diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 52 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 4 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 38 | ||||
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 885 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 111 | ||||
| -rw-r--r-- | kernel/trace/trace_sched_switch.c | 48 | ||||
| -rw-r--r-- | kernel/trace/trace_syscalls.c | 42 |
7 files changed, 939 insertions, 241 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f3dadae8388..888b611897d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3328,7 +3328,7 @@ static int start_graph_tracing(void) /* The cpu_boot init_task->ret_stack will never be freed */ for_each_online_cpu(cpu) { if (!idle_task(cpu)->ret_stack) - ftrace_graph_init_task(idle_task(cpu)); + ftrace_graph_init_idle_task(idle_task(cpu), cpu); } do { @@ -3418,6 +3418,49 @@ void unregister_ftrace_graph(void) mutex_unlock(&ftrace_lock); } +static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); + +static void +graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) +{ + atomic_set(&t->tracing_graph_pause, 0); + atomic_set(&t->trace_overrun, 0); + t->ftrace_timestamp = 0; + /* make curr_ret_stack visable before we add the ret_stack */ + smp_wmb(); + t->ret_stack = ret_stack; +} + +/* + * Allocate a return stack for the idle task. May be the first + * time through, or it may be done by CPU hotplug online. + */ +void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) +{ + t->curr_ret_stack = -1; + /* + * The idle task has no parent, it either has its own + * stack or no stack at all. + */ + if (t->ret_stack) + WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); + + if (ftrace_graph_active) { + struct ftrace_ret_stack *ret_stack; + + ret_stack = per_cpu(idle_ret_stack, cpu); + if (!ret_stack) { + ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH + * sizeof(struct ftrace_ret_stack), + GFP_KERNEL); + if (!ret_stack) + return; + per_cpu(idle_ret_stack, cpu) = ret_stack; + } + graph_init_task(t, ret_stack); + } +} + /* Allocate a return stack for newly created task */ void ftrace_graph_init_task(struct task_struct *t) { @@ -3433,12 +3476,7 @@ void ftrace_graph_init_task(struct task_struct *t) GFP_KERNEL); if (!ret_stack) return; - atomic_set(&t->tracing_graph_pause, 0); - atomic_set(&t->trace_overrun, 0); - t->ftrace_timestamp = 0; - /* make curr_ret_stack visable before we add the ret_stack */ - smp_wmb(); - t->ret_stack = ret_stack; + graph_init_task(t, ret_stack); } } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index dc53ecb8058..8dc8da6733f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2710,6 +2710,10 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf, mutex_lock(&trace_types_lock); if (tracer_enabled ^ val) { + + /* Only need to warn if this is used to change the state */ + WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on"); + if (val) { tracer_enabled = 1; if (current_trace->start) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9021f8c0c0c..856e73cc1d3 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -661,8 +661,10 @@ struct ftrace_event_field { }; struct event_filter { - int n_preds; - struct filter_pred **preds; + int n_preds; /* Number assigned */ + int a_preds; /* allocated */ + struct filter_pred *preds; + struct filter_pred *root; char *filter_string; }; @@ -674,11 +676,23 @@ struct event_subsystem { int nr_events; }; +#define FILTER_PRED_INVALID ((unsigned short)-1) +#define FILTER_PRED_IS_RIGHT (1 << 15) +#define FILTER_PRED_FOLD (1 << 15) + +/* + * The max preds is the size of unsigned short with + * two flags at the MSBs. One bit is used for both the IS_RIGHT + * and FOLD flags. The other is reserved. + * + * 2^14 preds is way more than enough. + */ +#define MAX_FILTER_PRED 16384 + struct filter_pred; struct regex; -typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, - int val1, int val2); +typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event); typedef int (*regex_match_func)(char *str, struct regex *r, int len); @@ -700,11 +714,23 @@ struct filter_pred { filter_pred_fn_t fn; u64 val; struct regex regex; - char *field_name; + /* + * Leaf nodes use field_name, ops is used by AND and OR + * nodes. The field_name is always freed when freeing a pred. + * We can overload field_name for ops and have it freed + * as well. + */ + union { + char *field_name; + unsigned short *ops; + }; int offset; int not; int op; - int pop_n; + unsigned short index; + unsigned short parent; + unsigned short left; + unsigned short right; }; extern struct list_head ftrace_common_fields; diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 36d40104b17..3249b4f77ef 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -123,9 +123,13 @@ struct filter_parse_state { } operand; }; +struct pred_stack { + struct filter_pred **preds; + int index; +}; + #define DEFINE_COMPARISON_PRED(type) \ -static int filter_pred_##type(struct filter_pred *pred, void *event, \ - int val1, int val2) \ +static int filter_pred_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ @@ -152,8 +156,7 @@ static int filter_pred_##type(struct filter_pred *pred, void *event, \ } #define DEFINE_EQUALITY_PRED(size) \ -static int