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authorIngo Molnar <mingo@elte.hu>2008-07-18 19:53:16 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-18 19:53:16 +0200
commit9b610fda0df5d0f0b0c64242e37441ad1b384aac (patch)
tree0ea14b15f2e6546f37fe18d8ac3dc83077ec0e55 /arch/x86/lib/putuser.S
parentnohz: prevent tick stop outside of the idle loop (diff)
parentMerge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2 (diff)
downloadlinux-dev-9b610fda0df5d0f0b0c64242e37441ad1b384aac.tar.xz
linux-dev-9b610fda0df5d0f0b0c64242e37441ad1b384aac.zip
Merge branch 'linus' into timers/nohz
Diffstat (limited to 'arch/x86/lib/putuser.S')
-rw-r--r--arch/x86/lib/putuser.S97
1 files changed, 97 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
new file mode 100644
index 000000000000..36b0d15ae6e9
--- /dev/null
+++ b/arch/x86/lib/putuser.S
@@ -0,0 +1,97 @@
+/*
+ * __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>
+
+
+/*
+ * __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 ret ; \
+ CFI_ENDPROC
+
+.text
+ENTRY(__put_user_1)
+ ENTER
+ cmp TI_addr_limit(%_ASM_BX),%_ASM_CX
+ jae bad_put_user
+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
+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
+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
+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)
+
+.section __ex_table,"a"
+ _ASM_PTR 1b,bad_put_user
+ _ASM_PTR 2b,bad_put_user
+ _ASM_PTR 3b,bad_put_user
+ _ASM_PTR 4b,bad_put_user
+#ifdef CONFIG_X86_32
+ _ASM_PTR 5b,bad_put_user
+#endif
+.previous