diff options
Diffstat (limited to 'arch/x86/lib/putuser_32.S')
-rw-r--r-- | arch/x86/lib/putuser_32.S | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser_32.S b/arch/x86/lib/putuser_32.S new file mode 100644 index 00000000000..f58fba109d1 --- /dev/null +++ b/arch/x86/lib/putuser_32.S @@ -0,0 +1,98 @@ +/* + * __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 <linux/linkage.h> +#include <asm/dwarf2.h> +#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 CFI_STARTPROC ; \ + pushl %ebx ; \ + CFI_ADJUST_CFA_OFFSET 4 ; \ + CFI_REL_OFFSET ebx, 0 ; \ + GET_THREAD_INFO(%ebx) +#define EXIT popl %ebx ; \ + CFI_ADJUST_CFA_OFFSET -4 ; \ + CFI_RESTORE ebx ; \ + ret ; \ + CFI_ENDPROC + +.text +ENTRY(__put_user_1) + ENTER + cmpl TI_addr_limit(%ebx),%ecx + jae bad_put_user +1: movb %al,(%ecx) + xorl %eax,%eax + EXIT +ENDPROC(__put_user_1) + +ENTRY(__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 +ENDPROC(__put_user_2) + +ENTRY(__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 +ENDPROC(__put_user_4) + +ENTRY(__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 +ENDPROC(__put_user_8) + +bad_put_user: + CFI_STARTPROC simple + CFI_DEF_CFA esp, 2*4 + CFI_OFFSET eip, -1*4 + CFI_OFFSET ebx, -2*4 + movl $-14,%eax + EXIT +END(bad_put_user) + +.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 |