]> rtime.felk.cvut.cz Git - linux-imx.git/blobdiff - kernel/trace/trace.c
tracing: Change tracing_entries_fops to rely on tracing_get_cpu()
[linux-imx.git] / kernel / trace / trace.c
index 0cd500bffd9b0a26fc9d5f7107f51e8037e1d4bd..68b46851666f0dae17964a958204cefe165068ed 100644 (file)
@@ -2843,6 +2843,17 @@ 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,
@@ -2971,24 +2982,6 @@ static int tracing_open_generic_tr(struct inode *inode, struct file *filp)
        filp->private_data = inode->i_private;
 
        return 0;
-       
-}
-
-static int tracing_open_generic_tc(struct inode *inode, struct file *filp)
-{
-       struct trace_cpu *tc = inode->i_private;
-       struct trace_array *tr = tc->tr;
-
-       if (tracing_disabled)
-               return -ENODEV;
-
-       if (trace_array_get(tr) < 0)
-               return -ENODEV;
-
-       filp->private_data = inode->i_private;
-
-       return 0;
-       
 }
 
 static int tracing_release(struct inode *inode, struct file *file)
@@ -3008,7 +3001,6 @@ static int tracing_release(struct inode *inode, struct file *file)
 
        iter = m->private;
        tr = iter->tr;
-       trace_array_put(tr);
 
        mutex_lock(&trace_types_lock);
 
@@ -3023,6 +3015,9 @@ static int tracing_release(struct inode *inode, struct file *file)
        if (!iter->snapshot)
                /* reenable tracing if it was previously enabled */
                tracing_start_tr(tr);
+
+       __trace_array_put(tr);
+
        mutex_unlock(&trace_types_lock);
 
        mutex_destroy(&iter->mutex);
@@ -3042,15 +3037,6 @@ static int tracing_release_generic_tr(struct inode *inode, struct file *file)
        return 0;
 }
 
-static int tracing_release_generic_tc(struct inode *inode, struct file *file)
-{
-       struct trace_cpu *tc = inode->i_private;
-       struct trace_array *tr = tc->tr;
-
-       trace_array_put(tr);
-       return 0;
-}
-
 static int tracing_single_release_tr(struct inode *inode, struct file *file)
 {
        struct trace_array *tr = inode->i_private;
@@ -3447,6 +3433,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 static int tracing_trace_options_open(struct inode *inode, struct file *file)
 {
        struct trace_array *tr = inode->i_private;
+       int ret;
 
        if (tracing_disabled)
                return -ENODEV;
@@ -3454,7 +3441,11 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file)
        if (trace_array_get(tr) < 0)
                return -ENODEV;
 
-       return single_open(file, tracing_trace_options_show, inode->i_private);
+       ret = single_open(file, tracing_trace_options_show, inode->i_private);
+       if (ret < 0)
+               trace_array_put(tr);
+
+       return ret;
 }
 
 static const struct file_operations tracing_iter_fops = {
@@ -3537,14 +3528,14 @@ static const char readme_msg[] =
        "\n  snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n"
        "\t\t\t  Read the contents for more information\n"
 #endif
-#ifdef CONFIG_STACKTRACE
+#ifdef CONFIG_STACK_TRACER
        "  stack_trace\t\t- Shows the max stack trace when active\n"
        "  stack_max_size\t- Shows current max stack size that was traced\n"
        "\t\t\t  Write into this file to reset the max size (trigger a new trace)\n"
 #ifdef CONFIG_DYNAMIC_FTRACE
        "  stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n"
 #endif
-#endif /* CONFIG_STACKTRACE */
+#endif /* CONFIG_STACK_TRACER */
 ;
 
 static ssize_t
@@ -3941,8 +3932,7 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
 
 static int tracing_open_pipe(struct inode *inode, struct file *filp)
 {
-       struct trace_cpu *tc = inode->i_private;
-       struct trace_array *tr = tc->tr;
+       struct trace_array *tr = inode->i_private;
        struct trace_iterator *iter;
        int ret = 0;
 
@@ -3958,6 +3948,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
        iter = kzalloc(sizeof(*iter), GFP_KERNEL);
        if (!iter) {
                ret = -ENOMEM;
+               __trace_array_put(tr);
                goto out;
        }
 
@@ -3987,9 +3978,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
        if (trace_clocks[tr->clock_id].in_ns)
                iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
-       iter->cpu_file = tc->cpu;
-       iter->tr = tc->tr;
-       iter->trace_buffer = &tc->tr->trace_buffer;
+       iter->tr = tr;
+       iter->trace_buffer = &tr->trace_buffer;
+       iter->cpu_file = tracing_get_cpu(inode);
        mutex_init(&iter->mutex);
        filp->private_data = iter;
 
