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Diffstat (limited to 'arch/avr32/lib/copy_user.S')
| -rw-r--r-- | arch/avr32/lib/copy_user.S | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/avr32/lib/copy_user.S b/arch/avr32/lib/copy_user.S new file mode 100644 index 00000000000..ea59c04b07d --- /dev/null +++ b/arch/avr32/lib/copy_user.S @@ -0,0 +1,119 @@ +/* + * 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 |