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Diffstat (limited to 'arch/arm26/lib/uaccess-kernel.S')
| -rw-r--r-- | arch/arm26/lib/uaccess-kernel.S | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm26/lib/uaccess-kernel.S b/arch/arm26/lib/uaccess-kernel.S new file mode 100644 index 000000000000..3950a1f6bc99 --- /dev/null +++ b/arch/arm26/lib/uaccess-kernel.S @@ -0,0 +1,173 @@ +/* + * linux/arch/arm26/lib/uaccess-kernel.S + * + * Copyright (C) 1998 Russell King + * + * Note! Some code fragments found in here have a special calling + * convention - they are not APCS compliant! + * + * 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. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + + .text + +//FIXME - surely this can be done in C not asm, removing the problem of keeping C and asm in sync? (this is a struct uaccess_t) + + .globl uaccess_kernel +uaccess_kernel: + .word uaccess_kernel_put_byte + .word uaccess_kernel_get_byte + .word uaccess_kernel_put_half + .word uaccess_kernel_get_half + .word uaccess_kernel_put_word + .word uaccess_kernel_get_word + .word uaccess_kernel_put_dword + .word uaccess_kernel_copy + .word uaccess_kernel_copy + .word uaccess_kernel_clear + .word uaccess_kernel_strncpy + .word uaccess_kernel_strnlen + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_kernel_put_byte: + stmfd sp!, {lr} + strb r0, [r1] + ldmfd sp!, {pc}^ + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_kernel_put_half: + stmfd sp!, {lr} + strb r0, [r1] + mov r0, r0, lsr #8 + strb r0, [r1, #1] + ldmfd sp!, {pc}^ + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_kernel_put_word: + stmfd sp!, {lr} + str r0, [r1] + ldmfd sp!, {pc}^ + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_kernel_put_dword: + stmfd sp!, {lr} + str r0, [r1], #4 + str r0, [r1], #0 + ldmfd sp!, {pc}^ + +@ In : r0 = addr, r1 = error +@ Out: r0 = x, r1 = error +uaccess_kernel_get_byte: + stmfd sp!, {lr} + ldrb r0, [r0] + ldmfd sp!, {pc}^ + +@ In : r0 = addr, r1 = error +@ Out: r0 = x, r1 = error +uaccess_kernel_get_half: + stmfd sp!, {lr} + ldr r0, [r0] + mov r0, r0, lsl #16 + mov r0, r0, lsr #16 + ldmfd sp!, {pc}^ + +@ In : r0 = addr, r1 = error +@ Out: r0 = x, r1 = error +uaccess_kernel_get_word: + stmfd sp!, {lr} + ldr r0, [r0] + ldmfd sp!, {pc}^ + + +/* Prototype: int uaccess_kernel_copy(void *to, const char *from, size_t n) + * Purpose : copy a block to kernel memory from kernel memory + * Params : to - kernel memory + * : from - kernel memory + * : n - number of bytes to copy + * Returns : Number of bytes NOT copied. + */ +uaccess_kernel_copy: + stmfd sp!, {lr} + bl memcpy + mov r0, #0 + ldmfd sp!, {pc}^ + +/* Prototype: int uaccess_kernel_clear(void *addr, size_t sz) + * Purpose : clear some kernel memory + * Params : addr - kernel memory address to clear + * : sz - number of bytes to clear + * Returns : number of bytes NOT cleared + */ +uaccess_kernel_clear: + stmfd sp!, {lr} + mov r2, #0 + cmp r1, #4 + blt 2f + ands ip, r0, #3 + beq 1f + cmp ip, #1 + strb r2, [r0], #1 + strleb r2, [r0], #1 + strltb r2, [r0], #1 + rsb ip, ip, #4 + sub r1, r1, ip @ 7 6 5 4 3 2 1 +1: subs r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7 + bmi 2f + str r2, [r0], #4 + str r2, [r0], #4 + b 1b +2: adds r1, r1, #4 @ 3 2 1 0 -1 -2 -3 + strpl r2, [r0], #4 + tst r1, #2 @ 1x 1x 0x 0x 1x 1x 0x + strneb r2, [r0], #1 + strneb r2, [r0], #1 + tst r1, #1 @ x1 x0 x1 x0 x1 x0 x1 + strneb r2, [r0], #1 + mov r0, #0 + ldmfd sp!, {pc}^ + +/* Prototype: size_t uaccess_kernel_strncpy(char *dst, char *src, size_t len) + * Purpose : copy a string from kernel memory to kernel memory + * Params : dst - kernel memory destination + * : src - kernel memory source + * : len - maximum length of string + * Returns : number of characters copied + */ +uaccess_kernel_strncpy: + stmfd sp!, {lr} + mov ip, r2 +1: subs r2, r2, #1 + bmi 2f + ldrb r3, [r1], #1 + strb r3, [r0], #1 + teq r3, #0 + bne 1b +2: subs r0, ip, r2 + ldmfd sp!, {pc}^ + +/* Prototype: int uaccess_kernel_strlen(char *str, long n) + * Purpose : get length of a string in kernel memory + * Params : str - address of string in kernel memory + * Returns : length of string *including terminator*, + * or zero on exception, or n + 1 if too long + */ +uaccess_kernel_strnlen: + stmfd sp!, {lr} + mov r2, r0 +1: ldrb r1, [r0], #1 + teq r1, #0 + beq 2f + subs r1, r1, #1 + bne 1b + add r0, r0, #1 +2: sub r0, r0, r2 + ldmfd sp!, {pc}^ + |