linux_dsm_epyc7002/arch/hexagon/include/asm/uaccess.h
Thomas Gleixner 08dbd0f8ef treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 267
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 and
  only version 2 as published by the free software foundation this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details you should have received a
  copy of the gnu general public license along with this program if
  not write to the free software foundation inc 51 franklin street
  fifth floor boston ma 02110 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 94 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141334.043630402@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:30:29 +02:00

96 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* User memory access support for Hexagon
*
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
*/
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/mm.h>
#include <asm/sections.h>
/*
* access_ok: - Checks if a user space pointer is valid
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* Returns true (nonzero) if the memory block *may* be valid, false (zero)
* if it is definitely invalid.
*
* User address space in Hexagon, like x86, goes to 0xbfffffff, so the
* simple MSB-based tests used by MIPS won't work. Some further
* optimization is probably possible here, but for now, keep it
* reasonably simple and not *too* slow. After all, we've got the
* MMU for backup.
*/
#define __access_ok(addr, size) \
((get_fs().seg == KERNEL_DS.seg) || \
(((unsigned long)addr < get_fs().seg) && \
(unsigned long)size < (get_fs().seg - (unsigned long)addr)))
/*
* When a kernel-mode page fault is taken, the faulting instruction
* address is checked against a table of exception_table_entries.
* Each entry is a tuple of the address of an instruction that may
* be authorized to fault, and the address at which execution should
* be resumed instead of the faulting instruction, so as to effect
* a workaround.
*/
/* Assembly somewhat optimized copy routines */
unsigned long raw_copy_from_user(void *to, const void __user *from,
unsigned long n);
unsigned long raw_copy_to_user(void __user *to, const void *from,
unsigned long n);
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
__kernel_size_t __clear_user_hexagon(void __user *dest, unsigned long count);
#define __clear_user(a, s) __clear_user_hexagon((a), (s))
#define __strncpy_from_user(dst, src, n) hexagon_strncpy_from_user(dst, src, n)
/* get around the ifndef in asm-generic/uaccess.h */
#define __strnlen_user __strnlen_user
extern long __strnlen_user(const char __user *src, long n);
static inline long hexagon_strncpy_from_user(char *dst, const char __user *src,
long n);
#include <asm-generic/uaccess.h>
/* Todo: an actual accelerated version of this. */
static inline long hexagon_strncpy_from_user(char *dst, const char __user *src,
long n)
{
long res = __strnlen_user(src, n);
if (unlikely(!res))
return -EFAULT;
if (res > n) {
long left = raw_copy_from_user(dst, src, n);
if (unlikely(left))
memset(dst + (n - left), 0, left);
return n;
} else {
long left = raw_copy_from_user(dst, src, res);
if (unlikely(left))
memset(dst + (res - left), 0, left);
return res-1;
}
}
#endif