uaccess.S
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上传日期:2013-04-10
资源大小:33168k
文件大小:14k
- /*
- * linux/arch/arm/lib/uaccess.S
- *
- * Copyright (C) 1995, 1996,1997,1998 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.
- *
- * Routines to block copy data to/from user memory
- * These are highly optimised both for the 4k page size
- * and for various alignments.
- */
- #include <linux/linkage.h>
- #include <asm/assembler.h>
- #include <asm/errno.h>
- .text
- #define PAGE_SHIFT 12
- /* Prototype: int __arch_copy_to_user(void *to, const char *from, size_t n)
- * Purpose : copy a block to user memory from kernel memory
- * Params : to - user memory
- * : from - kernel memory
- * : n - number of bytes to copy
- * Returns : Number of bytes NOT copied.
- */
- .c2u_dest_not_aligned:
- rsb ip, ip, #4
- cmp ip, #2
- ldrb r3, [r1], #1
- USER( strbt r3, [r0], #1) @ May fault
- ldrgeb r3, [r1], #1
- USER( strgebt r3, [r0], #1) @ May fault
- ldrgtb r3, [r1], #1
- USER( strgtbt r3, [r0], #1) @ May fault
- sub r2, r2, ip
- b .c2u_dest_aligned
- ENTRY(__arch_copy_to_user)
- stmfd sp!, {r2, r4 - r7, lr}
- cmp r2, #4
- blt .c2u_not_enough
- ands ip, r0, #3
- bne .c2u_dest_not_aligned
- .c2u_dest_aligned:
- ands ip, r1, #3
- bne .c2u_src_not_aligned
- /*
- * Seeing as there has to be at least 8 bytes to copy, we can
- * copy one word, and force a user-mode page fault...
- */
- .c2u_0fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .c2u_0nowords
- ldr r3, [r1], #4
- USER( strt r3, [r0], #4) @ May fault
- mov ip, r0, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .c2u_0fupi
- /*
- * ip = max no. of bytes to copy before needing another "strt" insn
- */
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #32
- blt .c2u_0rem8lp
- .c2u_0cpy8lp: ldmia r1!, {r3 - r6}
- stmia r0!, {r3 - r6} @ Shouldnt fault
- ldmia r1!, {r3 - r6}
- stmia r0!, {r3 - r6} @ Shouldnt fault
- subs ip, ip, #32
- bpl .c2u_0cpy8lp
- .c2u_0rem8lp: cmn ip, #16
- ldmgeia r1!, {r3 - r6}
- stmgeia r0!, {r3 - r6} @ Shouldnt fault
- tst ip, #8
- ldmneia r1!, {r3 - r4}
- stmneia r0!, {r3 - r4} @ Shouldnt fault
- tst ip, #4
- ldrne r3, [r1], #4
- strnet r3, [r0], #4 @ Shouldnt fault
- ands ip, ip, #3
- beq .c2u_0fupi
- .c2u_0nowords: teq ip, #0
- beq .c2u_finished
- .c2u_nowords: cmp ip, #2
- ldrb r3, [r1], #1
- USER( strbt r3, [r0], #1) @ May fault
- ldrgeb r3, [r1], #1
- USER( strgebt r3, [r0], #1) @ May fault
- ldrgtb r3, [r1], #1
- USER( strgtbt r3, [r0], #1) @ May fault
- b .c2u_finished
- .c2u_not_enough:
- movs ip, r2
- bne .c2u_nowords
- .c2u_finished: mov r0, #0
- LOADREGS(fd,sp!,{r2, r4 - r7, pc})
- .c2u_src_not_aligned:
- bic r1, r1, #3
- ldr r7, [r1], #4
- cmp ip, #2
- bgt .c2u_3fupi
- beq .c2u_2fupi
- .c2u_1fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .c2u_1nowords
