| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 1996, 1999 by Ralf Baechle |
| 7 | * Copyright (C) 2011 MIPS Technologies, Inc. |
| 8 | */ |
| 9 | #include <linux/errno.h> |
| 10 | #include <asm/asm.h> |
| 11 | #include <asm/asm-offsets.h> |
| 12 | #include <asm/export.h> |
| 13 | #include <asm/regdef.h> |
| 14 | |
| 15 | #define EX(insn,reg,addr,handler) \ |
| 16 | 9: insn reg, addr; \ |
| 17 | .section __ex_table,"a"; \ |
| 18 | PTR 9b, handler; \ |
| 19 | .previous |
| 20 | |
| 21 | /* |
| 22 | * Returns: -EFAULT if exception before terminator, N if the entire |
| 23 | * buffer filled, else strlen. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | * Ugly special case have to check: we might get passed a user space |
| 28 | * pointer which wraps into the kernel space. We don't deal with that. If |
| 29 | * it happens at most some bytes of the exceptions handlers will be copied. |
| 30 | */ |
| 31 | |
| 32 | .macro __BUILD_STRNCPY_ASM func |
| 33 | LEAF(__strncpy_from_\func\()_asm) |
| 34 | LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? |
| 35 | and v0, a1 |
| 36 | bnez v0, .Lfault\@ |
| 37 | |
| 38 | move t0, zero |
| 39 | move v1, a1 |
| 40 | .ifeqs "\func","kernel" |
| 41 | 1: EX(lbu, v0, (v1), .Lfault\@) |
| 42 | .else |
| 43 | 1: EX(lbue, v0, (v1), .Lfault\@) |
| 44 | .endif |
| 45 | PTR_ADDIU v1, 1 |
| 46 | R10KCBARRIER(0(ra)) |
| 47 | sb v0, (a0) |
| 48 | beqz v0, 2f |
| 49 | PTR_ADDIU t0, 1 |
| 50 | PTR_ADDIU a0, 1 |
| 51 | bne t0, a2, 1b |
| 52 | 2: PTR_ADDU v0, a1, t0 |
| 53 | xor v0, a1 |
| 54 | bltz v0, .Lfault\@ |
| 55 | move v0, t0 |
| 56 | jr ra # return n |
| 57 | END(__strncpy_from_\func\()_asm) |
| 58 | |
| 59 | .Lfault\@: |
| 60 | li v0, -EFAULT |
| 61 | jr ra |
| 62 | |
| 63 | .section __ex_table,"a" |
| 64 | PTR 1b, .Lfault\@ |
| 65 | .previous |
| 66 | |
| 67 | .endm |
| 68 | |
| 69 | #ifndef CONFIG_EVA |
| 70 | /* Set aliases */ |
| 71 | .global __strncpy_from_user_asm |
| 72 | .set __strncpy_from_user_asm, __strncpy_from_kernel_asm |
| 73 | EXPORT_SYMBOL(__strncpy_from_user_asm) |
| 74 | #endif |
| 75 | |
| 76 | __BUILD_STRNCPY_ASM kernel |
| 77 | EXPORT_SYMBOL(__strncpy_from_kernel_asm) |
| 78 | |
| 79 | #ifdef CONFIG_EVA |
| 80 | .set push |
| 81 | .set eva |
| 82 | __BUILD_STRNCPY_ASM user |
| 83 | .set pop |
| 84 | EXPORT_SYMBOL(__strncpy_from_user_asm) |
| 85 | #endif |