cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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putuser.S (2774B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * __put_user functions.
      4 *
      5 * (C) Copyright 2005 Linus Torvalds
      6 * (C) Copyright 2005 Andi Kleen
      7 * (C) Copyright 2008 Glauber Costa
      8 *
      9 * These functions have a non-standard call interface
     10 * to make them more efficient, especially as they
     11 * return an error value in addition to the "real"
     12 * return value.
     13 */
     14#include <linux/linkage.h>
     15#include <asm/thread_info.h>
     16#include <asm/errno.h>
     17#include <asm/asm.h>
     18#include <asm/smap.h>
     19#include <asm/export.h>
     20
     21
     22/*
     23 * __put_user_X
     24 *
     25 * Inputs:	%eax[:%edx] contains the data
     26 *		%ecx contains the address
     27 *
     28 * Outputs:	%ecx is error code (0 or -EFAULT)
     29 *
     30 * Clobbers:	%ebx needed for task pointer
     31 *
     32 * These functions should not modify any other registers,
     33 * as they get called from within inline assembly.
     34 */
     35
     36#ifdef CONFIG_X86_5LEVEL
     37#define LOAD_TASK_SIZE_MINUS_N(n) \
     38	ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \
     39		    __stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57
     40#else
     41#define LOAD_TASK_SIZE_MINUS_N(n) \
     42	mov $(TASK_SIZE_MAX - (n)),%_ASM_BX
     43#endif
     44
     45.text
     46SYM_FUNC_START(__put_user_1)
     47	LOAD_TASK_SIZE_MINUS_N(0)
     48	cmp %_ASM_BX,%_ASM_CX
     49	jae .Lbad_put_user
     50SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL)
     51	ENDBR
     52	ASM_STAC
     531:	movb %al,(%_ASM_CX)
     54	xor %ecx,%ecx
     55	ASM_CLAC
     56	RET
     57SYM_FUNC_END(__put_user_1)
     58EXPORT_SYMBOL(__put_user_1)
     59EXPORT_SYMBOL(__put_user_nocheck_1)
     60
     61SYM_FUNC_START(__put_user_2)
     62	LOAD_TASK_SIZE_MINUS_N(1)
     63	cmp %_ASM_BX,%_ASM_CX
     64	jae .Lbad_put_user
     65SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL)
     66	ENDBR
     67	ASM_STAC
     682:	movw %ax,(%_ASM_CX)
     69	xor %ecx,%ecx
     70	ASM_CLAC
     71	RET
     72SYM_FUNC_END(__put_user_2)
     73EXPORT_SYMBOL(__put_user_2)
     74EXPORT_SYMBOL(__put_user_nocheck_2)
     75
     76SYM_FUNC_START(__put_user_4)
     77	LOAD_TASK_SIZE_MINUS_N(3)
     78	cmp %_ASM_BX,%_ASM_CX
     79	jae .Lbad_put_user
     80SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL)
     81	ENDBR
     82	ASM_STAC
     833:	movl %eax,(%_ASM_CX)
     84	xor %ecx,%ecx
     85	ASM_CLAC
     86	RET
     87SYM_FUNC_END(__put_user_4)
     88EXPORT_SYMBOL(__put_user_4)
     89EXPORT_SYMBOL(__put_user_nocheck_4)
     90
     91SYM_FUNC_START(__put_user_8)
     92	LOAD_TASK_SIZE_MINUS_N(7)
     93	cmp %_ASM_BX,%_ASM_CX
     94	jae .Lbad_put_user
     95SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL)
     96	ENDBR
     97	ASM_STAC
     984:	mov %_ASM_AX,(%_ASM_CX)
     99#ifdef CONFIG_X86_32
    1005:	movl %edx,4(%_ASM_CX)
    101#endif
    102	xor %ecx,%ecx
    103	ASM_CLAC
    104	RET
    105SYM_FUNC_END(__put_user_8)
    106EXPORT_SYMBOL(__put_user_8)
    107EXPORT_SYMBOL(__put_user_nocheck_8)
    108
    109SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
    110	ASM_CLAC
    111.Lbad_put_user:
    112	movl $-EFAULT,%ecx
    113	RET
    114SYM_CODE_END(.Lbad_put_user_clac)
    115
    116	_ASM_EXTABLE_UA(1b, .Lbad_put_user_clac)
    117	_ASM_EXTABLE_UA(2b, .Lbad_put_user_clac)
    118	_ASM_EXTABLE_UA(3b, .Lbad_put_user_clac)
    119	_ASM_EXTABLE_UA(4b, .Lbad_put_user_clac)
    120#ifdef CONFIG_X86_32
    121	_ASM_EXTABLE_UA(5b, .Lbad_put_user_clac)
    122#endif