X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftrace%2Fftrace.c;h=aa3a92b511e252c94c4e65f87735250700f37e05;hb=27a9da6538ee18046d7bff8e36a9f783542c54c3;hp=a8fe4782ebad3098979ccf7d287be6aa90e3d2be;hpb=4ba7978e98a3ff92cebfb0f31a02c309e3ffa1fe;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a8fe478..aa3a92b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -22,12 +22,13 @@ #include #include #include -#include #include #include +#include #include #include #include +#include #include @@ -60,6 +61,13 @@ static int last_ftrace_enabled; /* Quick disabling of function tracer. */ int function_trace_stop; +/* List for set_ftrace_pid's pids. */ +LIST_HEAD(ftrace_pids); +struct ftrace_pid { + struct list_head list; + struct pid *pid; +}; + /* * ftrace_disabled is set when an anomaly is discovered. * ftrace_disabled is much stronger than ftrace_enabled. @@ -78,18 +86,22 @@ ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; +/* + * Traverse the ftrace_list, invoking all entries. The reason that we + * can use rcu_dereference_raw() is that elements removed from this list + * are simply leaked, so there is no need to interact with a grace-period + * mechanism. The rcu_dereference_raw() calls are needed to handle + * concurrent insertions into the ftrace_list. + * + * Silly Alpha and silly pointer-speculation compiler optimizations! + */ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) { - struct ftrace_ops *op = ftrace_list; - - /* in case someone actually ports this to alpha! */ - read_barrier_depends(); + struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ while (op != &ftrace_list_end) { - /* silly alpha */ - read_barrier_depends(); op->func(ip, parent_ip); - op = op->next; + op = rcu_dereference_raw(op->next); /*see above*/ }; } @@ -144,8 +156,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) * the ops->next pointer is valid before another CPU sees * the ops pointer included into the ftrace_list. */ - smp_wmb(); - ftrace_list = ops; + rcu_assign_pointer(ftrace_list, ops); if (ftrace_enabled) { ftrace_func_t func; @@ -155,7 +166,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) else func = ftrace_list_func; - if (ftrace_pid_trace) { + if (!list_empty(&ftrace_pids)) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -203,7 +214,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (ftrace_list->next == &ftrace_list_end) { ftrace_func_t func = ftrace_list->func; - if (ftrace_pid_trace) { + if (!list_empty(&ftrace_pids)) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -225,9 +236,13 @@ static void ftrace_update_pid_func(void) if (ftrace_trace_function == ftrace_stub) return; +#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST func = ftrace_trace_function; +#else + func = __ftrace_trace_function; +#endif - if (ftrace_pid_trace) { + if (!list_empty(&ftrace_pids)) { set_ftrace_pid_function(func); func = ftrace_pid_func; } else { @@ -736,7 +751,7 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&ftrace_profile_lock); - filp->f_pos += cnt; + *ppos += cnt; return cnt; } @@ -817,8 +832,6 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer) } #endif /* CONFIG_FUNCTION_PROFILER */ -/* set when tracing only a pid */ -struct pid *ftrace_pid_trace; static struct pid * const ftrace_swapper_pid = &init_struct_pid; #ifdef CONFIG_DYNAMIC_FTRACE @@ -885,36 +898,6 @@ static struct dyn_ftrace *ftrace_free_records; } \ } -#ifdef CONFIG_KPROBES - -static int frozen_record_count; - -static inline void freeze_record(struct dyn_ftrace *rec) -{ - if (!