Commit 9d5b7c95 authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent edf292c7

arch/arm/kernel/sys_arm.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

}

arch/mips/kernel/linux32.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

}

arch/parisc/kernel/sys_parisc.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

}

arch/powerpc/kernel/sys_ppc32.c

+2 −2
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ 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,

	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low, len,

				 advice);

}

arch/powerpc/kernel/syscalls.c

+2 −2
Original line number Diff line number Diff line
@@ -119,7 +119,7 @@ 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,

	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,

				 (u64)len_high << 32 | len_low, advice);

}

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