forked from Minki/linux
930bff8822
IP28 needs special treatment to avoid speculative accesses. gcc takes care for .c code, but for assembly code we need to do it manually. This is taken from Peter Fuersts IP28 patches. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
60 lines
1.3 KiB
ArmAsm
60 lines
1.3 KiB
ArmAsm
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (c) 1996, 1999 by Ralf Baechle
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*/
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#include <linux/errno.h>
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#include <asm/asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/regdef.h>
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#define EX(insn,reg,addr,handler) \
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9: insn reg, addr; \
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.section __ex_table,"a"; \
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PTR 9b, handler; \
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.previous
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/*
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* Returns: -EFAULT if exception before terminator, N if the entire
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* buffer filled, else strlen.
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*/
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/*
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* Ugly special case have to check: we might get passed a user space
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* pointer which wraps into the kernel space. We don't deal with that. If
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* it happens at most some bytes of the exceptions handlers will be copied.
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*/
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LEAF(__strncpy_from_user_asm)
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LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
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and v0, a1
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bnez v0, fault
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FEXPORT(__strncpy_from_user_nocheck_asm)
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move v0, zero
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move v1, a1
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.set noreorder
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1: EX(lbu, t0, (v1), fault)
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PTR_ADDIU v1, 1
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R10KCBARRIER(0(ra))
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beqz t0, 2f
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sb t0, (a0)
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PTR_ADDIU v0, 1
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.set reorder
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PTR_ADDIU a0, 1
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bne v0, a2, 1b
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2: PTR_ADDU t0, a1, v0
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xor t0, a1
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bltz t0, fault
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jr ra # return n
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END(__strncpy_from_user_asm)
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fault: li v0, -EFAULT
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jr ra
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.section __ex_table,"a"
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PTR 1b, fault
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.previous
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