- mov r3, r7, lsr #8
- ldr r7, [r1], #4
- orr r3, r3, r7, lsl #24
- USER( strt r3, [r0], #4) @ May fault
- mov ip, r0, lsl #32 - PAGE_SHIFT
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .c2u_1fupi
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #16
- blt .c2u_1rem8lp
- .c2u_1cpy8lp: mov r3, r7, lsr #8
- ldmia r1!, {r4 - r7}
- orr r3, r3, r4, lsl #24
- mov r4, r4, lsr #8
- orr r4, r4, r5, lsl #24
- mov r5, r5, lsr #8
- orr r5, r5, r6, lsl #24
- mov r6, r6, lsr #8
- orr r6, r6, r7, lsl #24
- stmia r0!, {r3 - r6} @ Shouldnt fault
- subs ip, ip, #16
- bpl .c2u_1cpy8lp
- .c2u_1rem8lp: tst ip, #8
- movne r3, r7, lsr #8
- ldmneia r1!, {r4, r7}
- orrne r3, r3, r4, lsl #24
- movne r4, r4, lsr #8
- orrne r4, r4, r7, lsl #24
- stmneia r0!, {r3 - r4} @ Shouldnt fault
- tst ip, #4
- movne r3, r7, lsr #8
- ldrne r7, [r1], #4
- orrne r3, r3, r7, lsl #24
- strnet r3, [r0], #4 @ Shouldnt fault
- ands ip, ip, #3
- beq .c2u_1fupi
- .c2u_1nowords: mov r3, r7, lsr #8
- teq ip, #0
- beq .c2u_finished
- cmp ip, #2
- USER( strbt r3, [r0], #1) @ May fault
- movge r3, r3, lsr #8
- USER( strgebt r3, [r0], #1) @ May fault
- movgt r3, r3, lsr #8
- USER( strgtbt r3, [r0], #1) @ May fault
- b .c2u_finished
- .c2u_2fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .c2u_2nowords
- mov r3, r7, lsr #16
- ldr r7, [r1], #4
- orr r3, r3, r7, lsl #16
- USER( strt r3, [r0], #4) @ May fault
- mov ip, r0, lsl #32 - PAGE_SHIFT
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .c2u_2fupi
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #16
- blt .c2u_2rem8lp
- .c2u_2cpy8lp: mov r3, r7, lsr #16
- ldmia r1!, {r4 - r7}
- orr r3, r3, r4, lsl #16
- mov r4, r4, lsr #16
- orr r4, r4, r5, lsl #16
- mov r5, r5, lsr #16
- orr r5, r5, r6, lsl #16
- mov r6, r6, lsr #16
- orr r6, r6, r7, lsl #16
- stmia r0!, {r3 - r6} @ Shouldnt fault
- subs ip, ip, #16
- bpl .c2u_2cpy8lp
- .c2u_2rem8lp: tst ip, #8
- movne r3, r7, lsr #16
- ldmneia r1!, {r4, r7}
- orrne r3, r3, r4, lsl #16
- movne r4, r4, lsr #16
- orrne r4, r4, r7, lsl #16
- stmneia r0!, {r3 - r4} @ Shouldnt fault
- tst ip, #4
- movne r3, r7, lsr #16
- ldrne r7, [r1], #4
- orrne r3, r3, r7, lsl #16
- strnet r3, [r0], #4 @ Shouldnt fault
- ands ip, ip, #3
- beq .c2u_2fupi
- .c2u_2nowords: mov r3, r7, lsr #16
- teq ip, #0
- beq .c2u_finished
- cmp ip, #2
- USER( strbt r3, [r0], #1) @ May fault
- movge r3, r3, lsr #8
- USER( strgebt r3, [r0], #1) @ May fault
- ldrgtb r3, [r1], #0
- USER( strgtbt r3, [r0], #1) @ May fault
- b .c2u_finished
- .c2u_3fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .c2u_3nowords
- mov r3, r7, lsr #24
- ldr r7, [r1], #4
- orr r3, r3, r7, lsl #8
- USER( strt r3, [r0], #4) @ May fault
- mov ip, r0, lsl #32 - PAGE_SHIFT
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .c2u_3fupi
