diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 1450 |
1 files changed, 225 insertions, 1225 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ebd996f8710e..6eb4d3097a4d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -47,7 +47,6 @@ #include <linux/trace.h> #include <linux/sched/clock.h> #include <linux/sched/rt.h> -#include <linux/fsnotify.h> #include <linux/irq_work.h> #include <linux/workqueue.h> #include <linux/sort.h> @@ -219,14 +218,36 @@ static void ftrace_trace_userstack(struct trace_array *tr, static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; static char *default_bootup_tracer; -static bool allocate_snapshot; -static bool snapshot_at_boot; - static char boot_instance_info[COMMAND_LINE_SIZE] __initdata; static int boot_instance_index; -static char boot_snapshot_info[COMMAND_LINE_SIZE] __initdata; -static int boot_snapshot_index; +/* + * Repeated boot parameters, including Bootconfig array expansions, need + * to stay in the delimiter form that the existing parser consumes. + */ +void __init trace_append_boot_param(char *buf, const char *str, char sep, + int size) +{ + int len, needed, str_len; + + if (!*str) + return; + + len = strlen(buf); + str_len = strlen(str); + needed = len + str_len + 1; + + /* For continuation, account for the separator. */ + if (len) + needed++; + if (needed > size) + return; + + if (len) + buf[len++] = sep; + + strscpy(buf + len, str, size - len); +} static int __init set_cmdline_ftrace(char *str) { @@ -276,38 +297,6 @@ static int __init stop_trace_on_warning(char *str) } __setup("traceoff_on_warning", stop_trace_on_warning); -static int __init boot_alloc_snapshot(char *str) -{ - char *slot = boot_snapshot_info + boot_snapshot_index; - int left = sizeof(boot_snapshot_info) - boot_snapshot_index; - int ret; - - if (str[0] == '=') { - str++; - if (strlen(str) >= left) - return -1; - - ret = snprintf(slot, left, "%s\t", str); - boot_snapshot_index += ret; - } else { - allocate_snapshot = true; - /* We also need the main ring buffer expanded */ - trace_set_ring_buffer_expanded(NULL); - } - return 1; -} -__setup("alloc_snapshot", boot_alloc_snapshot); - - -static int __init boot_snapshot(char *str) -{ - snapshot_at_boot = true; - boot_alloc_snapshot(str); - return 1; -} -__setup("ftrace_boot_snapshot", boot_snapshot); - - static int __init boot_instance(char *str) { char *slot = boot_instance_info + boot_instance_index; @@ -329,7 +318,8 @@ static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; static int __init set_trace_boot_options(char *str) { - strscpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); + trace_append_boot_param(trace_boot_options_buf, str, ',', + MAX_TRACER_SIZE); return 1; } __setup("trace_options=", set_trace_boot_options); @@ -555,7 +545,7 @@ static bool update_marker_trace(struct trace_array *tr, int enabled) lockdep_assert_held(&event_mutex); if (enabled) { - if (!list_empty(&tr->marker_list)) + if (tr->trace_flags & TRACE_ITER(COPY_MARKER)) return false; list_add_rcu(&tr->marker_list, &marker_copies); @@ -563,10 +553,10 @@ static bool update_marker_trace(struct trace_array *tr, int enabled) return true; } - if (list_empty(&tr->marker_list)) + if (!(tr->trace_flags & TRACE_ITER(COPY_MARKER))) return false; - list_del_init(&tr->marker_list); + list_del_rcu(&tr->marker_list); tr->trace_flags &= ~TRACE_ITER(COPY_MARKER); return true; } @@ -578,8 +568,59 @@ void trace_set_ring_buffer_expanded(struct trace_array *tr) tr->ring_buffer_expanded = true; } +static void trace_array_autoremove(struct work_struct *work) +{ + struct trace_array *tr = container_of(work, struct trace_array, autoremove_work); + + trace_array_destroy(tr); +} + +static struct workqueue_struct *autoremove_wq; + +static void trace_array_kick_autoremove(struct trace_array *tr) +{ + if (autoremove_wq) + queue_work(autoremove_wq, &tr->autoremove_work); +} + +static void trace_array_cancel_autoremove(struct trace_array *tr) +{ + /* + * Since this can be called inside trace_array_autoremove(), + * it has to avoid deadlock of the workqueue. + */ + if (work_pending(&tr->autoremove_work)) + cancel_work_sync(&tr->autoremove_work); +} + +static void trace_array_init_autoremove(struct trace_array *tr) +{ + INIT_WORK(&tr->autoremove_work, trace_array_autoremove); +} + +static void trace_array_start_autoremove(void) +{ + if (autoremove_wq) + return; + + autoremove_wq = alloc_workqueue("tr_autoremove_wq", + WQ_UNBOUND | WQ_HIGHPRI, 0); + if (!autoremove_wq) + pr_warn("Unable to allocate tr_autoremove_wq. autoremove disabled.\n"); +} + LIST_HEAD(ftrace_trace_arrays); +static int __trace_array_get(struct trace_array *this_tr) +{ + /* When free_on_close is set, this is not available anymore. */ + if (autoremove_wq && this_tr->free_on_close) + return -ENODEV; + + this_tr->ref++; + return 0; +} + int trace_array_get(struct trace_array *this_tr) { struct trace_array *tr; @@ -587,8 +628,7 @@ int trace_array_get(struct trace_array *this_tr) guard(mutex)(&trace_types_lock); list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (tr == this_tr) { - tr->ref++; - return 0; + return __trace_array_get(tr); } } @@ -599,6 +639,12 @@ static void __trace_array_put(struct trace_array *this_tr) { WARN_ON(!this_tr->ref); this_tr->ref--; + /* + * When free_on_close is set, prepare removing the array + * when the last reference is released. + */ + if (this_tr->ref == 1 && this_tr->free_on_close) + trace_array_kick_autoremove(this_tr); } /** @@ -807,47 +853,6 @@ void tracing_on(void) EXPORT_SYMBOL_GPL(tracing_on); #ifdef CONFIG_TRACER_SNAPSHOT -static void tracing_snapshot_instance_cond(struct trace_array *tr, - void *cond_data) -{ - unsigned long flags; - - if (in_nmi()) { - trace_array_puts(tr, "*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); - trace_array_puts(tr, "*** snapshot is being ignored ***\n"); - return; - } - - if (!tr->allocated_snapshot) { - trace_array_puts(tr, "*** SNAPSHOT NOT ALLOCATED ***\n"); - trace_array_puts(tr, "*** stopping trace here! ***\n"); - tracer_tracing_off(tr); - return; - } - - if (tr->mapped) { - trace_array_puts(tr, "*** BUFFER MEMORY MAPPED ***\n"); - trace_array_puts(tr, "*** Can not use snapshot (sorry) ***\n"); - return; - } - - /* Note, snapshot can not be used when the tracer uses it */ - if (tracer_uses_snapshot(tr->current_trace)) { - trace_array_puts(tr, "*** LATENCY TRACER ACTIVE ***\n"); - trace_array_puts(tr, "*** Can not use snapshot (sorry) ***\n"); - return; - } - - local_irq_save(flags); - update_max_tr(tr, current, smp_processor_id(), cond_data); - local_irq_restore(flags); -} - -void tracing_snapshot_instance(struct trace_array *tr) -{ - tracing_snapshot_instance_cond(tr, NULL); -} - /** * tracing_snapshot - take a snapshot of the current buffer. * @@ -871,138 +876,6 @@ void tracing_snapshot(void) EXPORT_SYMBOL_GPL(tracing_snapshot); /** - * tracing_snapshot_cond - conditionally take a snapshot of the current buffer. - * @tr: The tracing instance to snapshot - * @cond_data: The data to be tested conditionally, and possibly saved - * - * This is the same as tracing_snapshot() except that the snapshot is - * conditional - the snapshot will only happen if the - * cond_snapshot.update() implementation receiving the cond_data - * returns true, which means that the trace array's cond_snapshot - * update() operation used the cond_data to determine whether the - * snapshot should be taken, and if it was, presumably saved it along - * with the snapshot. - */ -void tracing_snapshot_cond(struct trace_array *tr, void *cond_data) -{ - tracing_snapshot_instance_cond(tr, cond_data); -} -EXPORT_SYMBOL_GPL(tracing_snapshot_cond); - -/** - * tracing_cond_snapshot_data - get the user data associated with a snapshot - * @tr: The tracing instance - * - * When the user enables a conditional snapshot using - * tracing_snapshot_cond_enable(), the user-defined cond_data is saved - * with the snapshot. This accessor is used to retrieve it. - * - * Should not be called from cond_snapshot.update(), since it takes - * the tr->max_lock lock, which the code calling - * cond_snapshot.update() has already done. - * - * Returns the cond_data associated with the trace array's snapshot. - */ -void *tracing_cond_snapshot_data(struct trace_array *tr) -{ - void *cond_data = NULL; - - local_irq_disable(); - arch_spin_lock(&tr->max_lock); - - if (tr->cond_snapshot) - cond_data = tr->cond_snapshot->cond_data; - - arch_spin_unlock(&tr->max_lock); - local_irq_enable(); - - return cond_data; -} -EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data); - -static int resize_buffer_duplicate_size(struct array_buffer *trace_buf, - struct array_buffer *size_buf, int cpu_id); -static void set_buffer_entries(struct array_buffer *buf, unsigned long val); - -int tracing_alloc_snapshot_instance(struct trace_array *tr) -{ - int order; - int ret; - - if (!tr->allocated_snapshot) { - - /* Make the snapshot buffer have the same order as main buffer */ - order = ring_buffer_subbuf_order_get(tr->array_buffer.buffer); - ret = ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, order); - if (ret < 0) - return ret; - - /* allocate spare buffer */ - ret = resize_buffer_duplicate_size(&tr->snapshot_buffer, - &tr->array_buffer, RING_BUFFER_ALL_CPUS); - if (ret < 0) - return ret; - - tr->allocated_snapshot = true; - } - - return 0; -} - -static void free_snapshot(struct trace_array *tr) -{ - /* - * We don't free the ring buffer. instead, resize it because - * The max_tr ring buffer has some state (e.g. ring->clock) and - * we want preserve it. - */ - ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, 0); - ring_buffer_resize(tr->snapshot_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); - set_buffer_entries(&tr->snapshot_buffer, 1); - tracing_reset_online_cpus(&tr->snapshot_buffer); - tr->allocated_snapshot = false; -} - -static int tracing_arm_snapshot_locked(struct trace_array *tr) -{ - int ret; - - lockdep_assert_held(&trace_types_lock); - - spin_lock(&tr->snapshot_trigger_lock); - if (tr->snapshot == UINT_MAX || tr->mapped) { - spin_unlock(&tr->snapshot_trigger_lock); - return -EBUSY; - } - - tr->snapshot++; - spin_unlock(&tr->snapshot_trigger_lock); - - ret = tracing_alloc_snapshot_instance(tr); - if (ret) { - spin_lock(&tr->snapshot_trigger_lock); - tr->snapshot--; - spin_unlock(&tr->snapshot_trigger_lock); - } - - return ret; -} - -int tracing_arm_snapshot(struct trace_array *tr) -{ - guard(mutex)(&trace_types_lock); - return tracing_arm_snapshot_locked(tr); -} - -void tracing_disarm_snapshot(struct trace_array *tr) -{ - spin_lock(&tr->snapshot_trigger_lock); - if (!WARN_ON(!tr->snapshot)) - tr->snapshot--; - spin_unlock(&tr->snapshot_trigger_lock); -} - -/** * tracing_alloc_snapshot - allocate snapshot buffer. * * This only allocates the snapshot buffer if it isn't already @@ -1022,159 +895,18 @@ int tracing_alloc_snapshot(void) return ret; } -EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); - -/** - * tracing_snapshot_alloc - allocate and take a snapshot of the current buffer. - * - * This is similar to tracing_snapshot(), but it will allocate the - * snapshot buffer if it isn't already allocated. Use this only - * where it is safe to sleep, as the allocation may sleep. - * - * This causes a swap between the snapshot buffer and the current live - * tracing buffer. You can use this to take snapshots of the live - * trace when some condition is triggered, but continue to trace. - */ -void tracing_snapshot_alloc(void) -{ - int ret; - - ret = tracing_alloc_snapshot(); - if (ret < 0) - return; - - tracing_snapshot(); -} -EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); - -/** - * tracing_snapshot_cond_enable - enable conditional snapshot for an instance - * @tr: The tracing instance - * @cond_data: User data to associate with the snapshot - * @update: Implementation of the cond_snapshot update function - * - * Check whether the conditional snapshot for the given instance has - * already been enabled, or if the current tracer is already using a - * snapshot; if so, return -EBUSY, else create a cond_snapshot and - * save the cond_data and update function inside. - * - * Returns 0 if successful, error otherwise. - */ -int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, - cond_update_fn_t update) -{ - struct cond_snapshot *cond_snapshot __free(kfree) = - kzalloc_obj(*cond_snapshot); - int ret; - - if (!cond_snapshot) - return -ENOMEM; - - cond_snapshot->cond_data = cond_data; - cond_snapshot->update = update; - - guard(mutex)(&trace_types_lock); - - if (tracer_uses_snapshot(tr->current_trace)) - return -EBUSY; - - /* - * The cond_snapshot can only change to NULL without the - * trace_types_lock. We don't care if we race with it going - * to NULL, but we want to make sure