diff options
| -rw-r--r-- | include/linux/ftrace_event.h | 2 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 66 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 86 | ||||
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 1020 |
4 files changed, 884 insertions, 290 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index e61a740..5fff40c 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -112,7 +112,7 @@ struct ftrace_event_call { #endif }; -#define MAX_FILTER_PRED 8 +#define MAX_FILTER_PRED 32 #define MAX_FILTER_STR_VAL 128 extern int init_preds(struct ftrace_event_call *call); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 866d010..7736fe8 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -735,6 +735,7 @@ struct ftrace_event_field { struct event_filter { int n_preds; struct filter_pred **preds; + char *filter_string; }; struct event_subsystem { @@ -746,7 +747,8 @@ struct event_subsystem { struct filter_pred; -typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event); +typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, + int val1, int val2); struct filter_pred { filter_pred_fn_t fn; @@ -756,23 +758,18 @@ struct filter_pred { char *field_name; int offset; int not; - int or; - int compound; - int clear; + int op; + int pop_n; }; -extern void filter_free_pred(struct filter_pred *pred); -extern void filter_print_preds(struct ftrace_event_call *call, +extern void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s); -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_disable_preds(struct ftrace_event_call *call); -extern void filter_free_subsystem_preds(struct event_subsystem *system); -extern void filter_print_subsystem_preds(struct event_subsystem *system, +extern int apply_event_filter(struct ftrace_event_call *call, + char *filter_string); +extern int apply_subsystem_event_filter(struct event_subsystem *system, + char *filter_string); +extern void print_subsystem_event_filter(struct event_subsystem *system, struct trace_seq *s); -extern int filter_add_subsystem_pred(struct event_subsystem *system, - struct filter_pred *pred); static inline int filter_check_discard(struct ftrace_event_call *call, void *rec, @@ -787,6 +784,47 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, return 0; } +#define DEFINE_COMPARISON_PRED(type) \ +static int filter_pred_##type(struct filter_pred *pred, void *event, \ + int val1, int val2) \ +{ \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + int match = 0; \ + \ + switch (pred->op) { \ + case OP_LT: \ + match = (*addr < val); \ + break; \ + case OP_LE: \ + match = (*addr <= val); \ + break; \ + case OP_GT: \ + match = (*addr > val); \ + break; \ + case OP_GE: \ + match = (*addr >= val); \ + break; \ + default: \ + break; \ + } \ + \ + return match; \ +} + +#define DEFINE_EQUALITY_PRED(size) \ +static int filter_pred_##size(struct filter_pred *pred, void *event, \ + int val1, int val2) \ +{ \ + u##size *addr = (u##size *)(event + pred->offset); \ + u##size val = (u##size)pred->val; \ + int match; \ + \ + match = (val == *addr) ^ pred->not; \ + \ + return match; \ +} + extern struct list_head ftrace_events; extern const char *__start___trace_bprintk_fmt[]; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index bbbea74..f789ca5 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -492,7 +492,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, trace_seq_init(s); - filter_print_preds(call, s); + print_event_filter(call, s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); kfree(s); @@ -505,40 +505,26 @@ 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; + char *buf; int err; - if (cnt >= sizeof(buf)) + if (cnt >= PAGE_SIZE) return -EINVAL; - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - buf[cnt] = '\0'; - - pred = kzalloc(sizeof(*pred), GFP_KERNEL); - if (!pred) + buf = (char *)__get_free_page(GFP_TEMPORARY); + if (!buf) return -ENOMEM; - err = filter_parse(&pbuf, pred); - if (err < 