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #16
- blt .c2u_3rem8lp
- .c2u_3cpy8lp: mov r3, r7, lsr #24
- ldmia r1!, {r4 - r7}
- orr r3, r3, r4, lsl #8
- mov r4, r4, lsr #24
- orr r4, r4, r5, lsl #8
- mov r5, r5, lsr #24
- orr r5, r5, r6, lsl #8
- mov r6, r6, lsr #24
- orr r6, r6, r7, lsl #8
- stmia r0!, {r3 - r6} @ Shouldnt fault
- subs ip, ip, #16
- bpl .c2u_3cpy8lp
- .c2u_3rem8lp: tst ip, #8
- movne r3, r7, lsr #24
- ldmneia r1!, {r4, r7}
- orrne r3, r3, r4, lsl #8
- movne r4, r4, lsr #24
- orrne r4, r4, r7, lsl #8
- stmneia r0!, {r3 - r4} @ Shouldnt fault
- tst ip, #4
- movne r3, r7, lsr #24
- ldrne r7, [r1], #4
- orrne r3, r3, r7, lsl #8
- strnet r3, [r0], #4 @ Shouldnt fault
- ands ip, ip, #3
- beq .c2u_3fupi
- .c2u_3nowords: mov r3, r7, lsr #24
- teq ip, #0
- beq .c2u_finished
- cmp ip, #2
- USER( strbt r3, [r0], #1) @ May fault
- ldrge r3, [r1], #0
- USER( strgebt r3, [r0], #1) @ May fault
- movgt r3, r3, lsr #8
- USER( strgtbt r3, [r0], #1) @ May fault
- b .c2u_finished
- .section .fixup,"ax"
- .align 0
- 9001: LOADREGS(fd,sp!, {r0, r4 - r7, pc})
- .previous
- /* Prototype: unsigned long __arch_copy_from_user(void *to,const void *from,unsigned long n);
- * Purpose : copy a block from user memory to kernel memory
- * Params : to - kernel memory
- * : from - user memory
- * : n - number of bytes to copy
- * Returns : Number of bytes NOT copied.
- */
- .cfu_dest_not_aligned:
- rsb ip, ip, #4
- cmp ip, #2
- USER( ldrbt r3, [r1], #1) @ May fault
- strb r3, [r0], #1
- USER( ldrgebt r3, [r1], #1) @ May fault
- strgeb r3, [r0], #1
- USER( ldrgtbt r3, [r1], #1) @ May fault
- strgtb r3, [r0], #1
- sub r2, r2, ip
- b .cfu_dest_aligned
- ENTRY(__arch_copy_from_user)
- stmfd sp!, {r0, r2, r4 - r7, lr}
- cmp r2, #4
- blt .cfu_not_enough
- ands ip, r0, #3
- bne .cfu_dest_not_aligned
- .cfu_dest_aligned:
- ands ip, r1, #3
- bne .cfu_src_not_aligned
- /*
- * Seeing as there has to be at least 8 bytes to copy, we can
- * copy one word, and force a user-mode page fault...
- */
- .cfu_0fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .cfu_0nowords
- USER( ldrt r3, [r1], #4)
- str r3, [r0], #4
- mov ip, r1, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .cfu_0fupi
- /*
- * ip = max no. of bytes to copy before needing another "strt" insn
- */
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #32
- blt .cfu_0rem8lp
- .cfu_0cpy8lp: ldmia r1!, {r3 - r6} @ Shouldnt fault
- stmia r0!, {r3 - r6}
- ldmia r1!, {r3 - r6} @ Shouldnt fault
- stmia r0!, {r3 - r6}
- subs ip, ip, #32
- bpl .cfu_0cpy8lp
- .cfu_0rem8lp: cmn ip, #16
- ldmgeia r1!, {r3 - r6} @ Shouldnt fault
- stmgeia r0!, {r3 - r6}
- tst ip, #8
- ldmneia r1!, {r3 - r4} @ Shouldnt fault
- stmneia r0!, {r3 - r4}
- tst ip, #4
- ldrnet r3, [r1], #4 @ Shouldnt fault
- strne r3, [r0], #4
