3.10-stable review patch. If anyone has any objections, please let me know.
------------------ From: Oleg Nesterov <[email protected]> commit 4d3435b8a4c3357695e09c5e7a3bf73a19fca5b0 upstream. tracing_open_generic_tc() is racy, the memory inode->i_private points to can be already freed. 1. Change one of its users, tracing_stats_fops, to use tracing_*_generic_tr() instead. 2. Change trace_create_cpu_file("stats", data) to pass "data = tr". 3. Change tracing_stats_read() to use tracing_get_cpu(). Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/trace/trace.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2973,7 +2973,6 @@ int tracing_open_generic_tr(struct inode filp->private_data = inode->i_private; return 0; - } int tracing_open_generic_tc(struct inode *inode, struct file *filp) @@ -5277,14 +5276,14 @@ 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) @@ -5337,10 +5336,10 @@ tracing_stats_read(struct file *filp, ch } static const struct file_operations tracing_stats_fops = { - .open = tracing_open_generic_tc, + .open = tracing_open_generic_tr, .read = tracing_stats_read, .llseek = generic_file_llseek, - .release = tracing_release_generic_tc, + .release = tracing_release_generic_tr, }; #ifdef CONFIG_DYNAMIC_FTRACE @@ -5570,7 +5569,7 @@ tracing_init_debugfs_percpu(struct trace tr, cpu, &tracing_buffers_fops); trace_create_cpu_file("stats", 0444, d_cpu, - &data->trace_cpu, cpu, &tracing_stats_fops); + tr, cpu, &tracing_stats_fops); trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, &data->trace_cpu, cpu, &tracing_entries_fops); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
