From a75d30c772078546ac00399a94ecdc82df1a4d72 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 27 May 2017 06:07:19 -0400 Subject: [PATCH] fs/locks: pass kernel struct flock to fcntl_getlk/setlk This will make it easier to implement a sane compat fcntl syscall. [ jlayton: fix undeclared identifiers in 32-bit fcntl64 syscall handler ] Signed-off-by: Christoph Hellwig Reviewed-by: Jeff Layton Signed-off-by: Jeff Layton --- fs/fcntl.c | 27 +++++++++++++--- fs/locks.c | 79 +++++++++++++--------------------------------- include/linux/fs.h | 8 ++--- 3 files changed, 48 insertions(+), 66 deletions(-) diff --git a/fs/fcntl.c b/fs/fcntl.c index f4e7267d117f..ed4283d500a3 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -246,6 +246,8 @@ static int f_getowner_uids(struct file *filp, unsigned long arg) static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, struct file *filp) { + void __user *argp = (void __user *)arg; + struct flock flock; long err = -EINVAL; switch (cmd) { @@ -273,7 +275,11 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, case F_OFD_GETLK: #endif case F_GETLK: - err = fcntl_getlk(filp, cmd, (struct flock __user *) arg); + if (copy_from_user(&flock, argp, sizeof(flock))) + return -EFAULT; + err = fcntl_getlk(filp, cmd, &flock); + if (!err && copy_to_user(argp, &flock, sizeof(flock))) + return -EFAULT; break; #if BITS_PER_LONG != 32 /* 32-bit arches must use fcntl64() */ @@ -283,7 +289,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, /* Fallthrough */ case F_SETLK: case F_SETLKW: - err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); + if (copy_from_user(&flock, argp, sizeof(flock))) + return -EFAULT; + err = fcntl_setlk(fd, filp, cmd, &flock); break; case F_GETOWN: /* @@ -383,7 +391,9 @@ SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, unsigned long, arg) { + void __user *argp = (void __user *)arg; struct fd f = fdget_raw(fd); + struct flock64 flock; long err = -EBADF; if (!f.file) @@ -401,14 +411,21 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, switch (cmd) { case F_GETLK64: case F_OFD_GETLK: - err = fcntl_getlk64(f.file, cmd, (struct flock64 __user *) arg); + err = -EFAULT; + if (copy_from_user(&flock, argp, sizeof(flock))) + break; + err = fcntl_getlk64(f.file, cmd, &flock); + if (!err && copy_to_user(argp, &flock, sizeof(flock))) + err = -EFAULT; break; case F_SETLK64: case F_SETLKW64: case F_OFD_SETLK: case F_OFD_SETLKW: - err = fcntl_setlk64(fd, f.file, cmd, - (struct flock64 __user *) arg); + err = -EFAULT; + if (copy_from_user(&flock, argp, sizeof(flock))) + break; + err = fcntl_setlk64(fd, f.file, cmd, &flock); break; default: err = do_fcntl(fd, cmd, arg, f.file); diff --git a/fs/locks.c b/fs/locks.c index 4a4543a7f9c1..afefeb4ad6de 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2084,26 +2084,22 @@ static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) /* Report the first existing lock that would conflict with l. * This implements the F_GETLK command of fcntl(). */ -int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l) +int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) { struct file_lock file_lock; - struct flock flock; int error; - error = -EFAULT; - if (copy_from_user(&flock, l, sizeof(flock))) - goto out; error = -EINVAL; - if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK)) + if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) goto out; - error = flock_to_posix_lock(filp, &file_lock, &flock); + error = flock_to_posix_lock(filp, &file_lock, flock); if (error) goto out; if (cmd == F_OFD_GETLK) { error = -EINVAL; - if (flock.l_pid != 0) + if (flock->l_pid != 0) goto out; cmd = F_GETLK; @@ -2115,15 +2111,12 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l) if (error) goto out; - flock.l_type = file_lock.fl_type; + flock->l_type = file_lock.fl_type; if (file_lock.fl_type != F_UNLCK) { - error = posix_lock_to_flock(&flock, &file_lock); + error = posix_lock_to_flock(flock, &file_lock); if (error) goto rel_priv; } - error = -EFAULT; - if (!copy_to_user(l, &flock, sizeof(flock))) - error = 0; rel_priv: locks_release_private(&file_lock); out: @@ -2216,26 +2209,16 @@ check_fmode_for_setlk(struct file_lock *fl) * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, - struct flock __user *l) + struct flock *flock) { struct file_lock *file_lock = locks_alloc_lock(); - struct