8404663f81
The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.
This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.
[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
98 lines
2.3 KiB
ArmAsm
98 lines
2.3 KiB
ArmAsm
/*
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* linux/arch/arm/lib/putuser.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
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* them more efficient, especially as they return an error
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* value in addition to the "real" return value.
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*
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* __put_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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* r2, r3 contains the value
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* Outputs: r0 is the error code
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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 __put_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(__put_user_1)
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check_uaccess r0, 1, r1, ip, __put_user_bad
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1: TUSER(strb) r2, [r0]
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mov r0, #0
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mov pc, lr
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ENDPROC(__put_user_1)
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ENTRY(__put_user_2)
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check_uaccess r0, 2, r1, ip, __put_user_bad
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mov ip, r2, lsr #8
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#ifdef CONFIG_THUMB2_KERNEL
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#ifndef __ARMEB__
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2: TUSER(strb) r2, [r0]
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3: TUSER(strb) ip, [r0, #1]
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#else
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2: TUSER(strb) ip, [r0]
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3: TUSER(strb) r2, [r0, #1]
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#endif
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#else /* !CONFIG_THUMB2_KERNEL */
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#ifndef __ARMEB__
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2: TUSER(strb) r2, [r0], #1
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3: TUSER(strb) ip, [r0]
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#else
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2: TUSER(strb) ip, [r0], #1
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3: TUSER(strb) r2, [r0]
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#endif
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#endif /* CONFIG_THUMB2_KERNEL */
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mov r0, #0
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mov pc, lr
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ENDPROC(__put_user_2)
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ENTRY(__put_user_4)
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check_uaccess r0, 4, r1, ip, __put_user_bad
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4: TUSER(str) r2, [r0]
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mov r0, #0
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mov pc, lr
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ENDPROC(__put_user_4)
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ENTRY(__put_user_8)
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check_uaccess r0, 8, r1, ip, __put_user_bad
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#ifdef CONFIG_THUMB2_KERNEL
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5: TUSER(str) r2, [r0]
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6: TUSER(str) r3, [r0, #4]
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#else
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5: TUSER(str) r2, [r0], #4
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6: TUSER(str) r3, [r0]
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#endif
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mov r0, #0
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mov pc, lr
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ENDPROC(__put_user_8)
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__put_user_bad:
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mov r0, #-EFAULT
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mov pc, lr
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ENDPROC(__put_user_bad)
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.pushsection __ex_table, "a"
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.long 1b, __put_user_bad
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.long 2b, __put_user_bad
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.long 3b, __put_user_bad
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.long 4b, __put_user_bad
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.long 5b, __put_user_bad
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.long 6b, __put_user_bad
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.popsection
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