@@ -4012,8 +4003,7 @@ fail:
 static int tracing_release_pipe(struct inode *inode, struct file *file)
 {
        struct trace_iterator *iter = file->private_data;
-       struct trace_cpu *tc = inode->i_private;
-       struct trace_array *tr = tc->tr;
+       struct trace_array *tr = inode->i_private;
 
        mutex_lock(&trace_types_lock);
 
@@ -4366,15 +4356,16 @@ static ssize_t
 tracing_entries_read(struct file *filp, char __user *ubuf,
                     size_t cnt, loff_t *ppos)
 {
-       struct trace_cpu *tc = filp->private_data;
-       struct trace_array *tr = tc->tr;
+       struct inode *inode = file_inode(filp);
+       struct trace_array *tr = inode->i_private;
+       int cpu = tracing_get_cpu(inode);
        char buf[64];
        int r = 0;
        ssize_t ret;
 
        mutex_lock(&trace_types_lock);
 
-       if (tc->cpu == RING_BUFFER_ALL_CPUS) {
+       if (cpu == RING_BUFFER_ALL_CPUS) {
                int cpu, buf_size_same;
                unsigned long size;
 
@@ -4401,7 +4392,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
                } else
                        r = sprintf(buf, "X\n");
        } else
-               r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, tc->cpu)->entries >> 10);
+               r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);
 
        mutex_unlock(&trace_types_lock);
 
@@ -4413,7 +4404,8 @@ static ssize_t
 tracing_entries_write(struct file *filp, const char __user *ubuf,
                      size_t cnt, loff_t *ppos)
 {
-       struct trace_cpu *tc = filp->private_data;
+       struct inode *inode = file_inode(filp);
+       struct trace_array *tr = inode->i_private;
        unsigned long val;
        int ret;
 
@@ -4427,8 +4419,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
        /* value is in KB */
        val <<= 10;
-
-       ret = tracing_resize_ring_buffer(tc->tr, val, tc->cpu);
+       ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));
        if (ret < 0)
                return ret;
 
@@ -4704,21 +4695,24 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file)
                        ret = PTR_ERR(iter);
        } else {
                /* Writes still need the seq_file to hold the private data */
+               ret = -ENOMEM;
                m = kzalloc(sizeof(*m), GFP_KERNEL);
                if (!m)
-                       return -ENOMEM;
+                       goto out;
                iter = kzalloc(sizeof(*iter), GFP_KERNEL);
                if (!iter) {
                        kfree(m);
-                       return -ENOMEM;
+                       goto out;
                }
+               ret = 0;
+
                iter->tr = tr;
                iter->trace_buffer = &tc->tr->max_buffer;
                iter->cpu_file = tc->cpu;
                m->private = iter;
                file->private_data = m;
        }
-
+out:
        if (ret < 0)
                trace_array_put(tr);
 
@@ -4873,11 +4867,11 @@ static const struct file_operations tracing_pipe_fops = {
 };
 
 static const struct file_operations tracing_entries_fops = {
-       .open           = tracing_open_generic_tc,
+       .open           = tracing_open_generic_tr,
        .read           = tracing_entries_read,
        .write          = tracing_entries_write,
        .llseek         = generic_file_llseek,
-       .release        = tracing_release_generic_tc,
+       .release        = tracing_release_generic_tr,
 };
 
 static const struct file_operations tracing_total_entries_fops = {
@@ -4929,8 +4923,7 @@ static const struct file_operations snapshot_raw_fops = {
 
 static int tracing_buffers_open(struct inode *inode, struct file *filp)
 {
-       struct trace_cpu *tc = inode->i_private;
-       struct trace_array *tr = tc->tr;
+       struct trace_array *tr = inode->i_private;
        struct ftrace_buffer_info *info;
        int ret;
 
@@ -4948,10 +4941,8 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
 
        mutex_lock(&trace_types_lock);
 