filter_pred_##size(struct filter_pred *pred, void *event, \ - int val1, int val2) \ +static int filter_pred_##size(struct filter_pred *pred, void *event) \ { \ u##size *addr = (u##size *)(event + pred->offset); \ u##size val = (u##size)pred->val; \ @@ -178,23 +181,8 @@ 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) -{ - return val1 && val2; -} - -static int filter_pred_or(struct filter_pred *pred __attribute((unused)), - void *event __attribute((unused)), - int val1, int val2) -{ - return val1 || val2; -} - /* Filter predicate for fixed sized arrays of characters */ -static int filter_pred_string(struct filter_pred *pred, void *event, - int val1, int val2) +static int filter_pred_string(struct filter_pred *pred, void *event) { char *addr = (char *)(event + pred->offset); int cmp, match; @@ -207,8 +195,7 @@ static int filter_pred_string(struct filter_pred *pred, void *event, } /* Filter predicate for char * pointers */ -static int filter_pred_pchar(struct filter_pred *pred, void *event, - int val1, int val2) +static int filter_pred_pchar(struct filter_pred *pred, void *event) { char **addr = (char **)(event + pred->offset); int cmp, match; @@ -231,8 +218,7 @@ static int filter_pred_pchar(struct filter_pred *pred, void *event, * and add it to the address of the entry, and at last we have * the address of the string. */ -static int filter_pred_strloc(struct filter_pred *pred, void *event, - int val1, int val2) +static int filter_pred_strloc(struct filter_pred *pred, void *event) { u32 str_item = *(u32 *)(event + pred->offset); int str_loc = str_item & 0xffff; @@ -247,8 +233,7 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event, return match; } -static int filter_pred_none(struct filter_pred *pred, void *event, - int val1, int val2) +static int filter_pred_none(struct filter_pred *pred, void *event) { return 0; } @@ -377,32 +362,147 @@ static void filter_build_regex(struct filter_pred *pred) pred->not ^= not; } +enum move_type { + MOVE_DOWN, + MOVE_UP_FROM_LEFT, + MOVE_UP_FROM_RIGHT +}; + +static struct filter_pred * +get_pred_parent(struct filter_pred *pred, struct filter_pred *preds, + int index, enum move_type *move) +{ + if (pred->parent & FILTER_PRED_IS_RIGHT) + *move = MOVE_UP_FROM_RIGHT; + else + *move = MOVE_UP_FROM_LEFT; + pred = &preds[pred->parent & ~FILTER_PRED_IS_RIGHT]; + + return pred; +} + +/* + * A series of AND or ORs where found together. Instead of + * climbing up and down the tree branches, an array of the + * ops were made in order of checks. We can just move across + * the array and short circuit if needed. + */ +static int process_ops(struct filter_pred *preds, + struct filter_pred *op, void *rec) +{ + struct filter_pred *pred; + int type; + int match; + int i; + + /* + * Micro-optimization: We set type to true if op + * is an OR and false otherwise (AND). Then we + * just need to test if the match is equal to + * the type, and if it is, we can short circuit the + * rest of the checks: + * + * if ((match && op->op == OP_OR) || + * (!match && op->op == OP_AND)) + * return match; + */ + type = op->op == OP_OR; + + for (i = 0; i < op->val; i++) { + pred = &preds[op->ops[i]]; + match = pred->fn(pred, rec); + if (!!match == type) + return match; + } + return match; +} + /* return 1 if event matches, 0 otherwise (discard) */ int filter_match_preds(struct event_filter *filter, void *rec) { - int match, top = 0, val1 = 0, val2 = 0; - int stack[MAX_FILTER_PRED]; + int match = -1; + enum move_type move = MOVE_DOWN; + struct filter_pred *preds; struct filter_pred *pred; - int i; + struct filter_pred *root; + int n_preds; + int done = 0; + + /* no filter is considered a match */ + if (!filter) + return 1; + + n_preds = filter->n_preds; + + if (!n_preds) + return 1; + + /* + * n_preds, root and filter->preds are protect with preemption disabled. + */ + preds = rcu_dereference_sched(filter->preds); + root = rcu_dereference_sched(filter->root); + if (!root) + return 1; + + pred = root; - for (i = 0; i < filter->n_preds; i++) { - pred = filter->preds[i]; - if (!pred->pop_n) { - match = pred->fn(pred, rec, val1, val2); - stack[top++] = match; + /* match is currently meaningless */ + match = -1; + + do { + switch (move) { + case MOVE_DOWN: + /* only AND and OR have children */ + if (pred->left != FILTER_PRED_INVALID) { + /* If ops is set, then it was folded. */ + if (!pred->ops) { + /* keep going to down the left side */ + pred = &preds[pred->left]; + continue; + } + /* We can treat folded ops as a leaf node */ + match = process_ops(preds, pred, rec); + } else + match = pred->fn(pred, rec); + /* If this pred is the only pred */ + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + case MOVE_UP_FROM_LEFT: + /* + * Check for short circuits. + * + * Optimization: !!match == (pred->op == OP_OR) + * is the same as: + * if ((match && pred->op == OP_OR) || + * (!match && pred->op == OP_AND)) + */ + if (!!match == (pred->op == OP_OR)) { + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + } + /* now go down the right side of the tree. */ + pred = &preds[pred->right]; + move = MOVE_DOWN; + continue; + case MOVE_UP_FROM_RIGHT: + /* We finished this equation. */ + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); continue; } - 