mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64()
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>
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index df2acb1..401bd8ec 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,