that it's not set to - * something other than NULL when we get here, which we can - * do safely with only holding the trace_types_lock and not - * having to take the max_lock. - */ - if (tr->cond_snapshot) - return -EBUSY; - - ret = tracing_arm_snapshot_locked(tr); - if (ret) - return ret; - - local_irq_disable(); - arch_spin_lock(&tr->max_lock); - tr->cond_snapshot = no_free_ptr(cond_snapshot); - arch_spin_unlock(&tr->max_lock); - local_irq_enable(); - - return 0; -} -EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable); - -/** - * tracing_snapshot_cond_disable - disable conditional snapshot for an instance - * @tr: The tracing instance - * - * Check whether the conditional snapshot for the given instance is - * enabled; if so, free the cond_snapshot associated with it, - * otherwise return -EINVAL. - * - * Returns 0 if successful, error otherwise. - */ -int tracing_snapshot_cond_disable(struct trace_array *tr) -{ - int ret = 0; - - local_irq_disable(); - arch_spin_lock(&tr->max_lock); - - if (!tr->cond_snapshot) - ret = -EINVAL; - else { - kfree(tr->cond_snapshot); - tr->cond_snapshot = NULL; - } - - arch_spin_unlock(&tr->max_lock); - local_irq_enable(); - - tracing_disarm_snapshot(tr); - - return ret; -} -EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable); #else void tracing_snapshot(void) { WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); } EXPORT_SYMBOL_GPL(tracing_snapshot); -void tracing_snapshot_cond(struct trace_array *tr, void *cond_data) -{ - WARN_ONCE(1, "Snapshot feature not enabled, but internal conditional snapshot used"); -} -EXPORT_SYMBOL_GPL(tracing_snapshot_cond); -int tracing_alloc_snapshot(void) -{ - WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used"); - return -ENODEV; -} -EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); void tracing_snapshot_alloc(void) { /* Give warning */ tracing_snapshot(); } EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); -void *tracing_cond_snapshot_data(struct trace_array *tr) -{ - return NULL; -} -EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data); -int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update) -{ - return -ENODEV; -} -EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable); -int tracing_snapshot_cond_disable(struct trace_array *tr) -{ - return false; -} -EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable); -#define free_snapshot(tr) do { } while (0) -#define tracing_arm_snapshot_locked(tr) ({ -EBUSY; }) #endif /* CONFIG_TRACER_SNAPSHOT */ void tracer_tracing_off(struct trace_array *tr) @@ -1487,206 +1219,6 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) unsigned long __read_mostly tracing_thresh; -#ifdef CONFIG_TRACER_MAX_TRACE -#ifdef LATENCY_FS_NOTIFY -static struct workqueue_struct *fsnotify_wq; - -static void latency_fsnotify_workfn(struct work_struct *work) -{ - struct trace_array *tr = container_of(work, struct trace_array, - fsnotify_work); - fsnotify_inode(tr->d_max_latency->d_inode, FS_MODIFY); -} - -static void latency_fsnotify_workfn_irq(struct irq_work *iwork) -{ - struct trace_array *tr = container_of(iwork, struct trace_array, - fsnotify_irqwork); - queue_work(fsnotify_wq, &tr->fsnotify_work); -} - -__init static int latency_fsnotify_init(void) -{ - fsnotify_wq = alloc_workqueue("tr_max_lat_wq", - WQ_UNBOUND | WQ_HIGHPRI, 0); - if (!fsnotify_wq) { - pr_err("Unable to allocate tr_max_lat_wq\n"); - return -ENOMEM; - } - return 0; -} - -late_initcall_sync(latency_fsnotify_init); - -void latency_fsnotify(struct trace_array *tr) -{ - if (!fsnotify_wq) - return; - /* - * We cannot call queue_work(&tr->fsnotify_work) from here because it's - * possible that we are called from __schedule() or do_idle(), which - * could cause a deadlock. - */ - irq_work_queue(&tr->fsnotify_irqwork); -} -#endif /* !LATENCY_FS_NOTIFY */ - -static const struct file_operations tracing_max_lat_fops; - -static void trace_create_maxlat_file(struct trace_array *tr, - struct dentry *d_tracer) -{ -#ifdef LATENCY_FS_NOTIFY - INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn); - init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq); -#endif - tr->d_max_latency = trace_create_file("tracing_max_latency", - TRACE_MODE_WRITE, - d_tracer, tr, - &tracing_max_lat_fops); -} - -/* - * Copy the new maximum trace into the separate maximum-trace - * structure. (this way the maximum trace is permanently saved, - * for later retrieval via /sys/kernel/tracing/tracing_max_latency) - */ -static void -__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) -{ - struct array_buffer *trace_buf = &tr->array_buffer; - struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); - struct array_buffer *max_buf = &tr->snapshot_buffer; - struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); - - max_buf->cpu = cpu; - max_buf->time_start = data->preempt_timestamp; - - max_data->saved_latency = tr->max_latency; - max_data->critical_start = data->critical_start; - max_data->critical_end = data->critical_end; - - strscpy(max_data->comm, tsk->comm); - max_data->pid = tsk->pid; - /* - * If tsk == current, then use current_uid(), as that does not use - * RCU. The irq tracer can be called out of RCU scope. - */ - if (tsk == current) - max_data->uid = current_uid(); - else - max_data->uid = task_uid(tsk); - - max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; - max_data->policy = tsk->policy; - max_data->rt_priority = tsk->rt_priority; - - /* record this tasks comm */ - tracing_record_cmdline(tsk); - latency_fsnotify(tr); -} -#else -static inline void trace_create_maxlat_file(struct trace_array *tr, - struct dentry *d_tracer) { } -static inline void __update_max_tr(struct trace_array *tr, - struct task_struct *tsk, int cpu) { } -#endif /* CONFIG_TRACER_MAX_TRACE */ - -#ifdef CONFIG_TRACER_SNAPSHOT -/** - * update_max_tr - snapshot all trace buffers from global_trace to max_tr - * @tr: tracer - * @tsk: the task with the latency - * @cpu: The cpu that initiated the trace. - * @cond_data: User data associated with a conditional snapshot - * - * Flip the buffers between the @tr and the max_tr and record information - * about which task was the cause of this latency. - */ -void -update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu, - void *cond_data) -{ - if (tr->stop_count) - return; - - WARN_ON_ONCE(!irqs_disabled()); - - if (!tr->allocated_snapshot) { - /* Only