Using this helper allows us to avoid the in-kernel calls to the sys_getdents64() 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_getdents64(). 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/readdir.c | 11 +++++++++-- include/linux/syscalls.h | 2 ++ init/initramfs.c | 4 ++-- 3 files changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/readdir.c b/fs/readdir.c index 1b83b0ad183b..d97f548e6323 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -292,8 +292,8 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen, return -EFAULT; } -SYSCALL_DEFINE3(getdents64, unsigned int, fd, - struct linux_dirent64 __user *, dirent, unsigned int, count) +int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent, + unsigned int count) { struct fd f; struct linux_dirent64 __user * lastdirent; @@ -326,6 +326,13 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, return error; } + +SYSCALL_DEFINE3(getdents64, unsigned int, fd, + struct linux_dirent64 __user *, dirent, unsigned int, count) +{ + return ksys_getdents64(fd, dirent, count); +} + #ifdef CONFIG_COMPAT struct compat_old_linux_dirent { compat_ulong_t d_ino; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index f9df17dcec1c..c056aff6d7ad 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -955,6 +955,8 @@ ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count); int ksys_chdir(const char __user *filename); 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); /* * The following kernel syscall equivalents are just wrappers to fs-internal diff --git a/init/initramfs.c b/init/initramfs.c index 5f2ff1d2370e..13643c46ebab 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -579,7 +579,7 @@ static void __init clean_rootfs(void) } dirp = buf; - num = sys_getdents64(fd, dirp, BUF_SIZE); + num = ksys_getdents64(fd, dirp, BUF_SIZE); while (num > 0) { while (num > 0) { struct kstat st; @@ -599,7 +599,7 @@ static void __init clean_rootfs(void) } dirp = buf; memset(buf, 0, BUF_SIZE); - num = sys_getdents64(fd, dirp, BUF_SIZE); + num = ksys_getdents64(fd, dirp, BUF_SIZE); } ksys_close(fd); -- 2.16.3
