Using the ksys_close() wrapper allows us to get rid of in-kernel calls to the sys_close() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_close(), with one subtle difference: The few places which checked the return value did not care about the return value re-writing in sys_close(), so simply use a wrapper around __close_fd(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- fs/autofs4/dev-ioctl.c | 2 +- fs/binfmt_misc.c | 2 +- fs/file.c | 1 + fs/open.c | 1 - include/linux/syscalls.h | 12 ++++++++++++ init/do_mounts.c | 4 ++-- init/do_mounts_initrd.c | 2 +- init/do_mounts_md.c | 8 ++++---- init/do_mounts_rd.c | 6 +++--- init/initramfs.c | 8 ++++---- 10 files changed, 29 insertions(+), 17 deletions(-) diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index b7c816f39404..26f6b4f41ce6 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -310,7 +310,7 @@ static int autofs_dev_ioctl_closemount(struct file *fp, struct autofs_sb_info *sbi, struct autofs_dev_ioctl *param) { - return sys_close(param->ioctlfd); + return ksys_close(param->ioctlfd); } /* diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index a7c5a9861bef..a41b48f82a70 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -241,7 +241,7 @@ static int load_misc_binary(struct linux_binprm *bprm) return retval; error: if (fd_binary > 0) - sys_close(fd_binary); + ksys_close(fd_binary); bprm->interp_flags = 0; bprm->interp_data = 0; goto ret; diff --git a/fs/file.c b/fs/file.c index d304004f0b65..7ffd6e9d103d 100644 --- a/fs/file.c +++ b/fs/file.c @@ -638,6 +638,7 @@ int __close_fd(struct files_struct *files, unsigned fd) spin_unlock(&files->file_lock); return -EBADF; } +EXPORT_SYMBOL(__close_fd); /* for ksys_close() */ void do_close_on_exec(struct files_struct *files) { diff --git a/fs/open.c b/fs/open.c index b3f3b2cd9f19..710102fc262b 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1200,7 +1200,6 @@ SYSCALL_DEFINE1(close, unsigned int, fd) return retval; } -EXPORT_SYMBOL(sys_close); /* * This routine simulates a hangup on the tty, to arrange that users diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 41023177c8ec..38805f3447ea 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1045,4 +1045,16 @@ static inline long ksys_ftruncate(unsigned int fd, unsigned long length) return do_sys_ftruncate(fd, length, 1); } +extern int __close_fd(struct files_struct *files, unsigned int fd); + +/* + * In contrast to sys_close(), this stub does not check whether the syscall + * should or should not be restarted, but returns the raw error codes from + * __close_fd(). + */ +static inline int ksys_close(unsigned int fd) +{ + return __close_fd(current->files, fd); +} + #endif diff --git a/init/do_mounts.c b/init/do_mounts.c index 89f18985fa90..a28dd42d1f84 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -492,7 +492,7 @@ void __init change_floppy(char *fmt, ...) fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0); if (fd >= 0) { sys_ioctl(fd, FDEJECT, 0); - sys_close(fd); + ksys_close(fd); } printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); fd = sys_open("/dev/console", O_RDWR, 0); @@ -503,7 +503,7 @@ void __init change_floppy(char *fmt, ...) sys_read(fd, &c, 1); termios.c_lflag |= ICANON; sys_ioctl(fd, TCSETSF, (long)&termios); - sys_close(fd); + ksys_close(fd); } } #endif diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index 99922d1ebfe6..6907c6dbc443 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -111,7 +111,7 @@ static void __init handle_initrd(void) error = fd; } else { error = sys_ioctl(fd, BLKFLSBUF, 0); - sys_close(fd); + ksys_close(fd); } printk(!error ? "okay\n" : "failed\n"); } diff --git a/init/do_mounts_md.c b/init/do_mounts_md.c index 3f733c760a8c..ebd4013d589e 100644 --- a/init/do_mounts_md.c +++ b/init/do_mounts_md.c @@ -191,7 +191,7 @@ static void __init md_setup_drive(void) printk(KERN_WARNING "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n", minor); - sys_close(fd); + ksys_close(fd); continue; } @@ -243,11 +243,11 @@ static void __init md_setup_drive(void) * boot a kernel with devfs compiled in from partitioned md * array without it */ - sys_close(fd); + ksys_close(fd); fd = sys_open(name, 0, 0); sys_ioctl(fd, BLKRRPART, 0); } - sys_close(fd); + ksys_close(fd); } } @@ -297,7 +297,7 @@ static void __init autodetect_raid(void) fd = sys_open("/dev/md0", 0, 0); if (fd >= 0) { sys_ioctl(fd, RAID_AUTORUN, raid_autopart); - sys_close(fd); + ksys_close(fd); } } diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index 5b69056f610a..f1aa341862d3 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -257,7 +257,7 @@ int __init rd_load_image(char *from) if (i && (i % devblocks == 0)) { printk("done disk #%d.\n", disk++); rotate = 0; - if (sys_close(in_fd)) { + if (ksys_close(in_fd)) { printk("Error closing the disk.\n"); goto noclose_input; } @@ -283,9 +283,9 @@ int __init rd_load_image(char *from) successful_load: res = 1; done: - sys_close(in_fd); + ksys_close(in_fd); noclose_input: - sys_close(out_fd); + ksys_close(out_fd); out: kfree(buf); ksys_unlink("/dev/ram"); diff --git a/init/initramfs.c b/init/initramfs.c index 0d3b001b0dc5..ce2bcad97cdf 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -373,7 +373,7 @@ static int __init do_copy(void) if (byte_count >= body_len) { if (xwrite(wfd, victim, body_len) != body_len) error("write error"); - sys_close(wfd); + ksys_close(wfd); do_utime(vcollected, mtime); kfree(vcollected); eat(body_len); @@ -574,7 +574,7 @@ static void __init clean_rootfs(void) buf = kzalloc(BUF_SIZE, GFP_KERNEL); WARN_ON(!buf); if (!buf) { - sys_close(fd); + ksys_close(fd); return; } @@ -602,7 +602,7 @@ static void __init clean_rootfs(void) num = sys_getdents64(fd, dirp, BUF_SIZE); } - sys_close(fd); + ksys_close(fd); kfree(buf); } #endif @@ -639,7 +639,7 @@ static int __init populate_rootfs(void) pr_err("/initrd.image: incomplete write (%zd != %ld)\n", written, initrd_end - initrd_start); - sys_close(fd); + ksys_close(fd); free_initrd(); } done: -- 2.16.3
