[RFC PATCH 35/35] syscalls: do not call sys_close() within the kernel
From: Dominik Brodowski
Date: Sun Mar 11 2018 - 06:58:33 EST
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 to __close_fd().
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 | 2 +-
include/linux/syscalls.h | 6 ++++++
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, 24 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..aab4ad7d9c9a 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1200,7 +1200,7 @@ 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 fd1dcdc7fb1b..dda95f614916 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1042,4 +1042,10 @@ static inline long ksys_lchown(const char __user *filename, uid_t user,
return do_fchownat(AT_FDCWD, filename, user, group,
AT_SYMLINK_NOFOLLOW);
}
+
+extern int __close_fd(struct files_struct *files, unsigned int 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 d30db6bbf014..50decd9999b7 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:
--
2.16.2