diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-02-22 17:04:52 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-02-25 10:34:48 +0100 |
| commit | 7dc52157982ab771f40e3c0b7dc55b954c3c2d19 (patch) | |
| tree | a41e39174d9535f0c678eb36249ceee4a1775d6b | |
| parent | 497f0ab39cd25bed317b29482c147c967f7ecd1f (diff) | |
vfs: Apply lockdep-based checking to rcu_dereference() uses
Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable()
and fcheck_files().
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | fs/file.c | 2 | ||||
| -rw-r--r-- | fs/proc/array.c | 2 | ||||
| -rw-r--r-- | fs/proc/base.c | 6 | ||||
| -rw-r--r-- | include/linux/fdtable.h | 8 |
4 files changed, 14 insertions, 4 deletions
diff --git a/fs/file.c b/fs/file.c index 87e129030ab..38039af6766 100644 --- a/fs/file.c +++ b/fs/file.c @@ -478,7 +478,7 @@ repeat: error = fd; #if 1 /* Sanity check */ - if (rcu_dereference(fdt->fd[fd]) != NULL) { + if (rcu_dereference_raw(fdt->fd[fd]) != NULL) { printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd); rcu_assign_pointer(fdt->fd[fd], NULL); } diff --git a/fs/proc/array.c b/fs/proc/array.c index 13b5d070817..18e20feee25 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -270,7 +270,9 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p) blocked = p->blocked; collect_sigign_sigcatch(p, &ignored, &caught); num_threads = atomic_read(&p->signal->count); + rcu_read_lock(); /* FIXME: is this correct? */ qsize = atomic_read(&__task_cred(p)->user->sigpending); + rcu_read_unlock(); qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur; unlock_task_sighand(p, &flags); } diff --git a/fs/proc/base.c b/fs/proc/base.c index 58324c29916..623e2ffb5d2 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1095,8 +1095,12 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, if (!capable(CAP_AUDIT_CONTROL)) return -EPERM; - if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) + rcu_read_lock(); + if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { + rcu_read_unlock(); return -EPERM; + } + rcu_read_unlock(); if (count >= PAGE_SIZE) count = PAGE_SIZE - 1; diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index a2ec74bc481..144412fface 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -57,7 +57,11 @@ struct files_struct { struct file * fd_array[NR_OPEN_DEFAULT]; }; -#define files_fdtable(files) (rcu_dereference((files)->fdt)) +#define files_fdtable(files) \ + (rcu_dereference_check((files)->fdt, \ + rcu_read_lock_held() || \ + lockdep_is_held(&(files)->file_lock) || \ + atomic_read(&files->count) == 1)) struct file_operations; struct vfsmount; @@ -78,7 +82,7 @@ static inline struct file * fcheck_files(struct files_struct *files, unsigned in struct fdtable *fdt = files_fdtable(files); if (fd < fdt->max_fds) - file = rcu_dereference(fdt->fd[fd]); + file = rcu_dereference_check(fdt->fd[fd], rcu_read_lock_held() || lockdep_is_held(&files->file_lock) || atomic_read(&files->count) == 1); return file; } |