3.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
commit 7b85af63034818e43aee6c1d7bf1c7c6796a9073 upstream.
When a trace file is opened that may access a trace array, it must
increment its ref count to prevent it from being deleted.
Reported-by: Alexander Lam <azl@xxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 112 insertions(+), 9 deletions(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2902,6 +2902,43 @@ int tracing_open_generic(struct inode *i
return 0;
}
+/*
+ * Open and update trace_array ref count.
+ * Must have the current trace_array passed to it.
+ */
+int tracing_open_generic_tr(struct inode *inode, struct file *filp)
+{
+ struct trace_array *tr = inode->i_private;
+
+ if (tracing_disabled)
+ return -ENODEV;
+
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
+
+ filp->private_data = inode->i_private;
+
+ return 0;
+
+}
+
+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)
{
struct seq_file *m = file->private_data;
@@ -2945,6 +2982,32 @@ static int tracing_release(struct inode
return 0;
}
+static int tracing_release_generic_tr(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+ 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;
+
+ trace_array_put(tr);
+
+ return single_release(inode, file);
+}
+
static int tracing_open(struct inode *inode, struct file *file)
{
struct trace_cpu *tc = inode->i_private;
@@ -3331,9 +3394,14 @@ tracing_trace_options_write(struct file
static int tracing_trace_options_open(struct inode *inode, struct file *file)
{
+ struct trace_array *tr = inode->i_private;
+
if (tracing_disabled)
return -ENODEV;
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
+
return single_open(file, tracing_trace_options_show, inode->i_private);
}
@@ -3341,7 +3409,7 @@ static const struct file_operations trac
.open = tracing_trace_options_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = single_release,
+ .release = tracing_single_release_tr,
.write = tracing_trace_options_write,
};
@@ -3829,6 +3897,9 @@ static int tracing_open_pipe(struct inod
if (tracing_disabled)
return -ENODEV;
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
+
mutex_lock(&trace_types_lock);
/* create a buffer to store the information to pass to userspace */
@@ -3881,6 +3952,7 @@ out:
fail:
kfree(iter->trace);
kfree(iter);
+ __trace_array_put(tr);
mutex_unlock(&trace_types_lock);
return ret;
}
@@ -3888,6 +3960,8 @@ 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;
mutex_lock(&trace_types_lock);
@@ -3901,6 +3975,8 @@ static int tracing_release_pipe(struct i
kfree(iter->trace);
kfree(iter);
+ trace_array_put(tr);
+
return 0;
}
@@ -4358,6 +4434,8 @@ tracing_free_buffer_release(struct inode
/* resize the ring buffer to 0 */
tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
+ trace_array_put(tr);
+
return 0;
}
@@ -4534,10 +4612,20 @@ static ssize_t tracing_clock_write(struc
static int tracing_clock_open(struct inode *inode, struct file *file)
{
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
if (tracing_disabled)
return -ENODEV;
- return single_open(file, tracing_clock_show, inode->i_private);
+ if (trace_array_get(tr))
+ return -ENODEV;
+
+ ret = single_open(file, tracing_clock_show, inode->i_private);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
}
struct ftrace_buffer_info {
@@ -4733,34 +4821,38 @@ static const struct file_operations trac
};
static const struct file_operations tracing_entries_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_generic_tc,
.read = tracing_entries_read,
.write = tracing_entries_write,
.llseek = generic_file_llseek,
+ .release = tracing_release_generic_tc,
};
static const struct file_operations tracing_total_entries_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_generic_tr,
.read = tracing_total_entries_read,
.llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
};
static const struct file_operations tracing_free_buffer_fops = {
+ .open = tracing_open_generic_tr,
.write = tracing_free_buffer_write,
.release = tracing_free_buffer_release,
};
static const struct file_operations tracing_mark_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_generic_tr,
.write = tracing_mark_write,
.llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
};
static const struct file_operations trace_clock_fops = {
.open = tracing_clock_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = single_release,
+ .release = tracing_single_release_tr,
.write = tracing_clock_write,
};
@@ -4788,13 +4880,19 @@ static int tracing_buffers_open(struct i
struct trace_cpu *tc = inode->i_private;
struct trace_array *tr = tc->tr;
struct ftrace_buffer_info *info;
+ int ret;
if (tracing_disabled)
return -ENODEV;
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
+
info = kzalloc(sizeof(*info), GFP_KERNEL);
- if (!info)
+ if (!info) {
+ trace_array_put(tr);
return -ENOMEM;
+ }
mutex_lock(&trace_types_lock);
@@ -4812,7 +4910,11 @@ static int tracing_buffers_open(struct i
mutex_unlock(&trace_types_lock);
- return nonseekable_open(inode, filp);
+ ret = nonseekable_open(inode, filp);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
}
static unsigned int
@@ -5707,9 +5809,10 @@ rb_simple_write(struct file *filp, const
}
static const struct file_operations rb_simple_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_generic_tr,
.read = rb_simple_read,
.write = rb_simple_write,
+ .release = tracing_release_generic_tr,
.llseek = default_llseek,
};
--
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