0) { - filter_free_pred(pred); - return err; - } - - if (pred->clear) { - filter_disable_preds(call); - filter_free_pred(pred); - return cnt; + if (copy_from_user(buf, ubuf, cnt)) { + free_page((unsigned long) buf); + return -EFAULT; } + buf[cnt] = '\0'; - err = filter_add_pred(call, pred); - if (err < 0) { - filter_free_pred(pred); + err = apply_event_filter(call, buf); + free_page((unsigned long) buf); + if (err < 0) return err; - } - - filter_free_pred(pred); *ppos += cnt; @@ -562,7 +548,7 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, trace_seq_init(s); - filter_print_subsystem_preds(system, s); + print_subsystem_event_filter(system, s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); kfree(s); @@ -575,38 +561,26 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct event_subsystem *system = filp->private_data; - char buf[64], *pbuf = buf; - struct filter_pred *pred; + char *buf; int err; - if (cnt >= sizeof(buf)) + if (cnt >= PAGE_SIZE) return -EINVAL; - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - buf[cnt] = '\0'; - - pred = kzalloc(sizeof(*pred), GFP_KERNEL); - if (!pred) + buf = (char *)__get_free_page(GFP_TEMPORARY); + if (!buf) return -ENOMEM; - err = filter_parse(&pbuf, pred); - if (err < 0) { - filter_free_pred(pred); - return err; - } - - if (pred->clear) { - filter_free_subsystem_preds(system); - filter_free_pred(pred); - return cnt; + if (copy_from_user(buf, ubuf, cnt)) { + free_page((unsigned long) buf); + return -EFAULT; } + buf[cnt] = '\0'; - err = filter_add_subsystem_pred(system, pred); - if (err < 0) { - filter_free_pred(pred); + err = apply_subsystem_event_filter(system, buf); + free_page((unsigned long) buf); + if (err < 0) return err; - } *ppos += cnt; @@ -760,11 +734,21 @@ event_subsystem_dir(const char *name, struct dentry *d_events) system->filter = NULL; + system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); + if (!system->filter) { + pr_warning("Could not allocate filter for subsystem " + "'%s'\n", name); + return system->entry; + } + entry = debugfs_create_file("filter", 0644, system->entry, system, &ftrace_subsystem_filter_fops); - if (!entry) + if (!entry) { + kfree(system->filter); + system->filter = NULL; pr_warning("Could not create debugfs " "'%s/filter' entry\n", name); + } return system->entry; } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 1e861ec..f494866 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -29,51 +29,130 @@ static DEFINE_MUTEX(filter_mutex); -static int filter_pred_64(struct filter_pred *pred, void *event) +enum filter_op_ids { - 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) + OP_OR, + OP_AND, + OP_NE, + OP_EQ, + OP_LT, + OP_LE, + OP_GT, + OP_GE, + OP_NONE, + OP_OPEN_PAREN, +}; + +struct filter_op { + int id; + char *string; + int precedence; +}; + +static struct filter_op filter_ops[] = { + { OP_OR, "||", 1 }, + { OP_AND, "&&", 2 }, + { OP_NE, "!=", 4 }, + { OP_EQ, "==", 4 }, + { OP_LT, "<", 5 }, + { OP_LE, "<=", 5 }, + { OP_GT, ">", 5 }, + { OP_GE, ">=", 5 }, + { OP_NONE, "OP_NONE", 0 }, + { OP_OPEN_PAREN, "(", 0 }, +}; + +enum { + FILT_ERR_NONE, + FILT_ERR_INVALID_OP, + FILT_ERR_UNBALANCED_PAREN, + FILT_ERR_TOO_MANY_OPERANDS, + FILT_ERR_OPERAND_TOO_LONG, + FILT_ERR_FIELD_NOT_FOUND, + FILT_ERR_ILLEGAL_FIELD_OP, + FILT_ERR_ILLEGAL_INTVAL, + FILT_ERR_BAD_SUBSYS_FILTER, + FILT_ERR_TOO_MANY_PREDS, + FILT_ERR_MISSING_FIELD, + FILT_ERR_INVALID_FILTER, +}; + +static char *err_text[] = { + "No error", + "Invalid operator", + "Unbalanced parens", + "Too many operands", + "Operand too long", + "Field not found", + "Illegal operation for field type", + "Illegal integer value", + "Couldn't find or set field in one of a subsystem's events", + "Too many terms in predicate expression", + "Missing field name and/or value", + "Meaningless filter expression", +}; + +struct opstack_op { + int op; + struct list_head list; +}; + +struct postfix_elt { + int op; + char *operand; + struct list_head list; +}; + +struct