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-rw-r--r--kernel/arch/x86/lib/putuser.S101
1 files changed, 101 insertions, 0 deletions
diff --git a/kernel/arch/x86/lib/putuser.S b/kernel/arch/x86/lib/putuser.S
new file mode 100644
index 000000000..fc6ba17a7
--- /dev/null
+++ b/kernel/arch/x86/lib/putuser.S
@@ -0,0 +1,101 @@
+/*
+ * __put_user functions.
+ *
+ * (C) Copyright 2005 Linus Torvalds
+ * (C) Copyright 2005 Andi Kleen
+ * (C) Copyright 2008 Glauber Costa
+ *
+ * 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>
+#include <asm/errno.h>
+#include <asm/asm.h>
+#include <asm/smap.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 ; \
+ GET_THREAD_INFO(%_ASM_BX)
+#define EXIT ASM_CLAC ; \
+ ret ; \
+ CFI_ENDPROC
+
+.text
+ENTRY(__put_user_1)
+ ENTER
+ cmp TI_addr_limit(%_ASM_BX),%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+1: movb %al,(%_ASM_CX)
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_1)
+
+ENTRY(__put_user_2)
+ ENTER
+ mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+ sub $1,%_ASM_BX
+ cmp %_ASM_BX,%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+2: movw %ax,(%_ASM_CX)
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_2)
+
+ENTRY(__put_user_4)
+ ENTER
+ mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+ sub $3,%_ASM_BX
+ cmp %_ASM_BX,%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+3: movl %eax,(%_ASM_CX)
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_4)
+
+ENTRY(__put_user_8)
+ ENTER
+ mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+ sub $7,%_ASM_BX
+ cmp %_ASM_BX,%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+4: mov %_ASM_AX,(%_ASM_CX)
+#ifdef CONFIG_X86_32
+5: movl %edx,4(%_ASM_CX)
+#endif
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_8)
+
+bad_put_user:
+ CFI_STARTPROC
+ movl $-EFAULT,%eax
+ EXIT
+END(bad_put_user)
+
+ _ASM_EXTABLE(1b,bad_put_user)
+ _ASM_EXTABLE(2b,bad_put_user)
+ _ASM_EXTABLE(3b,bad_put_user)
+ _ASM_EXTABLE(4b,bad_put_user)
+#ifdef CONFIG_X86_32
+ _ASM_EXTABLE(5b,bad_put_user)
+#endif