[PATCH] m32r: security fix of {get,put}_user macros

Update {get,put}_user macros for m32r kernel.
- Modify get_user to use __get_user_asm macro, instead of __get_user_x macro.
- Remove arch/m32r/lib/{get,put}user.S.
- Some cosmetic updates.

I would like to thank NIIBE Yutaka for his reporting about the m32r kernel's
security problem in {get,put}_user macros.

There were no address checking for user space access in {get,put}_user macros.
 ;-)
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: NIIBE Yutaka <gniibe@fsij.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/m32r/kernel/m32r_ksyms.c

@@ -38,10 +38,6 @@ EXPORT_SYMBOL(__udelay);
 EXPORT_SYMBOL(__delay);
 EXPORT_SYMBOL(__const_udelay);
 
-EXPORT_SYMBOL(__get_user_1);
-EXPORT_SYMBOL(__get_user_2);
-EXPORT_SYMBOL(__get_user_4);
-
 EXPORT_SYMBOL(strpbrk);
 EXPORT_SYMBOL(strstr);
 

arch/m32r/lib/Makefile

@@ -2,6 +2,6 @@
 # Makefile for M32R-specific library files..
 #
 
-lib-y  := checksum.o ashxdi3.o memset.o memcpy.o getuser.o \
-	  putuser.o delay.o strlen.o usercopy.o csum_partial_copy.o
+lib-y  := checksum.o ashxdi3.o memset.o memcpy.o \
+	  delay.o strlen.o usercopy.o csum_partial_copy.o
 

arch/m32r/lib/getuser.S

-/*
- * __get_user functions.
- *
- * (C) Copyright 2001 Hirokazu Takata
- *
- * 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/config.h>
-
-/*
- * __get_user_X
- *
- * Inputs:	r0 contains the address
- *
- * Outputs:	r0 is error code (0 or -EFAULT)
- *		r1 contains zero-extended value
- *
- * These functions should not modify any other registers,
- * as they get called from within inline assembly.
- */
-
-#ifdef CONFIG_ISA_DUAL_ISSUE
-
-	.text
-	.balign 4
-	.globl __get_user_1
-__get_user_1:
-1:	ldub	r1, @r0		    ||	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __get_user_2
-__get_user_2:
-2:	lduh	r1, @r0		    ||	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __get_user_4
-__get_user_4:
-3:	ld	r1, @r0		    ||	ldi	r0, #0
-	jmp	r14
-
-bad_get_user:
-	ldi	r1, #0		    ||	ldi	r0, #-14
-	jmp	r14
-
-#else /* not CONFIG_ISA_DUAL_ISSUE */
-
-	.text
-	.balign 4
-	.globl __get_user_1
-__get_user_1:
-1:	ldub	r1, @r0
-	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __get_user_2
-__get_user_2:
-2:	lduh	r1, @r0
-	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __get_user_4
-__get_user_4:
-3:	ld	r1, @r0
-	ldi	r0, #0
-	jmp	r14
-
-bad_get_user:
-	ldi	r1, #0
-	ldi	r0, #-14
-	jmp	r14
-
-#endif /* not CONFIG_ISA_DUAL_ISSUE */
-
-.section __ex_table,"a"
-	.long 1b,bad_get_user
-	.long 2b,bad_get_user
-	.long 3b,bad_get_user
-.previous
-
-	.end

arch/m32r/lib/putuser.S

-/*
- * __put_user functions.
- *
- * (C) Copyright 1998 Linus Torvalds
- * (C) Copyright 2001 Hirokazu Takata
- *
- * These functions have a non-standard call interface
- * to make them more efficient.
- */
-
-#include <linux/config.h>
-
-/*
- * __put_user_X
- *
- * Inputs:	r0 contains the address
- *		r1 contains the value
- *
- * Outputs:	r0 is error code (0 or -EFAULT)
- *		r1 is corrupted (will contain "current_task").
- *
- * These functions should not modify any other registers,
- * as they get called from within inline assembly.
- */
-
-#ifdef CONFIG_ISA_DUAL_ISSUE
-
-	.text
-	.balign 4
-	.globl __put_user_1
-__put_user_1:
-1:	stb	r1, @r0		    ||	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __put_user_2
-__put_user_2:
-2:	sth	r1, @r0		    ||	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __put_user_4
-__put_user_4:
-3:	st	r1, @r0		    ||	ldi	r0, #0
-	jmp	r14
-
-bad_put_user:
-	ldi	r0, #-14	    ||	jmp	r14
-
-#else /* not CONFIG_ISA_DUAL_ISSUE */
-
-	.text
-	.balign 4
-	.globl __put_user_1
-__put_user_1:
-1:	stb	r1, @r0
-	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __put_user_2
-__put_user_2:
-2:	sth	r1, @r0
-	ldi	r0, #0
-	jmp	r14
-
-	.balign 4
-	.globl __put_user_4
-__put_user_4:
-3:	st	r1, @r0
-	ldi	r0, #0
-	jmp	r14
-
-bad_put_user:
-	ldi	r0, #-14
-	jmp	r14
-
-#endif /* not CONFIG_ISA_DUAL_ISSUE */
-
-.section __ex_table,"a"
-	.long 1b,bad_put_user
-	.long 2b,bad_put_user
-	.long 3b,bad_put_user
-.previous