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; - } + done = 1; + } while (!done); - return stack[--top]; + return match; } EXPORT_SYMBOL_GPL(filter_match_preds); @@ -414,6 +514,9 @@ static void parse_error(struct filter_parse_state *ps, int err, int pos) static void remove_filter_string(struct event_filter *filter) { + if (!filter) + return; + kfree(filter->filter_string); filter->filter_string = NULL; } @@ -473,9 +576,10 @@ static void append_filter_err(struct filter_parse_state *ps, void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s) { - struct event_filter *filter = call->filter; + struct event_filter *filter; mutex_lock(&event_mutex); + filter = call->filter; if (filter && filter->filter_string) trace_seq_printf(s, "%s\n", filter->filter_string); else @@ -486,9 +590,10 @@ void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s) void print_subsystem_event_filter(struct event_subsystem *system, struct trace_seq *s) { - struct event_filter *filter = system->filter; + struct event_filter *filter; mutex_lock(&event_mutex); + filter = system->filter; if (filter && filter->filter_string) trace_seq_printf(s, "%s\n", filter->filter_string); else @@ -539,10 +644,58 @@ static void filter_clear_pred(struct filter_pred *pred) pred->regex.len = 0; } -static int filter_set_pred(struct filter_pred *dest, +static int __alloc_pred_stack(struct pred_stack *stack, int n_preds) +{ + stack->preds = kzalloc(sizeof(*stack->preds)*(n_preds + 1), GFP_KERNEL); + if (!stack->preds) + return -ENOMEM; + stack->index = n_preds; + return 0; +} + +static void __free_pred_stack(struct pred_stack *stack) +{ + kfree(stack->preds); + stack->index = 0; +} + +static int __push_pred_stack(struct pred_stack *stack, + struct filter_pred *pred) +{ + int index = stack->index; + + if (WARN_ON(index == 0)) + return -ENOSPC; + + stack->preds[--index] = pred; + stack->index = index; + return 0; +} + +static struct filter_pred * +__pop_pred_stack(struct pred_stack *stack) +{ + struct filter_pred *pred; + int index = stack->index; + + pred = stack->preds[index++]; + if (!pred) + return NULL; + + stack->index = index; + return pred; +} + +static int filter_set_pred(struct event_filter *filter, + int idx, + struct pred_stack *stack, struct filter_pred *src, filter_pred_fn_t fn) { + struct filter_pred *dest = &filter->preds[idx]; + struct filter_pred *left; + struct filter_pred *right; + *dest = *src; if (src->field_name) { dest->field_name = kstrdup(src->field_name, GFP_KERNEL); @@ -550,116 +703,140 @@ static int filter_set_pred(struct filter_pred *dest, return -ENOMEM; } dest->fn = fn; + dest->index = idx; - return 0; + if (dest->op == OP_OR || dest->op == OP_AND) { + right = __pop_pred_stack(stack); + left = __pop_pred_stack(stack); + if (!left || !right) + return -EINVAL; + /* + * If both children can be folded + * and they are the same op as this op or a leaf, + * then this op can be folded. + */ + if (left->index & FILTER_PRED_FOLD && + (left->op == dest->op || + left->left == FILTER_PRED_INVALID) && + right->index & FILTER_PRED_FOLD && + (right->op == dest->op || + right->left == FILTER_PRED_INVALID)) + dest->index |= FILTER_PRED_FOLD; + + dest->left = left->index & ~FILTER_PRED_FOLD; + dest->right = right->index & ~FILTER_PRED_FOLD; + left->parent = dest->index & ~FILTER_PRED_FOLD; + right->parent = dest->index | FILTER_PRED_IS_RIGHT; + } else { + /* + * Make dest->left invalid to be used as a quick + * way to know this is a leaf node. + */ + dest->left = FILTER_PRED_INVALID; + + /* All leafs allow folding the parent ops. */ + dest->index |= FILTER_PRED_FOLD; + } + + return __push_pred_stack(stack, dest); } -static void filter_disable_preds(struct ftrace_event_call *call) +static void __free_preds(struct event_filter *filter) { - struct event_filter *filter = call->filter; int i; - call->flags &= ~TRACE_EVENT_FL_FILTERED; + if (filter->preds) { + for (i = 0; i < filter->a_preds; i++) + kfree(filter->preds[i].field_name); + kfree(filter->preds); + filter->preds = NULL; + } + filter->a_preds = 0; filter->n_preds = 0; - - for (i = 0; i < MAX_FILTER_PRED; i++) - filter->preds[i]->fn = filter_pred_none; } -static void __free_preds(struct event_filter *filter) +static void filter_disable(struct ftrace_event_call *call) { - int i; + call->flags &= ~TRACE_EVENT_FL_FILTERED; +} +static void __free_filter(struct event_filter *filter) +{ if (!filter) return; - for (i = 0; i < MAX_FILTER_PRED; i++) { - if (filter->preds[i]) - filter_free_pred(filter->preds[i]); - } - kfree(filter->preds); + __free_preds(filter); kfree(filter->filter_string); kfree(filter); } +/* + * Called when destroying the ftrace_event_call. + * The call is being freed, so we do not need to worry about + * the call being currently used. This is for module code removing + * the tracepoints from within it. + */ void destroy_preds(struct ftrace_event_call *call) { - __free_preds(call->filter); + __free_filter(call->filter); call->filter = NULL; - call->flags &= ~TRACE_EVENT_FL_FILTERED; } -static struct event_filter *__alloc_preds(void) +static struct event_filter *__alloc_filter(void) { struct event_filter *filter; + + filter = kzalloc(sizeof(*filter), GFP_KERNEL); + return filter; +} + +static int __alloc_preds(struct event_filter *filter, int n_preds) +{ struct filter_pred *pred; int i; - filter = kzalloc(sizeof(*filter), GFP_KERNEL); - if (!filter) - return ERR_PTR(-ENOMEM); + if (filter->preds) + __free_preds(filter); - filter->n_preds = 0; + filter->preds = + kzalloc(sizeof(*filter->preds) * n_preds, GFP_KERNEL); - filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL); if (!filter->preds) - goto oom; + return -ENOMEM; - for (i = 0; i < MAX_FILTER_PRED; i++) { - pred = kzalloc(sizeof(*pred), GFP_KERNEL); - if (!pred) - goto oom; + filter->a_preds = n_preds; + filter->n_preds = 0; + + for (i = 0; i < n_preds; i++) { + pred = &filter->preds[i]; pred->fn = filter_pred_none; - filter->preds[i] = pred; } - return filter; - -oom: - __free_preds(filter); - return ERR_PTR(-ENOMEM); -} - -static int init_preds(struct ftrace_event_call *call) -{ - if (call->filter) - return 0; - - call->flags &= ~TRACE_EVENT_FL_FILTERED; - call->filter = __alloc_preds(); - if (IS_ERR(call->filter)) - return PTR_ERR(call->filter); - return 0; } -static int init_subsystem_preds(struct event_subsystem *system) +static void filter_free_subsystem_preds(struct event_subsystem *system) { struct ftrace_event_call *call; - int err; list_for_each_entry(call, &ftrace_events, list) { if (strcmp(call->class->system, system->name) != 0) continue; - err = init_preds(call); - if (err) - return err; + filter_disable(call); + remove_filter_string(call->filter); } - - return 0; } -static void filter_free_subsystem_preds(struct event_subsystem *system) +static void filter_free_subsystem_filters(struct event_subsystem *system) { struct ftrace_event_call *call; list_for_each_entry(call, &ftrace_events, list) { if (strcmp(call->class->system, system->name) != 0) continue; - - filter_disable_preds(call); - remove_filter_string(call->filter); + __free_filter(call->filter); + call->filter = NULL; } } @@ -667,18 +844,19 @@ static int filter_add_pred_fn(struct filter_parse_state *ps, struct ftrace_event_call *call, struct event_filter *filter, struct filter_pred *pred, + struct pred_stack *stack, filter_pred_fn_t fn) { int idx, err; - if (filter->n_preds == MAX_FILTER_PRED) { + if (WARN_ON(filter->n_preds == filter->a_preds)) { parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); return -ENOSPC; } idx = filter->n_preds; - filter_clear_pred(filter->preds[idx]); - err = filter_set_pred(filter->preds[idx], pred, fn); + filter_clear_pred(&filter->preds[idx]); + err = filter_set_pred(filter, idx, stack, pred, fn); if (err) return err; @@ -763,6 +941,7 @@ static int filter_add_pred(struct filter_parse_state *ps, struct ftrace_event_call *call, struct event_filter *filter, struct filter_pred *pred, + struct pred_stack *stack, bool dry_run) { struct ftrace_event_field *field; @@ -770,17 +949,12 @@ static int filter_add_pred(struct filter_parse_state *ps, unsigned long long val; int ret; - pred->fn = filter_pred_none; + fn = pred->fn = filter_pred_none; - if (pred->op == OP_AND) { - pred->pop_n = 2; - fn = filter_pred_and; + if (pred->op == OP_AND) goto add_pred_fn; - } else if (pred->op == OP_OR) { - pred->pop_n = 2; - fn = filter_pred_or; + else if (pred->op == OP_OR) goto add_pred_fn; - } field = find_event_field(call, pred->field_name); if (!field) { @@ -829,7 +1003,7 @@ static int filter_add_pred(struct filter_parse_state *ps, add_pred_fn: if (!dry_run) - return filter_add_pred_fn(ps, call, filter, pred, fn); + return filter_add_pred_fn(ps, call, filter, pred, stack, fn); return 0; } @@ -1187,6 +1361,234 @@ static int check_preds(struct filter_parse_state *ps) return 0; } +static int count_preds(struct filter_parse_state *ps) +{ + struct postfix_elt *elt; + int n_preds = 0; + + list_for_each_entry(elt, &ps->postfix, list) { + if (elt->op == OP_NONE) + continue; + n_preds++; + } + + return n_preds; +} + +/* + * The tree is walked at filtering of an event. If the tree is not correctly + * built, it may cause an infinite loop. Check here that the tree does + * indeed terminate. + */ +static int check_pred_tree(struct event_filter *filter, + struct filter_pred *root) +{ + struct filter_pred *preds; + struct filter_pred *pred; + enum move_type move = MOVE_DOWN; + int count = 0; + int done = 0; + int max; + + /* + * The max that we can hit a node is three times. + * Once going down, once coming up from left, and + * once coming up from right. This is more than enough + * since leafs are only hit a single time. + */ + max = 3 * filter->n_preds; + + preds = filter->preds; + if (!preds) + return -EINVAL; + pred = root; + + do { + if (WARN_ON(count++ > max)) + return -EINVAL; + + switch (move) { + case MOVE_DOWN: + if (pred->left != FILTER_PRED_INVALID) { + pred = &preds[pred->left]; + continue; + } + /* A leaf at the root is just a leaf in the tree */ + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + case MOVE_UP_FROM_LEFT: + pred = &preds[pred->right]; + move = MOVE_DOWN; + continue; + case MOVE_UP_FROM_RIGHT: + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + } + done = 1; + } while (!done); + + /* We are fine. */ + return 0; +} + +static int count_leafs(struct filter_pred *preds, struct filter_pred *root) +{ + struct filter_pred *pred; + enum move_type move = MOVE_DOWN; + int