(rec->flags & FTRACE_FL_FROZEN)) { - rec->flags |= FTRACE_FL_FROZEN; - frozen_record_count++; - } -} - -static inline void unfreeze_record(struct dyn_ftrace *rec) -{ - if (rec->flags & FTRACE_FL_FROZEN) { - rec->flags &= ~FTRACE_FL_FROZEN; - frozen_record_count--; - } -} - -static inline int record_frozen(struct dyn_ftrace *rec) -{ - return rec->flags & FTRACE_FL_FROZEN; -} -#else -# define freeze_record(rec) ({ 0; }) -# define unfreeze_record(rec) ({ 0; }) -# define record_frozen(rec) ({ 0; }) -#endif /* CONFIG_KPROBES */ - static void ftrace_free_rec(struct dyn_ftrace *rec) { rec->freelist = ftrace_free_records; @@ -1012,6 +995,21 @@ static void ftrace_bug(int failed, unsigned long ip) } +/* Return 1 if the address range is reserved for ftrace */ +int ftrace_text_reserved(void *start, void *end) +{ + struct dyn_ftrace *rec; + struct ftrace_page *pg; + + do_for_each_ftrace_rec(pg, rec) { + if (rec->ip <= (unsigned long)end && + rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) + return 1; + } while_for_each_ftrace_rec(); + return 0; +} + + static int __ftrace_replace_code(struct dyn_ftrace *rec, int enable) { @@ -1063,25 +1061,12 @@ static void ftrace_replace_code(int enable) !(rec->flags & FTRACE_FL_CONVERTED)) continue; - /* ignore updates to this record's mcount site */ - if (get_kprobe((void *)rec->ip)) { - freeze_record(rec); - continue; - } else { - unfreeze_record(rec); - } - failed = __ftrace_replace_code(rec, enable); if (failed) { rec->flags |= FTRACE_FL_FAILED; - if ((system_state == SYSTEM_BOOTING) || - !core_kernel_text(rec->ip)) { - ftrace_free_rec(rec); - } else { - ftrace_bug(failed, rec->ip); - /* Stop processing */ - return; - } + ftrace_bug(failed, rec->ip); + /* Stop processing */ + return; } } while_for_each_ftrace_rec(); } @@ -1262,12 +1247,34 @@ static int ftrace_update_code(struct module *mod) ftrace_new_addrs = p->newlist; p->flags = 0L; - /* convert record (i.e, patch mcount-call with NOP) */ - if (ftrace_code_disable(mod, p)) { - p->flags |= FTRACE_FL_CONVERTED; - ftrace_update_cnt++; - } else + /* + * Do the initial record convertion from mcount jump + * to the NOP instructions. + */ + if (!ftrace_code_disable(mod, p)) { ftrace_free_rec(p); + continue; + } + + p->flags |= FTRACE_FL_CONVERTED; + ftrace_update_cnt++; + + /* + * If the tracing is enabled, go ahead and enable the record. + * + * The reason not to enable the record immediatelly is the + * inherent check of ftrace_make_nop/ftrace_make_call for + * correct previous instructions. Making first the NOP + * conversion puts the module to the correct state, thus + * passing the ftrace_make_call check. + */ + if (ftrace_start_up) { + int failed = __ftrace_replace_code(p, 1); + if (failed) { + ftrace_bug(failed, p->ip); + ftrace_free_rec(p); + } + } } stop = ftrace_now(raw_smp_processor_id()); @@ -1520,7 +1527,7 @@ static int t_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations show_ftrace_seq_ops = { +static const struct seq_operations show_ftrace_seq_ops = { .start = t_start, .next = t_next, .stop = t_stop, @@ -1621,8 +1628,10 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable) if (!ret) { struct seq_file *m = file->private_data; m->private = iter; - } else + } else { + trace_parser_put(&iter->parser); kfree(iter); + } } else file->private_data = iter; mutex_unlock(&ftrace_regex_lock); @@ -1655,64 +1664,10 @@ ftrace_regex_lseek(struct file *file, loff_t offset, int origin) return ret; } -enum { - MATCH_FULL, - MATCH_FRONT_ONLY, - MATCH_MIDDLE_ONLY, - MATCH_END_ONLY, -}; - -/* - * (static function - no need for kernel doc) - * - * Pass in a buffer containing a glob and this function will - * set search to point to the search part of the buffer and - * return the type of search it is (see enum above). - * This does modify buff. - * - * Returns enum type. - * search returns the pointer to use for comparison. - * not returns 1 if buff started with a '!' - * 0 otherwise. - */ -static int -ftrace_setup_glob(char *buff, int len, char **search, int *not) -{ - int type = MATCH_FULL; - int i; - - if (buff[0] == '!') { - *not = 1; - buff++; - len--; - } else - *not = 0; - - *search = buff; - - for (i = 0; i < len; i++) { - if (buff[i] == '*') { - if (!i) { - *search = buff + 1; - type = MATCH_END_ONLY; - } else { - if (type == MATCH_END_ONLY) - type = MATCH_MIDDLE_ONLY; - else - type = MATCH_FRONT_ONLY; - buff[i] = 0; - break; - } - } - } - - return type; -} - static int ftrace_match(char *str, char *regex, int len, int type) { int matched = 0; - char *ptr; + int slen; switch (type) { case MATCH_FULL: @@ -1728,8 +1683,8 @@ static int ftrace_match(char *str, char *regex, int len, int