- ands ip, ip, #3
- beq .cfu_0fupi
- .cfu_0nowords: teq ip, #0
- beq .cfu_finished
- .cfu_nowords: cmp ip, #2
- USER( ldrbt r3, [r1], #1) @ May fault
- strb r3, [r0], #1
- USER( ldrgebt r3, [r1], #1) @ May fault
- strgeb r3, [r0], #1
- USER( ldrgtbt r3, [r1], #1) @ May fault
- strgtb r3, [r0], #1
- b .cfu_finished
- .cfu_not_enough:
- movs ip, r2
- bne .cfu_nowords
- .cfu_finished: mov r0, #0
- add sp, sp, #8
- LOADREGS(fd,sp!,{r4 - r7, pc})
- .cfu_src_not_aligned:
- bic r1, r1, #3
- USER( ldrt r7, [r1], #4) @ May fault
- cmp ip, #2
- bgt .cfu_3fupi
- beq .cfu_2fupi
- .cfu_1fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .cfu_1nowords
- mov r3, r7, lsr #8
- USER( ldrt r7, [r1], #4) @ May fault
- orr r3, r3, r7, lsl #24
- str r3, [r0], #4
- mov ip, r1, lsl #32 - PAGE_SHIFT
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .cfu_1fupi
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #16
- blt .cfu_1rem8lp
- .cfu_1cpy8lp: mov r3, r7, lsr #8
- ldmia r1!, {r4 - r7} @ Shouldnt fault
- orr r3, r3, r4, lsl #24
- mov r4, r4, lsr #8
- orr r4, r4, r5, lsl #24
- mov r5, r5, lsr #8
- orr r5, r5, r6, lsl #24
- mov r6, r6, lsr #8
- orr r6, r6, r7, lsl #24
- stmia r0!, {r3 - r6}
- subs ip, ip, #16
- bpl .cfu_1cpy8lp
- .cfu_1rem8lp: tst ip, #8
- movne r3, r7, lsr #8
- ldmneia r1!, {r4, r7} @ Shouldnt fault
- orrne r3, r3, r4, lsl #24
- movne r4, r4, lsr #8
- orrne r4, r4, r7, lsl #24
- stmneia r0!, {r3 - r4}
- tst ip, #4
- movne r3, r7, lsr #8
- USER( ldrnet r7, [r1], #4) @ May fault
- orrne r3, r3, r7, lsl #24
- strne r3, [r0], #4
- ands ip, ip, #3
- beq .cfu_1fupi
- .cfu_1nowords: mov r3, r7, lsr #8
- teq ip, #0
- beq .cfu_finished
- cmp ip, #2
- strb r3, [r0], #1
- movge r3, r3, lsr #8
- strgeb r3, [r0], #1
- movgt r3, r3, lsr #8
- strgtb r3, [r0], #1
- b .cfu_finished
- .cfu_2fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .cfu_2nowords
- mov r3, r7, lsr #16
- USER( ldrt r7, [r1], #4) @ May fault
- orr r3, r3, r7, lsl #16
- str r3, [r0], #4
- mov ip, r1, lsl #32 - PAGE_SHIFT
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .cfu_2fupi
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #16
- blt .cfu_2rem8lp
- .cfu_2cpy8lp: mov r3, r7, lsr #16
- ldmia r1!, {r4 - r7} @ Shouldnt fault
- orr r3, r3, r4, lsl #16
- mov r4, r4, lsr #16
- orr r4, r4, r5, lsl #16
- mov r5, r5, lsr #16
- orr r5, r5, r6, lsl #16
- mov r6, r6, lsr #16
- orr r6, r6, r7, lsl #16
- stmia r0!, {r3 - r6}
- subs ip, ip, #16
- bpl .cfu_2cpy8lp
- .cfu_2rem8lp: tst ip, #8
- movne r3, r7, lsr #16
- ldmneia r1!, {r4, r7} @ Shouldnt fault
- orrne r3, r3, r4, lsl #16
- movne r4, r4, lsr #16
- orrne r4, r4, r7, lsl #16
- stmneia r0!, {r3 - r4}
- tst ip, #4
- movne r3, r7, lsr #16
- USER( ldrnet r7, [r1], #4) @ May fault
- orrne r3, r3, r7, lsl #16
- strne r3, [r0], #4