count = 0; + int done = 0; + + pred = root; + + do { + switch (move) { + case MOVE_DOWN: + if (pred->left != FILTER_PRED_INVALID) { + pred = &preds[pred->left]; + continue; + } + /* A leaf at the root is just a leaf in the tree */ + if (pred == root) + return 1; + count++; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + case MOVE_UP_FROM_LEFT: + pred = &preds[pred->right]; + move = MOVE_DOWN; + continue; + case MOVE_UP_FROM_RIGHT: + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + } + done = 1; + } while (!done); + + return count; +} + +static int fold_pred(struct filter_pred *preds, struct filter_pred *root) +{ + struct filter_pred *pred; + enum move_type move = MOVE_DOWN; + int count = 0; + int children; + int done = 0; + + /* No need to keep the fold flag */ + root->index &= ~FILTER_PRED_FOLD; + + /* If the root is a leaf then do nothing */ + if (root->left == FILTER_PRED_INVALID) + return 0; + + /* count the children */ + children = count_leafs(preds, &preds[root->left]); + children += count_leafs(preds, &preds[root->right]); + + root->ops = kzalloc(sizeof(*root->ops) * children, GFP_KERNEL); + if (!root->ops) + return -ENOMEM; + + root->val = children; + + pred = root; + do { + switch (move) { + case MOVE_DOWN: + if (pred->left != FILTER_PRED_INVALID) { + pred = &preds[pred->left]; + continue; + } + if (WARN_ON(count == children)) + return -EINVAL; + pred->index &= ~FILTER_PRED_FOLD; + root->ops[count++] = pred->index; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + case MOVE_UP_FROM_LEFT: + pred = &preds[pred->right]; + move = MOVE_DOWN; + continue; + case MOVE_UP_FROM_RIGHT: + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + } + done = 1; + } while (!done); + + return 0; +} + +/* + * To optimize the processing of the ops, if we have several "ors" or + * "ands" together, we can put them in an array and process them all + * together speeding up the filter logic. + */ +static int fold_pred_tree(struct event_filter *filter, + struct filter_pred *root) +{ + struct filter_pred *preds; + struct filter_pred *pred; + enum move_type move = MOVE_DOWN; + int done = 0; + int err; + + preds = filter->preds; + if (!preds) + return -EINVAL; + pred = root; + + do { + switch (move) { + case MOVE_DOWN: + if (pred->index & FILTER_PRED_FOLD) { + err = fold_pred(preds, pred); + if (err) + return err; + /* Folded nodes are like leafs */ + } else if (pred->left != FILTER_PRED_INVALID) { + pred = &preds[pred->left]; + continue; + } + + /* A leaf at the root is just a leaf in the tree */ + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + case MOVE_UP_FROM_LEFT: + pred = &preds[pred->right]; + move = MOVE_DOWN; + continue; + case MOVE_UP_FROM_RIGHT: + if (pred == root) + break; + pred = get_pred_parent(pred, preds, + pred->parent, &move); + continue; + } + done = 1; + } while (!done); + + return 0; +} + static int replace_preds(struct ftrace_event_call *call, struct event_filter *filter, struct filter_parse_state *ps, @@ -1195,14 +1597,32 @@ static int replace_preds(struct ftrace_event_call *call, { char *operand1 = NULL, *operand2 = NULL; struct filter_pred *pred; + struct filter_pred *root; struct postfix_elt *elt; + struct pred_stack stack = { }; /* init to NULL */ int err; int n_preds = 0; + n_preds = count_preds(ps); + if (n_preds >= MAX_FILTER_PRED) { + parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); + return -ENOSPC; + } + err = check_preds(ps); if (err) return err; + if (!dry_run) { + err = __alloc_pred_stack(&stack, n_preds); + if (err) + return err; + err = __alloc_preds(filter, n_preds); + if (err) + goto fail; + } + + n_preds = 0; list_for_each_entry(elt, &ps->postfix, list) { if (elt->op == OP_NONE) { if (!operand1) @@ -1211,14 +1631,16 @@ static int replace_preds(struct ftrace_event_call *call, operand2 = elt->operand; else { parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0); - return -EINVAL; + err = -EINVAL; + goto fail; } continue; } - if (n_preds++ == MAX_FILTER_PRED) { + if (WARN_ON(n_preds++ == MAX_FILTER_PRED)) { parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); - return -ENOSPC; + err = -ENOSPC; + goto fail; } if (elt->op == OP_AND || elt->op == OP_OR) { @@ -1228,76 +1650,181 @@ static int replace_preds(struct ftrace_event_call *call, if (!operand1 || !operand2) { parse_error(ps, FILT_ERR_MISSING_FIELD, 0); - return -EINVAL; + err = -EINVAL; + goto fail; } pred = create_pred(elt->op, operand1, operand2); add_pred: - if (!pred) - return -ENOMEM; - err = filter_add_pred(ps, call, filter, pred, dry_run); + if (!pred) { + err = -ENOMEM; + goto fail; + } + err = filter_add_pred(ps, call, filter, pred, &stack, dry_run); filter_free_pred(pred); if (err) - return err; + goto fail; operand1 = operand2 = NULL; } - return 0; + if (!dry_run) { + /* We should have one item left on the stack */ + pred = __pop_pred_stack(&stack); + if (!pred) + return -EINVAL; + /* This item is where we start from in matching */ + root = pred; + /* Make sure the stack is empty */ + pred = __pop_pred_stack(&stack); + if (WARN_ON(pred)) { + err = -EINVAL; + filter->root = NULL; + goto fail; + } + err = check_pred_tree(filter, root); + if (err) + goto fail; + + /* Optimize the tree */ + err = fold_pred_tree(filter, root); + if (err) + goto fail; + + /* We don't set root until we know it works */ + barrier(); + filter->root = root; + } + + err = 0; +fail: + __free_pred_stack(&stack); + return err; } +struct filter_list { + struct list_head list; + struct event_filter *filter; +}; + static int replace_system_preds(struct event_subsystem *system, struct filter_parse_state *ps, char *filter_string) { struct ftrace_event_call *call; + struct filter_list *filter_item; + struct filter_list *tmp; + LIST_HEAD(filter_list); bool fail = true; int err; list_for_each_entry(call, &ftrace_events, list) { - struct event_filter *filter = call->filter; if (strcmp(call->class->system, system->name) != 0) continue; - /* try to see if the filter can be applied */ - err = replace_preds(call, filter, ps, filter_string, true); + /* + * Try to see if the filter can be applied + * (filter arg is ignored on dry_run) + */ + err = replace_preds(call, NULL, ps, filter_string, true); if (err) + goto fail; + } + + list_for_each_entry(call, &ftrace_events, list) { + struct event_filter *filter; + + if (strcmp(call->class->system, system->name) != 0) continue; - /* really apply the filter */ - filter_disable_preds(call); - err = replace_preds(call, filter, ps, filter_string, false); + filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL); + if (!filter_item) + goto fail_mem; + + list_add_tail(&filter_item->list, &filter_list); + + filter_item->filter = __alloc_filter(); + if (!filter_item->filter) + goto fail_mem; + filter = filter_item->filter; + + /* Can only fail on no memory */ + err = replace_filter_string(filter, filter_string); if (err) - filter_disable_preds(call); - else { + goto fail_mem; + + err = replace_preds(call, filter, ps, filter_string, false); + if (err) { + filter_disable(call); + parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); + append_filter_err(ps, filter); + } else call->flags |= TRACE_EVENT_FL_FILTERED; - replace_filter_string(filter, filter_string); - } + /* + * Regardless of if this returned an error, we still + * replace the filter for the call. + */ + filter = call->filter; + call->filter = filter_item->filter; + filter_item->filter = filter; + fail = false; } - if (fail) { - parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); - return -EINVAL; + if (fail) + goto fail; + + /* + * The calls can still be using the old filters. + * Do a synchronize_sched() to ensure all calls are + * done with them before we free them. + */ + synchronize_sched(); + list_for_each_entry_safe(filter_item, tmp, &filter_list, list) { + __free_filter(filter_item->filter); + list_del(&filter_item->list); + kfree(filter_item); } return 0; + fail: + /* No call succeeded */ + list_for_each_entry_safe(filter_item, tmp, &filter_list, list) { + list_del(&filter_item->list); + kfree(filter_item); + } + parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); + return -EINVAL; + fail_mem: + /* If any call succeeded, we still need to sync */ + if (!fail) + synchronize_sched(); + list_for_each_entry_safe(filter_item, tmp, &filter_list, list) { + __free_filter(filter_item->filter); + list_del(&filter_item->list); + kfree(filter_item); + } + return -ENOMEM; } int apply_event_filter(struct ftrace_event_call *call, char *filter_string) { - int err; struct filter_parse_state *ps; + struct event_filter *filter; + struct event_filter *tmp; + int err = 0; mutex_lock(&event_mutex); - err = init_preds(call); - if (err) - goto out_unlock; - if (!strcmp(strstrip(filter_string), "0")) { - filter_disable_preds(call); - remove_filter_string(call->filter); + filter_disable(call); + filter = call->filter; + if (!filter) + goto out_unlock; + call->filter = NULL; + /* Make sure the filter is not being used */ + synchronize_sched(); + __free_filter(filter); goto out_unlock; } @@ -1306,22 +1833,41 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) if (!ps) goto out_unlock; - filter_disable_preds(call); - replace_filter_string(call->filter, filter_string); + 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, call->filter); + append_filter_err(ps, filter); goto out; } - err = replace_preds(call, call->filter, ps, filter_string, false); - if (err) - append_filter_err(ps, call->filter); - else + 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; + 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); @@ -1334,18 +1880,21 @@ out_unlock: int apply_subsystem_event_filter(struct event_subsystem *system, char *filter_string) { - int err; struct filter_parse_state *ps; + struct event_filter *filter; + int err = 0; mutex_lock(&event_mutex); - err = init_subsystem_preds(system); - if (err) - goto out_unlock; - if (!strcmp(strstrip(filter_string), "0")) { filter_free_subsystem_preds(system); remove_filter_string(system->filter); + filter = system->filter; + system->filter = NULL; + /* Ensure all filters are no longer used */ + synchronize_sched(); + filter_free_subsystem_filters(system); + __free_filter(filter); goto out_unlock; } @@ -1354,7 +1903,17 @@ int apply_subsystem_event_filter(struct event_subsystem *system, if (!ps) goto out_unlock; - replace_filter_string(system->filter, filter_string); + filter = __alloc_filter(); + if (!filter) + goto