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Diffstat (limited to 'arch/mips/lib/strnlen_user.S')
| -rw-r--r-- | arch/mips/lib/strnlen_user.S | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/mips/lib/strnlen_user.S b/arch/mips/lib/strnlen_user.S new file mode 100644 index 000000000..77e64942f --- /dev/null +++ b/arch/mips/lib/strnlen_user.S @@ -0,0 +1,83 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle + * Copyright (c) 1999 Silicon Graphics, Inc. + */ +#include <asm/asm.h> +#include <asm/asm-offsets.h> +#include <asm/regdef.h> + +#define EX(insn,reg,addr,handler) \ +9: insn reg, addr; \ + .section __ex_table,"a"; \ + PTR 9b, handler; \ + .previous + +/* + * Return the size of a string including the ending NUL character up to a + * maximum of a1 or 0 in case of error. + * + * Note: for performance reasons we deliberately accept that a user may + * make strlen_user and strnlen_user access the first few KSEG0 + * bytes. There's nothing secret there. On 64-bit accessing beyond + * the maximum is a tad hairier ... + */ + .macro __BUILD_STRNLEN_ASM func +LEAF(__strnlen_\func\()_asm) + LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? + and v0, a0 + bnez v0, .Lfault\@ + +FEXPORT(__strnlen_\func\()_nocheck_asm) + move v0, a0 + PTR_ADDU a1, a0 # stop pointer +1: +#ifdef CONFIG_CPU_DADDI_WORKAROUNDS + .set noat + li AT, 1 +#endif + beq v0, a1, 1f # limit reached? +.ifeqs "\func", "kernel" + EX(lb, t0, (v0), .Lfault\@) +.else + EX(lbe, t0, (v0), .Lfault\@) +.endif + .set noreorder + bnez t0, 1b +1: +#ifndef CONFIG_CPU_DADDI_WORKAROUNDS + PTR_ADDIU v0, 1 +#else + PTR_ADDU v0, AT + .set at +#endif + .set reorder + PTR_SUBU v0, a0 + jr ra + END(__strnlen_\func\()_asm) + +.Lfault\@: + move v0, zero + jr ra + .endm + +#ifndef CONFIG_EVA + /* Set aliases */ + .global __strnlen_user_asm + .global __strnlen_user_nocheck_asm + .set __strnlen_user_asm, __strnlen_kernel_asm + .set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm +#endif + +__BUILD_STRNLEN_ASM kernel + +#ifdef CONFIG_EVA + + .set push + .set eva +__BUILD_STRNLEN_ASM user + .set pop +#endif |