flock flock; - struct inode *inode; + struct inode *inode = locks_inode(filp); struct file *f; int error; if (file_lock == NULL) return -ENOLCK; - inode = locks_inode(filp); - - /* - * This might block, so we do it before checking the inode. - */ - error = -EFAULT; - if (copy_from_user(&flock, l, sizeof(flock))) - goto out; - /* Don't allow mandatory locks on files that may be memory mapped * and shared. */ @@ -2244,7 +2227,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, goto out; } - error = flock_to_posix_lock(filp, file_lock, &flock); + error = flock_to_posix_lock(filp, file_lock, flock); if (error) goto out; @@ -2259,7 +2242,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, switch (cmd) { case F_OFD_SETLK: error = -EINVAL; - if (flock.l_pid != 0) + if (flock->l_pid != 0) goto out; cmd = F_SETLK; @@ -2268,7 +2251,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, break; case F_OFD_SETLKW: error = -EINVAL; - if (flock.l_pid != 0) + if (flock->l_pid != 0) goto out; cmd = F_SETLKW; @@ -2313,26 +2296,22 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, /* Report the first existing lock that would conflict with l. * This implements the F_GETLK command of fcntl(). */ -int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) +int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock) { struct file_lock file_lock; - struct flock64 flock; int error; - error = -EFAULT; - if (copy_from_user(&flock, l, sizeof(flock))) - goto out; error = -EINVAL; - if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK)) + if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) goto out; - error = flock64_to_posix_lock(filp, &file_lock, &flock); + error = flock64_to_posix_lock(filp, &file_lock, flock); if (error) goto out; if (cmd == F_OFD_GETLK) { error = -EINVAL; - if (flock.l_pid != 0) + if (flock->l_pid != 0) goto out; cmd = F_GETLK64; @@ -2344,13 +2323,9 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) if (error) goto out; - flock.l_type = file_lock.fl_type; + flock->l_type = file_lock.fl_type; if (file_lock.fl_type != F_UNLCK) - posix_lock_to_flock64(&flock, &file_lock); - - error = -EFAULT; - if (!copy_to_user(l, &flock, sizeof(flock))) - error = 0; + posix_lock_to_flock64(flock, &file_lock); locks_release_private(&file_lock); out: @@ -2361,26 +2336,16 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, - struct flock64 __user *l) + struct flock64 *flock) { struct file_lock *file_lock = locks_alloc_lock(); - struct flock64 flock; - struct inode *inode; + struct inode *inode = locks_inode(filp); struct file *f; int error; if (file_lock == NULL) return -ENOLCK; - /* - * This might block, so we do it before checking the inode. - */ - error = -EFAULT; - if (copy_from_user(&flock, l, sizeof(flock))) - goto out; - - inode = locks_inode(filp); - /* Don't allow mandatory locks on files that may be memory mapped * and shared. */ @@ -2389,7 +2354,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, goto out; } - error = flock64_to_posix_lock(filp, file_lock, &flock); + error = flock64_to_posix_lock(filp, file_lock, flock); if (error) goto out; @@ -2404,7 +2369,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, switch (cmd) { case F_OFD_SETLK: error = -EINVAL; - if (flock.l_pid != 0) + if (flock->l_pid != 0) goto out; cmd = F_SETLK64; @@ -2413,7 +2378,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, break; case F_OFD_SETLKW: error = -EINVAL; - if (flock.l_pid != 0) + if (flock->l_pid != 0) goto out; cmd = F_SETLKW64; diff --git a/include/linux/fs.h b/include/linux/fs.h index 803e5a9b2654..aa4affb38c39 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1038,14 +1038,14 @@ static inline struct inode *locks_inode(const struct file *f) } #ifdef CONFIG_FILE_LOCKING -extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *); +extern int fcntl_getlk(struct file *, unsigned int, struct flock *); extern int fcntl_setlk(unsigned int, struct file *, unsigned int, - struct flock __user *); + struct flock *); #if BITS_PER_LONG == 32 -extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *); +extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 *); extern int fcntl_setlk64(unsigned int, struct file *, unsigned int, - struct flock64 __user *); + struct flock64 *); #endif extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg); -- 2.45.2