| 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, 1998, 1999, 2004 by Ralf Baechle |
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| 7 | * Copyright (c) 1999 Silicon Graphics, Inc. |
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| 8 | */ |
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| 9 | #include <linux/export.h> |
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| 10 | #include <asm/asm.h> |
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| 11 | #include <asm/asm-offsets.h> |
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| 12 | #include <asm/regdef.h> |
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| 13 | |
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| 14 | #define EX(insn,reg,addr,handler) \ |
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| 15 | 9: insn reg, addr; \ |
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| 16 | .section __ex_table,"a"; \ |
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| 17 | PTR_WD 9b, handler; \ |
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| 18 | .previous |
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| 19 | |
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| 20 | /* |
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| 21 | * Return the size of a string including the ending NUL character up to a |
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| 22 | * maximum of a1 or 0 in case of error. |
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| 23 | * |
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| 24 | * Note: for performance reasons we deliberately accept that a user may |
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| 25 | * make strlen_user and strnlen_user access the first few KSEG0 |
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| 26 | * bytes. There's nothing secret there. On 64-bit accessing beyond |
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| 27 | * the maximum is a tad hairier ... |
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| 28 | */ |
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| 29 | LEAF(__strnlen_user_asm) |
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| 30 | move v0, a0 |
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| 31 | PTR_ADDU a1, a0 # stop pointer |
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| 32 | 1: |
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| 33 | #ifdef CONFIG_CPU_DADDI_WORKAROUNDS |
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| 34 | .set noat |
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| 35 | li AT, 1 |
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| 36 | #endif |
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| 37 | beq v0, a1, 1f # limit reached? |
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| 38 | #ifdef CONFIG_EVA |
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| 39 | .set push |
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| 40 | .set eva |
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| 41 | EX(lbe, t0, (v0), .Lfault) |
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| 42 | .set pop |
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| 43 | #else |
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| 44 | EX(lb, t0, (v0), .Lfault) |
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| 45 | #endif |
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| 46 | .set noreorder |
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| 47 | bnez t0, 1b |
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| 48 | 1: |
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| 49 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS |
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| 50 | PTR_ADDIU v0, 1 |
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| 51 | #else |
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| 52 | PTR_ADDU v0, AT |
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| 53 | .set at |
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| 54 | #endif |
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| 55 | .set reorder |
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| 56 | PTR_SUBU v0, a0 |
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| 57 | jr ra |
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| 58 | END(__strnlen_user_asm) |
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| 59 | |
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| 60 | .Lfault: |
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| 61 | move v0, zero |
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| 62 | jr ra |
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| 63 | |
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| 64 | EXPORT_SYMBOL(__strnlen_user_asm) |
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| 65 | |
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