From: Manfred Spraul <manfred@colorfullife.com>
What about the attached patch?
The lifetime of dentries is quite long, thus I'd prefer if the race
between proc_pid_lookup and sys_exit is closed.
fs/proc/base.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)
diff -puN fs/proc/base.c~proc_pid_lookup-vs-exit-race-fix fs/proc/base.c
--- 25/fs/proc/base.c~proc_pid_lookup-vs-exit-race-fix 2003-10-26 15:50:11.000000000 -0800
+++ 25-akpm/fs/proc/base.c 2003-10-26 15:50:11.000000000 -0800
@@ -1524,6 +1524,7 @@ struct dentry *proc_pid_lookup(struct in
struct inode *inode;
struct proc_inode *ei;
unsigned tgid;
+ int died;
if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
inode = new_inode(dir->i_sb);
@@ -1567,12 +1568,21 @@ struct dentry *proc_pid_lookup(struct in
dentry->d_op = &pid_base_dentry_operations;
+ died = 0;
+ d_add(dentry, inode);
spin_lock(&task->proc_lock);
task->proc_dentry = dentry;
- d_add(dentry, inode);
+ if (!pid_alive(task)) {
+ dentry = proc_pid_unhash(task);
+ died = 1;
+ }
spin_unlock(&task->proc_lock);
put_task_struct(task);
+ if (died) {
+ proc_pid_flush(dentry);
+ goto out;
+ }
return NULL;
out:
return ERR_PTR(-ENOENT);
@@ -1612,10 +1622,7 @@ static struct dentry *proc_task_lookup(s
dentry->d_op = &pid_base_dentry_operations;
- spin_lock(&task->proc_lock);
- task->proc_dentry = dentry;
d_add(dentry, inode);
- spin_unlock(&task->proc_lock);
put_task_struct(task);
return NULL;
_