From 7e2d8c29ecdd86afbcedb9d9a977bab8af527add Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 11 Aug 2021 08:30:24 +0100 Subject: [PATCH] ARM: 9111/1: oabi-compat: rework fcntl64() emulation This is one of the last users of get_fs(), and this is fairly easy to change, since the infrastructure for it is already there. The replacement here is essentially a copy of the existing fcntl64() syscall entry function. Acked-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle) --- arch/arm/kernel/sys_oabi-compat.c | 93 +++++++++++++++++++++++++-------------- 1 file changed, 60 insertions(+), 33 deletions(-) diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c index 5ea365c..223ee46 100644 --- a/arch/arm/kernel/sys_oabi-compat.c +++ b/arch/arm/kernel/sys_oabi-compat.c @@ -194,56 +194,83 @@ struct oabi_flock64 { pid_t l_pid; } __attribute__ ((packed,aligned(4))); -static long do_locks(unsigned int fd, unsigned int cmd, - unsigned long arg) +static int get_oabi_flock(struct flock64 *kernel, struct oabi_flock64 __user *arg) { - struct flock64 kernel; struct oabi_flock64 user; - mm_segment_t fs; - long ret; if (copy_from_user(&user, (struct oabi_flock64 __user *)arg, sizeof(user))) return -EFAULT; - kernel.l_type = user.l_type; - kernel.l_whence = user.l_whence; - kernel.l_start = user.l_start; - kernel.l_len = user.l_len; - kernel.l_pid = user.l_pid; - - fs = get_fs(); - set_fs(KERNEL_DS); - ret = sys_fcntl64(fd, cmd, (unsigned long)&kernel); - set_fs(fs); - - if (!ret && (cmd == F_GETLK64 || cmd == F_OFD_GETLK)) { - user.l_type = kernel.l_type; - user.l_whence = kernel.l_whence; - user.l_start = kernel.l_start; - user.l_len = kernel.l_len; - user.l_pid = kernel.l_pid; - if (copy_to_user((struct oabi_flock64 __user *)arg, - &user, sizeof(user))) - ret = -EFAULT; - } - return ret; + + kernel->l_type = user.l_type; + kernel->l_whence = user.l_whence; + kernel->l_start = user.l_start; + kernel->l_len = user.l_len; + kernel->l_pid = user.l_pid; + + return 0; +} + +static int put_oabi_flock(struct flock64 *kernel, struct oabi_flock64 __user *arg) +{ + struct oabi_flock64 user; + + user.l_type = kernel->l_type; + user.l_whence = kernel->l_whence; + user.l_start = kernel->l_start; + user.l_len = kernel->l_len; + user.l_pid = kernel->l_pid; + + if (copy_to_user((struct oabi_flock64 __user *)arg, + &user, sizeof(user))) + return -EFAULT; + + return 0; } asmlinkage long sys_oabi_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) + goto out; + switch (cmd) { - case F_OFD_GETLK: - case F_OFD_SETLK: - case F_OFD_SETLKW: case F_GETLK64: + case F_OFD_GETLK: + err = security_file_fcntl(f.file, cmd, arg); + if (err) + break; + err = get_oabi_flock(&flock, argp); + if (err) + break; + err = fcntl_getlk64(f.file, cmd, &flock); + if (!err) + err = put_oabi_flock(&flock, argp); + break; case F_SETLK64: case F_SETLKW64: - return do_locks(fd, cmd, arg); - + case F_OFD_SETLK: + case F_OFD_SETLKW: + err = security_file_fcntl(f.file, cmd, arg); + if (err) + break; + err = get_oabi_flock(&flock, argp); + if (err) + break; + err = fcntl_setlk64(fd, f.file, cmd, &flock); + break; default: - return sys_fcntl64(fd, cmd, arg); + err = sys_fcntl64(fd, cmd, arg); + break; } + fdput(f); +out: + return err; } struct oabi_epoll_event { -- 2.7.4