diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 715 | ||||
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 283 | ||||
| -rw-r--r-- | kernel/trace/trace_stack.c | 30 |
3 files changed, 683 insertions, 345 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b1e8943fed1..683d559a0ee 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -22,11 +22,13 @@ #include <linux/hardirq.h> #include <linux/kthread.h> #include <linux/uaccess.h> +#include <linux/bsearch.h> #include <linux/module.h> #include <linux/ftrace.h> #include <linux/sysctl.h> #include <linux/slab.h> #include <linux/ctype.h> +#include <linux/sort.h> #include <linux/list.h> #include <linux/hash.h> #include <linux/rcupdate.h> @@ -947,13 +949,6 @@ struct ftrace_func_probe { struct rcu_head rcu; }; -enum { - FTRACE_ENABLE_CALLS = (1 << 0), - FTRACE_DISABLE_CALLS = (1 << 1), - FTRACE_UPDATE_TRACE_FUNC = (1 << 2), - FTRACE_START_FUNC_RET = (1 << 3), - FTRACE_STOP_FUNC_RET = (1 << 4), -}; struct ftrace_func_entry { struct hlist_node hlist; unsigned long ip; @@ -984,18 +979,19 @@ static struct ftrace_ops global_ops = { .filter_hash = EMPTY_HASH, }; -static struct dyn_ftrace *ftrace_new_addrs; - static DEFINE_MUTEX(ftrace_regex_lock); struct ftrace_page { struct ftrace_page *next; + struct dyn_ftrace *records; int index; - struct dyn_ftrace records[]; + int size; }; -#define ENTRIES_PER_PAGE \ - ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) +static struct ftrace_page *ftrace_new_pgs; + +#define ENTRY_SIZE sizeof(struct dyn_ftrace) +#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) /* estimate from running different kernels */ #define NR_TO_INIT 10000 @@ -1003,7 +999,10 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static struct dyn_ftrace *ftrace_free_records; +static bool ftrace_hash_empty(struct ftrace_hash *hash) +{ + return !hash || !hash->count; +} static struct ftrace_func_entry * ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) @@ -1013,7 +1012,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) struct hlist_head *hhd; struct hlist_node *n; - if (!hash->count) + if (ftrace_hash_empty(hash)) return NULL; if (hash->size_bits > 0) @@ -1157,7 +1156,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) return NULL; /* Empty hash? */ - if (!hash || !hash->count) + if (ftrace_hash_empty(hash)) return new_hash; size = 1 << hash->size_bits; @@ -1282,9 +1281,9 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) filter_hash = rcu_dereference_raw(ops->filter_hash); notrace_hash = rcu_dereference_raw(ops->notrace_hash); - if ((!filter_hash || !filter_hash->count || + if ((ftrace_hash_empty(filter_hash) || ftrace_lookup_ip(filter_hash, ip)) && - (!notrace_hash || !notrace_hash->count || + (ftrace_hash_empty(notrace_hash) || !ftrace_lookup_ip(notrace_hash, ip))) ret = 1; else @@ -1307,6 +1306,47 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) } \ } + +static int ftrace_cmp_recs(const void *a, const void *b) +{ + const struct dyn_ftrace *reca = a; + const struct dyn_ftrace *recb = b; + + if (reca->ip > recb->ip) + return 1; + if (reca->ip < recb->ip) + return -1; + return 0; +} + +/** + * ftrace_location - return true if the ip giving is a traced location + * @ip: the instruction pointer to check + * + * Returns 1 if @ip given is a pointer to a ftrace location. + * That is, the instruction that is either a NOP or call to + * the function tracer. It checks the ftrace internal tables to + * determine if the address belongs or not. + */ +int ftrace_location(unsigned long ip) +{ + struct ftrace_page *pg; + struct dyn_ftrace *rec; + struct dyn_ftrace key; + + key.ip = ip; + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + rec = bsearch(&key, pg->records, pg->index, + sizeof(struct dyn_ftrace), + ftrace_cmp_recs); + if (rec) + return 1; + } + + return 0; +} + static void __ftrace_hash_rec_update(struct ftrace_ops *ops, int filter_hash, bool inc) @@ -1336,7 +1376,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, if (filter_hash) { hash = ops->filter_hash; other_hash = ops->notrace_hash; - if (!hash || !hash->count) + if (ftrace_hash_empty(hash)) all = 1; } else { inc = !inc; @@ -1346,7 +1386,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, * If the notrace hash has no items, * then there's nothing to do. */ - if (hash && !hash->count) + if (ftrace_hash_empty(hash)) return; } @@ -1363,8 +1403,8 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) match = 1; } else { - in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip); - in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip); + in_hash = !!ftrace_lookup_ip(hash, rec->ip); + in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); /* * @@ -1372,7 +1412,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, if (filter_hash && in_hash && !in_other_hash) match = 1; else if (!filter_hash && in_hash && - (in_other_hash || !other_hash->count)) + (in_other_hash || ftrace_hash_empty(other_hash))) match = 1; } if (!match) @@ -1406,40 +1446,12 @@ static