the nop tracer should hit this when disabling */ - WARN_ON_ONCE(tr->current_trace != &nop_trace); - return; - } - - arch_spin_lock(&tr->max_lock); - - /* Inherit the recordable setting from array_buffer */ - if (ring_buffer_record_is_set_on(tr->array_buffer.buffer)) - ring_buffer_record_on(tr->snapshot_buffer.buffer); - else - ring_buffer_record_off(tr->snapshot_buffer.buffer); - - if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) { - arch_spin_unlock(&tr->max_lock); - return; - } - - swap(tr->array_buffer.buffer, tr->snapshot_buffer.buffer); - - __update_max_tr(tr, tsk, cpu); - - arch_spin_unlock(&tr->max_lock); - - /* Any waiters on the old snapshot buffer need to wake up */ - ring_buffer_wake_waiters(tr->array_buffer.buffer, RING_BUFFER_ALL_CPUS); -} - -/** - * update_max_tr_single - only copy one trace over, and reset the rest - * @tr: tracer - * @tsk: task with the latency - * @cpu: the cpu of the buffer to copy. - * - * Flip the trace of a single CPU buffer between the @tr and the max_tr. - */ -void -update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) -{ - int ret; - - if (tr->stop_count) - return; - - WARN_ON_ONCE(!irqs_disabled()); - if (!tr->allocated_snapshot) { - /* Only the nop tracer should hit this when disabling */ - WARN_ON_ONCE(tr->current_trace != &nop_trace); - return; - } - - arch_spin_lock(&tr->max_lock); - - ret = ring_buffer_swap_cpu(tr->snapshot_buffer.buffer, tr->array_buffer.buffer, cpu); - - if (ret == -EBUSY) { - /* - * We failed to swap the buffer due to a commit taking - * place on this CPU. We fail to record, but we reset - * the max trace buffer (no one writes directly to it) - * and flag that it failed. - * Another reason is resize is in progress. - */ - trace_array_printk_buf(tr->snapshot_buffer.buffer, _THIS_IP_, - "Failed to swap buffers due to commit or resize in progress\n"); - } - - WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); - - __update_max_tr(tr, tsk, cpu); - arch_spin_unlock(&tr->max_lock); -} -#endif /* CONFIG_TRACER_SNAPSHOT */ - struct pipe_wait { struct trace_iterator *iter; int wait_index; @@ -1995,7 +1527,7 @@ int __init register_tracer(struct tracer *type) return 0; } -static void tracing_reset_cpu(struct array_buffer *buf, int cpu) +void tracing_reset_cpu(struct array_buffer *buf, int cpu) { struct trace_buffer *buffer = buf->buffer; @@ -3760,50 +3292,6 @@ static void test_ftrace_alive(struct seq_file *m) "# MAY BE MISSING FUNCTION EVENTS\n"); } -#ifdef CONFIG_TRACER_SNAPSHOT -static void show_snapshot_main_help(struct seq_file *m) -{ - seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n" - "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" - "# Takes a snapshot of the main buffer.\n" - "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n" - "# (Doesn't have to be '2' works with any number that\n" - "# is not a '0' or '1')\n"); -} - -static void show_snapshot_percpu_help(struct seq_file *m) -{ - seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); -#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP - seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" - "# Takes a snapshot of the main buffer for this cpu.\n"); -#else - seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n" - "# Must use main snapshot file to allocate.\n"); -#endif - seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n" - "# (Doesn't have to be '2' works with any number that\n" - "# is not a '0' or '1')\n"); -} - -static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) -{ - if (iter->tr->allocated_snapshot) - seq_puts(m, "#\n# * Snapshot is allocated *\n#\n"); - else - seq_puts(m, "#\n# * Snapshot is freed *\n#\n"); - - seq_puts(m, "# Snapshot commands:\n"); - if (iter->cpu_file == RING_BUFFER_ALL_CPUS) - show_snapshot_main_help(m); - else - show_snapshot_percpu_help(m); -} -#else -/* Should never be called */ -static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } -#endif - static int s_show(struct seq_file *m, void *v) { struct trace_iterator *iter = v; @@ -3852,17 +3340,6 @@ static int s_show(struct seq_file *m, void *v) return 0; } -/* - * Should be used after trace_array_get(), trace_types_lock - * ensures that i_cdev was already initialized. - */ -static inline int tracing_get_cpu(struct inode *inode) -{ - if (inode->i_cdev) /* See trace_create_cpu_file() */ - return (long)inode->i_cdev - 1; - return RING_BUFFER_ALL_CPUS; -} - static const struct seq_operations tracer_seq_ops = { .start = s_start, .next = s_next, @@ -3889,7 +3366,7 @@ static void free_trace_iter_content(struct trace_iterator *iter) free_cpumask_var(iter->started); } -static struct trace_iterator * +struct trace_iterator * __tracing_open(struct inode *inode, struct file *file, bool snapshot) { struct trace_array *tr = inode->i_private; @@ -4022,6 +3499,11 @@ int tracing_open_generic_tr(struct inode *inode, struct file *filp) if (ret) return ret; + if ((filp->f_mode & FMODE_WRITE) && trace_array_is_readonly(tr)) { + trace_array_put(tr); + return -EACCES; + } + filp->private_data = inode->i_private; return 0; @@ -4050,8 +3532,6 @@ int tracing_open_file_tr(struct inode *inode, struct file *filp) event_file_get(file); } - filp->private_data = inode->i_private; - return 0; } @@ -4071,7 +3551,7 @@ int tracing_single_release_file_tr(struct inode *inode, struct file *filp) return single_release(inode, filp); } -static int tracing_release(struct inode *inode, struct file *file) +int tracing_release(struct inode *inode, struct file *file) { struct trace_array *tr = inode->i_private; struct seq_file *m = file->private_data; @@ -5222,7 +4702,7 @@ int tracer_init(struct tracer *t, struct trace_array *tr) return t->init(tr); } -static void set_buffer_entries(struct array_buffer *buf, unsigned long val) +void trace_set_buffer_entries(struct array_buffer *buf, unsigned long val) { int cpu; @@ -5233,40 +4713,12 @@ static void set_buffer_entries(struct array_buffer *buf, unsigned long val) static void update_buffer_entries(struct array_buffer *buf, int cpu) { if (cpu == RING_BUFFER_ALL_CPUS) { - set_buffer_entries(buf, ring_buffer_size(buf->buffer, 0)); + trace_set_buffer_entries(buf, ring_buffer_size(buf->buffer, 0)); } else { per_cpu_ptr(buf->data, cpu)->entries = ring_buffer_size(buf->buffer, cpu); } } -#ifdef CONFIG_TRACER_SNAPSHOT -/* resize @tr's buffer to the size of @size_tr's entries */ -static int