *ubuf, |
| 1464 | size_t cnt, loff_t *ppos) |
| 1465 | { |
| 1466 | char buf[64]; |
| 1467 | int r; |
| 1468 | |
| 1469 | if (ftrace_pid_trace >= 0) |
| 1470 | r = sprintf(buf, "%u\n", ftrace_pid_trace); |
| 1471 | else |
| 1472 | r = sprintf(buf, "no pid\n"); |
| 1473 | |
| 1474 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 1475 | } |
| 1476 | |
| 1477 | static ssize_t |
| 1478 | ftrace_pid_write(struct file *filp, const char __user *ubuf, |
| 1479 | size_t cnt, loff_t *ppos) |
| 1480 | { |
| 1481 | char buf[64]; |
| 1482 | long val; |
| 1483 | int ret; |
| 1484 | |
| 1485 | if (cnt >= sizeof(buf)) |
| 1486 | return -EINVAL; |
| 1487 | |
| 1488 | if (copy_from_user(&buf, ubuf, cnt)) |
| 1489 | return -EFAULT; |
| 1490 | |
| 1491 | buf[cnt] = 0; |
| 1492 | |
| 1493 | ret = strict_strtol(buf, 10, &val); |
| 1494 | if (ret < 0) |
| 1495 | return ret; |
| 1496 | |
| 1497 | mutex_lock(&ftrace_start_lock); |
| 1498 | if (ret < 0) { |
| 1499 | /* disable pid tracing */ |
| 1500 | if (ftrace_pid_trace < 0) |
| 1501 | goto out; |
| 1502 | ftrace_pid_trace = -1; |
| 1503 | |
| 1504 | } else { |
| 1505 | |
| 1506 | if (ftrace_pid_trace == val) |
| 1507 | goto out; |
| 1508 | |
| 1509 | ftrace_pid_trace = val; |
| 1510 | } |
| 1511 | |
| 1512 | /* update the function call */ |
| 1513 | ftrace_update_pid_func(); |
| 1514 | ftrace_startup_enable(0); |
| 1515 | |
| 1516 | out: |
| 1517 | mutex_unlock(&ftrace_start_lock); |
| 1518 | |
| 1519 | return cnt; |
| 1520 | } |
| 1521 | |
| 1522 | static struct file_operations ftrace_pid_fops = { |
| 1523 | .read = ftrace_pid_read, |
| 1524 | .write = ftrace_pid_write, |
| 1525 | }; |
| 1526 | |
| 1527 | static __init int ftrace_init_debugfs(void) |
| 1528 | { |
| 1529 | struct dentry *d_tracer; |
| 1530 | struct dentry *entry; |
| 1531 | |
| 1532 | d_tracer = tracing_init_dentry(); |
| 1533 | if (!d_tracer) |
| 1534 | return 0; |
| 1535 | |
| 1536 | ftrace_init_dyn_debugfs(d_tracer); |
| 1537 | |
| 1538 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, |
| 1539 | NULL, &ftrace_pid_fops); |
| 1540 | if (!entry) |
| 1541 | pr_warning("Could not create debugfs " |
| 1542 | "'set_ftrace_pid' entry\n"); |
| 1543 | return 0; |
| 1544 | } |
| 1545 | |
| 1546 | fs_initcall(ftrace_init_debugfs); |
| 1547 | |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1548 | /** |
Steven Rostedt | 81adbdc | 2008-10-23 09:33:02 -0400 | [diff] [blame] | 1549 | * ftrace_kill - kill ftrace |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1550 | * |
| 1551 | * This function should be used by panic code. It stops ftrace |
| 1552 | * but in a not so nice way. If you need to simply kill ftrace |
| 1553 | * from a non-atomic section, use ftrace_kill. |
| 1554 | */ |
Steven Rostedt | 81adbdc | 2008-10-23 09:33:02 -0400 | [diff] [blame] | 1555 | void ftrace_kill(void) |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1556 | { |
| 1557 | ftrace_disabled = 1; |
| 1558 | ftrace_enabled = 0; |
Steven Rostedt | a2bb6a3 | 2008-07-10 20:58:15 -0400 | [diff] [blame] | 1559 | clear_ftrace_function(); |
| 1560 | } |
| 1561 | |
| 1562 | /** |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1563 | * register_ftrace_function - register a function for profiling |
| 1564 | * @ops - ops structure that holds the function for profiling. |
| 1565 | * |
| 1566 | * Register a function to be called by all functions in the |
| 1567 | * kernel. |
| 1568 | * |
| 1569 | * Note: @ops->func and all the functions it calls must be labeled |
| 1570 | * with "notrace", otherwise it will go into a |
| 1571 | * recursive loop. |
| 1572 | */ |
| 1573 | int register_ftrace_function(struct ftrace_ops *ops) |
| 1574 | { |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1575 | int ret; |
| 1576 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1577 | if (unlikely(ftrace_disabled)) |
| 1578 | return -1; |
| 1579 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1580 | mutex_lock(&ftrace_sysctl_lock); |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1581 | |
| 1582 | if (ftrace_tracing_type == FTRACE_TYPE_RETURN) { |
| 1583 | ret = -EBUSY; |
| 1584 | goto out; |
| 1585 | } |
| 1586 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1587 | ret = __register_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1588 | ftrace_startup(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1589 | |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1590 | out: |
| 1591 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1592 | return ret; |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1593 | } |
| 1594 | |
| 1595 | /** |
| 1596 | * unregister_ftrace_function - unresgister a function for profiling. |
