Using the ksys_ftruncate() wrapper allows us to get rid of in-kernel calls to the sys_ftruncate() 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_ftruncate(). 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> --- arch/mips/kernel/linux32.c | 2 +- arch/parisc/kernel/sys_parisc.c | 4 ++-- arch/powerpc/kernel/sys_ppc32.c | 2 +- arch/s390/kernel/compat_linux.c | 2 +- arch/sparc/kernel/sys_sparc32.c | 2 +- arch/x86/ia32/sys_ia32.c | 2 +- fs/internal.h | 1 + fs/open.c | 2 +- include/linux/syscalls.h | 7 +++++++ init/initramfs.c | 2 +- 10 files changed, 17 insertions(+), 9 deletions(-) diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c index b332f6fc1e72..3c90449742a0 100644 --- a/arch/mips/kernel/linux32.c +++ b/arch/mips/kernel/linux32.c @@ -88,7 +88,7 @@ SYSCALL_DEFINE4(32_truncate64, const char __user *, path, SYSCALL_DEFINE4(32_ftruncate64, unsigned long, fd, unsigned long, __dummy, unsigned long, a2, unsigned long, a3) { - return sys_ftruncate(fd, merge_64(a2, a3)); + return ksys_ftruncate(fd, merge_64(a2, a3)); } SYSCALL_DEFINE5(32_llseek, unsigned int, fd, unsigned int, offset_high, diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index 378a754ca186..6d2a64859c22 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -298,7 +298,7 @@ asmlinkage long parisc_truncate64(const char __user * path, asmlinkage long parisc_ftruncate64(unsigned int fd, unsigned int high, unsigned int low) { - return sys_ftruncate(fd, (long)high << 32 | low); + return ksys_ftruncate(fd, (long)high << 32 | low); } /* stubs for the benefit of the syscall_table since truncate64 and truncate @@ -309,7 +309,7 @@ asmlinkage long sys_truncate64(const char __user * path, unsigned long length) } asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length) { - return sys_ftruncate(fd, length); + return ksys_ftruncate(fd, length); } asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg) { diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c index 15f216d022e2..e0c9b7f1bf38 100644 --- a/arch/powerpc/kernel/sys_ppc32.c +++ b/arch/powerpc/kernel/sys_ppc32.c @@ -107,7 +107,7 @@ asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo, asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high, unsigned long low) { - return sys_ftruncate(fd, (high << 32) | low); + return ksys_ftruncate(fd, (high << 32) | low); } long ppc32_fadvise64(int fd, u32 unused, u32 offset_high, u32 offset_low, diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 9a9bb395359c..9c5e975f71a6 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -307,7 +307,7 @@ COMPAT_SYSCALL_DEFINE3(s390_truncate64, const char __user *, path, u32, high, u3 COMPAT_SYSCALL_DEFINE3(s390_ftruncate64, unsigned int, fd, u32, high, u32, low) { - return sys_ftruncate(fd, (unsigned long)high << 32 | low); + return ksys_ftruncate(fd, (unsigned long)high << 32 | low); } COMPAT_SYSCALL_DEFINE5(s390_pread64, unsigned int, fd, char __user *, ubuf, diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c index 6d964bdefbaa..d64b425fff93 100644 --- a/arch/sparc/kernel/sys_sparc32.c +++ b/arch/sparc/kernel/sys_sparc32.c @@ -65,7 +65,7 @@ asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned if ((int)high < 0) return -EINVAL; else - return sys_ftruncate(fd, (high << 32) | low); + return ksys_ftruncate(fd, (high << 32) | low); } static int cp_compat_stat64(struct kstat *stat, diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c index 23a5260eae67..1979e5b4ad9a 100644 --- a/arch/x86/ia32/sys_ia32.c +++ b/arch/x86/ia32/sys_ia32.c @@ -61,7 +61,7 @@ COMPAT_SYSCALL_DEFINE3(x86_truncate64, const char __user *, filename, COMPAT_SYSCALL_DEFINE3(x86_ftruncate64, unsigned int, fd, unsigned long, offset_low, unsigned long, offset_high) { - return sys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low); + return ksys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low); } /* diff --git a/fs/internal.h b/fs/internal.h index c797480cbd6f..980d005b21b4 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -119,6 +119,7 @@ extern struct file *do_filp_open(int dfd, struct filename *pathname, extern struct file *do_file_open_root(struct dentry *, struct vfsmount *, const char *, const struct open_flags *); +long do_sys_ftruncate(unsigned int fd, loff_t length, int small); long do_faccessat(int dfd, const char __user *filename, int mode); int do_fchmodat(int dfd, const char __user *filename, umode_t mode); int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, diff --git a/fs/open.c b/fs/open.c index 7b2eccb541f2..b3f3b2cd9f19 100644 --- a/fs/open.c +++ b/fs/open.c @@ -162,7 +162,7 @@ COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length } #endif -static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) +long do_sys_ftruncate(unsigned int fd, loff_t length, int small) { struct inode *inode; struct dentry *dentry; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index df0d1e818a6e..41023177c8ec 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1038,4 +1038,11 @@ static inline long ksys_lchown(const char __user *filename, uid_t user, AT_SYMLINK_NOFOLLOW); } +extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small); + +static inline long ksys_ftruncate(unsigned int fd, unsigned long length) +{ + return do_sys_ftruncate(fd, length, 1); +} + #endif diff --git a/init/initramfs.c b/init/initramfs.c index 35173bef7c00..0d3b001b0dc5 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -346,7 +346,7 @@ static int __init do_name(void) ksys_fchown(wfd, uid, gid); ksys_fchmod(wfd, mode); if (body_len) - sys_ftruncate(wfd, body_len); + ksys_ftruncate(wfd, body_len); vcollected = kstrdup(collected, GFP_KERNEL); state = CopyFile; } -- 2.16.3