void ftrace_hash_rec_enable(struct ftrace_ops *ops, __ftrace_hash_rec_update(ops, filter_hash, 1); } -static void ftrace_free_rec(struct dyn_ftrace *rec) -{ - rec->freelist = ftrace_free_records; - ftrace_free_records = rec; - rec->flags |= FTRACE_FL_FREE; -} - static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) { - struct dyn_ftrace *rec; - - /* First check for freed records */ - if (ftrace_free_records) { - rec = ftrace_free_records; - - if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { - FTRACE_WARN_ON_ONCE(1); - ftrace_free_records = NULL; + if (ftrace_pages->index == ftrace_pages->size) { + /* We should have allocated enough */ + if (WARN_ON(!ftrace_pages->next)) return NULL; - } - - ftrace_free_records = rec->freelist; - memset(rec, 0, sizeof(*rec)); - return rec; - } - - if (ftrace_pages->index == ENTRIES_PER_PAGE) { - if (!ftrace_pages->next) { - /* allocate another page */ - ftrace_pages->next = - (void *)get_zeroed_page(GFP_KERNEL); - if (!ftrace_pages->next) - return NULL; - } ftrace_pages = ftrace_pages->next; } @@ -1459,8 +1471,6 @@ ftrace_record_ip(unsigned long ip) return NULL; rec->ip = ip; - rec->newlist = ftrace_new_addrs; - ftrace_new_addrs = rec; return rec; } @@ -1475,7 +1485,19 @@ static void print_ip_ins(const char *fmt, unsigned char *p) printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); } -static void ftrace_bug(int failed, unsigned long ip) +/** + * ftrace_bug - report and shutdown function tracer + * @failed: The failed type (EFAULT, EINVAL, EPERM) + * @ip: The address that failed + * + * The arch code that enables or disables the function tracing + * can call ftrace_bug() when it has detected a problem in + * modifying the code. @failed should be one of either: + * EFAULT - if the problem happens on reading the @ip address + * EINVAL - if what is read at @ip is not what was expected + * EPERM - if the problem happens on writting to the @ip address + */ +void ftrace_bug(int failed, unsigned long ip) { switch (failed) { case -EFAULT: @@ -1517,24 +1539,19 @@ int ftrace_text_reserved(void *start, void *end) return 0; } - -static int -__ftrace_replace_code(struct dyn_ftrace *rec, int enable) +static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) { - unsigned long ftrace_addr; unsigned long flag = 0UL; - ftrace_addr = (unsigned long)FTRACE_ADDR; - /* - * If we are enabling tracing: + * If we are updating calls: * * If the record has a ref count, then we need to enable it * because someone is using it. * * Otherwise we make sure its disabled. * - * If we are disabling tracing, then disable all records that + * If we are disabling calls, then disable all records that * are enabled. */ if (enable && (rec->flags & ~FTRACE_FL_MASK)) @@ -1542,18 +1559,72 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) /* If the state of this record hasn't changed, then do nothing */ if ((rec->flags & FTRACE_FL_ENABLED) == flag) - return 0; + return FTRACE_UPDATE_IGNORE; if (flag) { - rec->flags |= FTRACE_FL_ENABLED; + if (update) + rec->flags |= FTRACE_FL_ENABLED; + return FTRACE_UPDATE_MAKE_CALL; + } + + if (update) + rec->flags &= ~FTRACE_FL_ENABLED; + + return FTRACE_UPDATE_MAKE_NOP; +} + +/** + * ftrace_update_record, set a record that now is tracing or not + * @rec: the record to update + * @enable: set to 1 if the record is tracing, zero to force disable + * + * The records that represent all functions that can be traced need + * to be updated when tracing has been enabled. + */ +int ftrace_update_record(struct dyn_ftrace *rec, int enable) +{ + return ftrace_check_record(rec, enable, 1); +} + +/** + * ftrace_test_record, check if the record has been enabled or not + * @rec: the record to test + * @enable: set to 1 to check if enabled, 0 if it is disabled + * + * The arch code may need to test if a record is already set to + * tracing to determine how to modify the function code that it + * represents. + */ +int ftrace_test_record(struct dyn_ftrace *rec, int enable) +{ + return ftrace_check_record(rec, enable, 0); +} + +static int +__ftrace_replace_code(struct dyn_ftrace *rec, int enable) +{ + unsigned long ftrace_addr; + int ret; + + ftrace_addr = (unsigned long)FTRACE_ADDR; + + ret = ftrace_update_record(rec, enable); + + switch (ret) { + case FTRACE_UPDATE_IGNORE: + return 0; + + case FTRACE_UPDATE_MAKE_CALL: return ftrace_make_call(rec, ftrace_addr); + + case FTRACE_UPDATE_MAKE_NOP: + return ftrace_make_nop(NULL, rec, ftrace_addr); } - rec->flags &= ~FTRACE_FL_ENABLED; - return ftrace_make_nop(NULL, rec, ftrace_addr); + return -1; /* unknow ftrace bug */ } -static void ftrace_replace_code(int enable) +static void ftrace_replace_code(int update) { struct dyn_ftrace *rec; struct ftrace_page *pg; @@ -1563,11 +1634,7 @@ static void ftrace_replace_code(int enable) return; do_for_each_ftrace_rec(pg, rec) { - /* Skip over free records */ - if (rec->flags & FTRACE_FL_FREE) - continue; - - failed = __ftrace_replace_code(rec, enable); + failed = __ftrace_replace_code(rec, update); if (failed) { ftrace_bug(failed, rec->ip); /* Stop processing */ @@ -1576,6 +1643,78 @@ static void ftrace_replace_code(int enable) } while_for_each_ftrace_rec(); } +struct ftrace_rec_iter { + struct ftrace_page *pg; + int index; +}; + +/** + * ftrace_rec_iter_start, start up iterating over traced functions + * + * Returns an iterator handle that is used to iterate over all + * the records that represent address locations where functions + * are traced. + * + * May return NULL if no records are available. + */ +struct ftrace_rec_iter *ftrace_rec_iter_start(void) +{ + /* + * We only use a single iterator. + * Protected by the ftrace_lock mutex. + */ + static struct ftrace_rec_iter ftrace_rec_iter; + struct ftrace_rec_iter *iter = &ftrace_rec_iter; + + iter->pg = ftrace_pages_start; + iter->index = 0; + + /* Could have empty pages */ + while (iter->pg && !iter->pg->index) + iter->pg = iter->pg->next; + + if (!iter->pg) + return NULL; + + return iter; +} + +/** + * ftrace_rec_iter_next, get the next record to process. + * @iter: The handle to the iterator. + * + * Returns the next iterator after the given iterator @iter. + */ +struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) +{ + iter->index++; + + if (iter->index >= iter->pg->index) { + iter->pg = iter->pg->next; + iter->index = 0; + + /* Could have empty pages */ + while (iter->pg && !iter->pg->index) + iter->pg = iter->pg->next; + } + + if (!iter->pg) + return NULL; + + return iter; +} + +/** + * ftrace_rec_iter_record, get the record at the iterator location + * @iter: The current iterator location + * + * Returns the record that the current @iter is at. + */ +struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) +{ + return &iter->pg->records[iter->index]; +} + static int ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) { @@ -1617,13 +1756,7 @@ static int __ftrace_modify_code(void *data) { int *command = data; - /* - * Do not call function tracer while we update the code. - * We are in stop machine, no worrying about races. - */ - function_trace_stop++; - - if (*command & FTRACE_ENABLE_CALLS) + if (*command & FTRACE_UPDATE_CALLS) ftrace_replace_code(1); else if (*command & FTRACE_DISABLE_CALLS) ftrace_replace_code(0); @@ -1636,21 +1769,33 @@ static int __ftrace_modify_code(void *data) else if (*command & FTRACE_STOP_FUNC_RET) ftrace_disable_ftrace_graph_caller(); -#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST - /* - * For archs that call ftrace_test_stop_func(), we must - * wait till after we update all the function callers - * before we update the callback. This keeps different - * ops that record different functions from corrupting - * each other. - */ - __ftrace_trace_function = __ftrace_trace_function_delay; -#endif - function_trace_stop--; - return 0; } +/** + * ftrace_run_stop_machine, go back to the stop machine method + * @command: The command to tell ftrace what to do + * + * If an arch needs to fall back to the stop machine method, the + * it can call this function. + */ +void ftrace_run_stop_machine(int command) +{ + stop_machine(__ftrace_modify_code, &command, NULL); +} + +/** + * arch_ftrace_update_code, modify the code to trace or not trace + * @command: The command that needs to be done + * + * Archs can override this function if it does not need to + * run stop_machine() to modify code. + */ +void __weak arch_ftrace_update_code(int command) +{ + ftrace_run_stop_machine(command); +} + static void ftrace_run_update_code(int command) { int ret; @@ -1659,8 +1804,31 @@ static void ftrace_run_update_code(int command) FTRACE_WARN_ON(ret); if (ret) return; + /* + * Do not call function tracer while we update the code. + * We are in stop machine. + */ + function_trace_stop++; - stop_machine(__ftrace_modify_code, &command, NULL); + /* + * By default we use stop_machine() to modify the code. + * But archs can do what ever they want as long as it + * is safe. The stop_machine() is the safest, but also + * produces the most overhead. + */ + arch_ftrace_update_code(command); + +#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST + /* + * For archs that call ftrace_test_stop_func(), we must + * wait till after we update all the function callers + * before we update the callback. This keeps different + * ops that record different functions from corrupting + * each other. + */ + __ftrace_trace_function = __ftrace_trace_function_delay; +#endif + function_trace_stop--; ret = ftrace_arch_code_modify_post_process(); FTRACE_WARN_ON(ret); @@ -1691,7 +1859,7 @@ static int ftrace_startup(struct ftrace_ops *ops, int command) return -ENODEV; ftrace_start_up++; - command |= FTRACE_ENABLE_CALLS; + command |= FTRACE_UPDATE_CALLS; /* ops marked global share the filter hashes */ if (ops->flags & FTRACE_OPS_FL_GLOBAL) { @@ -1743,8 +1911,7 @@ static void ftrace_shutdown(struct ftrace_ops *ops, int command) if (ops != &global_ops || !global_start_up) ops->flags &= ~FTRACE_OPS_FL_ENABLED; - if (!ftrace_start_up) - command |= FTRACE_DISABLE_CALLS; + command |= FTRACE_UPDATE_CALLS; if (saved_ftrace_func != ftrace_trace_function) { saved_ftrace_func = ftrace_trace_function; @@ -1766,7 +1933,7 @@ static void ftrace_startup_sysctl(void) saved_ftrace_func = NULL; /* ftrace_start_up is true if we want ftrace running */ if (ftrace_start_up) - ftrace_run_update_code(FTRACE_ENABLE_CALLS); + ftrace_run_update_code(FTRACE_UPDATE_CALLS); } static void ftrace_shutdown_sysctl(void) @@ -1788,14 +1955,16 @@ static int ops_traces_mod(struct ftrace_ops *ops) struct ftrace_hash *hash; hash = ops->filter_hash; - return !!