| 1597 | * @ops - ops structure that holds the function to unregister |
| 1598 | * |
| 1599 | * Unregister a function that was added to be called by ftrace profiling. |
| 1600 | */ |
| 1601 | int unregister_ftrace_function(struct ftrace_ops *ops) |
| 1602 | { |
| 1603 | int ret; |
| 1604 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1605 | mutex_lock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1606 | ret = __unregister_ftrace_function(ops); |
Steven Rostedt | d61f82d | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1607 | ftrace_shutdown(); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1608 | mutex_unlock(&ftrace_sysctl_lock); |
| 1609 | |
| 1610 | return ret; |
| 1611 | } |
| 1612 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 1613 | int |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1614 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1615 | struct file *file, void __user *buffer, size_t *lenp, |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1616 | loff_t *ppos) |
| 1617 | { |
| 1618 | int ret; |
| 1619 | |
Steven Rostedt | 4eebcc8 | 2008-05-12 21:20:48 +0200 | [diff] [blame] | 1620 | if (unlikely(ftrace_disabled)) |
| 1621 | return -ENODEV; |
| 1622 | |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1623 | mutex_lock(&ftrace_sysctl_lock); |
| 1624 | |
Steven Rostedt | 5072c59 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1625 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
Steven Rostedt | b0fc494 | 2008-05-12 21:20:43 +0200 | [diff] [blame] | 1626 | |
| 1627 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) |
| 1628 | goto out; |
| 1629 | |
| 1630 | last_ftrace_enabled = ftrace_enabled; |
| 1631 | |
| 1632 | if (ftrace_enabled) { |
| 1633 | |
| 1634 | ftrace_startup_sysctl(); |
| 1635 | |
| 1636 | /* we are starting ftrace again */ |
| 1637 | if (ftrace_list != &ftrace_list_end) { |
| 1638 | if (ftrace_list->next == &ftrace_list_end) |
| 1639 | ftrace_trace_function = ftrace_list->func; |
| 1640 | else |
| 1641 | ftrace_trace_function = ftrace_list_func; |
| 1642 | } |
| 1643 | |
| 1644 | } else { |
| 1645 | /* stopping ftrace calls (just send to ftrace_stub) */ |
| 1646 | ftrace_trace_function = ftrace_stub; |
| 1647 | |
| 1648 | ftrace_shutdown_sysctl(); |
| 1649 | } |
| 1650 | |
| 1651 | out: |
| 1652 | mutex_unlock(&ftrace_sysctl_lock); |
Steven Rostedt | 3d08339 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1653 | return ret; |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1654 | } |
Ingo Molnar | f17845e | 2008-10-24 12:47:10 +0200 | [diff] [blame] | 1655 | |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 1656 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1657 | |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1658 | static atomic_t ftrace_graph_active; |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1659 | |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1660 | /* The callbacks that hook a function */ |
| 1661 | trace_func_graph_ret_t ftrace_graph_return = |
| 1662 | (trace_func_graph_ret_t)ftrace_stub; |
| 1663 | trace_func_graph_ent_t ftrace_graph_entry = |
| 1664 | (trace_func_graph_ent_t)ftrace_stub; |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1665 | |
| 1666 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ |
| 1667 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) |
| 1668 | { |
| 1669 | int i; |
| 1670 | int ret = 0; |
| 1671 | unsigned long flags; |
| 1672 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; |
| 1673 | struct task_struct *g, *t; |
| 1674 | |
| 1675 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { |
| 1676 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH |
| 1677 | * sizeof(struct ftrace_ret_stack), |
| 1678 | GFP_KERNEL); |
| 1679 | if (!ret_stack_list[i]) { |
| 1680 | start = 0; |
| 1681 | end = i; |
| 1682 | ret = -ENOMEM; |
| 1683 | goto free; |
| 1684 | } |
| 1685 | } |
| 1686 | |
| 1687 | read_lock_irqsave(&tasklist_lock, flags); |
| 1688 | do_each_thread(g, t) { |
| 1689 | if (start == end) { |
| 1690 | ret = -EAGAIN; |
| 1691 | goto unlock; |
| 1692 | } |
| 1693 | |
| 1694 | if (t->ret_stack == NULL) { |
| 1695 | t->ret_stack = ret_stack_list[start++]; |
| 1696 | t->curr_ret_stack = -1; |
| 1697 | atomic_set(&t->trace_overrun, 0); |
| 1698 | } |
| 1699 | } while_each_thread(g, t); |
| 1700 | |
| 1701 | unlock: |
| 1702 | read_unlock_irqrestore(&tasklist_lock, flags); |
| 1703 | free: |
| 1704 | for (i = start; i < end; i++) |
| 1705 | kfree(ret_stack_list[i]); |
| 1706 | return ret; |
| 1707 | } |
| 1708 | |
