/* * linux/arch/arm26/lib/getuser.S * * Copyright (C) 2001 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Idea from x86 version, (C) Copyright 1998 Linus Torvalds * * These functions have a non-standard call interface to make them more * efficient, especially as they return an error value in addition to * the "real" return value. * * __get_user_X * * Inputs: r0 contains the address * Outputs: r0 is the error code * r1, r2 contains the zero-extended value * lr corrupted * * No other registers must be altered. (see include/asm-arm/uaccess.h * for specific ASM register usage). * * Note that ADDR_LIMIT is either 0 or 0xc0000000. * Note also that it is intended that __get_user_bad is not global. */ #include <asm/asm-offsets.h> #include <asm/thread_info.h> #include <asm/errno.h> .global __get_user_1 __get_user_1: bic r1, sp, #0x1f00 bic r1, r1, #0x00ff str lr, [sp, #-4]! ldr r1, [r1, #TI_ADDR_LIMIT] sub r1, r1, #1 cmp r0, r1 bge __get_user_bad cmp r0, #0x02000000 1: ldrlsbt r1, [r0] ldrgeb r1, [r0] mov r0, #0 ldmfd sp!, {pc}^ .global __get_user_2 __get_user_2: bic r2, sp, #0x1f00 bic r2, r2, #0x00ff str lr, [sp, #-4]! ldr r2, [r2, #TI_ADDR_LIMIT] sub r2, r2, #2 cmp r0, r2 bge __get_user_bad cmp r0, #0x02000000 2: ldrlsbt r1, [r0], #1 3: ldrlsbt r2, [r0] ldrgeb r1, [r0], #1 ldrgeb r2, [r0] orr r1, r1, r2, lsl #8 mov r0, #0 ldmfd sp!, {pc}^ .global __get_user_4 __get_user_4: bic r1, sp, #0x1f00 bic r1, r1, #0x00ff str lr, [sp, #-4]! ldr r1, [r1, #TI_ADDR_LIMIT] sub r1, r1, #4 cmp r0, r1 bge __get_user_bad cmp r0, #0x02000000 4: ldrlst r1, [r0] ldrge r1, [r0] mov r0, #0 ldmfd sp!, {pc}^ .global __get_user_8 __get_user_8: bic r2, sp, #0x1f00 bic r2, r2, #0x00ff str lr, [sp, #-4]! ldr r2, [r2, #TI_ADDR_LIMIT] sub r2, r2, #8 cmp r0, r2 bge __get_user_bad_8 cmp r0, #0x02000000 5: ldrlst r1, [r0], #4 6: ldrlst r2, [r0] ldrge r1, [r0], #4 ldrge r2, [r0] mov r0, #0 ldmfd sp!, {pc}^ __get_user_bad_8: mov r2, #0 __get_user_bad: mov r1, #0 mov r0, #-EFAULT ldmfd sp!, {pc}^ .section __ex_table, "a" .long 1b, __get_user_bad .long 2b, __get_user_bad .long 3b, __get_user_bad .long 4b, __get_user_bad .long 5b, __get_user_bad_8 .long 6b, __get_user_bad_8 .previous