(!hash || !hash->count); + return ftrace_hash_empty(hash); } static int ftrace_update_code(struct module *mod) { + struct ftrace_page *pg; struct dyn_ftrace *p; cycle_t start, stop; unsigned long ref = 0; + int i; /* * When adding a module, we need to check if tracers are @@ -1817,46 +1986,44 @@ static int ftrace_update_code(struct module *mod) start = ftrace_now(raw_smp_processor_id()); ftrace_update_cnt = 0; - while (ftrace_new_addrs) { + for (pg = ftrace_new_pgs; pg; pg = pg->next) { - /* If something went wrong, bail without enabling anything */ - if (unlikely(ftrace_disabled)) - return -1; + for (i = 0; i < pg->index; i++) { + /* If something went wrong, bail without enabling anything */ + if (unlikely(ftrace_disabled)) + return -1; - p = ftrace_new_addrs; - ftrace_new_addrs = p->newlist; - p->flags = ref; + p = &pg->records[i]; + p->flags = ref; - /* - * Do the initial record conversion from mcount jump - * to the NOP instructions. - */ - if (!ftrace_code_disable(mod, p)) { - ftrace_free_rec(p); - /* Game over */ - break; - } + /* + * Do the initial record conversion from mcount jump + * to the NOP instructions. + */ + if (!ftrace_code_disable(mod, p)) + break; - ftrace_update_cnt++; + 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 && ref) { - int failed = __ftrace_replace_code(p, 1); - if (failed) { - ftrace_bug(failed, p->ip); - ftrace_free_rec(p); + /* + * 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 && ref) { + int failed = __ftrace_replace_code(p, 1); + if (failed) + ftrace_bug(failed, p->ip); } } } + ftrace_new_pgs = NULL; + stop = ftrace_now(raw_smp_processor_id()); ftrace_update_time = stop - start; ftrace_update_tot_cnt += ftrace_update_cnt; @@ -1864,57 +2031,108 @@ static int ftrace_update_code(struct module *mod) return 0; } -static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) +static int ftrace_allocate_records(struct ftrace_page *pg, int count) { - struct ftrace_page *pg; + int order; int cnt; - int i; - /* allocate a few pages */ - ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); - if (!ftrace_pages_start) - return -1; + if (WARN_ON(!count)) + return -EINVAL; + + order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); /* - * Allocate a few more pages. - * - * TODO: have some parser search vmlinux before - * final linking to find all calls to ftrace. - * Then we can: - * a) know how many pages to allocate. - * and/or - * b) set up the table then. - * - * The dynamic code is still necessary for - * modules. + * We want to fill as much as possible. No more than a page + * may be empty. */ + while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) + order--; - pg = ftrace_pages = ftrace_pages_start; + again: + pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); - cnt = num_to_init / ENTRIES_PER_PAGE; - pr_info("ftrace: allocating %ld entries in %d pages\n", - num_to_init, cnt + 1); + if (!pg->records) { + /* if we can't allocate this size, try something smaller */ + if (!order) + return -ENOMEM; + order >>= 1; + goto again; + } - for (i = 0; i < cnt; i++) { - pg->next = (void *)get_zeroed_page(GFP_KERNEL); + cnt = (PAGE_SIZE << order) / ENTRY_SIZE; + pg->size = cnt; - /* If we fail, we'll try later anyway */ - if (!pg->next) + if (cnt > count) + cnt = count; + + return cnt; +} + +static struct ftrace_page * +ftrace_allocate_pages(unsigned long num_to_init) +{ + struct ftrace_page *start_pg; + struct ftrace_page *pg; + int order; + int cnt; + + if (!num_to_init) + return 0; + + start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); + if (!pg) + return NULL; + + /* + * Try to allocate as much as possible in one continues + * location that fills in all of the space. We want to + * waste as little space as possible. + */ + for (;;) { + cnt = ftrace_allocate_records(pg, num_to_init); + if (cnt < 0) + goto free_pages; + + num_to_init -= cnt; + if (!num_to_init) break; + pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); + if (!pg->next) + goto free_pages; + pg = pg->next; } - return 0; + return start_pg; + + free_pages: + while (start_pg) { + order = get_count_order(pg->size / ENTRIES_PER_PAGE); + free_pages((unsigned long)pg->records, order); + start_pg = pg->next; + kfree(pg); + pg = start_pg; + } + pr_info("ftrace: FAILED to allocate memory for functions\n"); + return NULL; } -enum { - FTRACE_ITER_FILTER = (1 << 0), - FTRACE_ITER_NOTRACE = (1 << 1), - FTRACE_ITER_PRINTALL = (1 << 2), - FTRACE_ITER_HASH = (1 << 3), - FTRACE_ITER_ENABLED = (1 << 4), -}; +static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) +{ + int cnt; + + if (!num_to_init) { + pr_info("ftrace: No functions to be traced?