| 1709 | /* Allocate a return stack for each task */ |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 1710 | static int start_graph_tracing(void) |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1711 | { |
| 1712 | struct ftrace_ret_stack **ret_stack_list; |
| 1713 | int ret; |
| 1714 | |
| 1715 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * |
| 1716 | sizeof(struct ftrace_ret_stack *), |
| 1717 | GFP_KERNEL); |
| 1718 | |
| 1719 | if (!ret_stack_list) |
| 1720 | return -ENOMEM; |
| 1721 | |
| 1722 | do { |
| 1723 | ret = alloc_retstack_tasklist(ret_stack_list); |
| 1724 | } while (ret == -EAGAIN); |
| 1725 | |
| 1726 | kfree(ret_stack_list); |
| 1727 | return ret; |
| 1728 | } |
| 1729 | |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1730 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
| 1731 | trace_func_graph_ent_t entryfunc) |
Frederic Weisbecker | 15e6cb3 | 2008-11-11 07:14:25 +0100 | [diff] [blame] | 1732 | { |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1733 | int ret = 0; |
| 1734 | |
| 1735 | mutex_lock(&ftrace_sysctl_lock); |
| 1736 | |
| 1737 | /* |
| 1738 | * Don't launch return tracing if normal function |
| 1739 | * tracing is already running. |
| 1740 | */ |
| 1741 | if (ftrace_trace_function != ftrace_stub) { |
| 1742 | ret = -EBUSY; |
| 1743 | goto out; |
| 1744 | } |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1745 | atomic_inc(&ftrace_graph_active); |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 1746 | ret = start_graph_tracing(); |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1747 | if (ret) { |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1748 | atomic_dec(&ftrace_graph_active); |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1749 | goto out; |
| 1750 | } |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1751 | ftrace_tracing_type = FTRACE_TYPE_RETURN; |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1752 | ftrace_graph_return = retfunc; |
| 1753 | ftrace_graph_entry = entryfunc; |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1754 | ftrace_startup(); |
| 1755 | |
| 1756 | out: |
| 1757 | mutex_unlock(&ftrace_sysctl_lock); |
| 1758 | return ret; |
Frederic Weisbecker | 15e6cb3 | 2008-11-11 07:14:25 +0100 | [diff] [blame] | 1759 | } |
| 1760 | |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 1761 | void unregister_ftrace_graph(void) |
Frederic Weisbecker | 15e6cb3 | 2008-11-11 07:14:25 +0100 | [diff] [blame] | 1762 | { |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1763 | mutex_lock(&ftrace_sysctl_lock); |
| 1764 | |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1765 | atomic_dec(&ftrace_graph_active); |
| 1766 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
| 1767 | ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub; |
Frederic Weisbecker | e7d3737 | 2008-11-16 06:02:06 +0100 | [diff] [blame] | 1768 | ftrace_shutdown(); |
| 1769 | /* Restore normal tracing type */ |
| 1770 | ftrace_tracing_type = FTRACE_TYPE_ENTER; |
| 1771 | |
| 1772 | mutex_unlock(&ftrace_sysctl_lock); |
Frederic Weisbecker | 15e6cb3 | 2008-11-11 07:14:25 +0100 | [diff] [blame] | 1773 | } |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1774 | |
| 1775 | /* Allocate a return stack for newly created task */ |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 1776 | void ftrace_graph_init_task(struct task_struct *t) |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1777 | { |
Frederic Weisbecker | 287b6e6 | 2008-11-26 00:57:25 +0100 | [diff] [blame] | 1778 | if (atomic_read(&ftrace_graph_active)) { |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1779 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
| 1780 | * sizeof(struct ftrace_ret_stack), |
| 1781 | GFP_KERNEL); |
| 1782 | if (!t->ret_stack) |
| 1783 | return; |
| 1784 | t->curr_ret_stack = -1; |
| 1785 | atomic_set(&t->trace_overrun, 0); |
| 1786 | } else |
| 1787 | t->ret_stack = NULL; |
| 1788 | } |
| 1789 | |
Frederic Weisbecker | fb52607 | 2008-11-25 21:07:04 +0100 | [diff] [blame] | 1790 | void ftrace_graph_exit_task(struct task_struct *t) |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1791 | { |
Frederic Weisbecker | eae849c | 2008-11-23 17:33:12 +0100 | [diff] [blame] | 1792 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
| 1793 | |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1794 | t->ret_stack = NULL; |
Frederic Weisbecker | eae849c | 2008-11-23 17:33:12 +0100 | [diff] [blame] | 1795 | /* NULL must become visible to IRQs before we free it: */ |
| 1796 | barrier(); |
| 1797 | |
| 1798 | kfree(ret_stack); |
Frederic Weisbecker | f201ae2 | 2008-11-23 06:22:56 +0100 | [diff] [blame] | 1799 | } |
Frederic Weisbecker | 15e6cb3 | 2008-11-11 07:14:25 +0100 | [diff] [blame] | 1800 | #endif |
| 1801 | |