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!
diff --git a/arch/arm26/lib/uaccess-user.S b/arch/arm26/lib/uaccess-user.S
new file mode 100644
index 0000000..130b8f2
--- /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
+