filter_parse_state { + struct filter_op *ops; + struct list_head opstack; + struct list_head postfix; + int lasterr; + int lasterr_pos; + + struct { + char *string; + unsigned int cnt; + unsigned int tail; + } infix; + + struct { + char string[MAX_FILTER_STR_VAL]; + int pos; + unsigned int tail; + } operand; +}; + +DEFINE_COMPARISON_PRED(s64); +DEFINE_COMPARISON_PRED(u64); +DEFINE_COMPARISON_PRED(s32); +DEFINE_COMPARISON_PRED(u32); +DEFINE_COMPARISON_PRED(s16); +DEFINE_COMPARISON_PRED(u16); +DEFINE_COMPARISON_PRED(s8); +DEFINE_COMPARISON_PRED(u8); + +DEFINE_EQUALITY_PRED(64); +DEFINE_EQUALITY_PRED(32); +DEFINE_EQUALITY_PRED(16); +DEFINE_EQUALITY_PRED(8); + +static int filter_pred_and(struct filter_pred *pred __attribute((unused)), + void *event __attribute((unused)), + int val1, int val2) { - u16 *addr = (u16 *)(event + pred->offset); - u16 val = (u16)pred->val; - int match; - - match = (val == *addr) ^ pred->not; - - return match; + return val1 && val2; } -static int filter_pred_8(struct filter_pred *pred, void *event) +static int filter_pred_or(struct filter_pred *pred __attribute((unused)), + void *event __attribute((unused)), + int val1, int val2) { - u8 *addr = (u8 *)(event + pred->offset); - u8 val = (u8)pred->val; - int match; - - match = (val == *addr) ^ pred->not; - - return match; + return val1 || val2; } -static int filter_pred_string(struct filter_pred *pred, void *event) +static int filter_pred_string(struct filter_pred *pred, void *event, + int val1, int val2) { char *addr = (char *)(event + pred->offset); int cmp, match; @@ -85,7 +164,8 @@ static int filter_pred_string(struct filter_pred *pred, void *event) return match; } -static int filter_pred_none(struct filter_pred *pred, void *event) +static int filter_pred_none(struct filter_pred *pred, void *event, + int val1, int val2) { return 0; } @@ -94,66 +174,119 @@ static int filter_pred_none(struct filter_pred *pred, void *event) int filter_match_preds(struct ftrace_event_call *call, void *rec) { struct event_filter *filter = call->filter; - int i, matched, and_failed = 0; + int match, top = 0, val1 = 0, val2 = 0; + int stack[MAX_FILTER_PRED]; struct filter_pred *pred; + int i; for (i = 0; i < filter->n_preds; i++) { pred = filter->preds[i]; - if (and_failed && !pred->or) + if (!pred->pop_n) { + match = pred->fn(pred, rec, val1, val2); + stack[top++] = match; continue; - matched = pred->fn(pred, rec); - if (!matched && !pred->or) { - and_failed = 1; - continue; - } else if (matched && pred->or) - return 1; + } + if (pred->pop_n > top) { + WARN_ON_ONCE(1); + return 0; + } + val1 = stack[--top]; + val2 = stack[--top]; + match = pred->fn(pred, rec, val1, val2); + stack[top++] = match; } - if (and_failed) - return 0; - - return 1; + return stack[--top]; } EXPORT_SYMBOL_GPL(filter_match_preds); -static void __filter_print_preds(struct event_filter *filter, - struct trace_seq *s) +static void parse_error(struct filter_parse_state *ps, int err, int pos) { - struct filter_pred *pred; - char *field_name; - int i; + ps->lasterr = err; + ps->lasterr_pos = pos; +} - if (!filter || !filter->n_preds) { - trace_seq_printf(s, "none\n"); +static void remove_filter_string(struct event_filter *filter) +{ + kfree(filter->filter_string); + filter->filter_string = NULL; +} + +static int replace_filter_string(struct event_filter *filter, + char *filter_string) +{ + kfree(filter->filter_string); + filter->filter_string = kstrdup(filter_string, GFP_KERNEL); + if (!filter->filter_string) + return -ENOMEM; + + return 0; +} + +static int append_filter_string(struct event_filter *filter, + char *string) +{ + int newlen; + char *new_filter_string; + + BUG_ON(!filter->filter_string); + newlen = strlen(filter->filter_string) + strlen(string) + 1; + new_filter_string = kmalloc(newlen, GFP_KERNEL); + if (!new_filter_string) + return -ENOMEM; + + strcpy(new_filter_string, filter->filter_string); + strcat(new_filter_string, string); + kfree(filter->filter_string); + filter->filter_string = new_filter_string; + + return 0; +} + +static void append_filter_err(struct filter_parse_state *ps, + struct event_filter *filter) +{ + int pos = ps->lasterr_pos; + char *buf, *pbuf; + + buf = (char *)__get_free_page(GFP_TEMPORARY); + if (!buf) return; - } - for (i = 0; i < filter->n_preds; i++) { - pred = filter->preds[i]; - field_name = pred->field_name; - if (i) - trace_seq_printf(s, pred->or ? "|| " : "&& "); - trace_seq_printf(s, "%s ", field_name); - trace_seq_printf(s, pred->not ? "!