diff options
| -rw-r--r-- | kernel/trace/Makefile | 1 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 28 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 77 | ||||
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 326 | ||||
| -rw-r--r-- | kernel/trace/trace_events_stage_3.h | 4 |
5 files changed, 436 insertions, 0 deletions
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 0e45c206c2f9..2630f5121ec1 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -45,5 +45,6 @@ obj-$(CONFIG_EVENT_TRACER) += events.o obj-$(CONFIG_EVENT_TRACER) += trace_export.o obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o +obj-$(CONFIG_EVENT_TRACER) += trace_events_filter.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9288dc7ad14f..d9eb39e4bb38 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -795,6 +795,7 @@ struct ftrace_event_call { int (*show_format)(struct trace_seq *s); int (*define_fields)(void); struct list_head fields; + struct filter_pred **preds; #ifdef CONFIG_EVENT_PROFILE atomic_t profile_count; @@ -803,8 +804,35 @@ struct ftrace_event_call { #endif }; +#define MAX_FILTER_PRED 8 + +struct filter_pred; + +typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event); + +struct filter_pred { + filter_pred_fn_t fn; + u64 val; + char *str_val; + int str_len; + char *field_name; + int offset; + int not; + int or; + int compound; + int clear; +}; + int trace_define_field(struct ftrace_event_call *call, char *type, char *name, int offset, int size); +extern void filter_free_pred(struct filter_pred *pred); +extern int filter_print_preds(struct filter_pred **preds, char *buf); +extern int filter_parse(char **pbuf, struct filter_pred *pred); +extern int filter_add_pred(struct ftrace_event_call *call, + struct filter_pred *pred); +extern void filter_free_preds(struct ftrace_event_call *call); +extern int filter_match_preds(struct ftrace_event_call *call, void *rec); + void event_trace_printk(unsigned long ip, const char *fmt, ...); extern struct ftrace_event_call __start_ftrace_events[]; extern struct ftrace_event_call __stop_ftrace_events[]; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 961b057da28b..97470c48956e 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -459,6 +459,71 @@ event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) return r; } +static ssize_t +event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + struct ftrace_event_call *call = filp->private_data; + struct trace_seq *s; + int r; + + if (*ppos) + return 0; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + trace_seq_init(s); + + r = filter_print_preds(call->preds, s->buffer); + r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, r); + + kfree(s); + + return r; +} + +static ssize_t +event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + struct ftrace_event_call *call = filp->private_data; + char buf[64], *pbuf = buf; + struct filter_pred *pred; + int err; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + pred = kzalloc(sizeof(*pred), GFP_KERNEL); + if (!pred) + return -ENOMEM; + + err = filter_parse(&pbuf, pred); + if (err < 0) { + filter_free_pred(pred); + return err; + } + + if (pred->clear) { + filter_free_preds(call); + return cnt; + } + + if (filter_add_pred(call, pred)) { + filter_free_pred(pred); + return -EINVAL; + } + + *ppos += cnt; + + return cnt; +} + static const struct seq_operations show_event_seq_ops = { .start = t_start, .next = t_next, @@ -504,6 +569,12 @@ static const struct file_operations ftrace_event_id_fops = { .read = event_id_read, }; +static const struct file_operations ftrace_event_filter_fops = { + .open = tracing_open_generic, + .read = event_filter_read, + .write = event_filter_write, +}; + static struct dentry *event_trace_events_dir(void) { static struct dentry *d_tracer; @@ -619,6 +690,12 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) } } + entry = debugfs_create_file("filter", 0444, call->dir, call, + &ftrace_event_filter_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'%s/filter' entry\n", call->name); + /* A trace may not want to export its format */ if (!call->show_format) return 0; diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c new file mode 100644 index 000000000000..8e8c5fa25be9 --- /dev/null +++ b/kernel/trace/trace_events_filter.c @@ -0,0 +1,326 @@ +/* + * trace_events_filter - generic event filtering + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com> + */ + +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/ctype.h> + +#include "trace.h" + +static int filter_pred_64(struct filter_pred *pred, void *event) +{ + u64 *addr = (u64 *)(event + pred->offset); + u64 val = (u64)pred->val; + int match; + + match = (val == *addr) ^ pred->not; + + return match; +} + +static int filter_pred_32(struct filter_pred *pred, void *event) +{ + u32 *addr = (u32 *)(event + pred->offset); + u32 val = (u32)pred->val; + int match; + + match = (val == *addr) ^ pred->not; + + return match; +} + +static int filter_pred_16(struct filter_pred *pred, void *event) +{ + u16 *addr = (u16 *)(event + pred->offset); + u16 val = (u16)pred->val; + int match; + + match = (val == *addr) ^ pred->not; + + return match; +} + +static int filter_pred_8(struct filter_pred *pred, void *event) +{ + u8 *addr = (u8 *)(event + pred->offset); + u8 val = (u8)pred->val; + int match; + + match = (val == *addr) ^ pred->not; + + return match; +} + +static int filter_pred_string(struct filter_pred *pred, void *event) +{ + char *addr = (char *)(event + pred->offset); + int cmp, match; + + cmp = strncmp(addr, pred->str_val, pred->str_len); + + match = (!cmp) ^ pred->not; + + return match; +} + +/* return 1 if event matches, 0 otherwise (discard) */ +int filter_match_preds(struct ftrace_event_call *call, void *rec) +{ + int i, matched, and_failed = 0; + struct filter_pred *pred; + + for (i = 0; i < MAX_FILTER_PRED; i++) { + if (call->preds[i]) { + pred = call->preds[i]; + if (and_failed && !pred->or) + continue; + matched = pred->fn(pred, rec); + if (!matched && !pred->or) { + and_failed = 1; + continue; + } else if (matched && pred->or) + return 1; + } else + break; + } + + if (and_failed) + return 0; + + return 1; +} + +int filter_print_preds(struct filter_pred **preds, char *buf) +{ + ssize_t this_len = 0; + char *field_name; + struct filter_pred *pred; + int i; + + if (!preds) { + this_len += sprintf(buf + this_len, "none\n"); + return this_len; + } + + for (i = 0; i < MAX_FILTER_PRED; i++) { + if (preds[i]) { + pred = preds[i]; + field_name = pred->field_name; + if (i) + this_len += sprintf(buf + this_len, + pred->or ? "|| " : "&& "); + this_len += sprintf(buf + this_len, + "%s ", field_name); + this_len += sprintf(buf + this_len, + pred->not ? "!= " : "== "); + if (pred->str_val) + this_len += sprintf(buf + this_len, + "%s\n", pred->str_val); + else + this_len += sprintf(buf + this_len, + "%llu\n", pred->val); + } else + break; + } + + return this_len; +} + +static struct ftrace_event_field * +find_event_field(struct ftrace_event_call *call, char *name) +{ + struct ftrace_event_field *field; + struct list_head *entry, *tmp; + + list_for_each_safe(entry, tmp, &call->fields) { + field = list_entry(entry, struct ftrace_event_field, link); + if (!strcmp(field->name, name)) + return field; + } + + return NULL; +} + +void filter_free_pred(struct filter_pred *pred) +{ + if (!pred) + return; + + kfree(pred->field_name); + kfree(pred->str_val); + kfree(pred); +} + +void filter_free_preds(struct ftrace_event_call *call) +{ + int i; + + if (call->preds) { + for (i = 0; i < MAX_FILTER_PRED; i++) + filter_free_pred(call->preds[i]); + kfree(call->preds); + call->preds = NULL; + } +} + +static int __filter_add_pred(struct ftrace_event_call *call, + struct filter_pred *pred) +{ + int i; + + if (call->preds && !pred->compound) + filter_free_preds(call); + + if (!call->preds) { + call->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), + GFP_KERNEL); + if (!call->preds) + return -ENOMEM; + } + + for (i = 0; i < MAX_FILTER_PRED; i++) { + if (!call->preds[i]) { + call->preds[i] = pred; + return 0; + } + } + + return -ENOMEM; +} + +static int is_string_field(const char *type) +{ + if (strchr(type, '[') && strstr(type, "char")) + return 1; + + return 0; +} + +int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) +{ + struct ftrace_event_field *field; + + field = find_event_field(call, pred->field_name); + if (!field) + return -EINVAL; + + pred->offset = field->offset; + + if (is_string_field(field->type)) { + pred->fn = filter_pred_string; + pred->str_len = field->size; + return __filter_add_pred(call, pred); + } + + switch (field->size) { + case 8: + pred->fn = filter_pred_64; + break; + case 4: + pred->fn = filter_pred_32; + break; + case 2: + pred->fn = filter_pred_16; + break; + case 1: + pred->fn = filter_pred_8; + break; + default: + return -EINVAL; + } + + return __filter_add_pred(call, pred); +} + +int filter_parse(char **pbuf, struct filter_pred *pred) +{ + char *tmp, *tok, *val_str = NULL; + int tok_n = 0; + + /* field ==/!= number, or/and field ==/!= number, number */ + while ((tok = strsep(pbuf, " \n"))) { + if (tok_n == 0) { + if (!strcmp(tok, "0")) { + pred->clear = 1; + return 0; + } else if (!strcmp(tok, "&&")) { + pred->or = 0; + pred->compound = 1; + } else if (!strcmp(tok, "||")) { + pred->or = 1; + pred->compound = 1; + } else + pred->field_name = tok; + tok_n = 1; + continue; + } + if (tok_n == 1) { + if (!pred->field_name) + pred->field_name = tok; + else if (!strcmp(tok, "!=")) + pred->not = 1; + else if (!strcmp(tok, "==")) + pred->not = 0; + else { + pred->field_name = NULL; + return -EINVAL; + } + tok_n = 2; + continue; + } + if (tok_n == 2) { + if (pred->compound) { + if (!strcmp(tok, "!=")) + pred->not = 1; + else if (!strcmp(tok, "==")) + pred->not = 0; + else { + pred->field_name = NULL; + return -EINVAL; + } + } else { + val_str = tok; + break; /* done */ + } + tok_n = 3; + continue; + } + if (tok_n == 3) { + val_str = tok; + break; /* done */ + } + } + + pred->field_name = kstrdup(pred->field_name, GFP_KERNEL); + if (!pred->field_name) + return -ENOMEM; + + pred->val = simple_strtoull(val_str, &tmp, 10); + if (tmp == val_str) { + pred->str_val = kstrdup(val_str, GFP_KERNEL); + if (!pred->str_val) + return -ENOMEM; + } + + return 0; +} + + diff --git a/kernel/trace/trace_events_stage_3.h b/kernel/trace/trace_events_stage_3.h index 468938f70141..ebf215e87d5e 100644 --- a/kernel/trace/trace_events_stage_3.h +++ b/kernel/trace/trace_events_stage_3.h @@ -204,6 +204,7 @@ static struct ftrace_event_call event_##call; \ \ static void ftrace_raw_event_##call(proto) \ { \ + struct ftrace_event_call *call = &event_##call; \ struct ring_buffer_event *event; \ struct ftrace_raw_##call *entry; \ unsigned long irq_flags; \ @@ -222,6 +223,9 @@ static void ftrace_raw_event_##call(proto) \ assign; \ \ trace_current_buffer_unlock_commit(event, irq_flags, pc); \ + \ + if (call->preds && !filter_match_preds(call, entry)) \ + ring_buffer_event_discard(event); \ } \ \ static int ftrace_raw_reg_event_##call(void) \ |