| /* |
| * 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}^ |
| |