out; + + replace_filter_string(filter, filter_string); + /* + * 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); @@ -1384,7 +1943,7 @@ void ftrace_profile_free_filter(struct perf_event *event) struct event_filter *filter = event->filter; event->filter = NULL; - __free_preds(filter); + __free_filter(filter); } int ftrace_profile_set_filter(struct perf_event *event, int event_id, @@ -1410,8 +1969,8 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id, if (event->filter) goto out_unlock; - filter = __alloc_preds(); - if (IS_ERR(filter)) { + filter = __alloc_filter(); + if (!filter) { err = PTR_ERR(filter); goto out_unlock; } @@ -1419,7 +1978,7 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id, err = -ENOMEM; ps = kzalloc(sizeof(*ps), GFP_KERNEL); if (!ps) - goto free_preds; + goto free_filter; parse_init(ps, filter_ops, filter_str); err = filter_parse(ps); @@ -1435,9 +1994,9 @@ free_ps: postfix_clear(ps); kfree(ps); -free_preds: +free_filter: if (err) - __free_preds(filter); + __free_filter(filter); out_unlock: mutex_unlock(&event_mutex); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 2dec9bcde8b..8435b43b178 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -353,6 +353,43 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) kfree(data); } +/* Bitfield fetch function */ +struct bitfield_fetch_param { + struct fetch_param orig; + unsigned char hi_shift; + unsigned char low_shift; +}; + +#define DEFINE_FETCH_bitfield(type) \ +static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ + void *data, void *dest) \ +{ \ + struct bitfield_fetch_param *bprm = data; \ + type buf = 0; \ + call_fetch(&bprm->orig, regs, &buf); \ + if (buf) { \ + buf <<= bprm->hi_shift; \ + buf >>= bprm->low_shift; \ + } \ + *(type *)dest = buf; \ +} +DEFINE_BASIC_FETCH_FUNCS(bitfield) +#define fetch_bitfield_string NULL +#define fetch_bitfield_string_size NULL + +static __kprobes void +free_bitfield_fetch_param(struct bitfield_fetch_param *data) +{ + /* + * Don't check the bitfield itself, because this must be the + * last fetch function. + */ + if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) + free_deref_fetch_param(data->orig.data); + else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) + free_symbol_cache(data->orig.data); + kfree(data); +} /* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) u##t #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) @@ -367,6 +404,7 @@ enum { FETCH_MTD_memory, FETCH_MTD_symbol, FETCH_MTD_deref, + FETCH_MTD_bitfield, FETCH_MTD_END, }; @@ -387,6 +425,7 @@ ASSIGN_FETCH_FUNC(retval, ftype), \ ASSIGN_FETCH_FUNC(memory, ftype), \ ASSIGN_FETCH_FUNC(symbol, ftype), \ ASSIGN_FETCH_FUNC(deref, ftype), \ +ASSIGN_FETCH_FUNC(bitfield, ftype), \ } \ } @@ -430,9 +469,33 @@ static const struct fetch_type *find_fetch_type(const char *type) if (!type) type = DEFAULT_FETCH_TYPE_STR; + /* Special case: bitfield */ + if (*type == 'b') { + unsigned long bs; + type = strchr(type, '/'); + if (!type) + goto fail; + type++; + if (strict_strtoul(type, 0, &bs)) + goto fail; + switch (bs) { + case 8: + return find_fetch_type("u8"); + case 16: + return find_fetch_type("u16"); + case 32: + return find_fetch_type("u32"); + case 64: + return find_fetch_type("u64"); + default: + goto fail; + } + } + for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) if (strcmp(type, fetch_type_table[i].name) == 0) return &fetch_type_table[i]; +fail: return NULL; } @@ -586,7 +649,9 @@ error: static void free_probe_arg(struct probe_arg *arg) { - if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) + if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) + free_bitfield_fetch_param(arg->fetch.data); + else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) free_deref_fetch_param(arg->fetch.data); else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) free_symbol_cache(arg->fetch.data); @@ -767,16 +832,15 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t, } break; case '+': /* deref memory */ + arg++; /* Skip '+', because strict_strtol() rejects it. */ case '-': tmp = strchr(arg, '('); if (!tmp) break; *tmp = '\0'; - ret = strict_strtol(arg + 1, 0, &offset); + ret = strict_strtol(arg, 0, &offset); if (ret) break; - if (arg[0] == '-') - offset = -offset; arg = tmp + 1; tmp = strrchr(arg, ')'); if (tmp) { @@ -807,6 +871,41 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t, return ret; } +#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) + +/* Bitfield type needs to be parsed into a fetch function */ +static int __parse_bitfield_probe_arg(const char *bf, + const struct fetch_type *t, + struct fetch_param *f) +{ + struct bitfield_fetch_param *bprm; + unsigned long bw, bo; + char *tail; + + if (*bf != 'b') + return 0; + + bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + if (!bprm) + return -ENOMEM; + bprm->orig = *f; + f->fn = t->fetch[FETCH_MTD_bitfield]; + f->data = (void *)bprm; + + bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ + if (bw == 0 || *tail != '@') + return -EINVAL; + + bf = tail + 1; + bo = simple_strtoul(bf, &tail, 0); + if (tail == bf || *tail != '/') + return -EINVAL; + + bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); + bprm->low_shift = bprm->hi_shift + bo; + return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; +} + /* String