Re: [RFC][PATCH] fix csum_and_copy_..._user() idiocy. Re: AW: [PATCH] amd64: Fix csum_partial_copy_generic()

From: Al Viro
Date: Sun Oct 22 2023 - 15:46:32 EST

On Sun, Oct 22, 2023 at 08:40:20PM +0100, Al Viro wrote:
> On Sat, Oct 21, 2023 at 11:22:03PM +0100, Al Viro wrote:
> > On Sat, Oct 21, 2023 at 08:15:25AM +0100, Al Viro wrote:
> >
> > > I don't think -rc7 is a good time for that, though. At the
> > > very least it needs a review on linux-arch - I think I hadn't
> > > fucked the ABI for returning u64 up, but...
> > >
> > > Anyway, completely untested patch follows:
> >
> > ... and now something that at least builds (with some brainos fixed); it's still
> > slightly suboptimal representation on big-endian 32bit - there it would be better to
> > have have the csum in upper half of the 64bit getting returned and use the lower
> > half as fault indicator, but dealing with that cleanly takes some massage of
> > includes in several places, so I'd left that alone for now. In any case, the
> > overhead of that is pretty much noise.
>
> OK, here's what I have in mind for the next cycle. It's still untested (builds,
> but that's it). Conversion to including <net/checksum.h> rather than
> <asm/checksum.h> is going to get carved out into a separate patch.
> I _think_ I've got the asm parts (and ABI for returning 64bit) right,
> but I would really appreciate review and testing.

Gyah.... What I got wrong is the lib/iov_iter.c part - check for faults is
backwards ;-/ Hopefully fixed variant follows:

diff --git a/arch/alpha/include/asm/asm-prototypes.h b/arch/alpha/include/asm/asm-prototypes.h
index c8ae46fc2e74..0cf90f406d00 100644
--- a/arch/alpha/include/asm/asm-prototypes.h
+++ b/arch/alpha/include/asm/asm-prototypes.h
@@ -1,10 +1,10 @@
#include <linux/spinlock.h>

-#include <asm/checksum.h>
#include <asm/console.h>
#include <asm/page.h>
#include <asm/string.h>
#include <linux/uaccess.h>
+#include <net/checksum.h> // for csum_ipv6_magic()

#include <asm-generic/asm-prototypes.h>

diff --git a/arch/alpha/include/asm/checksum.h b/arch/alpha/include/asm/checksum.h
index 99d631e146b2..d3abe290ae4e 100644
--- a/arch/alpha/include/asm/checksum.h
+++ b/arch/alpha/include/asm/checksum.h
@@ -43,7 +43,7 @@ extern __wsum csum_partial(const void *buff, int len, __wsum sum);
*/
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
#define _HAVE_ARCH_CSUM_AND_COPY
-__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len);

__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);

diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c
index 4d180d96f09e..5f75fcd19287 100644
--- a/arch/alpha/lib/csum_partial_copy.c
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -52,7 +52,7 @@ __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
__guu_err; \
})

-static inline unsigned short from64to16(unsigned long x)
+static inline __wsum_fault from64to16(unsigned long x)
{
/* Using extract instructions is a bit more efficient
than the original shift/bitmask version. */
@@ -72,7 +72,7 @@ static inline unsigned short from64to16(unsigned long x)
+ (unsigned long) tmp_v.us[2];

/* Similarly, out_v.us[2] is always zero for the final add. */
- return out_v.us[0] + out_v.us[1];
+ return to_wsum_fault((__force __wsum)(out_v.us[0] + out_v.us[1]));
}


@@ -80,17 +80,17 @@ static inline unsigned short from64to16(unsigned long x)
/*
* Ok. This isn't fun, but this is the EASY case.
*/
-static inline unsigned long
+static inline __wsum_fault
csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
long len)
{
- unsigned long checksum = ~0U;
+ unsigned long checksum = 0;
unsigned long carry = 0;

while (len >= 0) {
unsigned long word;
if (__get_word(ldq, word, src))
- return 0;
+ return CSUM_FAULT;
checksum += carry;
src++;
checksum += word;
@@ -104,7 +104,7 @@ csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
if (len) {
unsigned long word, tmp;
if (__get_word(ldq, word, src))
- return 0;
+ return CSUM_FAULT;
tmp = *dst;
mskql(word, len, word);
checksum += word;
@@ -113,14 +113,14 @@ csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
*dst = word | tmp;
checksum += carry;
}
- return checksum;
+ return from64to16 (checksum);
}

/*
* This is even less fun, but this is still reasonably
* easy.
*/
-static inline unsigned long
+static inline __wsum_fault
csum_partial_cfu_dest_aligned(const unsigned long __user *src,
unsigned long *dst,
unsigned long soff,
@@ -129,16 +129,16 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
unsigned long first;
unsigned long word, carry;
unsigned long lastsrc = 7+len+(unsigned long)src;
- unsigned long checksum = ~0U;
+ unsigned long checksum = 0;

if (__get_word(ldq_u, first,src))
- return 0;
+ return CSUM_FAULT;
carry = 0;
while (len >= 0) {
unsigned long second;

if (__get_word(ldq_u, second, src+1))
- return 0;
+ return CSUM_FAULT;
extql(first, soff, word);
len -= 8;
src++;
@@ -157,7 +157,7 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
unsigned long tmp;
unsigned long second;
if (__get_word(ldq_u, second, lastsrc))
- return 0;
+ return CSUM_FAULT;
tmp = *dst;
extql(first, soff, word);
extqh(second, soff, first);
@@ -169,13 +169,13 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
*dst = word | tmp;
checksum += carry;
}
- return checksum;
+ return from64to16 (checksum);
}

