Using the ksys_truncate() wrapper allows us to get rid of in-kernel calls to the sys_truncate() 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_truncate(). 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 | 6 +++--- 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 | 3 ++- fs/open.c | 2 +- include/linux/syscalls.h | 7 +++++++ 8 files changed, 17 insertions(+), 9 deletions(-) diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c index 57b3310873f0..58e7dd27f106 100644 --- a/arch/mips/kernel/linux32.c +++ b/arch/mips/kernel/linux32.c @@ -82,7 +82,7 @@ struct rlimit32 { SYSCALL_DEFINE4(32_truncate64, const char __user *, path, unsigned long, __dummy, unsigned long, a2, unsigned long, a3) { - return sys_truncate(path, merge_64(a2, a3)); + return ksys_truncate(path, merge_64(a2, a3)); } SYSCALL_DEFINE4(32_ftruncate64, unsigned long, fd, unsigned long, __dummy, diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index ef995b5d97ef..3377a00163c3 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -292,7 +292,7 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len, asmlinkage long parisc_truncate64(const char __user * path, unsigned int high, unsigned int low) { - return sys_truncate(path, (long)high << 32 | low); + return ksys_truncate(path, (long)high << 32 | low); } asmlinkage long parisc_ftruncate64(unsigned int fd, @@ -305,7 +305,7 @@ asmlinkage long parisc_ftruncate64(unsigned int fd, * are identical on LP64 */ asmlinkage long sys_truncate64(const char __user * path, unsigned long length) { - return sys_truncate(path, length); + return ksys_truncate(path, length); } asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length) { @@ -320,7 +320,7 @@ asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg asmlinkage long parisc_truncate64(const char __user * path, unsigned int high, unsigned int low) { - return sys_truncate64(path, (loff_t)high << 32 | low); + return ksys_truncate(path, (loff_t)high << 32 | low); } asmlinkage long parisc_ftruncate64(unsigned int fd, diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c index 664e4c5b5855..a0a251d7c9c5 100644 --- a/arch/powerpc/kernel/sys_ppc32.c +++ b/arch/powerpc/kernel/sys_ppc32.c @@ -94,7 +94,7 @@ compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offhi, u32 offlo, u32 co asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4, unsigned long high, unsigned long low) { - return sys_truncate(path, (high << 32) | low); + return ksys_truncate(path, (high << 32) | low); } asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo, diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 605f6f026e44..e4092ec17ea5 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -302,7 +302,7 @@ COMPAT_SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, compat_ulong_t, second, COMPAT_SYSCALL_DEFINE3(s390_truncate64, const char __user *, path, u32, high, u32, low) { - return sys_truncate(path, (unsigned long)high << 32 | low); + return ksys_truncate(path, (unsigned long)high << 32 | low); } COMPAT_SYSCALL_DEFINE3(s390_ftruncate64, unsigned int, fd, u32, high, u32, low) diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c index af18b9ff86be..aab2428b17b5 100644 --- a/arch/sparc/kernel/sys_sparc32.c +++ b/arch/sparc/kernel/sys_sparc32.c @@ -57,7 +57,7 @@ asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, u if ((int)high < 0) return -EINVAL; else - return sys_truncate(path, (high << 32) | low); + return ksys_truncate(path, (high << 32) | low); } asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low) diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c index 0c5f8932c136..90e7a2b3dc5b 100644 --- a/arch/x86/ia32/sys_ia32.c +++ b/arch/x86/ia32/sys_ia32.c @@ -55,7 +55,8 @@ COMPAT_SYSCALL_DEFINE3(x86_truncate64, const char __user *, filename, unsigned long, offset_low, unsigned long, offset_high) { - return sys_truncate(filename, ((loff_t) offset_high << 32) | offset_low); + return ksys_truncate(filename, + ((loff_t) offset_high << 32) | offset_low); } COMPAT_SYSCALL_DEFINE3(x86_ftruncate64, unsigned int, fd, diff --git a/fs/open.c b/fs/open.c index 8a42a2961130..2e816fc7bd56 100644 --- a/fs/open.c +++ b/fs/open.c @@ -128,7 +128,7 @@ long vfs_truncate(const struct path *path, loff_t length) } EXPORT_SYMBOL_GPL(vfs_truncate); -static long do_sys_truncate(const char __user *pathname, loff_t length) +long do_sys_truncate(const char __user *pathname, loff_t length) { unsigned int lookup_flags = LOOKUP_FOLLOW; struct path path; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 331da76f66e2..78b79e3a1279 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1078,4 +1078,11 @@ static inline long ksys_open(const char __user *filename, int flags, return do_sys_open(AT_FDCWD, filename, flags, mode); } +extern long do_sys_truncate(const char __user *pathname, loff_t length); + +static inline long ksys_truncate(const char __user *pathname, loff_t length) +{ + return do_sys_truncate(pathname, length); +} + #endif -- 2.16.3