length checking wrapper */ static int parse_probe_arg(char *arg, struct trace_probe *tp, struct probe_arg *parg, int is_return) @@ -836,6 +935,8 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp, parg->offset = tp->size; tp->size += parg->type->size; ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); + if (ret >= 0 && t != NULL) + ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); if (ret >= 0) { parg->fetch_size.fn = get_fetch_size_function(parg->type, parg->fetch.fn); @@ -1130,7 +1231,7 @@ static int command_trace_probe(const char *buf) return ret; } -#define WRITE_BUFSIZE 128 +#define WRITE_BUFSIZE 4096 static ssize_t probes_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 8f758d070c4..7e62c0a1845 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -247,51 +247,3 @@ void tracing_sched_switch_assign_trace(struct trace_array *tr) ctx_trace = tr; } -static void stop_sched_trace(struct trace_array *tr) -{ - tracing_stop_sched_switch_record(); -} - -static int sched_switch_trace_init(struct trace_array *tr) -{ - ctx_trace = tr; - tracing_reset_online_cpus(tr); - tracing_start_sched_switch_record(); - return 0; -} - -static void sched_switch_trace_reset(struct trace_array *tr) -{ - if (sched_ref) - stop_sched_trace(tr); -} - -static void sched_switch_trace_start(struct trace_array *tr) -{ - sched_stopped = 0; -} - -static void sched_switch_trace_stop(struct trace_array *tr) -{ - sched_stopped = 1; -} - -static struct tracer sched_switch_trace __read_mostly = -{ - .name = "sched_switch", - .init = sched_switch_trace_init, - .reset = sched_switch_trace_reset, - .start = sched_switch_trace_start, - .stop = sched_switch_trace_stop, - .wait_pipe = poll_wait_pipe, -#ifdef CONFIG_FTRACE_SELFTEST - .selftest = trace_selftest_startup_sched_switch, -#endif -}; - -__init static int init_sched_switch_trace(void) -{ - return register_tracer(&sched_switch_trace); -} -device_initcall(init_sched_switch_trace); - diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 5c9fe08d209..ee7b5a0bb9f 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -60,6 +60,19 @@ extern struct syscall_metadata *__stop_syscalls_metadata[]; static struct syscall_metadata **syscalls_metadata; +#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME +static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) +{ + /* + * Only compare after the "sys" prefix. Archs that use + * syscall wrappers may have syscalls symbols aliases prefixed + * with "SyS" instead of "sys", leading to an unwanted + * mismatch. + */ + return !strcmp(sym + 3, name + 3); +} +#endif + static __init struct syscall_metadata * find_syscall_meta(unsigned long syscall) { @@ -72,14 +85,11 @@ find_syscall_meta(unsigned long syscall) stop = __stop_syscalls_metadata; kallsyms_lookup(syscall, NULL, NULL, NULL, str); + if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) + return NULL; + for ( ; start < stop; start++) { - /* - * Only compare after the "sys" prefix. Archs that use - * syscall wrappers may have syscalls symbols aliases prefixed - * with "SyS" instead of "sys", leading to an unwanted - * mismatch. - */ - if ((*start)->name && !strcmp((*start)->name + 3, str + 3)) + if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) return *start; } return NULL; @@ -359,7 +369,7 @@ int reg_event_syscall_enter(struct ftrace_event_call *call) int num; num = ((struct syscall_metadata *)call->data)->syscall_nr; - if (num < 0 || num >= NR_syscalls) + if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return -ENOSYS; mutex_lock(&syscall_trace_lock); if (!sys_refcount_enter) @@ -377,7 +387,7 @@ void unreg_event_syscall_enter(struct ftrace_event_call *call) int num; num = ((struct syscall_metadata *)call->data)->syscall_nr; - if (num < 0 || num >= NR_syscalls) + if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return; mutex_lock(&syscall_trace_lock); sys_refcount_enter--; @@ -393,7 +403,7 @@ int reg_event_syscall_exit(struct ftrace_event_call *call) int num; num = ((struct syscall_metadata *)call->data)->syscall_nr; - if (num < 0 || num >= NR_syscalls) + if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return -ENOSYS; mutex_lock(&syscall_trace_lock); if (!sys_refcount_exit) @@ -411,7 +421,7 @@ void unreg_event_syscall_exit(struct ftrace_event_call *call) int num; num = ((struct syscall_metadata *)call->data)->syscall_nr; - if (num < 0 || num >= NR_syscalls) + if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return; mutex_lock(&syscall_trace_lock); sys_refcount_exit--; @@ -424,6 +434,14 @@ void unreg_event_syscall_exit(struct ftrace_event_call *call) int init_syscall_trace(struct ftrace_event_call *call) { int id; + int num; + + num = ((struct syscall_metadata *)call->data)->syscall_nr; + if (num < 0 || num >= NR_syscalls) { + pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", + ((struct syscall_metadata *)call->data)->name); + return -ENOSYS; + } if (set_syscall_print_fmt(call) < 0) return -ENOMEM; @@ -438,7 +456,7 @@ int init_syscall_trace(struct ftrace_event_call *call) return id; } -unsigned long __init arch_syscall_addr(int nr) +unsigned long __init __weak arch_syscall_addr(int nr) { return (unsigned long)sys_call_table[nr]; } |