= " : "== "); - if (pred->str_len) - trace_seq_printf(s, "%s\n", pred->str_val); - else - trace_seq_printf(s, "%llu\n", pred->val); - } + append_filter_string(filter, "\n"); + memset(buf, ' ', PAGE_SIZE); + if (pos > PAGE_SIZE - 128) + pos = 0; + buf[pos] = '^'; + pbuf = &buf[pos] + 1; + + sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]); + append_filter_string(filter, buf); + free_page((unsigned long) buf); } -void filter_print_preds(struct ftrace_event_call *call, struct trace_seq *s) +void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s) { + struct event_filter *filter = call->filter; + mutex_lock(&filter_mutex); - __filter_print_preds(call->filter, s); + if (filter->filter_string) + trace_seq_printf(s, "%s\n", filter->filter_string); + else + trace_seq_printf(s, "none\n"); mutex_unlock(&filter_mutex); } -void filter_print_subsystem_preds(struct event_subsystem *system, +void print_subsystem_event_filter(struct event_subsystem *system, struct trace_seq *s) { + struct event_filter *filter = system->filter; + mutex_lock(&filter_mutex); - __filter_print_preds(system->filter, s); + if (filter->filter_string) + trace_seq_printf(s, "%s\n", filter->filter_string); + else + trace_seq_printf(s, "none\n"); mutex_unlock(&filter_mutex); } @@ -170,7 +303,7 @@ find_event_field(struct ftrace_event_call *call, char *name) return NULL; } -void filter_free_pred(struct filter_pred *pred) +static void filter_free_pred(struct filter_pred *pred) { if (!pred) return; @@ -191,15 +324,17 @@ static int filter_set_pred(struct filter_pred *dest, filter_pred_fn_t fn) { *dest = *src; - dest->field_name = kstrdup(src->field_name, GFP_KERNEL); - if (!dest->field_name) - return -ENOMEM; + if (src->field_name) { + dest->field_name = kstrdup(src->field_name, GFP_KERNEL); + if (!dest->field_name) + return -ENOMEM; + } dest->fn = fn; return 0; } -static void __filter_disable_preds(struct ftrace_event_call *call) +static void filter_disable_preds(struct ftrace_event_call *call) { struct event_filter *filter = call->filter; int i; @@ -211,13 +346,6 @@ static void __filter_disable_preds(struct ftrace_event_call *call) filter->preds[i]->fn = filter_pred_none; } -void filter_disable_preds(struct ftrace_event_call *call) -{ - mutex_lock(&filter_mutex); - __filter_disable_preds(call); - mutex_unlock(&filter_mutex); -} - int init_preds(struct ftrace_event_call *call) { struct event_filter *filter; @@ -258,48 +386,43 @@ oom: } EXPORT_SYMBOL_GPL(init_preds); -static void __filter_free_subsystem_preds(struct event_subsystem *system) +static void filter_free_subsystem_preds(struct event_subsystem *system) { struct event_filter *filter = system->filter; struct ftrace_event_call *call; int i; - if (filter && filter->n_preds) { + if (filter->n_preds) { for (i = 0; i < filter->n_preds; i++) filter_free_pred(filter->preds[i]); kfree(filter->preds); - kfree(filter); - system->filter = NULL; + filter->preds = NULL; + filter->n_preds = 0; } list_for_each_entry(call, &ftrace_events, list) { if (!call->define_fields) continue; - if (!strcmp(call->system, system->name)) - __filter_disable_preds(call); + if (!strcmp(call->system, system->name)) { + filter_disable_preds(call); + remove_filter_string(call->filter); + } } } -void filter_free_subsystem_preds(struct event_subsystem *system) -{ - mutex_lock(&filter_mutex); - __filter_free_subsystem_preds(system); - mutex_unlock(&filter_mutex); -} - -static int