\n"); + return -1; + } + + cnt = num_to_init / ENTRIES_PER_PAGE; + pr_info("ftrace: allocating %ld entries in %d pages\n", + num_to_init, cnt + 1); + + return 0; +} #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ @@ -1980,6 +2198,9 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos) void *p = NULL; loff_t l; + if (!(iter->flags & FTRACE_ITER_DO_HASH)) + return NULL; + if (iter->func_pos > *pos) return NULL; @@ -2023,7 +2244,7 @@ static void * t_next(struct seq_file *m, void *v, loff_t *pos) { struct ftrace_iterator *iter = m->private; - struct ftrace_ops *ops = &global_ops; + struct ftrace_ops *ops = iter->ops; struct dyn_ftrace *rec = NULL; if (unlikely(ftrace_disabled)) @@ -2047,9 +2268,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos) } } else { rec = &iter->pg->records[iter->idx++]; - if ((rec->flags & FTRACE_FL_FREE) || - - ((iter->flags & FTRACE_ITER_FILTER) && + if (((iter->flags & FTRACE_ITER_FILTER) && !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || ((iter->flags & FTRACE_ITER_NOTRACE) && @@ -2081,7 +2300,7 @@ static void reset_iter_read(struct ftrace_iterator *iter) static void *t_start(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; - struct ftrace_ops *ops = &global_ops; + struct ftrace_ops *ops = iter->ops; void *p = NULL; loff_t l; @@ -2101,7 +2320,8 @@ static void *t_start(struct seq_file *m, loff_t *pos) * off, we can short cut and just print out that all * functions are enabled. */ - if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) { + if (iter->flags & FTRACE_ITER_FILTER && + ftrace_hash_empty(ops->filter_hash)) { if (*pos > 0) return t_hash_start(m, pos); iter->flags |= FTRACE_ITER_PRINTALL; @@ -2126,12 +2346,8 @@ static void *t_start(struct seq_file *m, loff_t *pos) break; } - if (!p) { - if (iter->flags & FTRACE_ITER_FILTER) - return t_hash_start(m, pos); - - return NULL; - } + if (!p) + return t_hash_start(m, pos); return iter; } @@ -2189,6 +2405,7 @@ ftrace_avail_open(struct inode *inode, struct file *file) return -ENOMEM; iter->pg = ftrace_pages_start; + iter->ops = &global_ops; ret = seq_open(file, &show_ftrace_seq_ops); if (!ret) { @@ -2217,6 +2434,7 @@ ftrace_enabled_open(struct inode *inode, struct file *file) iter->pg = ftrace_pages_start; iter->flags = FTRACE_ITER_ENABLED; + iter->ops = &global_ops; ret = seq_open(file, &show_ftrace_seq_ops); if (!ret) { @@ -2237,7 +2455,23 @@ static void ftrace_filter_reset(struct ftrace_hash *hash) mutex_unlock(&ftrace_lock); } -static int +/** + * ftrace_regex_open - initialize function tracer filter files + * @ops: The ftrace_ops that hold the hash filters + * @flag: The type of filter to process + * @inode: The inode, usually passed in to your open routine + * @file: The file, usually passed in to your open routine + * + * ftrace_regex_open() initializes the filter files for the + * @ops. Depending on @flag it may process the filter hash or + * the notrace hash of @ops. With this called from the open + * routine, you can use ftrace_filter_write() for the write + * routine if @flag has FTRACE_ITER_FILTER set, or + * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. + * ftrace_regex_lseek() should be used as the lseek routine, and + * release must call ftrace_regex_release(). + */ +int ftrace_regex_open(struct ftrace_ops *ops, int flag, struct inode *inode, struct file *file) { @@ -2306,8 +2540,9 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, static int ftrace_filter_open(struct inode *inode, struct file *file) { - return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER, - inode, file); + return ftrace_regex_open(&global_ops, + FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, + inode, file); } static int @@ -2317,7 +2552,7 @@ ftrace_notrace_open(struct inode *inode, struct file *file) inode, file); } -static loff_t +loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin) { loff_t ret; @@ -2426,7 +2661,6 @@ match_records(struct ftrace_hash *hash, char *buff, goto out_unlock; do_for_each_ftrace_rec(pg, rec) { - if (ftrace_match_record(rec, mod, search, search_len, type)) { ret = enter_record(hash, rec, not); if (ret < 0) { @@ -2871,14 +3105,14 @@ out_unlock: return ret; } -static ssize_t +ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { return ftrace_regex_write(file, ubuf, cnt, ppos, 1); } -static ssize_t +ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { @@ -2919,7 +3153,7 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, ret = ftrace_hash_move(ops, enable, orig_hash, hash); if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled) - ftrace_run_update_code(FTRACE_ENABLE_CALLS); + ftrace_run_update_code(FTRACE_UPDATE_CALLS); mutex_unlock(&ftrace_lock); @@ -3045,8 +3279,8 @@ static void __init set_ftrace_early_graph(char *buf) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -static void __init -set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable) +void __init +ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) { char *func; @@ -3059,17 +3293,16 @@ set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable) static void __init set_ftrace_early_filters(void) { if (ftrace_filter_buf[0]) - set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1); + ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); if (ftrace_notrace_buf[0]) - set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0); + ftrace_set_early_filter(&global_ops, 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 -ftrace_regex_release(struct inode *inode, struct file *file) +int ftrace_regex_release(struct inode *inode, struct file *file) { struct seq_file *m = (struct seq_file *)file->private_data; struct ftrace_iterator *iter; @@ -3107,7 +3340,7 @@ ftrace_regex_release(struct inode *inode, struct file *file) orig_hash, iter->hash); if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) && ftrace_enabled) - ftrace_run_update_code(FTRACE_ENABLE_CALLS); + ftrace_run_update_code(FTRACE_UPDATE_CALLS); mutex_unlock(&ftrace_lock); } @@ -3270,9 +3503,6 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FREE) - continue; - if (ftrace_match_record(rec, NULL, search, search_len, type)) { /* if it is in the array */ exists = false; @@ -3381,15 +3611,62 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) return 0; } +static void ftrace_swap_recs(void *a, void *b, int size) +{ + struct dyn_ftrace *reca = a; + struct dyn_ftrace *recb = b; + struct dyn_ftrace t; + + t = *reca; + *reca = *recb; + *recb = t; +} + static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end) { + struct ftrace_page *pg; + unsigned long count; unsigned long *p; unsigned long addr; unsigned long flags = 0; /* Shut up gcc */ + int ret = -ENOMEM; + + count = end - start; + + if (!count) + return 0; + + pg = ftrace_allocate_pages(count); + if (!pg) + return -ENOMEM; mutex_lock(&ftrace_lock); + + /* + * Core and each module needs their own pages, as + * modules will free them when they are removed. + * Force a new page to be allocated for modules. + */ + if (!mod) { + WARN_ON(ftrace_pages || ftrace_pages_start); + /* First initialization */ + ftrace_pages = ftrace_pages_start = pg; + } else { + if (!ftrace_pages) + goto out; + + if (WARN_ON(ftrace_pages->next)) { + /* Hmm, we have free pages? */ + while (ftrace_pages->next) + ftrace_pages = ftrace_pages->next; + } + + ftrace_pages->next = pg; + ftrace_pages = pg; + } + p = start; while (p < end) { addr = ftrace_call_adjust(*p++); @@ -3401,9 +3678,18 @@ static int ftrace_process_locs(struct module *mod, */ if (!addr) continue; - ftrace_record_ip(addr); + if (!ftrace_record_ip(addr)) + break; } + /* These new locations need to be initialized */ + ftrace_new_pgs = pg; + + /* Make each individual set of pages sorted by ips */ + for (; pg; pg = pg->next) + sort(pg->records, pg->index, sizeof(struct dyn_ftrace), + ftrace_cmp_recs, ftrace_swap_recs); + /* * We only need to disable interrupts on start up * because we are modifying code that an interrupt @@ -3417,32 +3703,55 @@ static int ftrace_process_locs(struct module *mod, ftrace_update_code(mod); if (!mod) local_irq_restore(flags); + ret = 0; + out: mutex_unlock(&ftrace_lock); - return 0; + return ret; } #ifdef CONFIG_MODULES + +#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) + void ftrace_release_mod(struct module *mod) { struct dyn_ftrace *rec; + struct ftrace_page **last_pg; struct ftrace_page *pg; + int order; mutex_lock(&ftrace_lock); if (ftrace_disabled) goto out_unlock; - do_for_each_ftrace_rec(pg, rec) { + /* + * Each module has its own ftrace_pages, remove + * them from the list. + */ + last_pg = &ftrace_pages_start; + for (pg = ftrace_pages_start; pg; pg = *last_pg) { + rec = &pg->records[0]; 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. + * As core pages are first, the first + * page should never be a module page. */ - FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); - ftrace_free_rec(rec); - } - } while_for_each_ftrace_rec(); + if (WARN_ON(pg == ftrace_pages_start)) + goto out_unlock; + + /* Check if we are deleting the last page */ + if (pg == ftrace_pages) + ftrace_pages = next_to_ftrace_page(last_pg); + + *last_pg = pg->next; + order = get_count_order(pg->size / ENTRIES_PER_PAGE); + free_pages((unsigned long)pg->records, order); + kfree(pg); + } else + last_pg = &pg->next; + } out_unlock: mutex_unlock(&ftrace_lock); } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index f04cc3136bd..24aee712745 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1738,11 +1738,121 @@ static int replace_system_preds(struct event_subsystem *system, return -ENOMEM; } +static int create_filter_start(char *filter_str, bool set_str, + struct filter_parse_state **psp, + struct event_filter **filterp) +{ + struct event_filter *filter; + struct filter_parse_state *ps = NULL; + int err = 0; + + WARN_ON_ONCE(*psp || *filterp); + + /* allocate everything, and if any fails, free all and fail */ + filter = __alloc_filter(); + if (filter && set_str) + err = replace_filter_string(filter, filter_str); + + ps = kzalloc(sizeof(*ps), GFP_KERNEL); + + if (!filter || !ps || err) { + kfree(ps); + __free_filter(filter); + return -ENOMEM; + } + + /* we're committed to creating a new filter */ + *filterp = filter; + *psp = ps; + + parse_init(ps, filter_ops, filter_str); + err = filter_parse(ps); + if (err && set_str) + append_filter_err(ps, filter); + return err; +} + +static void create_filter_finish(struct filter_parse_state *ps) +{ + if (ps) { + filter_opstack_clear(ps); + postfix_clear(ps); + kfree(ps); + } +} + +/** + * create_filter - create a filter for a ftrace_event_call + * @call: ftrace_event_call to create a filter for + * @filter_str: filter string + * @set_str: remember @filter_str and enable detailed error in filter + * @filterp: out param for created filter (always updated on return) + * + * Creates a filter for @call with @filter_str. If @set_str is %true, + * @filter_str is copied and recorded in the new filter. + * + * On success, returns 0 and *@filterp points to the new filter. On + * failure, returns -errno and *@filterp may point to %NULL or to a new + * filter. In the latter case, the returned filter contains error + * information if @set_str is %true and the caller is responsible for + * freeing it. + */ +static int create_filter(struct ftrace_event_call *call, + char *filter_str, bool set_str, + struct event_filter **filterp) +{ + struct event_filter *filter = NULL; + struct filter_parse_state *ps = NULL; + int err; + + err = create_filter_start(filter_str, set_str, &ps, &filter); + if (!err) { + err = replace_preds(call, filter, ps, filter_str, false); + if (err && set_str) + append_filter_err(ps, filter); + } + create_filter_finish(ps); + + *filterp = filter; + return err; +} + +/** + * create_system_filter - create a filter for an event_subsystem + * @system: event_subsystem to create a filter for + * @filter_str: filter string + * @filterp: out param for created filter (always updated on return) + * + * Identical to create_filter() except that it creates a subsystem filter + * and always remembers @filter_str. + */ +static int create_system_filter(struct event_subsystem *system, + char *filter_str, struct event_filter **filterp) +{ + struct event_filter *filter = NULL; + struct filter_parse_state *ps = NULL; + int err; + + err = create_filter_start(filter_str, true, &ps, &filter); + if (!err) { + err = replace_system_preds(system, ps, filter_str); + if (!err) { + /* System filters just show a default message */ + kfree(filter->filter_string); + filter->filter_string = NULL; + } else { + append_filter_err(ps, filter); + } + } + create_filter_finish(ps); + + *filterp = filter; + return err; +} + int apply_event_filter(struct ftrace_event_call *call, char *filter_string) { - struct filter_parse_state *ps; struct event_filter *filter; - struct event_filter *tmp; int err = 0; mutex_lock(&event_mutex); @@ -1759,49 +1869,30 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) goto out_unlock; } - err = -ENOMEM; - ps = kzalloc(sizeof(*ps), GFP_KERNEL); - if (!ps) - goto out_unlock; - - filter = __alloc_filter(); - if (!filter) { - kfree(ps); - goto out_unlock; - } - - replace_filter_string(filter, filter_string); - - parse_init(ps, filter_ops, filter_string); - err = filter_parse(ps); - if (err) { - append_filter_err(ps, filter); - goto out; - } + err = create_filter(call, filter_string, true, &filter); - err = replace_preds(call, filter, ps, filter_string, false); - if (err) { - filter_disable(call); - append_filter_err(ps, filter); - } else - call->flags |= TRACE_EVENT_FL_FILTERED; -out: /* * Always swap the call filter with the new filter * even if there was an error. If there was an error * in the filter, we disable the filter and show the error * string */ - tmp = call->filter; - rcu_assign_pointer(call->filter, filter); - if (tmp) { - /* Make sure the call is done with the filter */ - synchronize_sched(); - __free_filter(tmp); + if (filter) { + struct event_filter *tmp = call->filter; + + if (!err) + call->flags |= TRACE_EVENT_FL_FILTERED; + else + filter_disable(call); + + rcu_assign_pointer(call->filter, filter); + + if (tmp) { + /* Make sure the call is done with the filter */ + synchronize_sched(); + __free_filter(tmp); + } } - filter_opstack_clear(ps); - postfix_clear(ps); - kfree(ps); out_unlock: mutex_unlock(&event_mutex); @@ -1811,7 +1902,6 @@ out_unlock: int apply_subsystem_event_filter(struct event_subsystem *system, char *filter_string) { - struct filter_parse_state *ps; struct event_filter *filter; int err = 0; @@ -1835,48 +1925,19 @@ int apply_subsystem_event_filter(struct event_subsystem *system, goto out_unlock; } - err = -ENOMEM; - ps = kzalloc(sizeof(*ps), GFP_KERNEL); - if (!ps) - goto out_unlock; - - filter = __alloc_filter(); - if (!filter) - goto