"[PATCH] Fix leaks on /proc/{*/sched,sched_debug,timer_list,timer_stats}" and
"[PATCH] Fix leak on /proc/lockdep_stats" fixed 5 leaks which happen if one
uses single_open() as .open function and seq_release() as .release function.
Let's add small amount of runtime checking.
Sample output is:
memory leak: 'timer_list'
WARNING: at fs/seq_file.c:289 seq_release()
[<c015e311>] seq_release+0x53/0x68
[<c0171bd8>] proc_reg_release+0x63/0x74
[<c0149877>] __fput+0x28/0xd3
[<c0147681>] filp_close+0x48/0x4f
[<c014876a>] sys_close+0x74/0xbe
[<c010248e>] sysenter_past_esp+0x5f/0x85
=======================
Signed-off-by: Alexey Dobriyan <[EMAIL PROTECTED]>
---
fs/seq_file.c | 25 ++++++++++++++++++++-----
include/linux/seq_file.h | 1 +
2 files changed, 21 insertions(+), 5 deletions(-)
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -281,6 +281,13 @@ EXPORT_SYMBOL(seq_lseek);
int seq_release(struct inode *inode, struct file *file)
{
struct seq_file *m = (struct seq_file *)file->private_data;
+
+ if (m->seq_ops_allocated) {
+ struct dentry *dentry = file->f_dentry;
+ printk("memory leak: '%.*s'\n",
+ dentry->d_name.len, dentry->d_name.name);
+ WARN_ON(1);
+ }
kfree(m->buf);
kfree(m);
return 0;
@@ -401,9 +408,12 @@ int single_open(struct file *file, int (*show)(struct
seq_file *, void *),
op->stop = single_stop;
op->show = show;
res = seq_open(file, op);
- if (!res)
- ((struct seq_file *)file->private_data)->private = data;
- else
+ if (!res) {
+ struct seq_file *seq = file->private_data;
+
+ seq->private = data;
+ seq->seq_ops_allocated = 1;
+ } else
kfree(op);
}
return res;
@@ -412,8 +422,13 @@ EXPORT_SYMBOL(single_open);
int single_release(struct inode *inode, struct file *file)
{
- const struct seq_operations *op = ((struct seq_file
*)file->private_data)->op;
- int res = seq_release(inode, file);
+ struct seq_file *seq = file->private_data;
+ const struct seq_operations *op = seq->op;
+ int res;
+
+ /* All roads lead to seq_release(), so... */
+ seq->seq_ops_allocated = 0;
+ res = seq_release(inode, file);
kfree(op);
return res;
}
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -22,6 +22,7 @@ struct seq_file {
struct mutex lock;
const struct seq_operations *op;
void *private;
+ unsigned int seq_ops_allocated:1;
};
struct seq_operations {
-
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