powerpc: get rid of zeroing, switch to RAW_COPY_USER

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/powerpc/Kconfig

@@ -87,6 +87,7 @@ config PPC
 	select ARCH_HAS_DMA_SET_COHERENT_MASK
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_RAW_COPY_USER
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST

arch/powerpc/include/asm/uaccess.h

@@ -269,42 +269,19 @@ extern unsigned long __copy_tofrom_user(void __user *to,
 
 #ifndef __powerpc64__
 
-static inline unsigned long copy_from_user(void *to,
-		const void __user *from, unsigned long n)
-{
-	if (likely(access_ok(VERIFY_READ, from, n))) {
-		check_object_size(to, n, false);
-		return __copy_tofrom_user((__force void __user *)to, from, n);
-	}
-	memset(to, 0, n);
-	return n;
-}
-
-static inline unsigned long copy_to_user(void __user *to,
-		const void *from, unsigned long n)
-{
-	if (access_ok(VERIFY_WRITE, to, n)) {
-		check_object_size(from, n, true);
-		return __copy_tofrom_user(to, (__force void __user *)from, n);
-	}
-	return n;
-}
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
 
 #else /* __powerpc64__ */
 
-#define __copy_in_user(to, from, size) \
-	__copy_tofrom_user((to), (from), (size))
-
-extern unsigned long copy_from_user(void *to, const void __user *from,
-				    unsigned long n);
-extern unsigned long copy_to_user(void __user *to, const void *from,
-				  unsigned long n);
-extern unsigned long copy_in_user(void __user *to, const void __user *from,
-				  unsigned long n);
-
+static inline unsigned long
+raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	return __copy_tofrom_user(to, from, n);
+}
 #endif /* __powerpc64__ */
 
-static inline unsigned long __copy_from_user_inatomic(void *to,
+static inline unsigned long raw_copy_from_user(void *to,
 		const void __user *from, unsigned long n)
 {
 	if (__builtin_constant_p(n) && (n <= 8)) {
@@ -328,12 +305,10 @@ static inline unsigned long __copy_from_user_inatomic(void *to,
 			return 0;
 	}
 
-	check_object_size(to, n, false);
-
 	return __copy_tofrom_user((__force void __user *)to, from, n);
 }
 
-static inline unsigned long __copy_to_user_inatomic(void __user *to,
+static inline unsigned long raw_copy_to_user(void __user *to,
 		const void *from, unsigned long n)
 {
 	if (__builtin_constant_p(n) && (n <= 8)) {
@@ -357,25 +332,9 @@ static inline unsigned long __copy_to_user_inatomic(void __user *to,
 			return 0;
 	}
 
-	check_object_size(from, n, true);
-
 	return __copy_tofrom_user(to, (__force const void __user *)from, n);
 }
 
-static inline unsigned long __copy_from_user(void *to,
-		const void __user *from, unsigned long size)
-{
-	might_fault();
-	return __copy_from_user_inatomic(to, from, size);
-}
-
-static inline unsigned long __copy_to_user(void __user *to,
-		const void *from, unsigned long size)
-{
-	might_fault();
-	return __copy_to_user_inatomic(to, from, size);
-}
-
 extern unsigned long __clear_user(void __user *addr, unsigned long size);
 
 static inline unsigned long clear_user(void __user *addr, unsigned long size)

arch/powerpc/lib/Makefile

@@ -14,7 +14,7 @@ obj-y += string.o alloc.o crtsavres.o code-patching.o \
 
 obj-$(CONFIG_PPC32)	+= div64.o copy_32.o
 
-obj64-y	+= copypage_64.o copyuser_64.o usercopy_64.o mem_64.o hweight_64.o \
+obj64-y	+= copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
 	   copyuser_power7.o string_64.o copypage_power7.o memcpy_power7.o \
 	   memcpy_64.o memcmp_64.o
 

arch/powerpc/lib/copy_32.S

@@ -477,18 +477,6 @@ _GLOBAL(__copy_tofrom_user)
 	bdnz	130b
 /* then clear out the destination: r3 bytes starting at 4(r6) */
 132:	mfctr	r3
-	srwi.	r0,r3,2
-	li	r9,0
-	mtctr	r0
-	beq	113f
-112:	stwu	r9,4(r6)
-	bdnz	112b
-113:	andi.	r0,r3,3
-	mtctr	r0
-	beq	120f
-114:	stb	r9,4(r6)
-	addi	r6,r6,1
-	bdnz	114b
 120:	blr
 
 	EX_TABLE(30b,108b)
@@ -497,7 +485,5 @@ _GLOBAL(__copy_tofrom_user)
 	EX_TABLE(41b,111b)
 	EX_TABLE(130b,132b)
 	EX_TABLE(131b,120b)
-	EX_TABLE(112b,120b)
-	EX_TABLE(114b,120b)
 
 EXPORT_SYMBOL(__copy_tofrom_user)

arch/powerpc/lib/copyuser_64.S

@@ -319,32 +319,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
 	blr
 
 /*
- * here we have trapped again, need to clear ctr bytes starting at r3
+ * here we have trapped again, amount remaining is in ctr.
  */
-143:	mfctr	r5
-	li	r0,0
-	mr	r4,r3
-	mr	r3,r5		/* return the number of bytes not copied */
-1:	andi.	r9,r4,7
-	beq	3f
-90:	stb	r0,0(r4)
-	addic.	r5,r5,-1
-	addi	r4,r4,1
-	bne	1b
-	blr
-3:	cmpldi	cr1,r5,8
-	srdi	r9,r5,3
-	andi.	r5,r5,7
-	blt	cr1,93f
-	mtctr	r9
-91:	std	r0,0(r4)
-	addi	r4,r4,8
-	bdnz	91b
-93:	beqlr
-	mtctr	r5	
-92:	stb	r0,0(r4)
-	addi	r4,r4,1
-	bdnz	92b
+143:	mfctr	r3
 	blr
 
 /*
@@ -389,10 +366,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
 	ld	r5,-8(r1)
 	add	r6,r6,r5
 	subf	r3,r3,r6	/* #bytes not copied */
-190:
-191:
-192:
-	blr			/* #bytes not copied in r3 */
+	blr
 
 	EX_TABLE(20b,120b)
 	EX_TABLE(220b,320b)
@@ -451,9 +425,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
 	EX_TABLE(88b,188b)
 	EX_TABLE(43b,143b)
 	EX_TABLE(89b,189b)
-	EX_TABLE(90b,190b)
-	EX_TABLE(91b,191b)
-	EX_TABLE(92b,192b)
 
 /*
  * Routine to copy a whole page of data, optimized for POWER4.

arch/powerpc/lib/usercopy_64.c

-/*
- * Functions which are too large to be inlined.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-#include <linux/module.h>
-#include <linux/uaccess.h>
-
-unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
-{
-	if (likely(access_ok(VERIFY_READ, from, n)))
-		n = __copy_from_user(to, from, n);
-	else
-		memset(to, 0, n);
-	return n;
-}
-
-unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-	if (likely(access_ok(VERIFY_WRITE, to, n)))
-		n = __copy_to_user(to, from, n);
-	return n;
-}
-
-unsigned long copy_in_user(void __user *to, const void __user *from,
-			   unsigned long n)
-{
-	might_sleep();
-	if (likely(access_ok(VERIFY_READ, from, n) &&
-	    access_ok(VERIFY_WRITE, to, n)))
-		n =__copy_tofrom_user(to, from, n);
-	return n;
-}
-
-EXPORT_SYMBOL(copy_from_user);
-EXPORT_SYMBOL(copy_to_user);
-EXPORT_SYMBOL(copy_in_user);
-