Merge tag 'v3.10.108' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 56487c31d8c78266ad75c613e9c138a886723728..7d083107a044fe76b69375f9569176185a421b63 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3187,11 +3187,17 @@ static int tracing_open(struct inode *inode, struct file *file)
        /* If this file was open for write, then erase contents */
        if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
                int cpu = tracing_get_cpu(inode);
+               struct trace_buffer *trace_buf = &tr->trace_buffer;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+               if (tr->current_trace->print_max)
+                       trace_buf = &tr->max_buffer;
+#endif
 
                if (cpu == RING_BUFFER_ALL_CPUS)
-                       tracing_reset_online_cpus(&tr->trace_buffer);
+                       tracing_reset_online_cpus(trace_buf);
                else
-                       tracing_reset(&tr->trace_buffer, cpu);
+                       tracing_reset(trace_buf, cpu);
        }
 
        if (file->f_mode & FMODE_READ) {
@@ -4313,13 +4319,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
        struct trace_array *tr = iter->tr;
        ssize_t sret;
 
-       /* return any leftover data */
-       sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
-       if (sret != -EBUSY)
-               return sret;
-
-       trace_seq_init(&iter->seq);
-
        /* copy the tracer to avoid using a global lock all around */
        mutex_lock(&trace_types_lock);
        if (unlikely(iter->trace->name != tr->current_trace->name))
@@ -4332,6 +4331,14 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
         * is protected.
         */
        mutex_lock(&iter->mutex);
+
+       /* return any leftover data */
+       sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+       if (sret != -EBUSY)
+               goto out;
+
+       trace_seq_init(&iter->seq);
+
        if (iter->trace->read) {
                sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
                if (sret)
@@ -4543,7 +4550,10 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
 
        spd.nr_pages = i;
 
-       ret = splice_to_pipe(pipe, &spd);
+       if (i)
+               ret = splice_to_pipe(pipe, &spd);
+       else
+               ret = 0;
 out:
        splice_shrink_spd(&spd);
        return ret;
@@ -4786,7 +4796,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
        *fpos += written;
 
  out_unlock:
-       for (i = 0; i < nr_pages; i++){
+       for (i = nr_pages - 1; i >= 0; i--) {
                kunmap_atomic(map_page[i]);
                put_page(pages[i]);
        }
@@ -4848,7 +4858,7 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
        tracing_reset_online_cpus(&tr->trace_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-       if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
+       if (tr->max_buffer.buffer)
                ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
        tracing_reset_online_cpus(&tr->max_buffer);
 #endif
@@ -5363,11 +5373,6 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
        }
 #endif
 
-       if (splice_grow_spd(pipe, &spd)) {
-               ret = -ENOMEM;
-               goto out;
-       }
-
        if (*ppos & (PAGE_SIZE - 1)) {
                ret = -EINVAL;
                goto out;
@@ -5381,6 +5386,11 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
                len &= PAGE_MASK;
        }
 
+       if (splice_grow_spd(pipe, &spd)) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
  again:
        trace_access_lock(iter->cpu_file);
        entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
@@ -5436,21 +5446,22 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
        if (!spd.nr_pages) {
                if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) {
                        ret = -EAGAIN;
-                       goto out;
+                       goto out_shrink;
                }
                mutex_unlock(&trace_types_lock);
                ret = iter->trace->wait_pipe(iter);
                mutex_lock(&trace_types_lock);
                if (ret)
-                       goto out;
+                       goto out_shrink;
                if (signal_pending(current)) {
                        ret = -EINTR;
-                       goto out;
+                       goto out_shrink;
                }
                goto again;
        }
 
        ret = splice_to_pipe(pipe, &spd);
+out_shrink:
        splice_shrink_spd(&spd);
 out:
        mutex_unlock(&trace_types_lock);
@@ -5661,11 +5672,13 @@ ftrace_trace_snapshot_callback(struct ftrace_hash *hash,
                return ret;
 
  out_reg:
-       ret = register_ftrace_function_probe(glob, ops, count);
+       ret = alloc_snapshot(&global_trace);
+       if (ret < 0)
+               goto out;
 
-       if (ret >= 0)
-               alloc_snapshot(&global_trace);
+       ret = register_ftrace_function_probe(glob, ops, count);
 
+ out:
        return ret < 0 ? ret : 0;
 }
 
@@ -6306,7 +6319,7 @@ static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t m
        int ret;
 
        /* Paranoid: Make sure the parent is the "instances" directory */
-       parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+       parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
        if (WARN_ON_ONCE(parent != trace_instance_dir))
                return -ENOENT;
 
@@ -6333,7 +6346,7 @@ static int instance_rmdir(struct inode *inode, struct dentry *dentry)
        int ret;
 
        /* Paranoid: Make sure the parent is the "instances" directory */
-       parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+       parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
        if (WARN_ON_ONCE(parent != trace_instance_dir))
                return -ENOENT;