filter_add_pred_fn(struct ftrace_event_call *call, +static int filter_add_pred_fn(struct filter_parse_state *ps, + struct ftrace_event_call *call, struct filter_pred *pred, filter_pred_fn_t fn) { struct event_filter *filter = call->filter; int idx, err; - if (filter->n_preds && !pred->compound) - __filter_disable_preds(call); - - if (filter->n_preds == MAX_FILTER_PRED) + if (filter->n_preds == MAX_FILTER_PRED) { + parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); return -ENOSPC; + } idx = filter->n_preds; filter_clear_pred(filter->preds[idx]); @@ -321,94 +444,132 @@ static int is_string_field(const char *type) return 0; } -static int __filter_add_pred(struct ftrace_event_call *call, - struct filter_pred *pred) +static int is_legal_op(struct ftrace_event_field *field, int op) +{ + if (is_string_field(field->type) && (op != OP_EQ && op != OP_NE)) + return 0; + + return 1; +} + +static filter_pred_fn_t select_comparison_fn(int op, int field_size, + int field_is_signed) +{ + filter_pred_fn_t fn = NULL; + + switch (field_size) { + case 8: + if (op == OP_EQ || op == OP_NE) + fn = filter_pred_64; + else if (field_is_signed) + fn = filter_pred_s64; + else + fn = filter_pred_u64; + break; + case 4: + if (op == OP_EQ || op == OP_NE) + fn = filter_pred_32; + else if (field_is_signed) + fn = filter_pred_s32; + else + fn = filter_pred_u32; + break; + case 2: + if (op == OP_EQ || op == OP_NE) + fn = filter_pred_16; + else if (field_is_signed) + fn = filter_pred_s16; + else + fn = filter_pred_u16; + break; + case 1: + if (op == OP_EQ || op == OP_NE) + fn = filter_pred_8; + else if (field_is_signed) + fn = filter_pred_s8; + else + fn = filter_pred_u8; + break; + } + + return fn; +} + +static int filter_add_pred(struct filter_parse_state *ps, + struct ftrace_event_call *call, + struct filter_pred *pred) { struct ftrace_event_field *field; filter_pred_fn_t fn; unsigned long long val; + pred->fn = filter_pred_none; + + if (pred->op == OP_AND) { + pred->pop_n = 2; + return filter_add_pred_fn(ps, call, pred, filter_pred_and); + } else if (pred->op == OP_OR) { + pred->pop_n = 2; + return filter_add_pred_fn(ps, call, pred, filter_pred_or); + } + field = find_event_field(call, pred->field_name); - if (!field) + if (!field) { + parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0); return -EINVAL; + } - pred->fn = filter_pred_none; pred->offset = field->offset; + if (!is_legal_op(field, pred->op)) { + parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0); + return -EINVAL; + } + if (is_string_field(field->type)) { fn = filter_pred_string; pred->str_len = field->size; - return filter_add_pred_fn(call, pred, fn); + if (pred->op == OP_NE) + pred->not = 1; + return filter_add_pred_fn(ps, call, pred, fn); } else { - if (strict_strtoull(pred->str_val, 0, &val)) + if (strict_strtoull(pred->str_val, 0, &val)) { + parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0); return -EINVAL; + } pred->val = val; } - switch (field->size) { - case 8: - fn = filter_pred_64; - break; - case 4: - fn = filter_pred_32; - break; - case 2: - fn = filter_pred_16; - break; - case 1: - fn = filter_pred_8; - break; - default: + fn = select_comparison_fn(pred->op, field->size, field->is_signed); + if (!fn) { + parse_error(ps, FILT_ERR_INVALID_OP, 0); return -EINVAL; } - return filter_add_pred_fn(call, pred, fn); -} - -int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) -{ - int err; - - mutex_lock(&filter_mutex); - err = __filter_add_pred(call, pred); - mutex_unlock(&filter_mutex); + if (pred->op == OP_NE) + pred->not = 1; - return err; + return filter_add_pred_fn(ps, call, pred, fn); } -int filter_add_subsystem_pred(struct event_subsystem *system, - struct filter_pred *pred) +static int filter_add_subsystem_pred(struct filter_parse_state *ps, + struct event_subsystem *system, + struct filter_pred *pred, + char *filter_string) { struct event_filter *filter = system->filter; struct ftrace_event_call *call; - mutex_lock(&filter_mutex); - - if (filter && filter->n_preds && !pred->compound) { - __filter_free_subsystem_preds(system); - filter = NULL; - } - - if (!filter) { - system->filter = kzalloc(sizeof(*filter), GFP_KERNEL); - if (!system->filter) { - mutex_unlock(&filter_mutex); - return -ENOMEM; - } - filter = system->filter; + if (!filter->preds) { filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL); - if (!filter->preds) { - kfree(system->filter); - system->filter = NULL; - mutex_unlock(&filter_mutex); + if (!filter->preds) return -ENOMEM; - } } if (filter->n_preds == MAX_FILTER_PRED) { - mutex_unlock(&filter_mutex); + parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); return -ENOSPC; } @@ -424,97 +585,508 @@ int filter_add_subsystem_pred(struct event_subsystem *system, if (strcmp(call->system, system->name)) continue; - err = __filter_add_pred(call, pred); - if (err == -ENOMEM) { - filter->preds[filter->n_preds] = NULL; - filter->n_preds--; - mutex_unlock(&filter_mutex); + err = filter_add_pred(ps, call, pred); + if (err) { + filter_free_subsystem_preds(system); + parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); return err; } + replace_filter_string(call->filter, filter_string); } - mutex_unlock(&filter_mutex); + return 0; +} + +static void parse_init(struct filter_parse_state *ps, + struct filter_op *ops, + char *infix_string) +{ + memset(ps, '\0', sizeof(*ps)); + + ps->infix.string = infix_string; + ps->infix.cnt = strlen(infix_string); + ps->ops = ops; + + INIT_LIST_HEAD(&ps->opstack); + INIT_LIST_HEAD(&ps->postfix); +} + +static char infix_next(struct filter_parse_state *ps) +{ + ps->infix.cnt--; + + return ps->infix.string[ps->infix.tail++]; +} + +static char infix_peek(struct filter_parse_state *ps) +{ + if (ps->infix.tail == strlen(ps->infix.string)) + return 0; + + return ps->infix.string[ps->infix.tail]; +} + +static void infix_advance(struct filter_parse_state *ps) +{ + ps->infix.cnt--; + ps->infix.tail++; +} + +static inline int is_precedence_lower(struct filter_parse_state *ps, + int a, int b) +{ + return ps->ops[a].precedence < ps->ops[b].precedence; +} + +static inline int is_op_char(struct filter_parse_state *ps, char c) +{ + int i; + + for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { + if (ps->ops[i].string[0] == c) + return 1; + } return 0; } -/* - * The filter format can be - * - 0, which means remove all filter preds - * - [||/&&] <field> ==/!= <val> - */ -int filter_parse(char **pbuf, struct filter_pred *pred) -{ - char *tok, *val_str = NULL; - int tok_n = 0; - - 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; +static int infix_get_op(struct filter_parse_state *ps, char firstc) +{ + char nextc = infix_peek(ps); + char opstr[3]; + int i; + + opstr[0] = firstc; + opstr[1] = nextc; + opstr[2] = '\0'; + + for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { + if (!strcmp(opstr, ps->ops[i].string)) { + infix_advance(ps); + return ps->ops[i].id; } - 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; + } + + opstr[1] = '\0'; + + for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { + if (!strcmp(opstr, ps->ops[i].string)) + return ps->ops[i].id; + } + + return OP_NONE; +} + +static inline void clear_operand_string(struct filter_parse_state *ps) +{ + memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL); + ps->operand.tail = 0; +} + +static inline int append_operand_char(struct filter_parse_state *ps, char c) +{ + if (ps->operand.tail == MAX_FILTER_STR_VAL) + return -EINVAL; + + ps->operand.string[ps->operand.tail++] = c; + + return 0; +} + +static int filter_opstack_push(struct filter_parse_state *ps, int op) +{ + struct opstack_op *opstack_op; + + opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL); + if (!opstack_op) + return -ENOMEM; + + opstack_op->op = op; + list_add(&opstack_op->list, &ps->opstack); + + return 0; +} + +static int filter_opstack_empty(struct filter_parse_state *ps) +{ + return list_empty(&ps->opstack); +} + +static