Using the ksys_fadvise64_64() helper allows us to avoid the in-kernel calls to the sys_fadvise64_64() 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 ksys_fadvise64_64(). Some compat stubs called sys_fadvise64(), which then just passed through the arguments to sys_fadvise64_64(). Get rid of this indirection, and call ksys_fadvise64_64() directly. 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: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- arch/arm/kernel/sys_arm.c | 2 +- arch/mips/kernel/linux32.c | 2 +- arch/parisc/kernel/sys_parisc.c | 2 +- arch/powerpc/kernel/sys_ppc32.c | 4 ++-- arch/powerpc/kernel/syscalls.c | 4 ++-- arch/s390/kernel/compat_linux.c | 5 +++-- arch/sh/kernel/sys_sh32.c | 8 ++++---- arch/sparc/kernel/sys_sparc32.c | 10 +++++----- arch/x86/ia32/sys_ia32.c | 12 ++++++------ arch/xtensa/kernel/syscall.c | 2 +- include/linux/syscalls.h | 9 +++++++++ mm/fadvise.c | 10 ++++++++-- 12 files changed, 43 insertions(+), 27 deletions(-) diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c index 3151f5623d0e..bdf7514204ab 100644 --- a/arch/arm/kernel/sys_arm.c +++ b/arch/arm/kernel/sys_arm.c @@ -35,5 +35,5 @@ asmlinkage long sys_arm_fadvise64_64(int fd, int advice, loff_t offset, loff_t len) { - return sys_fadvise64_64(fd, offset, len, advice); + return ksys_fadvise64_64(fd, offset, len, advice); } diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c index 0779d474c8ad..1c5785e72db4 100644 --- a/arch/mips/kernel/linux32.c +++ b/arch/mips/kernel/linux32.c @@ -149,7 +149,7 @@ asmlinkage long sys32_fadvise64_64(int fd, int __pad, unsigned long a4, unsigned long a5, int flags) { - return sys_fadvise64_64(fd, + return ksys_fadvise64_64(fd, merge_64(a2, a3), merge_64(a4, a5), flags); } diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index 588fab336ddd..f36ab1f09595 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -352,7 +352,7 @@ asmlinkage long parisc_fadvise64_64(int fd, unsigned int high_off, unsigned int low_off, unsigned int high_len, unsigned int low_len, int advice) { - return sys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off, + return ksys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off, (loff_t)high_len << 32 | low_len, advice); } diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c index 68f11e1065f8..0b95fa13307f 100644 --- a/arch/powerpc/kernel/sys_ppc32.c +++ b/arch/powerpc/kernel/sys_ppc32.c @@ -113,8 +113,8 @@ asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long h long ppc32_fadvise64(int fd, u32 unused, u32 offset_high, u32 offset_low, size_t len, int advice) { - return sys_fadvise64(fd, (u64)offset_high << 32 | offset_low, len, - advice); + return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low, len, + advice); } asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags, diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c index a877bf8269fe..ecb981eea74b 100644 --- a/arch/powerpc/kernel/syscalls.c +++ b/arch/powerpc/kernel/syscalls.c @@ -119,8 +119,8 @@ long ppc64_personality(unsigned long personality) long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low, u32 len_high, u32 len_low) { - return sys_fadvise64(fd, (u64)offset_high << 32 | offset_low, - (u64)len_high << 32 | len_low, advice); + return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low, + (u64)len_high << 32 | len_low, advice); } long sys_switch_endian(void) diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 039858f9f128..9bb897e443a6 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -483,7 +483,8 @@ COMPAT_SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, high, u32, low, compat_size advise = POSIX_FADV_DONTNEED; else if (advise == 5) advise = POSIX_FADV_NOREUSE; - return sys_fadvise64(fd, (unsigned long)high << 32 | low, len, advise); + return ksys_fadvise64_64(fd, (unsigned long)high << 32 | low, len, + advise); } struct fadvise64_64_args { @@ -503,7 +504,7 @@ COMPAT_SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, arg a.advice = POSIX_FADV_DONTNEED; else if (a.advice == 5) a.advice = POSIX_FADV_NOREUSE; - return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice); + return ksys_fadvise64_64(a.fd, a.offset, a.len, a.advice); } COMPAT_SYSCALL_DEFINE6(s390_sync_file_range, int, fd, u32, offhigh, u32, offlow, diff --git a/arch/sh/kernel/sys_sh32.c b/arch/sh/kernel/sys_sh32.c index c37ee3d0c803..9dca568509a5 100644 --- a/arch/sh/kernel/sys_sh32.c +++ b/arch/sh/kernel/sys_sh32.c @@ -52,10 +52,10 @@ asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1, u32 len0, u32 len1, int advice) { #ifdef __LITTLE_ENDIAN__ - return sys_fadvise64_64(fd, (u64)offset1 << 32 | offset0, - (u64)len1 << 32 | len0, advice); + return ksys_fadvise64_64(fd, (u64)offset1 << 32 | offset0, + (u64)len1 << 32 | len0, advice); #else - return sys_fadvise64_64(fd, (u64)offset0 << 32 | offset1, - (u64)len0 << 32 | len1, advice); + return ksys_fadvise64_64(fd, (u64)offset0 << 32 | offset1, + (u64)len0 << 32 | len1, advice); #endif } diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c index 4ba62d676632..4da66aed50b4 100644 --- a/arch/sparc/kernel/sys_sparc32.c +++ b/arch/sparc/kernel/sys_sparc32.c @@ -225,7 +225,7 @@ long compat_sys_fadvise64(int fd, unsigned long offlo, compat_size_t len, int advice) { - return sys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice); + return ksys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice); } long compat_sys_fadvise64_64(int fd, @@ -233,10 +233,10 @@ long compat_sys_fadvise64_64(int fd, unsigned long lenhi, unsigned long lenlo, int advice) { - return sys_fadvise64_64(fd, - (offhi << 32) | offlo, - (lenhi << 32) | lenlo, - advice); + return ksys_fadvise64_64(fd, + (offhi << 32) | offlo, + (lenhi << 32) | lenlo, + advice); } long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned long off_low, unsigned long nb_high, unsigned long nb_low, unsigned int flags) diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c index df2acb13623f..401bd8ec9cf0 100644 --- a/arch/x86/ia32/sys_ia32.c +++ b/arch/x86/ia32/sys_ia32.c @@ -194,10 +194,10 @@ COMPAT_SYSCALL_DEFINE6(x86_fadvise64_64, int, fd, __u32, offset_low, __u32, offset_high, __u32, len_low, __u32, len_high, int, advice) { - return sys_fadvise64_64(fd, - (((u64)offset_high)<<32) | offset_low, - (((u64)len_high)<<32) | len_low, - advice); + return ksys_fadvise64_64(fd, + (((u64)offset_high)<<32) | offset_low, + (((u64)len_high)<<32) | len_low, + advice); } COMPAT_SYSCALL_DEFINE4(x86_readahead, int, fd, unsigned int, off_lo, @@ -218,8 +218,8 @@ COMPAT_SYSCALL_DEFINE6(x86_sync_file_range, int, fd, unsigned int, off_low, COMPAT_SYSCALL_DEFINE5(x86_fadvise64, int, fd, unsigned int, offset_lo, unsigned int, offset_hi, size_t, len, int, advice) { - return sys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo, - len, advice); + return ksys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo, + len, advice); } COMPAT_SYSCALL_DEFINE6(x86_fallocate, int, fd, int, mode, diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c index 74afbf02d07e..8201748da05b 100644 --- a/arch/xtensa/kernel/syscall.c +++ b/arch/xtensa/kernel/syscall.c @@ -55,7 +55,7 @@ asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg) asmlinkage long xtensa_fadvise64_64(int fd, int advice, unsigned long long offset, unsigned long long len) { - return sys_fadvise64_64(fd, offset, len, advice); + return ksys_fadvise64_64(fd, offset, len, advice); } #ifdef CONFIG_MMU diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 613b8127834d..466d408deefd 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -970,6 +970,15 @@ ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, size_t count, loff_t pos); int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len); +#ifdef CONFIG_ADVISE_SYSCALLS +int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice); +#else +static inline int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, + int advice) +{ + return -EINVAL; +} +#endif /* * The following kernel syscall equivalents are just wrappers to fs-internal diff --git a/mm/fadvise.c b/mm/fadvise.c index 767887f5f3bf..afa41491d324 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -26,7 +26,8 @@ * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could * deactivate the pages and clear PG_Referenced. */ -SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice) + +int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) { struct fd f = fdget(fd); struct inode *inode; @@ -185,11 +186,16 @@ SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice) return ret; } +SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice) +{ + return ksys_fadvise64_64(fd, offset, len, advice); +} + #ifdef __ARCH_WANT_SYS_FADVISE64 SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice) { - return sys_fadvise64_64(fd, offset, len, advice); + return ksys_fadvise64_64(fd, offset, len, advice); } #endif -- 2.16.3
