diff options
Diffstat (limited to 'arch/i386/lib/putuser.S')
-rw-r--r-- | arch/i386/lib/putuser.S | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/i386/lib/putuser.S b/arch/i386/lib/putuser.S new file mode 100644 index 00000000000..a32d9f570f4 --- /dev/null +++ b/arch/i386/lib/putuser.S @@ -0,0 +1,87 @@ +/* + * __put_user functions. + * + * (C) Copyright 2005 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 <asm/thread_info.h> + + +/* + * __put_user_X + * + * Inputs: %eax[:%edx] contains the data + * %ecx contains the address + * + * Outputs: %eax is error code (0 or -EFAULT) + * + * These functions should not modify any other registers, + * as they get called from within inline assembly. + */ + +#define ENTER pushl %ebx ; GET_THREAD_INFO(%ebx) +#define EXIT popl %ebx ; ret + +.text +.align 4 +.globl __put_user_1 +__put_user_1: + ENTER + cmpl TI_addr_limit(%ebx),%ecx + jae bad_put_user +1: movb %al,(%ecx) + xorl %eax,%eax + EXIT + +.align 4 +.globl __put_user_2 +__put_user_2: + ENTER + movl TI_addr_limit(%ebx),%ebx + subl $1,%ebx + cmpl %ebx,%ecx + jae bad_put_user +2: movw %ax,(%ecx) + xorl %eax,%eax + EXIT + +.align 4 +.globl __put_user_4 +__put_user_4: + ENTER + movl TI_addr_limit(%ebx),%ebx + subl $3,%ebx + cmpl %ebx,%ecx + jae bad_put_user +3: movl %eax,(%ecx) + xorl %eax,%eax + EXIT + +.align 4 +.globl __put_user_8 +__put_user_8: + ENTER + movl TI_addr_limit(%ebx),%ebx + subl $7,%ebx + cmpl %ebx,%ecx + jae bad_put_user +4: movl %eax,(%ecx) +5: movl %edx,4(%ecx) + xorl %eax,%eax + EXIT + +bad_put_user: + movl $-14,%eax + EXIT + +.section __ex_table,"a" + .long 1b,bad_put_user + .long 2b,bad_put_user + .long 3b,bad_put_user + .long 4b,bad_put_user + .long 5b,bad_put_user +.previous |