-       tr->ref++;
-
        info->iter.tr           = tr;
-       info->iter.cpu_file     = tc->cpu;
+       info->iter.cpu_file     = tracing_get_cpu(inode);
        info->iter.trace        = tr->current_trace;
        info->iter.trace_buffer = &tr->trace_buffer;
        info->spare             = NULL;
@@ -5268,14 +5259,14 @@ static ssize_t
 tracing_stats_read(struct file *filp, char __user *ubuf,
                   size_t count, loff_t *ppos)
 {
-       struct trace_cpu *tc = filp->private_data;
-       struct trace_array *tr = tc->tr;
+       struct inode *inode = file_inode(filp);
+       struct trace_array *tr = inode->i_private;
        struct trace_buffer *trace_buf = &tr->trace_buffer;
+       int cpu = tracing_get_cpu(inode);
        struct trace_seq *s;
        unsigned long cnt;
        unsigned long long t;
        unsigned long usec_rem;
-       int cpu = tc->cpu;
 
        s = kmalloc(sizeof(*s), GFP_KERNEL);
        if (!s)
@@ -5328,9 +5319,10 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 }
 
 static const struct file_operations tracing_stats_fops = {
-       .open           = tracing_open_generic,
+       .open           = tracing_open_generic_tr,
        .read           = tracing_stats_read,
        .llseek         = generic_file_llseek,
+       .release        = tracing_release_generic_tr,
 };
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -5519,6 +5511,17 @@ static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
        return tr->percpu_dir;
 }
 
+static struct dentry *
+trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent,
+                     void *data, long cpu, const struct file_operations *fops)
+{
+       struct dentry *ret = trace_create_file(name, mode, parent, data, fops);
+
+       if (ret) /* See tracing_get_cpu() */
+               ret->d_inode->i_cdev = (void *)(cpu + 1);
+       return ret;
+}
+
 static void
 tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
 {
@@ -5538,28 +5541,28 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
        }
 
        /* per cpu trace_pipe */
-       trace_create_file("trace_pipe", 0444, d_cpu,
-                       (void *)&data->trace_cpu, &tracing_pipe_fops);
+       trace_create_cpu_file("trace_pipe", 0444, d_cpu,
+                               tr, cpu, &tracing_pipe_fops);
 
        /* per cpu trace */
-       trace_create_file("trace", 0644, d_cpu,
-                       (void *)&data->trace_cpu, &tracing_fops);
+       trace_create_cpu_file("trace", 0644, d_cpu,
+                               &data->trace_cpu, cpu, &tracing_fops);
 
-       trace_create_file("trace_pipe_raw", 0444, d_cpu,
-                       (void *)&data->trace_cpu, &tracing_buffers_fops);
+       trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu,
+                               tr, cpu, &tracing_buffers_fops);
 
-       trace_create_file("stats", 0444, d_cpu,
-                       (void *)&data->trace_cpu, &tracing_stats_fops);
+       trace_create_cpu_file("stats", 0444, d_cpu,
+                               tr, cpu, &tracing_stats_fops);
 
-       trace_create_file("buffer_size_kb", 0444, d_cpu,
-                       (void *)&data->trace_cpu, &tracing_entries_fops);
+       trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,
+                               tr, cpu, &tracing_entries_fops);
 
 #ifdef CONFIG_TRACER_SNAPSHOT
-       trace_create_file("snapshot", 0644, d_cpu,
-                         (void *)&data->trace_cpu, &snapshot_fops);
+       trace_create_cpu_file("snapshot", 0644, d_cpu,
+                               &data->trace_cpu, cpu, &snapshot_fops);
 
-       trace_create_file("snapshot_raw", 0444, d_cpu,
-                       (void *)&data->trace_cpu, &snapshot_raw_fops);
+       trace_create_cpu_file("snapshot_raw", 0444, d_cpu,
+                               tr, cpu, &snapshot_raw_fops);
 #endif
 }
 
@@ -5973,8 +5976,10 @@ static int new_instance_create(const char *name)
                goto out_free_tr;
 
        ret = event_trace_add_tracer(tr->dir, tr);
-       if (ret)
+       if (ret) {
+               debugfs_remove_recursive(tr->dir);
                goto out_free_tr;
+       }
 
        init_tracer_debugfs(tr, tr->dir);
 
@@ -6123,10 +6128,10 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
                        (void *)&tr->trace_cpu, &tracing_fops);
 
        trace_create_file("trace_pipe", 0444, d_tracer,
-                       (void *)&tr->trace_cpu, &tracing_pipe_fops);
+                         tr, &tracing_pipe_fops);
 
        trace_create_file("buffer_size_kb", 0644, d_tracer,
-                       (void *)&tr->trace_cpu, &tracing_entries_fops);
+                         tr, &tracing_entries_fops);
 
        trace_create_file("buffer_total_size_kb", 0444, d_tracer,
                          tr, &tracing_total_entries_fops);