diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm26/lib/uaccess-user.S |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm26/lib/uaccess-user.S')
-rw-r--r-- | arch/arm26/lib/uaccess-user.S | 718 |
1 files changed, 718 insertions, 0 deletions
diff --git a/arch/arm26/lib/uaccess-user.S b/arch/arm26/lib/uaccess-user.S new file mode 100644 index 00000000000..130b8f28610 --- /dev/null +++ b/arch/arm26/lib/uaccess-user.S @@ -0,0 +1,718 @@ +/* + * linux/arch/arm26/lib/uaccess-user.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> +#include <asm/page.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_user +uaccess_user: + .word uaccess_user_put_byte + .word uaccess_user_get_byte + .word uaccess_user_put_half + .word uaccess_user_get_half + .word uaccess_user_put_word + .word uaccess_user_get_word + .word uaccess_user_put_dword + .word uaccess_user_copy_from_user + .word uaccess_user_copy_to_user + .word uaccess_user_clear_user + .word uaccess_user_strncpy_from_user + .word uaccess_user_strnlen_user + + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_user_put_byte: + stmfd sp!, {lr} +USER( strbt r0, [r1]) + ldmfd sp!, {pc}^ + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_user_put_half: + stmfd sp!, {lr} +USER( strbt r0, [r1], #1) + mov r0, r0, lsr #8 +USER( strbt r0, [r1]) + ldmfd sp!, {pc}^ + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_user_put_word: + stmfd sp!, {lr} +USER( strt r0, [r1]) + ldmfd sp!, {pc}^ + +@ In : r0 = x, r1 = addr, r2 = error +@ Out: r2 = error +uaccess_user_put_dword: + stmfd sp!, {lr} +USER( strt r0, [r1], #4) +USER( strt r0, [r1], #0) + ldmfd sp!, {pc}^ + +9001: mov r2, #-EFAULT + ldmfd sp!, {pc}^ + + +@ In : r0 = addr, r1 = error +@ Out: r0 = x, r1 = error +uaccess_user_get_byte: + stmfd sp!, {lr} +USER( ldrbt r0, [r0]) + ldmfd sp!, {pc}^ + +@ In : r0 = addr, r1 = error +@ Out: r0 = x, r1 = error +uaccess_user_get_half: + stmfd sp!, {lr} +USER( ldrt 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_user_get_word: + stmfd sp!, {lr} +USER( ldrt r0, [r0]) + ldmfd sp!, {pc}^ + +9001: mov r1, #-EFAULT + ldmfd sp!, {pc}^ + +/* Prototype: int uaccess_user_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(uaccess_user_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, pull #8 + ldr r7, [r1], #4 + orr r3, r3, r7, push #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, pull #8 + ldmia r1!, {r4 - r7} + orr r3, r3, r4, push #24 + mov r4, r4, pull #8 + orr r4, r4, r5, push #24 + mov r5, r5, pull #8 + orr r5, r5, r6, push #24 + mov r6, r6, pull #8 + orr r6, r6, r7, push #24 + stmia r0!, {r3 - r6} @ Shouldnt fault + subs ip, ip, #16 + bpl .c2u_1cpy8lp +.c2u_1rem8lp: tst ip, #8 + movne r3, r7, pull #8 + ldmneia r1!, {r4, r7} + orrne r3, r3, r4, push #24 + movne r4, r4, pull #8 + orrne r4, r4, r7, push #24 + stmneia r0!, {r3 - r4} @ Shouldnt fault + tst ip, #4 + movne r3, r7, pull #8 + ldrne r7, [r1], #4 + orrne r3, r3, r7, push #24 + strnet r3, [r0], #4 @ Shouldnt fault + ands ip, ip, #3 + beq .c2u_1fupi +.c2u_1nowords: mov r3, r7, lsr #byte(1) + teq ip, #0 + beq .c2u_finished + cmp ip, #2 +USER( strbt r3, [r0], #1) @ May fault + movge r3, r7, lsr #byte(2) +USER( strgebt r3, [r0], #1) @ May fault + movgt r3, r7, lsr #byte(3) +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, pull #16 + ldr r7, [r1], #4 + orr r3, r3, r7, push #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, pull #16 + ldmia r1!, {r4 - r7} + orr r3, r3, r4, push #16 + mov r4, r4, pull #16 + orr r4, r4, r5, push #16 + mov r5, r5, pull #16 + orr r5, r5, r6, push #16 + mov r6, r6, pull #16 + orr r6, r6, r7, push #16 + stmia r0!, {r3 - r6} @ Shouldnt fault + subs ip, ip, #16 + bpl .c2u_2cpy8lp +.c2u_2rem8lp: tst ip, #8 + movne r3, r7, pull #16 + ldmneia r1!, {r4, r7} + orrne r3, r3, r4, push #16 + movne r4, r4, pull #16 + orrne r4, r4, r7, push #16 + stmneia r0!, {r3 - r4} @ Shouldnt fault + tst ip, #4 + movne r3, r7, pull #16 + ldrne r7, [r1], #4 + orrne r3, r3, r7, push #16 + strnet r3, [r0], #4 @ Shouldnt fault + ands ip, ip, #3 + beq .c2u_2fupi +.c2u_2nowords: mov r3, r7, lsr #byte(2) + teq ip, #0 + beq .c2u_finished + cmp ip, #2 +USER( strbt r3, [r0], #1) @ May fault + movge r3, r7, lsr #byte(3) +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, pull #24 + ldr r7, [r1], #4 + orr r3, r3, r7, push #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, pull #24 + ldmia r1!, {r4 - r7} + orr r3, r3, r4, push #8 + mov r4, r4, pull #24 + orr r4, r4, r5, push #8 + mov r5, r5, pull #24 + orr r5, r5, r6, push #8 + mov r6, r6, pull #24 + orr r6, r6, r7, push #8 + stmia r0!, {r3 - r6} @ Shouldnt fault + subs ip, ip, #16 + bpl .c2u_3cpy8lp +.c2u_3rem8lp: tst ip, #8 + movne r3, r7, pull #24 + ldmneia r1!, {r4, r7} + orrne r3, r3, r4, push #8 + movne r4, r4, pull #24 + orrne r4, r4, r7, push #8 + stmneia r0!, {r3 - r4} @ Shouldnt fault + tst ip, #4 + movne r3, r7, pull #24 + ldrne r7, [r1], #4 + orrne r3, r3, r7, push #8 + strnet r3, [r0], #4 @ Shouldnt fault + ands ip, ip, #3 + beq .c2u_3fupi +.c2u_3nowords: mov r3, r7, lsr #byte(3) + teq ip, #0 + beq .c2u_finished + cmp ip, #2 +USER( strbt r3, [r0], #1) @ May fault + ldrgeb r3, [r1], #1 +USER( strgebt r3, [r0], #1) @ May fault + ldrgtb r3, [r1], #0 +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 uaccess_user_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(uaccess_user_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, pull #8 +USER( ldrt r7, [r1], #4) @ May fault + orr r3, r3, r7, push #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, pull #8 + ldmia r1!, {r4 - r7} @ Shouldnt fault + orr r3, r3, r4, push #24 + mov r4, r4, pull #8 + orr r4, r4, r5, push #24 + mov r5, r5, pull #8 + orr r5, r5, r6, push #24 + mov r6, r6, pull #8 + orr r6, r6, r7, push #24 + stmia r0!, {r3 - r6} + subs ip, ip, #16 + bpl .cfu_1cpy8lp +.cfu_1rem8lp: tst ip, #8 + movne r3, r7, pull #8 + ldmneia r1!, {r4, r7} @ Shouldnt fault + orrne r3, r3, r4, push #24 + movne r4, r4, pull #8 + orrne r4, r4, r7, push #24 + stmneia r0!, {r3 - r4} + tst ip, #4 + movne r3, r7, pull #8 +USER( ldrnet r7, [r1], #4) @ May fault + orrne r3, r3, r7, push #24 + strne r3, [r0], #4 + ands ip, ip, #3 + beq .cfu_1fupi +.cfu_1nowords: mov r3, r7, lsr #byte(1) + teq ip, #0 + beq .cfu_finished + cmp ip, #2 + strb r3, [r0], #1 + movge r3, r7, lsr #byte(2) + strgeb r3, [r0], #1 + movgt r3, r7, lsr #byte(3) + strgtb r3, [r0], #1 + b .cfu_finished + +.cfu_2fupi: subs r2, r2, #4 + addmi ip, r2, #4 + bmi .cfu_2nowords + mov r3, r7, pull #16 +USER( ldrt r7, [r1], #4) @ May fault + orr r3, r3, r7, push #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, pull #16 + ldmia r1!, {r4 - r7} @ Shouldnt fault + orr r3, r3, r4, push #16 + mov r4, r4, pull #16 + orr r4, r4, r5, push #16 + mov r5, r5, pull #16 + orr r5, r5, r6, push #16 + mov r6, r6, pull #16 + orr r6, r6, r7, push #16 + stmia r0!, {r3 - r6} + subs ip, ip, #16 + bpl .cfu_2cpy8lp +.cfu_2rem8lp: tst ip, #8 + movne r3, r7, pull #16 + ldmneia r1!, {r4, r7} @ Shouldnt fault + orrne r3, r3, r4, push #16 + movne r4, r4, pull #16 + orrne r4, r4, r7, push #16 + stmneia r0!, {r3 - r4} + tst ip, #4 + movne r3, r7, pull #16 +USER( ldrnet r7, [r1], #4) @ May fault + orrne r3, r3, r7, push #16 + strne r3, [r0], #4 + ands ip, ip, #3 + beq .cfu_2fupi +.cfu_2nowords: mov r3, r7, lsr #byte(2) + teq ip, #0 + beq .cfu_finished + cmp ip, #2 + strb r3, [r0], #1 + movge r3, r7, lsr #byte(3) + 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, pull #24 +USER( ldrt r7, [r1], #4) @ May fault + orr r3, r3, r7, push #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, pull #24 + ldmia r1!, {r4 - r7} @ Shouldnt fault + orr r3, r3, r4, push #8 + mov r4, r4, pull #24 + orr r4, r4, r5, push #8 + mov r5, r5, pull #24 + orr r5, r5, r6, push #8 + mov r6, r6, pull #24 + orr r6, r6, r7, push #8 + stmia r0!, {r3 - r6} + subs ip, ip, #16 + bpl .cfu_3cpy8lp +.cfu_3rem8lp: tst ip, #8 + movne r3, r7, pull #24 + ldmneia r1!, {r4, r7} @ Shouldnt fault + orrne r3, r3, r4, push #8 + movne r4, r4, pull #24 + orrne r4, r4, r7, push #8 + stmneia r0!, {r3 - r4} + tst ip, #4 + movne r3, r7, pull #24 +USER( ldrnet r7, [r1], #4) @ May fault + orrne r3, r3, r7, push #8 + strne r3, [r0], #4 + ands ip, ip, #3 + beq .cfu_3fupi +.cfu_3nowords: mov r3, r7, lsr #byte(3) + teq ip, #0 + beq .cfu_finished + cmp ip, #2 + 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 + + .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 __memzero + mov r0, r4 + LOADREGS(fd,sp!, {r4 - r7, pc}) + .previous + +/* Prototype: int uaccess_user_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(uaccess_user_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 + +/* + * Copy a string from user space to kernel space. + * r0 = dst, r1 = src, r2 = byte length + * returns the number of characters copied (strlen of copied string), + * -EFAULT on exception, or "len" if we fill the whole buffer + */ +ENTRY(uaccess_user_strncpy_from_user) + save_lr + mov ip, r1 +1: subs r2, r2, #1 +USER( ldrplbt r3, [r1], #1) + bmi 2f + strb r3, [r0], #1 + teq r3, #0 + bne 1b + sub r1, r1, #1 @ take NUL character out of count +2: sub r0, r1, ip + restore_pc + + .section .fixup,"ax" + .align 0 +9001: mov r3, #0 + strb r3, [r0, #0] @ null terminate + mov r0, #-EFAULT + restore_pc + .previous + +/* Prototype: unsigned long uaccess_user_strnlen_user(const char *str, long n) + * Purpose : get length of a string in user memory + * Params : str - address of string in user memory + * Returns : length of string *including terminator* + * or zero on exception, or n + 1 if too long + */ +ENTRY(uaccess_user_strnlen_user) + save_lr + mov r2, r0 +1: +USER( ldrbt r3, [r0], #1) + teq r3, #0 + beq 2f + subs r1, r1, #1 + bne 1b + add r0, r0, #1 +2: sub r0, r0, r2 + restore_pc + + .section .fixup,"ax" + .align 0 +9001: mov r0, #0 + restore_pc + .previous + |