out; - - /* System filters just show a default message */ - kfree(filter->filter_string); - filter->filter_string = NULL; - - /* - * No event actually uses the system filter - * we can free it without synchronize_sched(). - */ - __free_filter(system->filter); - system->filter = filter; - - parse_init(ps, filter_ops, filter_string); - err = filter_parse(ps); - if (err) - goto err_filter; - - err = replace_system_preds(system, ps, filter_string); - if (err) - goto err_filter; - -out: - filter_opstack_clear(ps); - postfix_clear(ps); - kfree(ps); + err = create_system_filter(system, filter_string, &filter); + if (filter) { + /* + * No event actually uses the system filter + * we can free it without synchronize_sched(). + */ + __free_filter(system->filter); + system->filter = filter; + } out_unlock: mutex_unlock(&event_mutex); return err; - -err_filter: - replace_filter_string(filter, filter_string); - append_filter_err(ps, system->filter); - goto out; } #ifdef CONFIG_PERF_EVENTS @@ -1894,7 +1955,6 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id, { int err; struct event_filter *filter; - struct filter_parse_state *ps; struct ftrace_event_call *call; mutex_lock(&event_mutex); @@ -1909,33 +1969,10 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id, if (event->filter) goto out_unlock; - filter = __alloc_filter(); - if (!filter) { - err = PTR_ERR(filter); - goto out_unlock; - } - - err = -ENOMEM; - ps = kzalloc(sizeof(*ps), GFP_KERNEL); - if (!ps) - goto free_filter; - - parse_init(ps, filter_ops, filter_str); - err = filter_parse(ps); - if (err) - goto free_ps; - - err = replace_preds(call, filter, ps, filter_str, false); + err = create_filter(call, filter_str, false, &filter); if (!err) event->filter = filter; - -free_ps: - filter_opstack_clear(ps); - postfix_clear(ps); - kfree(ps); - -free_filter: - if (err) + else __free_filter(filter); out_unlock: @@ -1954,43 +1991,6 @@ out_unlock: #define CREATE_TRACE_POINTS #include "trace_events_filter_test.h" -static int test_get_filter(char *filter_str, struct ftrace_event_call *call, - struct event_filter **pfilter) -{ - struct event_filter *filter; - struct filter_parse_state *ps; - int err = -ENOMEM; - - filter = __alloc_filter(); - if (!filter) - goto out; - - ps = kzalloc(sizeof(*ps), GFP_KERNEL); - if (!ps) - goto free_filter; - - parse_init(ps, filter_ops, filter_str); - err = filter_parse(ps); - if (err) - goto free_ps; - - err = replace_preds(call, filter, ps, filter_str, false); - if (!err) - *pfilter = filter; - - free_ps: - filter_opstack_clear(ps); - postfix_clear(ps); - kfree(ps); - - free_filter: - if (err) - __free_filter(filter); - - out: - return err; -} - #define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \ { \ .filter = FILTER, \ @@ -2109,12 +2109,13 @@ static __init int ftrace_test_event_filter(void) struct test_filter_data_t *d = &test_filter_data[i]; int err; - err = test_get_filter(d->filter, &event_ftrace_test_filter, - &filter); + err = create_filter(&event_ftrace_test_filter, d->filter, + false, &filter); if (err) { printk(KERN_INFO "Failed to get filter for '%s', err %d\n", d->filter, err); + __free_filter(filter); break; } diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 77575b386d9..d4545f49242 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -13,6 +13,9 @@ #include <linux/sysctl.h> #include <linux/init.h> #include <linux/fs.h> + +#include <asm/setup.h> + #include "trace.h" #define STACK_TRACE_ENTRIES 500 @@ -133,7 +136,6 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip) static struct ftrace_ops trace_ops __read_mostly = { .func = stack_trace_call, - .flags = FTRACE_OPS_FL_GLOBAL, }; static ssize_t @@ -311,6 +313,21 @@ static const struct file_operations stack_trace_fops = { .release = seq_release, }; +static int +stack_trace_filter_open(struct inode *inode, struct file *file) +{ + return ftrace_regex_open(&trace_ops, FTRACE_ITER_FILTER, + inode, file); +} + +static const struct file_operations stack_trace_filter_fops = { + .open = stack_trace_filter_open, + .read = seq_read, + .write = ftrace_filter_write, + .llseek = ftrace_regex_lseek, + .release = ftrace_regex_release, +}; + int stack_trace_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, @@ -338,8 +355,13 @@ stack_trace_sysctl(struct ctl_table *table, int write, return ret; } +static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata; + static __init int enable_stacktrace(char *str) { + if (strncmp(str, "_filter=", 8) == 0) + strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE); + stack_tracer_enabled = 1; last_stack_tracer_enabled = 1; return 1; @@ -358,6 +380,12 @@ static __init int stack_trace_init(void) trace_create_file("stack_trace", 0444, d_tracer, NULL, &stack_trace_fops); + trace_create_file("stack_trace_filter", 0444, d_tracer, + NULL, &stack_trace_filter_fops); + + if (stack_trace_filter_buf[0]) + ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1); + if (stack_tracer_enabled) register_ftrace_function(&trace_ops); |