resize_buffer_duplicate_size(struct array_buffer *trace_buf, - struct array_buffer *size_buf, int cpu_id) -{ - int cpu, ret = 0; - - if (cpu_id == RING_BUFFER_ALL_CPUS) { - for_each_tracing_cpu(cpu) { - ret = ring_buffer_resize(trace_buf->buffer, - per_cpu_ptr(size_buf->data, cpu)->entries, cpu); - if (ret < 0) - break; - per_cpu_ptr(trace_buf->data, cpu)->entries = - per_cpu_ptr(size_buf->data, cpu)->entries; - } - } else { - ret = ring_buffer_resize(trace_buf->buffer, - per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); - if (ret == 0) - per_cpu_ptr(trace_buf->data, cpu_id)->entries = - per_cpu_ptr(size_buf->data, cpu_id)->entries; - } - - return ret; -} -#endif /* CONFIG_TRACER_SNAPSHOT */ - static int __tracing_resize_ring_buffer(struct trace_array *tr, unsigned long size, int cpu) { @@ -5462,6 +4914,10 @@ static void update_last_data(struct trace_array *tr) /* Only if the buffer has previous boot data clear and update it. */ tr->flags &= ~TRACE_ARRAY_FL_LAST_BOOT; + /* If this is a backup instance, mark it for autoremove. */ + if (tr->flags & TRACE_ARRAY_FL_VMALLOC) + tr->free_on_close = true; + /* Reset the module list and reload them */ if (tr->scratch) { struct trace_scratch *tscratch = tr->scratch; @@ -5685,9 +5141,8 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, return ret; } -static ssize_t -tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, - size_t cnt, loff_t *ppos) +ssize_t tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, + size_t cnt, loff_t *ppos) { char buf[64]; int r; @@ -5699,9 +5154,8 @@ tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); } -static ssize_t -tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf, - size_t cnt, loff_t *ppos) +ssize_t tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf, + size_t cnt, loff_t *ppos) { unsigned long val; int ret; @@ -5743,28 +5197,6 @@ tracing_thresh_write(struct file *filp, const char __user *ubuf, return cnt; } -#ifdef CONFIG_TRACER_MAX_TRACE - -static ssize_t -tracing_max_lat_read(struct file *filp, char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - struct trace_array *tr = filp->private_data; - - return tracing_nsecs_read(&tr->max_latency, ubuf, cnt, ppos); -} - -static ssize_t -tracing_max_lat_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - struct trace_array *tr = filp->private_data; - - return tracing_nsecs_write(&tr->max_latency, ubuf, cnt, ppos); -} - -#endif - static int open_pipe_on_cpu(struct trace_array *tr, int cpu) { if (cpu == RING_BUFFER_ALL_CPUS) { @@ -6784,6 +6216,23 @@ char *trace_user_fault_read(struct trace_user_buf_info *tinfo, do { /* + * It is possible that something is trying to migrate this + * task. What happens then, is when preemption is enabled, + * the migration thread will preempt this task, try to + * migrate it, fail, then let it run again. That will + * cause this to loop again and never succeed. + * On failures, enabled and disable preemption with + * migration enabled, to allow the migration thread to + * migrate this task. + */ + if (trys) { + preempt_enable_notrace(); + preempt_disable_notrace(); + cpu = smp_processor_id(); + buffer = per_cpu_ptr(tinfo->tbuf, cpu)->buf; + } + + /* * If for some reason, copy_from_user() always causes a context * switch, this would then cause an infinite loop. * If this task is preempted by another user space task, it @@ -7080,6 +6529,11 @@ static int tracing_clock_open(struct inode *inode, struct file *file) if (ret) return ret; + if ((file->f_mode & FMODE_WRITE) && trace_array_is_readonly(tr)) { + trace_array_put(tr); + return -EACCES; + } + ret = single_open(file, tracing_clock_show, inode->i_private); if (ret < 0) trace_array_put(tr); @@ -7125,194 +6579,6 @@ u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_eve return ring_buffer_event_time_stamp(buffer, rbe); } -struct ftrace_buffer_info { - struct trace_iterator iter; - void *spare; - unsigned int spare_cpu; - unsigned int spare_size; - unsigned int read; -}; - -#ifdef CONFIG_TRACER_SNAPSHOT -static int tracing_snapshot_open(struct inode *inode, struct file *file) -{ - struct trace_array *tr = inode->i_private; - struct trace_iterator *iter; - struct seq_file *m; - int ret; - - ret = tracing_check_open_get_tr(tr); - if (ret) - return ret; - - if (file->f_mode & FMODE_READ) { - iter = __tracing_open(inode, file, true); - if (IS_ERR(iter)) - ret = PTR_ERR(iter); - } else { - /* Writes still need the seq_file to hold the private data */ - ret = -ENOMEM; - m = kzalloc_obj(*m); - if (!m) - goto out; - iter = kzalloc_obj(*iter); - if (!iter) { - kfree(m); - goto out; - } - ret = 0; - - iter->tr = tr; - iter->array_buffer = &tr->snapshot_buffer; - iter->cpu_file = tracing_get_cpu(inode); - m->private = iter; - file->private_data = m; - } -out: - if (ret < 0) - trace_array_put(tr); - - return ret; -} - -static void tracing_swap_cpu_buffer(void *tr) -{ - update_max_tr_single((struct trace_array *)tr, current, smp_processor_id()); -} - -static ssize_t -tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, - loff_t *ppos) -{ - struct seq_file *m = filp->private_data; - struct trace_iterator *iter = m->private; - struct trace_array *tr = iter->tr; - unsigned long val; - int ret; - - ret = tracing_update_buffers(tr); - if (ret < 0) - return ret; - - ret = kstrtoul_from_user(ubuf, cnt, 10, &val); - if (ret) - return ret; - - guard(mutex)(&trace_types_lock); - - if (tracer_uses_snapshot(tr->current_trace)) - return -EBUSY; - - local_irq_disable(); - arch_spin_lock(&tr->max_lock); - if (tr->cond_snapshot) - ret = -EBUSY; - arch_spin_unlock(&tr->max_lock); - local_irq_enable(); - if (ret) - return ret; - - switch (val) { - case 0: - if (iter->cpu_file != RING_BUFFER_ALL_CPUS) - return -EINVAL; - if (tr->allocated_snapshot) - free_snapshot(tr); - break; - case 1: -/* Only allow per-cpu swap if the ring buffer supports it */ -#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP - if (iter->cpu_file != RING_BUFFER_ALL_CPUS) - return -EINVAL; -#endif - if (tr->allocated_snapshot) - ret = resize_buffer_duplicate_size(&tr->snapshot_buffer, - &tr->array_buffer, iter->cpu_file); - - ret = tracing_arm_snapshot_locked(tr); - if (ret) - return ret; - - /* Now, we're going to swap */ - if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { - local_irq_disable(); - update_max_tr(tr, current, smp_processor_id(), NULL); - local_irq_enable(); - } else { - smp_call_function_single(iter->cpu_file, tracing_swap_cpu_buffer, - (void *)tr, 1); - } - tracing_disarm_snapshot(tr); - break; - default: - if (tr->allocated_snapshot) { - if (iter->cpu_file == RING_BUFFER_ALL_CPUS) - tracing_reset_online_cpus(&tr->snapshot_buffer); - else - tracing_reset_cpu(&tr->snapshot_buffer, iter->cpu_file); - } - break; - } - - if (ret >= 0) { - *ppos += cnt; - ret = cnt; - } - - return ret; -} - -static int tracing_snapshot_release(struct inode *inode, struct file *file) -{ - struct seq_file *m = file->private_data; - int ret; - - ret = tracing_release(inode, file); - - if (file->f_mode & FMODE_READ) - return ret; - - /* If write only, the seq_file is just a stub */ - if (m) - kfree(m->private); - kfree(m); - - return 0; -} - -static int tracing_buffers_open(struct inode *inode, struct file *filp); -static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, - size_t count, loff_t *ppos); -static int tracing_buffers_release(struct inode *inode, struct file *file); -static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, - struct pipe_inode_info *pipe, size_t len, unsigned int flags); - -static int snapshot_raw_open(struct inode *inode, struct file *filp) -{ - struct ftrace_buffer_info *info; - int ret; - - /* The following checks for tracefs lockdown */ - ret = tracing_buffers_open(inode, filp); - if (ret < 0) - return ret; - - info = filp->private_data; - - if (tracer_uses_snapshot(info->iter.trace)) { - tracing_buffers_release(inode, filp); - return -EBUSY; - } - - info->iter.snapshot = true; - info->iter.array_buffer = &info->iter.tr->snapshot_buffer; - - return ret; -} - -#endif /* CONFIG_TRACER_SNAPSHOT */ - - static const struct file_operations tracing_thresh_fops = { .open = tracing_open_generic, .read = tracing_thresh_read, @@ -7320,16 +6586,6 @@ static const struct file_operations tracing_thresh_fops = { .llseek = generic_file_llseek, }; -#ifdef CONFIG_TRACER_MAX_TRACE -static const struct file_operations tracing_max_lat_fops = { - .open = tracing_open_generic_tr, - .read = tracing_max_lat_read, - .write = tracing_max_lat_write, - .llseek = generic_file_llseek, - .release = tracing_release_generic_tr, -}; -#endif - static const struct file_operations set_tracer_fops = { .open = tracing_open_generic_tr, .read = tracing_set_trace_read, @@ -7416,24 +6672,6 @@ static const struct file_operations last_boot_fops = { .release = tracing_seq_release, }; -#ifdef CONFIG_TRACER_SNAPSHOT -static const struct file_operations snapshot_fops = { - .open = tracing_snapshot_open, - .read = seq_read, - .write = tracing_snapshot_write, - .llseek = tracing_lseek, - .release = tracing_snapshot_release, -}; - -static const struct file_operations snapshot_raw_fops = { - .open = snapshot_raw_open, - .read = tracing_buffers_read, - .release = tracing_buffers_release, - .splice_read = tracing_buffers_splice_read, -}; - -#endif /* CONFIG_TRACER_SNAPSHOT */ - /* * trace_min_max_write - Write a u64 value to a trace_min_max_param struct * @filp: The active open file structure @@ -7793,7 +7031,7 @@ static const struct file_operations tracing_err_log_fops = { .release = tracing_err_log_release, }; -static int tracing_buffers_open(struct inode *inode, struct file *filp) +int tracing_buffers_open(struct inode *inode, struct file *filp) { struct trace_array *tr = inode->i_private; struct ftrace_buffer_info *info; @@ -7841,9 +7079,8 @@ tracing_buffers_poll(struct file *filp, poll_table *poll_table) return trace_poll(iter, filp, poll_table); } -static ssize_t -tracing_buffers_read(struct file *filp, char __user *ubuf, - size_t count, loff_t *ppos) +ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) { struct ftrace_buffer_info *info = filp->private_data; struct trace_iterator *iter = &info->iter; @@ -7944,7 +7181,7 @@ static int tracing_buffers_flush(struct file *file, fl_owner_t id) return 0; } -static int tracing_buffers_release(struct inode *inode, struct file *file) +int tracing_buffers_release(struct inode *inode, struct file *file) { struct ftrace_buffer_info *info = file->private_data; struct trace_iterator *iter = &info->iter; @@ -8018,10 +7255,9 @@ static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) spd->partial[i].private = 0; } -static ssize_t -tracing_buffers_splice_read(struct file *file, loff_t *ppos, - struct pipe_inode_info *pipe, size_t len, - unsigned int flags) +ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { struct ftrace_buffer_info *info = file->private_data; struct trace_iterator *iter = &info->iter; @@ -8175,44 +7411,6 @@ static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned return 0; } -#ifdef CONFIG_TRACER_SNAPSHOT -static int get_snapshot_map(struct trace_array *tr) -{ - int err = 0; - - /* - * Called with mmap_lock held. lockdep would be unhappy if we would now - * take trace_types_lock. Instead use the specific - * snapshot_trigger_lock. - */ - spin_lock(&tr->snapshot_trigger_lock); - - if (tr->snapshot || tr->mapped == UINT_MAX) - err = -EBUSY; - else - tr->mapped++; - - spin_unlock(&tr->snapshot_trigger_lock); - - /* Wait for update_max_tr() to observe iter->tr->mapped */ - if (tr->mapped == 1) - synchronize_rcu(); - - return err; - -} -static void put_snapshot_map(struct trace_array *tr) -{ - spin_lock(&tr->snapshot_trigger_lock); - if (!WARN_ON(!tr->mapped)) - tr->mapped--; - spin_unlock(&tr->snapshot_trigger_lock); -} -#else -static inline int get_snapshot_map(struct trace_array *tr) { return 0; } -static inline void put_snapshot_map(struct trace_array *tr) { } -#endif - /* * This is called when a VMA is duplicated (e.g., on fork()) to increment * the user_mapped counter without remapping pages. @@ -8393,170 +7591,6 @@ static const struct file_operations tracing_dyn_info_fops = { }; #endif /* CONFIG_DYNAMIC_FTRACE */ -#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) -static void -ftrace_snapshot(unsigned long ip, unsigned long parent_ip, - struct trace_array *tr, struct ftrace_probe_ops *ops, - void *data) -{ - tracing_snapshot_instance(tr); -} - -static void -ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, - struct trace_array *tr, struct ftrace_probe_ops *ops, - void *data) -{ - struct ftrace_func_mapper *mapper = data; - long *count = NULL; - - if (mapper) - count = (long *)ftrace_func_mapper_find_ip(mapper, ip); - - if (count) { - - if (*count <= 