summary refs log tree commit diff
path: root/arch/arm26/lib/getuser.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm26/lib/getuser.S')
-rw-r--r--arch/arm26/lib/getuser.S112
1 files changed, 112 insertions, 0 deletions
diff --git a/arch/arm26/lib/getuser.S b/arch/arm26/lib/getuser.S
new file mode 100644
index 000000000000..e6d59b334851
--- /dev/null
+++ b/arch/arm26/lib/getuser.S
@@ -0,0 +1,112 @@
+/*
+ *  linux/arch/arm26/lib/getuser.S
+ *
+ *  Copyright (C) 2001 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  Idea from x86 version, (C) Copyright 1998 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.
+ *
+ * __get_user_X
+ *
+ * Inputs:	r0 contains the address
+ * Outputs:	r0 is the error code
+ *		r1, r2 contains the zero-extended value
+ *		lr corrupted
+ *
+ * No other registers must be altered.  (see include/asm-arm/uaccess.h
+ * for specific ASM register usage).
+ *
+ * Note that ADDR_LIMIT is either 0 or 0xc0000000.
+ * Note also that it is intended that __get_user_bad is not global.
+ */
+#include <asm/asm_offsets.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+
+        .global __get_user_1
+__get_user_1:
+        bic     r1, sp, #0x1f00
+        bic     r1, r1, #0x00ff
+        str     lr, [sp, #-4]!
+        ldr     r1, [r1, #TI_ADDR_LIMIT]
+        sub     r1, r1, #1
+        cmp     r0, r1
+        bge     __get_user_bad
+        cmp     r0, #0x02000000
+1:      ldrlsbt r1, [r0]
+        ldrgeb  r1, [r0]
+        mov     r0, #0
+        ldmfd   sp!, {pc}^
+
+        .global __get_user_2
+__get_user_2:
+        bic     r2, sp, #0x1f00
+        bic     r2, r2, #0x00ff
+        str     lr, [sp, #-4]!
+        ldr     r2, [r2, #TI_ADDR_LIMIT]
+        sub     r2, r2, #2
+        cmp     r0, r2
+        bge     __get_user_bad
+        cmp     r0, #0x02000000
+2:      ldrlsbt r1, [r0], #1
+3:      ldrlsbt r2, [r0]
+        ldrgeb  r1, [r0], #1
+        ldrgeb  r2, [r0]
+        orr     r1, r1, r2, lsl #8
+        mov     r0, #0
+        ldmfd   sp!, {pc}^
+
+        .global __get_user_4
+__get_user_4:
+        bic     r1, sp, #0x1f00
+        bic     r1, r1, #0x00ff
+        str     lr, [sp, #-4]!
+        ldr     r1, [r1, #TI_ADDR_LIMIT]
+        sub     r1, r1, #4
+        cmp     r0, r1
+        bge     __get_user_bad
+        cmp     r0, #0x02000000
+4:      ldrlst  r1, [r0]
+        ldrge   r1, [r0]
+        mov     r0, #0
+        ldmfd   sp!, {pc}^
+
+        .global __get_user_8
+__get_user_8:
+        bic     r2, sp, #0x1f00
+        bic     r2, r2, #0x00ff
+        str     lr, [sp, #-4]!
+        ldr     r2, [r2, #TI_ADDR_LIMIT]
+        sub     r2, r2, #8
+        cmp     r0, r2
+        bge     __get_user_bad_8
+        cmp     r0, #0x02000000
+5:      ldrlst  r1, [r0], #4
+6:      ldrlst  r2, [r0]
+        ldrge   r1, [r0], #4
+        ldrge   r2, [r0]
+        mov     r0, #0
+        ldmfd   sp!, {pc}^
+
+__get_user_bad_8:
+        mov     r2, #0
+__get_user_bad:
+        mov     r1, #0
+        mov     r0, #-EFAULT
+        ldmfd   sp!, {pc}^
+
+.section __ex_table, "a"
+	.long	1b, __get_user_bad
+	.long	2b, __get_user_bad
+	.long	3b, __get_user_bad
+	.long	4b, __get_user_bad
+	.long	5b, __get_user_bad_8
+	.long	6b, __get_user_bad_8
+.previous