- ands ip, ip, #3
- beq .cfu_2fupi
- .cfu_2nowords: mov r3, r7, lsr #16
- teq ip, #0
- beq .cfu_finished
- cmp ip, #2
- strb r3, [r0], #1
- movge r3, r3, lsr #8
- strgeb r3, [r0], #1
- USER( ldrgtbt r3, [r1], #0) @ May fault
- strgtb r3, [r0], #1
- b .cfu_finished
- .cfu_3fupi: subs r2, r2, #4
- addmi ip, r2, #4
- bmi .cfu_3nowords
- mov r3, r7, lsr #24
- USER( ldrt r7, [r1], #4) @ May fault
- orr r3, r3, r7, lsl #8
- str r3, [r0], #4
- mov ip, r1, lsl #32 - PAGE_SHIFT
- rsb ip, ip, #0
- movs ip, ip, lsr #32 - PAGE_SHIFT
- beq .cfu_3fupi
- cmp r2, ip
- movlt ip, r2
- sub r2, r2, ip
- subs ip, ip, #16
- blt .cfu_3rem8lp
- .cfu_3cpy8lp: mov r3, r7, lsr #24
- ldmia r1!, {r4 - r7} @ Shouldnt fault
- orr r3, r3, r4, lsl #8
- mov r4, r4, lsr #24
- orr r4, r4, r5, lsl #8
- mov r5, r5, lsr #24
- orr r5, r5, r6, lsl #8
- mov r6, r6, lsr #24
- orr r6, r6, r7, lsl #8
- stmia r0!, {r3 - r6}
- subs ip, ip, #16
- bpl .cfu_3cpy8lp
- .cfu_3rem8lp: tst ip, #8
- movne r3, r7, lsr #24
- ldmneia r1!, {r4, r7} @ Shouldnt fault
- orrne r3, r3, r4, lsl #8
- movne r4, r4, lsr #24
- orrne r4, r4, r7, lsl #8
- stmneia r0!, {r3 - r4}
- tst ip, #4
- movne r3, r7, lsr #24
- USER( ldrnet r7, [r1], #4) @ May fault
- orrne r3, r3, r7, lsl #8
- strne r3, [r0], #4
- ands ip, ip, #3
- beq .cfu_3fupi
- .cfu_3nowords: mov r3, r7, lsr #24
- teq ip, #0
- beq .cfu_finished
- cmp ip, #2
- strb r3, [r0], #1
- USER( ldrget r3, [r1], #0) @ May fault
- strgeb r3, [r0], #1
- movgt r3, r3, lsr #8
- strgtb r3, [r0], #1
- b .cfu_finished
- .section .fixup,"ax"
- .align 0
- /*
- * We took an exception. r0 contains a pointer to
- * the byte not copied.
- */
- 9001: ldr r2, [sp], #4 @ void *to
- sub r2, r0, r2 @ bytes copied
- ldr r1, [sp], #4 @ unsigned long count
- subs r4, r1, r2 @ bytes left to copy
- movne r1, r4
- blne SYMBOL_NAME(__memzero)
- mov r0, r4
- LOADREGS(fd,sp!, {r4 - r7, pc})
- .previous
- /* Prototype: int __arch_clear_user(void *addr, size_t sz)
- * Purpose : clear some user memory
- * Params : addr - user memory address to clear
- * : sz - number of bytes to clear
- * Returns : number of bytes NOT cleared
- */
- ENTRY(__arch_clear_user)
- stmfd sp!, {r1, lr}
- mov r2, #0
- cmp r1, #4
- blt 2f
- ands ip, r0, #3
- beq 1f
- cmp ip, #2
- USER( strbt r2, [r0], #1)
- USER( strlebt r2, [r0], #1)
- USER( strltbt 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
- USER( strplt r2, [r0], #4)
- USER( strplt r2, [r0], #4)
- bpl 1b
- adds r1, r1, #4 @ 3 2 1 0 -1 -2 -3
- USER( strplt r2, [r0], #4)
- 2: tst r1, #2 @ 1x 1x 0x 0x 1x 1x 0x
- USER( strnebt r2, [r0], #1)
- USER( strnebt r2, [r0], #1)
- tst r1, #1 @ x1 x0 x1 x0 x1 x0 x1
- USER( strnebt r2, [r0], #1)
- mov r0, #0
- LOADREGS(fd,sp!, {r1, pc})
- .section .fixup,"ax"
- .align 0
- 9001: LOADREGS(fd,sp!, {r0, pc})
- .previous