X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Ffcntl.c;h=ae413086db978093123b2a59947d78e23a02a693;hb=444528b3e614f7f2391488d9bca8e0b872db909b;hp=c594cc0e40fbcb2af3a6cb928e0bca2392d04156;hpb=86a264abe542cfececb4df129bc45a0338d8cdb9;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/fcntl.c b/fs/fcntl.c
index c594cc0..ae41308 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -49,7 +49,7 @@ static int get_close_on_exec(unsigned int fd)
 	return res;
 }
 
-asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
+SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
 {
 	int err = -EBADF;
 	struct file * file, *tofree;
@@ -112,20 +112,22 @@ out_unlock:
 	return err;
 }
 
-asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
+SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd)
 {
 	if (unlikely(newfd == oldfd)) { /* corner case */
 		struct files_struct *files = current->files;
+		int retval = oldfd;
+
 		rcu_read_lock();
 		if (!fcheck_files(files, oldfd))
-			oldfd = -EBADF;
+			retval = -EBADF;
 		rcu_read_unlock();
-		return oldfd;
+		return retval;
 	}
 	return sys_dup3(oldfd, newfd, 0);
 }
 
-asmlinkage long sys_dup(unsigned int fildes)
+SYSCALL_DEFINE1(dup, unsigned int, fildes)
 {
 	int ret = -EBADF;
 	struct file *file = fget(fildes);
@@ -140,7 +142,7 @@ asmlinkage long sys_dup(unsigned int fildes)
 	return ret;
 }
 
-#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME)
+#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
 
 static int setfl(int fd, struct file * filp, unsigned long arg)
 {
@@ -175,29 +177,39 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 	if (error)
 		return error;
 
-	if ((arg ^ filp->f_flags) & FASYNC) {
-		if (filp->f_op && filp->f_op->fasync) {
-			error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
-			if (error < 0)
-				goto out;
-		}
+	/*
+	 * ->fasync() is responsible for setting the FASYNC bit.
+	 */
+	if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op &&
+			filp->f_op->fasync) {
+		error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
+		if (error < 0)
+			goto out;
+		if (error > 0)
+			error = 0;
 	}
-
+	spin_lock(&filp->f_lock);
 	filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
+	spin_unlock(&filp->f_lock);
+
  out:
 	return error;
 }
 
 static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
-                     uid_t uid, uid_t euid, int force)
+                     int force)
 {
 	write_lock_irq(&filp->f_owner.lock);
 	if (force || !filp->f_owner.pid) {
 		put_pid(filp->f_owner.pid);
 		filp->f_owner.pid = get_pid(pid);
 		filp->f_owner.pid_type = type;
-		filp->f_owner.uid = uid;
-		filp->f_owner.euid = euid;
+
+		if (pid) {
+			const struct cred *cred = current_cred();
+			filp->f_owner.uid = cred->uid;
+			filp->f_owner.euid = cred->euid;
+		}
 	}
 	write_unlock_irq(&filp->f_owner.lock);
 }
@@ -205,14 +217,13 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
 int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
 		int force)
 {
-	const struct cred *cred = current_cred();
 	int err;
-	
+
 	err = security_file_set_fowner(filp);
 	if (err)
 		return err;
 
-	f_modown(filp, pid, type, cred->uid, cred->euid, force);
+	f_modown(filp, pid, type, force);
 	return 0;
 }
 EXPORT_SYMBOL(__f_setown);
@@ -238,7 +249,7 @@ EXPORT_SYMBOL(f_setown);
 
 void f_delown(struct file *filp)
 {
-	f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1);
+	f_modown(filp, NULL, PIDTYPE_PID, 1);
 }
 
 pid_t f_getown(struct file *filp)
@@ -328,7 +339,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 	return err;
 }
 
-asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
+SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 {	
 	struct file *filp;
 	long err = -EBADF;
@@ -351,7 +362,8 @@ out:
 }
 
 #if BITS_PER_LONG == 32
-asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
+SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
+		unsigned long, arg)
 {	
 	struct file * filp;
 	long err;
@@ -401,21 +413,34 @@ static const long band_table[NSIGPOLL] = {
 static inline int sigio_perm(struct task_struct *p,
                              struct fown_struct *fown, int sig)
 {
-	return (((fown->euid == 0) ||
-		 (fown->euid == p->cred->suid) || (fown->euid == p->cred->uid) ||
-		 (fown->uid == p->cred->suid) || (fown->uid == p->cred->uid)) &&
-		!security_file_send_sigiotask(p, fown, sig));
+	const struct cred *cred;
+	int ret;
+
+	rcu_read_lock();
+	cred = __task_cred(p);
+	ret = ((fown->euid == 0 ||
+		fown->euid == cred->suid || fown->euid == cred->uid ||
+		fown->uid  == cred->suid || fown->uid  == cred->uid) &&
+	       !security_file_send_sigiotask(p, fown, sig));
+	rcu_read_unlock();
+	return ret;
 }
 
 static void send_sigio_to_task(struct task_struct *p,
-			       struct fown_struct *fown, 
+			       struct fown_struct *fown,
 			       int fd,
 			       int reason)
 {
-	if (!sigio_perm(p, fown, fown->signum))
+	/*
+	 * F_SETSIG can change ->signum lockless in parallel, make
+	 * sure we read it once and use the same value throughout.
+	 */
+	int signum = ACCESS_ONCE(fown->signum);
+
+	if (!sigio_perm(p, fown, signum))
 		return;
 
-	switch (fown->signum) {
+	switch (signum) {
 		siginfo_t si;
 		default:
 			/* Queue a rt signal with the appropriate fd as its
@@ -424,7 +449,7 @@ static void send_sigio_to_task(struct task_struct *p,
 			   delivered even if we can't queue.  Failure to
 			   queue in this case _should_ be reported; we fall
 			   back to SIGIO in that case. --sct */
-			si.si_signo = fown->signum;
+			si.si_signo = signum;
 			si.si_errno = 0;
 		        si.si_code  = reason;
 			/* Make sure we are called with one of the POLL_*
@@ -436,7 +461,7 @@ static void send_sigio_to_task(struct task_struct *p,
 			else
 				si.si_band = band_table[reason - POLL_IN];
 			si.si_fd    = fd;
-			if (!group_send_sig_info(fown->signum, &si, p))
+			if (!group_send_sig_info(signum, &si, p))
 				break;
 		/* fall-through: fall back on the old plain SIGIO signal */
 		case 0:
@@ -501,7 +526,7 @@ static DEFINE_RWLOCK(fasync_lock);
 static struct kmem_cache *fasync_cache __read_mostly;
 
 /*
- * fasync_helper() is used by some character device drivers (mainly mice)
+ * fasync_helper() is used by almost all character device drivers
  * to set up the fasync queue. It returns negative on error, 0 if it did
  * no changes and positive if it added/deleted the entry.
  */
@@ -516,6 +541,12 @@ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fap
 		if (!new)
 			return -ENOMEM;
 	}
+
+	/*
+	 * We need to take f_lock first since it's not an IRQ-safe
+	 * lock.
+	 */
+	spin_lock(&filp->f_lock);
 	write_lock_irq(&fasync_lock);
 	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
 		if (fa->fa_file == filp) {
@@ -540,7 +571,12 @@ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fap
 		result = 1;
 	}
 out:
+	if (on)
+		filp->f_flags |= FASYNC;
+	else
+		filp->f_flags &= ~FASYNC;
 	write_unlock_irq(&fasync_lock);
+	spin_unlock(&filp->f_lock);
 	return result;
 }