0) - return; - - (*count)--; - } - - tracing_snapshot_instance(tr); -} - -static int -ftrace_snapshot_print(struct seq_file *m, unsigned long ip, - struct ftrace_probe_ops *ops, void *data) -{ - struct ftrace_func_mapper *mapper = data; - long *count = NULL; - - seq_printf(m, "%ps:", (void *)ip); - - seq_puts(m, "snapshot"); - - if (mapper) - count = (long *)ftrace_func_mapper_find_ip(mapper, ip); - - if (count) - seq_printf(m, ":count=%ld\n", *count); - else - seq_puts(m, ":unlimited\n"); - - return 0; -} - -static int -ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr, - unsigned long ip, void *init_data, void **data) -{ - struct ftrace_func_mapper *mapper = *data; - - if (!mapper) { - mapper = allocate_ftrace_func_mapper(); - if (!mapper) - return -ENOMEM; - *data = mapper; - } - - return ftrace_func_mapper_add_ip(mapper, ip, init_data); -} - -static void -ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr, - unsigned long ip, void *data) -{ - struct ftrace_func_mapper *mapper = data; - - if (!ip) { - if (!mapper) - return; - free_ftrace_func_mapper(mapper, NULL); - return; - } - - ftrace_func_mapper_remove_ip(mapper, ip); -} - -static struct ftrace_probe_ops snapshot_probe_ops = { - .func = ftrace_snapshot, - .print = ftrace_snapshot_print, -}; - -static struct ftrace_probe_ops snapshot_count_probe_ops = { - .func = ftrace_count_snapshot, - .print = ftrace_snapshot_print, - .init = ftrace_snapshot_init, - .free = ftrace_snapshot_free, -}; - -static int -ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash, - char *glob, char *cmd, char *param, int enable) -{ - struct ftrace_probe_ops *ops; - void *count = (void *)-1; - char *number; - int ret; - - if (!tr) - return -ENODEV; - - /* hash funcs only work with set_ftrace_filter */ - if (!enable) - return -EINVAL; - - ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; - - if (glob[0] == '!') { - ret = unregister_ftrace_function_probe_func(glob+1, tr, ops); - if (!ret) - tracing_disarm_snapshot(tr); - - return ret; - } - - if (!param) - goto out_reg; - - number = strsep(¶m, ":"); - - if (!strlen(number)) - goto out_reg; - - /* - * We use the callback data field (which is a pointer) - * as our counter. - */ - ret = kstrtoul(number, 0, (unsigned long *)&count); - if (ret) - return ret; - - out_reg: - ret = tracing_arm_snapshot(tr); - if (ret < 0) - return ret; - - ret = register_ftrace_function_probe(glob, tr, ops, count); - if (ret < 0) - tracing_disarm_snapshot(tr); - - return ret < 0 ? ret : 0; -} - -static struct ftrace_func_command ftrace_snapshot_cmd = { - .name = "snapshot", - .func = ftrace_trace_snapshot_callback, -}; - -static __init int register_snapshot_cmd(void) -{ - return register_ftrace_command(&ftrace_snapshot_cmd); -} -#else -static inline __init int register_snapshot_cmd(void) { return 0; } -#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ - static struct dentry *tracing_get_dentry(struct trace_array *tr) { /* Top directory uses NULL as the parent */ @@ -8589,7 +7623,7 @@ static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) return tr->percpu_dir; } -static struct dentry * +struct dentry * trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent, void *data, long cpu, const struct file_operations *fops) { @@ -9349,8 +8383,7 @@ static void setup_trace_scratch(struct trace_array *tr, memset(tscratch, 0, size); } -static int -allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, unsigned long size) +int allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size) { enum ring_buffer_flags rb_flags; struct trace_scratch *tscratch; @@ -9389,8 +8422,8 @@ allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, unsigned } /* Allocate the first page for all buffers */ - set_buffer_entries(&tr->array_buffer, - ring_buffer_size(tr->array_buffer.buffer, 0)); + trace_set_buffer_entries(&tr->array_buffer, + ring_buffer_size(tr->array_buffer.buffer, 0)); return 0; } @@ -9413,23 +8446,11 @@ static int allocate_trace_buffers(struct trace_array *tr, unsigned long size) if (ret) return ret; -#ifdef CONFIG_TRACER_SNAPSHOT - /* Fix mapped buffer trace arrays do not have snapshot buffers */ - if (tr->range_addr_start) - return 0; - - ret = allocate_trace_buffer(tr, &tr->snapshot_buffer, - allocate_snapshot ? size : 1); - if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) { + ret = trace_allocate_snapshot(tr, size); + if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) free_trace_buffer(&tr->array_buffer); - return -ENOMEM; - } - tr->allocated_snapshot = allocate_snapshot; - - allocate_snapshot = false; -#endif - return 0; + return ret; } static void free_trace_buffers(struct trace_array *tr) @@ -9510,8 +8531,8 @@ struct trace_array *trace_array_find_get(const char *instance) guard(mutex)(&trace_types_lock); tr = trace_array_find(instance); - if (tr) - tr->ref++; + if (tr && __trace_array_get(tr) < 0) + tr = NULL; return tr; } @@ -9608,6 +8629,8 @@ trace_array_create_systems(const char *name, const char *systems, if (ftrace_allocate_ftrace_ops(tr) < 0) goto out_free_tr; + trace_array_init_autoremove(tr); + ftrace_init_trace_array(tr); init_trace_flags_index(tr); @@ -9718,7 +8741,9 @@ struct trace_array *trace_array_get_by_name(const char *name, const char *system list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (tr->name && strcmp(tr->name, name) == 0) { - tr->ref++; + /* if this fails, @tr is going to be removed. */ + if (__trace_array_get(tr) < 0) + tr = NULL; return tr; } } @@ -9744,18 +8769,20 @@ static int __remove_instance(struct trace_array *tr) list_del(&tr->list); - /* Disable all the flags that were enabled coming in */ - for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) { - if ((1ULL << i) & ZEROED_TRACE_FLAGS) - set_tracer_flag(tr, 1ULL << i, 0); - } - if (printk_trace == tr) update_printk_trace(&global_trace); + /* Must be done before disabling all the flags */ if (update_marker_trace(tr, 0)) synchronize_rcu(); + /* Disable all the flags that were enabled coming in */ + for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) { + if ((1ULL << i) & ZEROED_TRACE_FLAGS) + set_tracer_flag(tr, 1ULL << i, 0); + } + + trace_array_cancel_autoremove(tr); tracing_set_nop(tr); clear_ftrace_function_probes(tr); event_trace_del_tracer(tr); @@ -9848,17 +8875,22 @@ static __init void create_trace_instances(struct dentry *d_tracer) static void init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) { + umode_t