linux_dsm_epyc7002/arch/parisc/kernel/parisc_ksyms.c
Helge Deller d19f5e41b3 parisc: Clean up fixup routines for get_user()/put_user()
Al Viro noticed that userspace accesses via get_user()/put_user() can be
simplified a lot with regard to usage of the exception handling.

This patch implements a fixup routine for get_user() and put_user() in such
that the exception handler will automatically load -EFAULT into the register
%r8 (the error value) in case on a fault on userspace.  Additionally the fixup
routine will zero the target register on fault in case of a get_user() call.
The target register is extracted out of the faulting assembly instruction.

This patch brings a few benefits over the old implementation:
1. Exception handling gets much cleaner, easier and smaller in size.
2. Helper functions like fixup_get_user_skip_1 (all of fixup.S) can be dropped.
3. No need to hardcode %r9 as target register for get_user() any longer. This
   helps the compiler register allocator and thus creates less assembler
   statements.
4. No dependency on the exception_data contents any longer.
5. Nested faults will be handled cleanly.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Helge Deller <deller@gmx.de>
2017-03-29 21:50:36 +02:00

155 lines
4.1 KiB
C

/*
* Architecture-specific kernel symbols
*
* Copyright (C) 2000-2001 Richard Hirst <rhirst with parisc-linux.org>
* Copyright (C) 2001 Dave Kennedy
* Copyright (C) 2001 Paul Bame <bame at parisc-linux.org>
* Copyright (C) 2001-2003 Grant Grundler <grundler with parisc-linux.org>
* Copyright (C) 2002-2003 Matthew Wilcox <willy at parisc-linux.org>
* Copyright (C) 2002 Randolph Chung <tausq at parisc-linux.org>
* Copyright (C) 2002-2007 Helge Deller <deller with parisc-linux.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/syscalls.h>
#include <linux/string.h>
EXPORT_SYMBOL(memset);
#include <linux/atomic.h>
EXPORT_SYMBOL(__xchg8);
EXPORT_SYMBOL(__xchg32);
EXPORT_SYMBOL(__cmpxchg_u32);
#ifdef CONFIG_SMP
EXPORT_SYMBOL(__atomic_hash);
#endif
#ifdef CONFIG_64BIT
EXPORT_SYMBOL(__xchg64);
EXPORT_SYMBOL(__cmpxchg_u64);
#endif
#include <linux/uaccess.h>
EXPORT_SYMBOL(lclear_user);
EXPORT_SYMBOL(lstrnlen_user);
#ifndef CONFIG_64BIT
/* Needed so insmod can set dp value */
extern int $global$;
EXPORT_SYMBOL($global$);
#endif
#include <asm/io.h>
EXPORT_SYMBOL(memcpy_toio);
EXPORT_SYMBOL(memcpy_fromio);
EXPORT_SYMBOL(memset_io);
extern void $$divI(void);
extern void $$divU(void);
extern void $$remI(void);
extern void $$remU(void);
extern void $$mulI(void);
extern void $$divU_3(void);
extern void $$divU_5(void);
extern void $$divU_6(void);
extern void $$divU_9(void);
extern void $$divU_10(void);
extern void $$divU_12(void);
extern void $$divU_7(void);
extern void $$divU_14(void);
extern void $$divU_15(void);
extern void $$divI_3(void);
extern void $$divI_5(void);
extern void $$divI_6(void);
extern void $$divI_7(void);
extern void $$divI_9(void);
extern void $$divI_10(void);
extern void $$divI_12(void);
extern void $$divI_14(void);
extern void $$divI_15(void);
EXPORT_SYMBOL($$divI);
EXPORT_SYMBOL($$divU);
EXPORT_SYMBOL($$remI);
EXPORT_SYMBOL($$remU);
EXPORT_SYMBOL($$mulI);
EXPORT_SYMBOL($$divU_3);
EXPORT_SYMBOL($$divU_5);
EXPORT_SYMBOL($$divU_6);
EXPORT_SYMBOL($$divU_9);
EXPORT_SYMBOL($$divU_10);
EXPORT_SYMBOL($$divU_12);
EXPORT_SYMBOL($$divU_7);
EXPORT_SYMBOL($$divU_14);
EXPORT_SYMBOL($$divU_15);
EXPORT_SYMBOL($$divI_3);
EXPORT_SYMBOL($$divI_5);
EXPORT_SYMBOL($$divI_6);
EXPORT_SYMBOL($$divI_7);
EXPORT_SYMBOL($$divI_9);
EXPORT_SYMBOL($$divI_10);
EXPORT_SYMBOL($$divI_12);
EXPORT_SYMBOL($$divI_14);
EXPORT_SYMBOL($$divI_15);
extern void __ashrdi3(void);
extern void __ashldi3(void);
extern void __lshrdi3(void);
extern void __muldi3(void);
extern void __ucmpdi2(void);
EXPORT_SYMBOL(__ashrdi3);
EXPORT_SYMBOL(__ashldi3);
EXPORT_SYMBOL(__lshrdi3);
EXPORT_SYMBOL(__muldi3);
EXPORT_SYMBOL(__ucmpdi2);
asmlinkage void * __canonicalize_funcptr_for_compare(void *);
EXPORT_SYMBOL(__canonicalize_funcptr_for_compare);
#ifdef CONFIG_64BIT
extern void __divdi3(void);
extern void __udivdi3(void);
extern void __umoddi3(void);
extern void __moddi3(void);
EXPORT_SYMBOL(__divdi3);
EXPORT_SYMBOL(__udivdi3);
EXPORT_SYMBOL(__umoddi3);
EXPORT_SYMBOL(__moddi3);
#endif
#ifndef CONFIG_64BIT
extern void $$dyncall(void);
EXPORT_SYMBOL($$dyncall);
#endif
#ifdef CONFIG_DISCONTIGMEM
#include <asm/mmzone.h>
EXPORT_SYMBOL(node_data);
EXPORT_SYMBOL(pfnnid_map);
#endif
#ifdef CONFIG_FUNCTION_TRACER
extern void _mcount(void);
EXPORT_SYMBOL(_mcount);
#endif
/* from pacache.S -- needed for clear/copy_page */
EXPORT_SYMBOL(clear_page_asm);
EXPORT_SYMBOL(copy_page_asm);