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mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64()

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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@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Dominik Brodowski 2018-03-11 11:34:45 +01:00
parent edf292c76b
commit 9d5b7c956b
12 changed files with 43 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/kernel/sys_arm.c
View File

@ -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);
}

2
arch/mips/kernel/linux32.c
View File

@ -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);
}

2
arch/parisc/kernel/sys_parisc.c
View File

@ -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);
}

4
arch/powerpc/kernel/sys_ppc32.c
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@ -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,

4
arch/powerpc/kernel/syscalls.c
View File

@ -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)

5
arch/s390/kernel/compat_linux.c
View File

@ -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,

8
arch/sh/kernel/sys_sh32.c
View File

@ -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
}

10
arch/sparc/kernel/sys_sparc32.c
View File

@ -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)

12
arch/x86/ia32/sys_ia32.c
View File

@ -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,

2
arch/xtensa/kernel/syscall.c
View File

@ -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

9
include/linux/syscalls.h
View File

@ -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

10
mm/fadvise.c
View File

@ -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 @@ out:
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