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e38361d'ARM: 8091/2: add get_user() support for 8 byte types' commit broke V7 BE get_user call when target var size is 64 bit, but '*ptr' size is 32 bit or smaller.e38361dchanged type of __r2 from 'register unsigned long' to 'register typeof(x) __r2 asm("r2")' i.e before the change even when target variable size was 64 bit, __r2 was still 32 bit. But aftere38361dcommit, for target var of 64 bit size, __r2 became 64 bit and now it should occupy 2 registers r2, and r3. The issue in BE case that r3 register is least significant word of __r2 and r2 register is most significant word of __r2. But __get_user_4 still copies result into r2 (most significant word of __r2). Subsequent code copies from __r2 into x, but for situation described it will pick up only garbage from r3 register. Special __get_user_64t_(124) functions are introduced. They are similar to corresponding __get_user_(124) function but result stored in r3 register (lsw in case of 64 bit __r2 in BE image). Those function are used by get_user macro in case of BE and target var size is 64bit. Also changed __get_user_lo8 name into __get_user_32t_8 to get consistent naming accross all cases. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
150 lines
3.1 KiB
ArmAsm
150 lines
3.1 KiB
ArmAsm
/*
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* linux/arch/arm/lib/getuser.S
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*
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* Copyright (C) 2001 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Idea from x86 version, (C) Copyright 1998 Linus Torvalds
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*
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* These functions have a non-standard call interface to make them more
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* efficient, especially as they return an error value in addition to
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* the "real" return value.
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*
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* __get_user_X
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*
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* Inputs: r0 contains the address
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* r1 contains the address limit, which must be preserved
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* Outputs: r0 is the error code
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* r2, r3 contains the zero-extended value
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* lr corrupted
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*
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* No other registers must be altered. (see <asm/uaccess.h>
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* for specific ASM register usage).
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*
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* Note that ADDR_LIMIT is either 0 or 0xc0000000.
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* Note also that it is intended that __get_user_bad is not global.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <asm/errno.h>
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#include <asm/domain.h>
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ENTRY(__get_user_1)
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check_uaccess r0, 1, r1, r2, __get_user_bad
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1: TUSER(ldrb) r2, [r0]
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mov r0, #0
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ret lr
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ENDPROC(__get_user_1)
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ENTRY(__get_user_2)
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check_uaccess r0, 2, r1, r2, __get_user_bad
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#ifdef CONFIG_CPU_USE_DOMAINS
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rb .req ip
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2: ldrbt r2, [r0], #1
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3: ldrbt rb, [r0], #0
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#else
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rb .req r0
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2: ldrb r2, [r0]
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3: ldrb rb, [r0, #1]
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#endif
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#ifndef __ARMEB__
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orr r2, r2, rb, lsl #8
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#else
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orr r2, rb, r2, lsl #8
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#endif
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mov r0, #0
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ret lr
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ENDPROC(__get_user_2)
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ENTRY(__get_user_4)
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check_uaccess r0, 4, r1, r2, __get_user_bad
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4: TUSER(ldr) r2, [r0]
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mov r0, #0
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ret lr
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ENDPROC(__get_user_4)
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ENTRY(__get_user_8)
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check_uaccess r0, 8, r1, r2, __get_user_bad
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#ifdef CONFIG_THUMB2_KERNEL
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5: TUSER(ldr) r2, [r0]
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6: TUSER(ldr) r3, [r0, #4]
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#else
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5: TUSER(ldr) r2, [r0], #4
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6: TUSER(ldr) r3, [r0]
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#endif
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mov r0, #0
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ret lr
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ENDPROC(__get_user_8)
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#ifdef __ARMEB__
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ENTRY(__get_user_32t_8)
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check_uaccess r0, 8, r1, r2, __get_user_bad
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#ifdef CONFIG_CPU_USE_DOMAINS
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add r0, r0, #4
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7: ldrt r2, [r0]
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#else
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7: ldr r2, [r0, #4]
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#endif
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mov r0, #0
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ret lr
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ENDPROC(__get_user_32t_8)
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ENTRY(__get_user_64t_1)
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check_uaccess r0, 1, r1, r2, __get_user_bad8
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8: TUSER(ldrb) r3, [r0]
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mov r0, #0
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ret lr
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ENDPROC(__get_user_64t_1)
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ENTRY(__get_user_64t_2)
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check_uaccess r0, 2, r1, r2, __get_user_bad8
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#ifdef CONFIG_CPU_USE_DOMAINS
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rb .req ip
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9: ldrbt r3, [r0], #1
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10: ldrbt rb, [r0], #0
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#else
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rb .req r0
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9: ldrb r3, [r0]
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10: ldrb rb, [r0, #1]
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#endif
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orr r3, rb, r3, lsl #8
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mov r0, #0
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ret lr
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ENDPROC(__get_user_64t_2)
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ENTRY(__get_user_64t_4)
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check_uaccess r0, 4, r1, r2, __get_user_bad8
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11: TUSER(ldr) r3, [r0]
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mov r0, #0
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ret lr
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ENDPROC(__get_user_64t_4)
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#endif
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__get_user_bad8:
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mov r3, #0
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__get_user_bad:
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mov r2, #0
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mov r0, #-EFAULT
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ret lr
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ENDPROC(__get_user_bad)
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ENDPROC(__get_user_bad8)
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.pushsection __ex_table, "a"
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.long 1b, __get_user_bad
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.long 2b, __get_user_bad
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.long 3b, __get_user_bad
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.long 4b, __get_user_bad
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.long 5b, __get_user_bad8
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.long 6b, __get_user_bad8
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#ifdef __ARMEB__
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.long 7b, __get_user_bad
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.long 8b, __get_user_bad8
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.long 9b, __get_user_bad8
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.long 10b, __get_user_bad8
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.long 11b, __get_user_bad8
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#endif
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.popsection
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