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authorOleg Nesterov <oleg@redhat.com>2013-07-23 17:26:06 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-29 09:47:32 -0700
commite5dd03c411713c066b94e1d448359e5216115c1c (patch)
tree3d48fdc9a0a333614a5a68ead416780619a61e3b
parent6dafb0f13798c998ec344bf910b2d89c51961481 (diff)
downloadvexpress-lsk-e5dd03c411713c066b94e1d448359e5216115c1c.tar.gz
tracing: Change tracing_entries_fops to rely on tracing_get_cpu()
commit 0bc392ee46d0fd8e6b678457ef71f074f19a03c5 upstream. tracing_open_generic_tc() is racy, the memory inode->i_private points to can be already freed. 1. Change its last user, tracing_entries_fops, to use tracing_*_generic_tr() instead. 2. Change debugfs_create_file("buffer_size_kb", data) callers to pass "data = tr". 3. Change tracing_entries_read() and tracing_entries_write() to use tracing_get_cpu(). 4. Kill the no longer used tracing_open_generic_tc() and tracing_release_generic_tc(). Link: http://lkml.kernel.org/r/20130723152606.GA23730@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/trace/trace.c49
1 files changed, 12 insertions, 37 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 801d72b84a2..83fba3c576e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2975,23 +2975,6 @@ int tracing_open_generic_tr(struct inode *inode, struct file *filp)
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;
@@ -3045,15 +3028,6 @@ 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;
@@ -4374,15 +4348,16 @@ 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;
@@ -4409,7 +4384,7 @@ 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);
@@ -4421,7 +4396,8 @@ 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;
@@ -4435,8 +4411,7 @@ 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;
@@ -4884,11 +4859,11 @@ 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 = {
@@ -5572,7 +5547,7 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
tr, cpu, &tracing_stats_fops);
trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,
- &data->trace_cpu, cpu, &tracing_entries_fops);
+ tr, cpu, &tracing_entries_fops);
#ifdef CONFIG_TRACER_SNAPSHOT
trace_create_cpu_file("snapshot", 0644, d_cpu,
@@ -6148,7 +6123,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
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);