| 1 | /* |
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| 2 | * This file is subject to the terms and conditions of the GNU General Public |
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| 3 | * License. See the file "COPYING" in the main directory of this archive |
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| 4 | * for more details. |
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| 5 | * |
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| 6 | * Copyright (C) 1996, 1999 by Ralf Baechle |
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| 7 | * Copyright (C) 2011 MIPS Technologies, Inc. |
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| 8 | */ |
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| 9 | #include <linux/errno.h> |
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| 10 | #include <linux/export.h> |
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| 11 | #include <asm/asm.h> |
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| 12 | #include <asm/asm-offsets.h> |
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| 13 | #include <asm/regdef.h> |
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| 14 | |
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| 15 | #define EX(insn,reg,addr,handler) \ |
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| 16 | 9: insn reg, addr; \ |
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| 17 | .section __ex_table,"a"; \ |
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| 18 | PTR_WD 9b, handler; \ |
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| 19 | .previous |
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| 20 | |
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| 21 | /* |
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| 22 | * Returns: -EFAULT if exception before terminator, N if the entire |
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| 23 | * buffer filled, else strlen. |
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| 24 | */ |
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| 25 | |
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| 26 | /* |
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| 27 | * Ugly special case have to check: we might get passed a user space |
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| 28 | * pointer which wraps into the kernel space. We don't deal with that. If |
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| 29 | * it happens at most some bytes of the exceptions handlers will be copied. |
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| 30 | */ |
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| 31 | |
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| 32 | LEAF(__strncpy_from_user_asm) |
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| 33 | move t0, zero |
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| 34 | move v1, a1 |
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| 35 | #ifdef CONFIG_EVA |
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| 36 | .set push |
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| 37 | .set eva |
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| 38 | 1: EX(lbue, v0, (v1), .Lfault) |
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| 39 | .set pop |
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| 40 | #else |
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| 41 | 1: EX(lbu, v0, (v1), .Lfault) |
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| 42 | #endif |
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| 43 | PTR_ADDIU v1, 1 |
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| 44 | R10KCBARRIER(0(ra)) |
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| 45 | sb v0, (a0) |
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| 46 | beqz v0, 2f |
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| 47 | PTR_ADDIU t0, 1 |
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| 48 | PTR_ADDIU a0, 1 |
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| 49 | bne t0, a2, 1b |
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| 50 | 2: PTR_ADDU v0, a1, t0 |
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| 51 | xor v0, a1 |
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| 52 | bltz v0, .Lfault |
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| 53 | move v0, t0 |
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| 54 | jr ra # return n |
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| 55 | END(__strncpy_from_user_asm) |
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| 56 | |
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| 57 | .Lfault: |
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| 58 | li v0, -EFAULT |
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| 59 | jr ra |
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| 60 | |
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| 61 | .section __ex_table,"a" |
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| 62 | PTR_WD 1b, .Lfault |
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| 63 | .previous |
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| 64 | |
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| 65 | EXPORT_SYMBOL(__strncpy_from_user_asm) |
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| 66 | |
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