| /* |
| * Copy to/from userspace with optional address space checking. |
| * |
| * Copyright 2004-2006 Atmel Corporation |
| * |
| * 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 <asm/page.h> |
| #include <asm/thread_info.h> |
| #include <asm/asm.h> |
| |
| /* |
| * __kernel_size_t |
| * __copy_user(void *to, const void *from, __kernel_size_t n) |
| * |
| * Returns the number of bytes not copied. Might be off by |
| * max 3 bytes if we get a fault in the main loop. |
| * |
| * The address-space checking functions simply fall through to |
| * the non-checking version. |
| */ |
| .text |
| .align 1 |
| .global copy_from_user |
| .type copy_from_user, @function |
| copy_from_user: |
| branch_if_kernel r8, __copy_user |
| ret_if_privileged r8, r11, r10, r10 |
| rjmp __copy_user |
| .size copy_from_user, . - copy_from_user |
| |
| .global copy_to_user |
| .type copy_to_user, @function |
| copy_to_user: |
| branch_if_kernel r8, __copy_user |
| ret_if_privileged r8, r12, r10, r10 |
| .size copy_to_user, . - copy_to_user |
| |
| .global __copy_user |
| .type __copy_user, @function |
| __copy_user: |
| mov r9, r11 |
| andl r9, 3, COH |
| brne 6f |
| |
| /* At this point, from is word-aligned */ |
| 1: sub r10, 4 |
| brlt 3f |
| |
| 2: |
| 10: ld.w r8, r11++ |
| 11: st.w r12++, r8 |
| sub r10, 4 |
| brge 2b |
| |
| 3: sub r10, -4 |
| reteq 0 |
| |
| /* |
| * Handle unaligned count. Need to be careful with r10 here so |
| * that we return the correct value even if we get a fault |
| */ |
| 4: |
| 20: ld.ub r8, r11++ |
| 21: st.b r12++, r8 |
| sub r10, 1 |
| reteq 0 |
| 22: ld.ub r8, r11++ |
| 23: st.b r12++, r8 |
| sub r10, 1 |
| reteq 0 |
| 24: ld.ub r8, r11++ |
| 25: st.b r12++, r8 |
| retal 0 |
| |
| /* Handle unaligned from-pointer */ |
| 6: cp.w r10, 4 |
| brlt 4b |
| rsub r9, r9, 4 |
| |
| 30: ld.ub r8, r11++ |
| 31: st.b r12++, r8 |
| sub r10, 1 |
| sub r9, 1 |
| breq 1b |
| 32: ld.ub r8, r11++ |
| 33: st.b r12++, r8 |
| sub r10, 1 |
| sub r9, 1 |
| breq 1b |
| 34: ld.ub r8, r11++ |
| 35: st.b r12++, r8 |
| sub r10, 1 |
| rjmp 1b |
| .size __copy_user, . - __copy_user |
| |
| .section .fixup,"ax" |
| .align 1 |
| 19: sub r10, -4 |
| 29: retal r10 |
| |
| .section __ex_table,"a" |
| .align 2 |
| .long 10b, 19b |
| .long 11b, 19b |
| .long 20b, 29b |
| .long 21b, 29b |
| .long 22b, 29b |
| .long 23b, 29b |
| .long 24b, 29b |
| .long 25b, 29b |
| .long 30b, 29b |
| .long 31b, 29b |
| .long 32b, 29b |
| .long 33b, 29b |
| .long 34b, 29b |
| .long 35b, 29b |