type) matched = 1; break; case MATCH_END_ONLY: - ptr = strstr(str, regex); - if (ptr && (ptr[len] == 0)) + slen = strlen(str); + if (slen >= len && memcmp(str + slen - len, regex, len) == 0) matched = 1; break; } @@ -1746,7 +1701,7 @@ ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) return ftrace_match(str, regex, len, type); } -static void ftrace_match_records(char *buff, int len, int enable) +static int ftrace_match_records(char *buff, int len, int enable) { unsigned int search_len; struct ftrace_page *pg; @@ -1755,9 +1710,10 @@ static void ftrace_match_records(char *buff, int len, int enable) char *search; int type; int not; + int found = 0; flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; - type = ftrace_setup_glob(buff, len, &search, ¬); + type = filter_parse_regex(buff, len, &search, ¬); search_len = strlen(search); @@ -1772,6 +1728,7 @@ static void ftrace_match_records(char *buff, int len, int enable) rec->flags &= ~flag; else rec->flags |= flag; + found = 1; } /* * Only enable filtering if we have a function that @@ -1781,6 +1738,8 @@ static void ftrace_match_records(char *buff, int len, int enable) ftrace_filtered = 1; } while_for_each_ftrace_rec(); mutex_unlock(&ftrace_lock); + + return found; } static int @@ -1802,7 +1761,7 @@ ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, return 1; } -static void ftrace_match_module_records(char *buff, char *mod, int enable) +static int ftrace_match_module_records(char *buff, char *mod, int enable) { unsigned search_len = 0; struct ftrace_page *pg; @@ -1811,6 +1770,7 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) char *search = buff; unsigned long flag; int not = 0; + int found = 0; flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; @@ -1825,7 +1785,7 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) } if (strlen(buff)) { - type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); + type = filter_parse_regex(buff, strlen(buff), &search, ¬); search_len = strlen(search); } @@ -1841,12 +1801,15 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) rec->flags &= ~flag; else rec->flags |= flag; + found = 1; } if (enable && (rec->flags & FTRACE_FL_FILTER)) ftrace_filtered = 1; } while_for_each_ftrace_rec(); mutex_unlock(&ftrace_lock); + + return found; } /* @@ -1875,8 +1838,9 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable) if (!strlen(mod)) return -EINVAL; - ftrace_match_module_records(func, mod, enable); - return 0; + if (ftrace_match_module_records(func, mod, enable)) + return 0; + return -EINVAL; } static struct ftrace_func_command ftrace_mod_cmd = { @@ -1990,7 +1954,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, int count = 0; char *search; - type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); + type = filter_parse_regex(glob, strlen(glob), &search, ¬); len = strlen(search); /* we do not support '!' for function probes */ @@ -2067,7 +2031,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, else if (glob) { int not; - type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); + type = filter_parse_regex(glob, strlen(glob), &search, ¬); len = strlen(search); /* we do not support '!' for function probes */ @@ -2173,8 +2137,9 @@ static int ftrace_process_regex(char *buff, int len, int enable) func = strsep(&next, ":"); if (!next) { - ftrace_match_records(func, len, enable); - return 0; + if (ftrace_match_records(func, len, enable)) + return 0; + return ret; } /* command found */ @@ -2220,16 +2185,15 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, !trace_parser_cont(parser)) { ret = ftrace_process_regex(parser->buffer, parser->idx, enable); - if (ret) - goto out; - trace_parser_clear(parser); + if (ret) + goto out_unlock; } ret = read; - +out_unlock: mutex_unlock(&ftrace_regex_lock); -out: + return ret; } @@ -2311,6 +2275,34 @@ static int __init set_ftrace_filter(char *str) } __setup("ftrace_filter=", set_ftrace_filter); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; +static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); + +static int __init set_graph_function(char *str) +{ + strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); + return 1; +} +__setup("ftrace_graph_filter=", set_graph_function); + +static void __init set_ftrace_early_graph(char *buf) +{ + int ret; + char *func; + + while (buf) { + func = strsep(&buf, ","); + /* we allow only one expression at a time */ + ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, + func); + if (ret) + printk(KERN_DEBUG "ftrace: function %s not " + "traceable\n", func); + } +} +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + static void __init set_ftrace_early_filter(char *buf, int enable) { char *func; @@ -2327,6 +2319,10 @@ static void __init set_ftrace_early_filters(void) set_ftrace_early_filter(ftrace_filter_buf, 1); if (ftrace_notrace_buf[0]) set_ftrace_early_filter(ftrace_notrace_buf, 0); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + if (ftrace_graph_buf[0]) + set_ftrace_early_graph(ftrace_graph_buf); +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ } static int @@ -2409,6 +2405,7 @@ static const struct file_operations ftrace_notrace_fops = { static DEFINE_MUTEX(graph_lock); int ftrace_graph_count; +int ftrace_graph_filter_enabled; unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; static void * @@ -2431,7 +2428,7 @@ static void *g_start(struct seq_file *m, loff_t *pos) mutex_lock(&graph_lock); /* Nothing, tell g_show to print all functions are enabled */ - if (!ftrace_graph_count && !*pos) + if (!ftrace_graph_filter_enabled && !*pos) return (void *)1; return __g_next(m, pos); @@ -2459,7 +2456,7 @@ static int g_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations ftrace_graph_seq_ops = { +static const struct seq_operations ftrace_graph_seq_ops = { .start = g_start, .next = g_next, .stop = g_stop, @@ -2477,6 +2474,7 @@ ftrace_graph_open(struct inode *inode, struct file *file) mutex_lock(&graph_lock); if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { + ftrace_graph_filter_enabled = 0; ftrace_graph_count = 0; memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); } @@ -2502,7 +2500,7 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) struct dyn_ftrace *rec; struct ftrace_page *pg; int search_len; - int found = 0; + int fail = 1; int type, not; char *search; bool exists; @@ -2512,39 +2510,52 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) return -ENODEV; /* decode regex */ - type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); - if (not) - return -EINVAL; + type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); + if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) + return -EBUSY; search_len = strlen(search); mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { - if (*idx >= FTRACE_GRAPH_MAX_FUNCS) - break; - if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) continue; if (ftrace_match_record(rec, search, search_len, type)) { - /* ensure it is not already in the array */ + /* if it is in the array */ exists = false; - for (i = 0; i < *idx; i++) + for (i = 0; i < *idx; i++) { if (array[i] == rec->ip) { exists = true; break; } - if (!exists) { - array[(*idx)++] = rec->ip; - found = 1; + } + + if (!not) { + fail = 0; + if (!exists) { + array[(*idx)++] = rec->ip; + if (*idx >= FTRACE_GRAPH_MAX_FUNCS) + goto out; + } + } else { + if (exists) { + array[i] = array[--(*idx)]; + array[*idx] = 0; + fail = 0; + } } } } while_for_each_ftrace_rec(); - +out: mutex_unlock(&ftrace_lock); - return found ? 0 : -EINVAL; + if (fail) + return -EINVAL; + + ftrace_graph_filter_enabled = 1; + return 0; } static ssize_t @@ -2554,19 +2565,14 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, struct trace_parser parser; ssize_t read, ret; - if (!cnt || cnt < 0) + if (!cnt) return 0; mutex_lock(&graph_lock); - if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { - ret = -EBUSY; - goto out; - } - if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { ret = -ENOMEM; - goto out; + goto out_unlock; } read = trace_get_user(&parser, ubuf, cnt, ppos); @@ -2578,12 +2584,14 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, parser.buffer); if (ret) - goto out; + goto out_free; } ret = read; - out: + +out_free: trace_parser_put(&parser); +out_unlock: mutex_unlock(&graph_lock); return ret; @@ -2621,7 +2629,7 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) return 0; } -static int ftrace_convert_nops(struct module *mod, +static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end) { @@ -2654,19 +2662,17 @@ static int ftrace_convert_nops(struct module *mod, } #ifdef CONFIG_MODULES -void ftrace_release(void *start, void *end) +void ftrace_release_mod(struct module *mod) { struct dyn_ftrace *rec; struct ftrace_page *pg; - unsigned long s = (unsigned long)start; - unsigned long e = (unsigned long)end; - if (ftrace_disabled || !start || start == end) + if (ftrace_disabled) return; mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { - if ((rec->ip >= s) && (rec->ip < e)) { + if (within_module_core(rec->ip, mod)) { /* * rec->ip is changed in ftrace_free_rec() * It should not between s and e if record was freed. @@ -2683,7 +2689,7 @@ static void ftrace_init_module(struct module *mod, { if (ftrace_disabled || start == end) return; - ftrace_convert_nops(mod, start, end); + ftrace_process_locs(mod, start, end); } static int ftrace_module_notify(struct notifier_block *self, @@ -2698,9 +2704,7 @@ static int ftrace_module_notify(struct notifier_block *self, mod->num_ftrace_callsites); break; case MODULE_STATE_GOING: - ftrace_release(mod->ftrace_callsites, - mod->ftrace_callsites + - mod->num_ftrace_callsites); + ftrace_release_mod(mod); break; } @@ -2746,7 +2750,7 @@ void __init ftrace_init(void) last_ftrace_enabled = ftrace_enabled = 1; - ret = ftrace_convert_nops(NULL, + ret = ftrace_process_locs(NULL, __start_mcount_loc, __stop_mcount_loc); @@ -2779,23 +2783,6 @@ static inline void ftrace_startup_enable(int command) { } # define ftrace_shutdown_sysctl() do { } while (0) #endif /* CONFIG_DYNAMIC_FTRACE */ -static ssize_t -ftrace_pid_read(struct file *file, char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - char buf[64]; - int r; - - if (ftrace_pid_trace == ftrace_swapper_pid) - r = sprintf(buf, "swapper tasks\n"); - else if (ftrace_pid_trace) - r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); - else - r = sprintf(buf, "no pid\n"); - - return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); -} - static void clear_ftrace_swapper(void) { struct task_struct *p; @@ -2846,14 +2833,12 @@ static void set_ftrace_pid(struct pid *pid) rcu_read_unlock(); } -static void clear_ftrace_pid_task(struct pid **pid) +static void clear_ftrace_pid_task(struct pid *pid) { - if (*pid == ftrace_swapper_pid) + if (pid == ftrace_swapper_pid) clear_ftrace_swapper(); else - clear_ftrace_pid(*pid); - - *pid = NULL; + clear_ftrace_pid(pid); } static void set_ftrace_pid_task(struct pid *pid) @@ -2864,74 +2849,184 @@ static void set_ftrace_pid_task(struct pid *pid) set_ftrace_pid(pid); } -static ssize_t -ftrace_pid_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) +static int ftrace_pid_add(int p) { struct pid *pid; - char buf[64]; - long val; - int ret; + struct ftrace_pid *fpid; + int ret = -EINVAL; - if (cnt >= sizeof(buf)) - return -EINVAL; + mutex_lock(&ftrace_lock); - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; + if (!p) + pid = ftrace_swapper_pid; + else + pid = find_get_pid(p); - buf[cnt] = 0; + if (!pid) + goto out; - ret = strict_strtol(buf, 10, &val); - if (ret < 0) - return ret; + ret = 0; - mutex_lock(&ftrace_lock); - if (val < 0) { - /* disable pid tracing */ - if (!ftrace_pid_trace) - goto out; + list_for_each_entry(fpid, &ftrace_pids, list) + if (fpid->pid == pid) + goto out_put; - clear_ftrace_pid_task(&ftrace_pid_trace); + ret = -ENOMEM; - } else { - /* swapper task is special */ - if (!val) { - pid = ftrace_swapper_pid; - if (pid == ftrace_pid_trace) - goto out; - } else { - pid = find_get_pid(val); + fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); + if (!fpid) + goto out_put; - if (pid == ftrace_pid_trace) { - put_pid(pid); - goto out; - } - } + list_add(&fpid->list, &ftrace_pids); + fpid->pid = pid; - if (ftrace_pid_trace) - clear_ftrace_pid_task(&ftrace_pid_trace); + set_ftrace_pid_task(pid); - if (!pid) - goto out; + ftrace_update_pid_func(); + ftrace_startup_enable(0); + + mutex_unlock(&ftrace_lock); + return 0; - ftrace_pid_trace = pid; +out_put: + if (pid != ftrace_swapper_pid) + put_pid(pid); - set_ftrace_pid_task(ftrace_pid_trace); +out: + mutex_unlock(&ftrace_lock); + return ret; +} + +static void ftrace_pid_reset(void) +{ + struct ftrace_pid *fpid, *safe; + + mutex_lock(&ftrace_lock); + list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { + struct pid *pid = fpid->pid; + + clear_ftrace_pid_task(pid); + + list_del(&fpid->list); + kfree(fpid); } - /* update the function call */ ftrace_update_pid_func(); ftrace_startup_enable(0); - out: mutex_unlock(&ftrace_lock); +} - return cnt; +static void *fpid_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&ftrace_lock); + + if (list_empty(&ftrace_pids) && (!*pos)) + return (void *) 1; + + return seq_list_start(&ftrace_pids, *pos); +} + +static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) +{ + if (v == (void *)1) + return NULL; + + return seq_list_next(v, &ftrace_pids, pos); +} + +static void fpid_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&ftrace_lock); +} + +static int fpid_show(struct seq_file *m, void *v) +{ + const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); + + if (v == (void *)1) { + seq_printf(m, "no pid\n"); + return 0; + } + + if (fpid->pid == ftrace_swapper_pid) + seq_printf(m, "swapper tasks\n"); + else + seq_printf(m, "%u\n", pid_vnr(fpid->pid)); + + return 0; +} + +static const struct seq_operations ftrace_pid_sops = { + .start = fpid_start, + .next = fpid_next, + .stop = fpid_stop, + .show = fpid_show, +}; + +static int +ftrace_pid_open(struct inode *inode, struct file *file) +{ + int ret = 0; + + if ((file->f_mode & FMODE_WRITE) && + (file->f_flags & O_TRUNC)) + ftrace_pid_reset(); + + if (file->f_mode & FMODE_READ) + ret = seq_open(file, &ftrace_pid_sops); + + return ret; +} + +static ssize_t +ftrace_pid_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[64], *tmp; + long val; + int ret; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + /* + * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" + * to clean the filter quietly. + */ + tmp = strstrip(buf); + if (strlen(tmp) == 0) + return 1; + + ret = strict_strtol(tmp, 10, &val); + if (ret < 0) + return ret; + + ret = ftrace_pid_add(val); + + return ret ? ret : cnt; +} + +static int +ftrace_pid_release(struct inode *inode, struct file *file) +{ + if (file->f_mode & FMODE_READ) + seq_release(inode, file); + + return 0; } static const struct file_operations ftrace_pid_fops = { - .read = ftrace_pid_read, - .write = ftrace_pid_write, + .open = ftrace_pid_open, + .write = ftrace_pid_write, + .read = seq_read, + .llseek = seq_lseek, + .release = ftrace_pid_release, }; static __init int ftrace_init_debugfs(void) @@ -3014,7 +3109,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops) int ftrace_enable_sysctl(struct ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *lenp, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; @@ -3024,7 +3119,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_lock(&ftrace_lock); - ret = proc_dointvec(table, write, file, buffer, lenp, ppos); + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) goto out; @@ -3117,8 +3212,7 @@ free: } static void -ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, - struct task_struct *next) +ftrace_graph_probe_sched_switch(struct task_struct *prev, struct task_struct *next) { unsigned long long timestamp; int index; @@ -3259,6 +3353,7 @@ void ftrace_graph_init_task(struct task_struct *t) { /* Make sure we do not use the parent ret_stack */ t->ret_stack = NULL; + t->curr_ret_stack = -1; if (ftrace_graph_active) { struct ftrace_ret_stack *ret_stack; @@ -3268,7 +3363,6 @@ void ftrace_graph_init_task(struct task_struct *t) GFP_KERNEL); if (!ret_stack) return; - t->curr_ret_stack = -1; atomic_set(&t->tracing_graph_pause, 0); atomic_set(&t->trace_overrun, 0); t->ftrace_timestamp = 0; @@ -3294,4 +3388,3 @@ void ftrace_graph_stop(void) ftrace_stop(); } #endif -