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-rw-r--r--arch/i386/lib/putuser.S87
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