writable_mode = TRACE_MODE_WRITE; int cpu; + if (trace_array_is_readonly(tr)) + writable_mode = TRACE_MODE_READ; + trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer, - tr, &show_traces_fops); + tr, &show_traces_fops); - trace_create_file("current_tracer", TRACE_MODE_WRITE, d_tracer, - tr, &set_tracer_fops); + trace_create_file("current_tracer", writable_mode, d_tracer, + tr, &set_tracer_fops); - trace_create_file("tracing_cpumask", TRACE_MODE_WRITE, d_tracer, + trace_create_file("tracing_cpumask", writable_mode, d_tracer, tr, &tracing_cpumask_fops); + /* Options are used for changing print-format even for readonly instance. */ trace_create_file("trace_options", TRACE_MODE_WRITE, d_tracer, tr, &tracing_iter_fops); @@ -9868,12 +8900,36 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_pipe", TRACE_MODE_READ, d_tracer, tr, &tracing_pipe_fops); - trace_create_file("buffer_size_kb", TRACE_MODE_WRITE, d_tracer, + trace_create_file("buffer_size_kb", writable_mode, d_tracer, tr, &tracing_entries_fops); trace_create_file("buffer_total_size_kb", TRACE_MODE_READ, d_tracer, tr, &tracing_total_entries_fops); + trace_create_file("trace_clock", writable_mode, d_tracer, tr, + &trace_clock_fops); + + trace_create_file("timestamp_mode", TRACE_MODE_READ, d_tracer, tr, + &trace_time_stamp_mode_fops); + + tr->buffer_percent = 50; + + trace_create_file("buffer_subbuf_size_kb", writable_mode, d_tracer, + tr, &buffer_subbuf_size_fops); + + create_trace_options_dir(tr); + + if (tr->range_addr_start) + trace_create_file("last_boot_info", TRACE_MODE_READ, d_tracer, + tr, &last_boot_fops); + + for_each_tracing_cpu(cpu) + tracing_init_tracefs_percpu(tr, cpu); + + /* Read-only instance has above files only. */ + if (trace_array_is_readonly(tr)) + return; + trace_create_file("free_buffer", 0200, d_tracer, tr, &tracing_free_buffer_fops); @@ -9885,49 +8941,29 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_marker_raw", 0220, d_tracer, tr, &tracing_mark_raw_fops); - trace_create_file("trace_clock", TRACE_MODE_WRITE, d_tracer, tr, - &trace_clock_fops); - - trace_create_file("tracing_on", TRACE_MODE_WRITE, d_tracer, - tr, &rb_simple_fops); - - trace_create_file("timestamp_mode", TRACE_MODE_READ, d_tracer, tr, - &trace_time_stamp_mode_fops); - - tr->buffer_percent = 50; - trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer, - tr, &buffer_percent_fops); - - trace_create_file("buffer_subbuf_size_kb", TRACE_MODE_WRITE, d_tracer, - tr, &buffer_subbuf_size_fops); + tr, &buffer_percent_fops); trace_create_file("syscall_user_buf_size", TRACE_MODE_WRITE, d_tracer, - tr, &tracing_syscall_buf_fops); + tr, &tracing_syscall_buf_fops); - create_trace_options_dir(tr); + trace_create_file("tracing_on", TRACE_MODE_WRITE, d_tracer, + tr, &rb_simple_fops); trace_create_maxlat_file(tr, d_tracer); if (ftrace_create_function_files(tr, d_tracer)) MEM_FAIL(1, "Could not allocate function filter files"); - if (tr->range_addr_start) { - trace_create_file("last_boot_info", TRACE_MODE_READ, d_tracer, - tr, &last_boot_fops); #ifdef CONFIG_TRACER_SNAPSHOT - } else { + if (!tr->range_addr_start) trace_create_file("snapshot", TRACE_MODE_WRITE, d_tracer, tr, &snapshot_fops); #endif - } trace_create_file("error_log", TRACE_MODE_WRITE, d_tracer, tr, &tracing_err_log_fops); - for_each_tracing_cpu(cpu) - tracing_init_tracefs_percpu(tr, cpu); - ftrace_init_tracefs(tr, d_tracer); } @@ -10536,47 +9572,6 @@ ssize_t trace_parse_run_command(struct file *file, const char __user *buffer, return done; } -#ifdef CONFIG_TRACER_SNAPSHOT -__init static bool tr_needs_alloc_snapshot(const char *name) -{ - char *test; - int len = strlen(name); - bool ret; - - if (!boot_snapshot_index) - return false; - - if (strncmp(name, boot_snapshot_info, len) == 0 && - boot_snapshot_info[len] == '\t') - return true; - - test = kmalloc(strlen(name) + 3, GFP_KERNEL); - if (!test) - return false; - - sprintf(test, "\t%s\t", name); - ret = strstr(boot_snapshot_info, test) == NULL; - kfree(test); - return ret; -} - -__init static void do_allocate_snapshot(const char *name) -{ - if (!tr_needs_alloc_snapshot(name)) - return; - - /* - * When allocate_snapshot is set, the next call to - * allocate_trace_buffers() (called by trace_array_get_by_name()) - * will allocate the snapshot buffer. That will also clear - * this flag. - */ - allocate_snapshot = true; -} -#else -static inline void do_allocate_snapshot(const char *name) { } -#endif - __init static int backup_instance_area(const char *backup, unsigned long *addr, phys_addr_t *size) { @@ -10726,8 +9721,7 @@ __init static void enable_instances(void) } } else { /* Only non mapped buffers have snapshot buffers */ - if (IS_ENABLED(CONFIG_TRACER_SNAPSHOT)) - do_allocate_snapshot(name); + do_allocate_snapshot(name); } tr = trace_array_create_systems(name, NULL, addr, size); @@ -10753,17 +9747,41 @@ __init static void enable_instances(void) /* * Backup buffers can be freed but need vfree(). */ - if (backup) - tr->flags |= TRACE_ARRAY_FL_VMALLOC; + if (backup) { + tr->flags |= TRACE_ARRAY_FL_VMALLOC | TRACE_ARRAY_FL_RDONLY; + trace_array_start_autoremove(); + } if (start || backup) { tr->flags |= TRACE_ARRAY_FL_BOOT | TRACE_ARRAY_FL_LAST_BOOT; tr->range_name = no_free_ptr(rname); } + /* + * Save the events to start and enabled them after all boot instances + * have been created. + */ + tr->boot_events = curr_str; + } + + /* Enable the events after all boot instances have been created */ + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + + if (!tr->boot_events || !(*tr->boot_events)) { + tr->boot_events = NULL; + continue; + } + + curr_str = tr->boot_events; + + /* Clear the instance if this is a persistent buffer */ + if (tr->flags & TRACE_ARRAY_FL_LAST_BOOT) + update_last_data(tr); + while ((tok = strsep(&curr_str, ","))) { early_enable_events(tr, tok, true); } + tr->boot_events = NULL; } } @@ -10919,24 +9937,6 @@ struct trace_array *trace_get_global_array(void) } #endif -void __init ftrace_boot_snapshot(void) -{ -#ifdef CONFIG_TRACER_SNAPSHOT - struct trace_array *tr; - - if (!snapshot_at_boot) - return; - - list_for_each_entry(tr, &ftrace_trace_arrays, list) { - if (!tr->allocated_snapshot) - continue; - - tracing_snapshot_instance(tr); - trace_array_puts(tr, "** Boot snapshot taken **\n"); - } -#endif -} - void __init early_trace_init(void) { if (tracepoint_printk) { |