1
linux/arch/sh/kernel/sys_sh32.c
Dominik Brodowski 9d5b7c956b 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>
2018-04-02 20:16:10 +02:00

62 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/ipc.h>
#include <asm/cacheflush.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
#include <asm/syscalls.h>
/*
* sys_pipe() is the normal C calling standard for creating
* a pipe. It's not the way Unix traditionally does this, though.
*/
asmlinkage int sys_sh_pipe(void)
{
int fd[2];
int error;
error = do_pipe_flags(fd, 0);
if (!error) {
current_pt_regs()->regs[1] = fd[1];
return fd[0];
}
return error;
}
asmlinkage ssize_t sys_pread_wrapper(unsigned int fd, char __user *buf,
size_t count, long dummy, loff_t pos)
{
return ksys_pread64(fd, buf, count, pos);
}
asmlinkage ssize_t sys_pwrite_wrapper(unsigned int fd, const char __user *buf,
size_t count, long dummy, loff_t pos)
{
return ksys_pwrite64(fd, buf, count, pos);
}
asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
u32 len0, u32 len1, int advice)
{
#ifdef __LITTLE_ENDIAN__
return ksys_fadvise64_64(fd, (u64)offset1 << 32 | offset0,
(u64)len1 << 32 | len0, advice);
#else
return ksys_fadvise64_64(fd, (u64)offset0 << 32 | offset1,
(u64)len0 << 32 | len1, advice);
#endif
}