| /* |
| * __get_user functions. |
| * |
| * (C) Copyright 1998 Linus Torvalds |
| * |
| * These functions have a non-standard call interface |
| * to make them more efficient, especially as they |
| * return an error value in addition to the "real" |
| * return value. |
| */ |
| #include <linux/linkage.h> |
| #include <asm/dwarf2.h> |
| #include <asm/thread_info.h> |
| |
| |
| /* |
| * __get_user_X |
| * |
| * Inputs: %eax contains the address |
| * |
| * Outputs: %eax is error code (0 or -EFAULT) |
| * %edx contains zero-extended value |
| * |
| * These functions should not modify any other registers, |
| * as they get called from within inline assembly. |
| */ |
| |
| .text |
| ENTRY(__get_user_1) |
| CFI_STARTPROC |
| GET_THREAD_INFO(%edx) |
| cmpl TI_addr_limit(%edx),%eax |
| jae bad_get_user |
| 1: movzbl (%eax),%edx |
| xorl %eax,%eax |
| ret |
| CFI_ENDPROC |
| ENDPROC(__get_user_1) |
| |
| ENTRY(__get_user_2) |
| CFI_STARTPROC |
| addl $1,%eax |
| jc bad_get_user |
| GET_THREAD_INFO(%edx) |
| cmpl TI_addr_limit(%edx),%eax |
| jae bad_get_user |
| 2: movzwl -1(%eax),%edx |
| xorl %eax,%eax |
| ret |
| CFI_ENDPROC |
| ENDPROC(__get_user_2) |
| |
| ENTRY(__get_user_4) |
| CFI_STARTPROC |
| addl $3,%eax |
| jc bad_get_user |
| GET_THREAD_INFO(%edx) |
| cmpl TI_addr_limit(%edx),%eax |
| jae bad_get_user |
| 3: movl -3(%eax),%edx |
| xorl %eax,%eax |
| ret |
| CFI_ENDPROC |
| ENDPROC(__get_user_4) |
| |
| bad_get_user: |
| CFI_STARTPROC |
| xorl %edx,%edx |
| movl $-14,%eax |
| ret |
| CFI_ENDPROC |
| END(bad_get_user) |
| |
| .section __ex_table,"a" |
| .long 1b,bad_get_user |
| .long 2b,bad_get_user |
| .long 3b,bad_get_user |
| .previous |