[PATCH 095/109] fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate()
From: Dominik Brodowski
Date: Thu Mar 29 2018 - 07:50:58 EST
Using the ksys_fallocate() wrapper allows us to get rid of in-kernel
calls to the sys_fallocate() 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_fallocate().
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 | 4 ++--
arch/parisc/kernel/sys_parisc.c | 4 ++--
arch/powerpc/kernel/sys_ppc32.c | 2 +-
arch/s390/kernel/compat_linux.c | 4 ++--
arch/sparc/kernel/sys_sparc32.c | 4 ++--
arch/x86/ia32/sys_ia32.c | 4 ++--
fs/open.c | 7 ++++++-
include/linux/syscalls.h | 1 +
8 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 91e85e2f8aa5..0779d474c8ad 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -157,6 +157,6 @@ asmlinkage long sys32_fadvise64_64(int fd, int __pad,
asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_a2,
unsigned offset_a3, unsigned len_a4, unsigned len_a5)
{
- return sys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
- merge_64(len_a4, len_a5));
+ return ksys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
+ merge_64(len_a4, len_a5));
}
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 4f47e8379854..588fab336ddd 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -367,8 +367,8 @@ asmlinkage long parisc_sync_file_range(int fd,
asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
- return sys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
- ((u64)lenhi << 32) | lenlo);
+ return ksys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
+ ((u64)lenhi << 32) | lenlo);
}
long parisc_personality(unsigned long personality)
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 36a651e6e033..68f11e1065f8 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -100,7 +100,7 @@ asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
- return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+ return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
((loff_t)lenhi << 32) | lenlo);
}
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 71e2c5bc4926..039858f9f128 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -516,6 +516,6 @@ COMPAT_SYSCALL_DEFINE6(s390_sync_file_range, int, fd, u32, offhigh, u32, offlow,
COMPAT_SYSCALL_DEFINE6(s390_fallocate, int, fd, int, mode, u32, offhigh, u32, offlow,
u32, lenhigh, u32, lenlow)
{
- return sys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
- ((u64)lenhigh << 32) + lenlow);
+ return ksys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
+ ((u64)lenhigh << 32) + lenlow);
}
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index 40c0d2e1db1d..4ba62d676632 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -250,6 +250,6 @@ long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned lon
asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
- return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
- ((loff_t)lenhi << 32) | lenlo);
+ return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+ ((loff_t)lenhi << 32) | lenlo);
}
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index c08c25f73d79..df2acb13623f 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -226,8 +226,8 @@ COMPAT_SYSCALL_DEFINE6(x86_fallocate, int, fd, int, mode,
unsigned int, offset_lo, unsigned int, offset_hi,
unsigned int, len_lo, unsigned int, len_hi)
{
- return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
- ((u64)len_hi << 32) | len_lo);
+ return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
+ ((u64)len_hi << 32) | len_lo);
}
/*
diff --git a/fs/open.c b/fs/open.c
index 2e816fc7bd56..d0e955b558ad 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -333,7 +333,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
}
EXPORT_SYMBOL_GPL(vfs_fallocate);
-SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
+int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
{
struct fd f = fdget(fd);
int error = -EBADF;
@@ -345,6 +345,11 @@ SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
return error;
}
+SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
+{
+ return ksys_fallocate(fd, mode, offset, len);
+}
+
/*
* access() needs to use the real uid/gid, not the effective uid/gid.
* We do this by temporarily clearing all FS-related capabilities and
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a30e4c2d0c27..613b8127834d 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -969,6 +969,7 @@ ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
loff_t pos);
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);
/*
* The following kernel syscall equivalents are just wrappers to fs-internal
--
2.16.3