int filter_opstack_top(struct filter_parse_state *ps) +{ + struct opstack_op *opstack_op; + + if (filter_opstack_empty(ps)) + return OP_NONE; + + opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list); + + return opstack_op->op; +} + +static int filter_opstack_pop(struct filter_parse_state *ps) +{ + struct opstack_op *opstack_op; + int op; + + if (filter_opstack_empty(ps)) + return OP_NONE; + + opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list); + op = opstack_op->op; + list_del(&opstack_op->list); + + kfree(opstack_op); + + return op; +} + +static void filter_opstack_clear(struct filter_parse_state *ps) +{ + while (!filter_opstack_empty(ps)) + filter_opstack_pop(ps); +} + +static char *curr_operand(struct filter_parse_state *ps) +{ + return ps->operand.string; +} + +static int postfix_append_operand(struct filter_parse_state *ps, char *operand) +{ + struct postfix_elt *elt; + + elt = kmalloc(sizeof(*elt), GFP_KERNEL); + if (!elt) + return -ENOMEM; + + elt->op = OP_NONE; + elt->operand = kstrdup(operand, GFP_KERNEL); + if (!elt->operand) { + kfree(elt); + return -ENOMEM; + } + + list_add_tail(&elt->list, &ps->postfix); + + return 0; +} + +static int postfix_append_op(struct filter_parse_state *ps, int op) +{ + struct postfix_elt *elt; + + elt = kmalloc(sizeof(*elt), GFP_KERNEL); + if (!elt) + return -ENOMEM; + + elt->op = op; + elt->operand = NULL; + + list_add_tail(&elt->list, &ps->postfix); + + return 0; +} + +static void postfix_clear(struct filter_parse_state *ps) +{ + struct postfix_elt *elt; + + while (!list_empty(&ps->postfix)) { + elt = list_first_entry(&ps->postfix, struct postfix_elt, list); + kfree(elt->operand); + list_del(&elt->list); + } +} + +static int filter_parse(struct filter_parse_state *ps) +{ + int op, top_op; + char ch; + + while ((ch = infix_next(ps))) { + if (isspace(ch)) + continue; + + if (is_op_char(ps, ch)) { + op = infix_get_op(ps, ch); + if (op == OP_NONE) { + parse_error(ps, FILT_ERR_INVALID_OP, 0); return -EINVAL; } - tok_n = 2; + + if (strlen(curr_operand(ps))) { + postfix_append_operand(ps, curr_operand(ps)); + clear_operand_string(ps); + } + + while (!filter_opstack_empty(ps)) { + top_op = filter_opstack_top(ps); + if (!is_precedence_lower(ps, top_op, op)) { + top_op = filter_opstack_pop(ps); + postfix_append_op(ps, top_op); + continue; + } + break; + } + + filter_opstack_push(ps, op); 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 */ + + if (ch == '(') { + filter_opstack_push(ps, OP_OPEN_PAREN); + continue; + } + + if (ch == ')') { + if (strlen(curr_operand(ps))) { + postfix_append_operand(ps, curr_operand(ps)); + clear_operand_string(ps); + } + + top_op = filter_opstack_pop(ps); + while (top_op != OP_NONE) { + if (top_op == OP_OPEN_PAREN) + break; + postfix_append_op(ps, top_op); + top_op = filter_opstack_pop(ps); + } + if (top_op == OP_NONE) { + parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0); + return -EINVAL; } - tok_n = 3; continue; } - if (tok_n == 3) { - val_str = tok; - break; /* done */ + if (append_operand_char(ps, ch)) { + parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0); + return -EINVAL; + } + } + + if (strlen(curr_operand(ps))) + postfix_append_operand(ps, curr_operand(ps)); + + while (!filter_opstack_empty(ps)) { + top_op = filter_opstack_pop(ps); + if (top_op == OP_NONE) + break; + if (top_op == OP_OPEN_PAREN) { + parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0); + return -EINVAL; + } + postfix_append_op(ps, top_op); + } + + return 0; +} + +static struct filter_pred *create_pred(int op, char *operand1, char *operand2) +{ + struct filter_pred *pred; + + pred = kzalloc(sizeof(*pred), GFP_KERNEL); + if (!pred) + return NULL; + + pred->field_name = kstrdup(operand1, GFP_KERNEL); + if (!pred->field_name) { + kfree(pred); + return NULL; + } + + strcpy(pred->str_val, operand2); + pred->str_len = strlen(operand2); + + pred->op = op; + + return pred; +} + +static struct filter_pred *create_logical_pred(int op) +{ + struct filter_pred *pred; + + pred = kzalloc(sizeof(*pred), GFP_KERNEL); + if (!pred) + return NULL; + + pred->op = op; + + return pred; +} + +static int check_preds(struct filter_parse_state *ps) +{ + int n_normal_preds = 0, n_logical_preds = 0; + struct postfix_elt *elt; + + list_for_each_entry(elt, &ps->postfix, list) { + if (elt->op == OP_NONE) + continue; + + if (elt->op == OP_AND || elt->op == OP_OR) { + n_logical_preds++; + continue; } + n_normal_preds++; } - if (!val_str || !strlen(val_str) - || strlen(val_str) >= MAX_FILTER_STR_VAL) { - pred->field_name = NULL; + if (!n_normal_preds || n_logical_preds >= n_normal_preds) { + parse_error(ps, FILT_ERR_INVALID_FILTER, 0); return -EINVAL; } - strcpy(pred->str_val, val_str); - pred->str_len = strlen(val_str); + return 0; +} - pred->field_name = kstrdup(pred->field_name, GFP_KERNEL); - if (!pred->field_name) - return -ENOMEM; +static int replace_preds(struct event_subsystem *system, + struct ftrace_event_call *call, + struct filter_parse_state *ps, + char *filter_string) +{ + char *operand1 = NULL, *operand2 = NULL; + struct filter_pred *pred; + struct postfix_elt *elt; + int err; + + err = check_preds(ps); + if (err) + return err; + + list_for_each_entry(elt, &ps->postfix, list) { + if (elt->op == OP_NONE) { + if (!operand1) + operand1 = elt->operand; + else if (!operand2) + operand2 = elt->operand; + else { + parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0); + return -EINVAL; + } + continue; + } + + if (elt->op == OP_AND || elt->op == OP_OR) { + pred = create_logical_pred(elt->op); + if (call) { + err = filter_add_pred(ps, call, pred); + filter_free_pred(pred); + } else + err = filter_add_subsystem_pred(ps, system, + pred, filter_string); + if (err) + return err; + + operand1 = operand2 = NULL; + continue; + } + + if (!operand1 || !operand2) { + parse_error(ps, FILT_ERR_MISSING_FIELD, 0); + return -EINVAL; + } + + pred = create_pred(elt->op, operand1, operand2); + if (call) { + err = filter_add_pred(ps, call, pred); + filter_free_pred(pred); + } else + err = filter_add_subsystem_pred(ps, system, pred, + filter_string); + if (err) + return err; + + operand1 = operand2 = NULL; + } return 0; } +int apply_event_filter(struct ftrace_event_call *call, char *filter_string) +{ + int err; + + struct filter_parse_state *ps; + + mutex_lock(&filter_mutex); + + if (!strcmp(strstrip(filter_string), "0")) { + filter_disable_preds(call); + remove_filter_string(call->filter); + mutex_unlock(&filter_mutex); + return 0; + } + + ps = kzalloc(sizeof(*ps), GFP_KERNEL); + if (!ps) + return -ENOMEM; + + filter_disable_preds(call); + replace_filter_string(call->filter, filter_string); + + parse_init(ps, filter_ops, filter_string); + err = filter_parse(ps); + if (err) { + append_filter_err(ps, call->filter); + goto out; + } + + err = replace_preds(NULL, call, ps, filter_string); + if (err) + append_filter_err(ps, call->filter); + +out: + filter_opstack_clear(ps); + postfix_clear(ps); + kfree(ps); + + mutex_unlock(&filter_mutex); + + return err; +} + +int apply_subsystem_event_filter(struct event_subsystem *system, + char *filter_string) +{ + int err; + + struct filter_parse_state *ps; + + mutex_lock(&filter_mutex); + + if (!strcmp(strstrip(filter_string), "0")) { + filter_free_subsystem_preds(system); + remove_filter_string(system->filter); + mutex_unlock(&filter_mutex); + return 0; + } + + ps = kzalloc(sizeof(*ps), GFP_KERNEL); + if (!ps) + return -ENOMEM; + + filter_free_subsystem_preds(system); + replace_filter_string(system->filter, filter_string); + + parse_init(ps, filter_ops, filter_string); + err = filter_parse(ps); + if (err) { + append_filter_err(ps, system->filter); + goto out; + } + + err = replace_preds(system, NULL, ps, filter_string); + if (err) + append_filter_err(ps, system->filter); + +out: + filter_opstack_clear(ps); + postfix_clear(ps); + kfree(ps); + + mutex_unlock(&filter_mutex); + + return err; +} |