Using this helper allows us to avoid the in-kernel calls to the sys_ioctl() 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_ioctl(). After careful review, at least some of these calls could be converted to do_vfs_ioctl() in future. 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: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- fs/ioctl.c | 7 ++++++- include/linux/syscalls.h | 1 + init/do_mounts.c | 8 ++++---- init/do_mounts_initrd.c | 2 +- init/do_mounts_md.c | 15 ++++++++------- init/do_mounts_rd.c | 4 ++-- 6 files changed, 22 insertions(+), 15 deletions(-) diff --git a/fs/ioctl.c b/fs/ioctl.c index 5ace7efb0d04..4823431d1c9d 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -689,7 +689,7 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, return error; } -SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) +int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg) { int error; struct fd f = fdget(fd); @@ -702,3 +702,8 @@ SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) fdput(f); return error; } + +SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) +{ + return ksys_ioctl(fd, cmd, arg); +} diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index c056aff6d7ad..5a959efd8fb7 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -957,6 +957,7 @@ int ksys_fchmod(unsigned int fd, umode_t mode); int ksys_fchown(unsigned int fd, uid_t user, gid_t group); int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent, unsigned int count); +int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg); /* * The following kernel syscall equivalents are just wrappers to fs-internal diff --git a/init/do_mounts.c b/init/do_mounts.c index cc1103477071..b17e0095eb4e 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -491,18 +491,18 @@ void __init change_floppy(char *fmt, ...) va_end(args); fd = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0); if (fd >= 0) { - sys_ioctl(fd, FDEJECT, 0); + ksys_ioctl(fd, FDEJECT, 0); ksys_close(fd); } printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); fd = ksys_open("/dev/console", O_RDWR, 0); if (fd >= 0) { - sys_ioctl(fd, TCGETS, (long)&termios); + ksys_ioctl(fd, TCGETS, (long)&termios); termios.c_lflag &= ~ICANON; - sys_ioctl(fd, TCSETSF, (long)&termios); + ksys_ioctl(fd, TCSETSF, (long)&termios); sys_read(fd, &c, 1); termios.c_lflag |= ICANON; - sys_ioctl(fd, TCSETSF, (long)&termios); + ksys_ioctl(fd, TCSETSF, (long)&termios); ksys_close(fd); } } diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index cedca8fd2590..03ec0c1b7553 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -110,7 +110,7 @@ static void __init handle_initrd(void) if (fd < 0) { error = fd; } else { - error = sys_ioctl(fd, BLKFLSBUF, 0); + error = ksys_ioctl(fd, BLKFLSBUF, 0); ksys_close(fd); } printk(!error ? "okay\n" : "failed\n"); diff --git a/init/do_mounts_md.c b/init/do_mounts_md.c index 76dcfaada3ed..7d85d172bc7e 100644 --- a/init/do_mounts_md.c +++ b/init/do_mounts_md.c @@ -187,7 +187,7 @@ static void __init md_setup_drive(void) "array %s\n", name); continue; } - if (sys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) { + if (ksys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) { printk(KERN_WARNING "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n", minor); @@ -210,7 +210,7 @@ static void __init md_setup_drive(void) ainfo.state = (1 << MD_SB_CLEAN); ainfo.layout = 0; ainfo.chunk_size = md_setup_args[ent].chunk; - err = sys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo); + err = ksys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo); for (i = 0; !err && i <= MD_SB_DISKS; i++) { dev = devices[i]; if (!dev) @@ -220,7 +220,8 @@ static void __init md_setup_drive(void) dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC); dinfo.major = MAJOR(dev); dinfo.minor = MINOR(dev); - err = sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo); + err = ksys_ioctl(fd, ADD_NEW_DISK, + (long)&dinfo); } } else { /* persistent */ @@ -230,11 +231,11 @@ static void __init md_setup_drive(void) break; dinfo.major = MAJOR(dev); dinfo.minor = MINOR(dev); - sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo); + ksys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo); } } if (!err) - err = sys_ioctl(fd, RUN_ARRAY, 0); + err = ksys_ioctl(fd, RUN_ARRAY, 0); if (err) printk(KERN_WARNING "md: starting md%d failed\n", minor); else { @@ -245,7 +246,7 @@ static void __init md_setup_drive(void) */ ksys_close(fd); fd = ksys_open(name, 0, 0); - sys_ioctl(fd, BLKRRPART, 0); + ksys_ioctl(fd, BLKRRPART, 0); } ksys_close(fd); } @@ -296,7 +297,7 @@ static void __init autodetect_raid(void) fd = ksys_open("/dev/md0", 0, 0); if (fd >= 0) { - sys_ioctl(fd, RAID_AUTORUN, raid_autopart); + ksys_ioctl(fd, RAID_AUTORUN, raid_autopart); ksys_close(fd); } } diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index a6706314baa7..4dafaed5736f 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -218,7 +218,7 @@ int __init rd_load_image(char *from) * NOTE NOTE: nblocks is not actually blocks but * the number of kibibytes of data to load into a ramdisk. */ - if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) + if (ksys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) rd_blocks = 0; else rd_blocks >>= 1; @@ -232,7 +232,7 @@ int __init rd_load_image(char *from) /* * OK, time to copy in the data */ - if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) + if (ksys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) devblocks = 0; else devblocks >>= 1; -- 2.16.3