/*
* This is slightly less fun than the above..
*/
-static inline unsigned long
+static inline __wsum_fault
csum_partial_cfu_src_aligned(const unsigned long __user *src,
unsigned long *dst,
unsigned long doff,
@@ -185,12 +185,12 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
unsigned long carry = 0;
unsigned long word;
unsigned long second_dest;
- unsigned long checksum = ~0U;
+ unsigned long checksum = 0;

mskql(partial_dest, doff, partial_dest);
while (len >= 0) {
if (__get_word(ldq, word, src))
- return 0;
+ return CSUM_FAULT;
len -= 8;
insql(word, doff, second_dest);
checksum += carry;
@@ -205,7 +205,7 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
if (len) {
checksum += carry;
if (__get_word(ldq, word, src))
- return 0;
+ return CSUM_FAULT;
mskql(word, len, word);
len -= 8;
checksum += word;
@@ -226,14 +226,14 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
stq_u(partial_dest | second_dest, dst);
out:
checksum += carry;
- return checksum;
+ return from64to16 (checksum);
}

/*
* This is so totally un-fun that it's frightening. Don't
* look at this too closely, you'll go blind.
*/
-static inline unsigned long
+static inline __wsum_fault
csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long * dst,
unsigned long soff, unsigned long doff,
@@ -242,10 +242,10 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long carry = 0;
unsigned long first;
unsigned long lastsrc;
- unsigned long checksum = ~0U;
+ unsigned long checksum = 0;

if (__get_word(ldq_u, first, src))
- return 0;
+ return CSUM_FAULT;
lastsrc = 7+len+(unsigned long)src;
mskql(partial_dest, doff, partial_dest);
while (len >= 0) {
@@ -253,7 +253,7 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long second_dest;

if (__get_word(ldq_u, second, src+1))
- return 0;
+ return CSUM_FAULT;
extql(first, soff, word);
checksum += carry;
len -= 8;
@@ -275,7 +275,7 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long second_dest;

if (__get_word(ldq_u, second, lastsrc))
- return 0;
+ return CSUM_FAULT;
extql(first, soff, word);
extqh(second, soff, first);
word |= first;
@@ -297,7 +297,7 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long second_dest;

if (__get_word(ldq_u, second, lastsrc))
- return 0;
+ return CSUM_FAULT;
extql(first, soff, word);
extqh(second, soff, first);
word |= first;
@@ -310,22 +310,21 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
stq_u(partial_dest | word | second_dest, dst);
checksum += carry;
}
- return checksum;
+ return from64to16 (checksum);
}

-static __wsum __csum_and_copy(const void __user *src, void *dst, int len)
+static __wsum_fault __csum_and_copy(const void __user *src, void *dst, int len)
{
unsigned long soff = 7 & (unsigned long) src;
unsigned long doff = 7 & (unsigned long) dst;
- unsigned long checksum;

if (!doff) {
if (!soff)
- checksum = csum_partial_cfu_aligned(
+ return csum_partial_cfu_aligned(
(const unsigned long __user *) src,
(unsigned long *) dst, len-8);
else
- checksum = csum_partial_cfu_dest_aligned(
+ return csum_partial_cfu_dest_aligned(
(const unsigned long __user *) src,
(unsigned long *) dst,
soff, len-8);
@@ -333,31 +332,28 @@ static __wsum __csum_and_copy(const void __user *src, void *dst, int len)
unsigned long partial_dest;
ldq_u(partial_dest, dst);
if (!soff)
- checksum = csum_partial_cfu_src_aligned(
+ return csum_partial_cfu_src_aligned(
(const unsigned long __user *) src,
(unsigned long *) dst,
doff, len-8, partial_dest);
else
- checksum = csum_partial_cfu_unaligned(
+ return csum_partial_cfu_unaligned(
(const unsigned long __user *) src,
(unsigned long *) dst,
soff, doff, len-8, partial_dest);
}
- return (__force __wsum)from64to16 (checksum);
}

-__wsum
-csum_and_copy_from_user(const void __user *src, void *dst, int len)
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
if (!access_ok(src, len))
- return 0;
+ return CSUM_FAULT;
return __csum_and_copy(src, dst, len);
}

-__wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len)
+__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return __csum_and_copy((__force const void __user *)src,
- dst, len);
+ return from_wsum_fault(__csum_and_copy((__force const void __user *)src,
+ dst, len));
}
EXPORT_SYMBOL(csum_partial_copy_nocheck);
diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
index d8a13959bff0..2b9bddb50967 100644
--- a/arch/arm/include/asm/checksum.h
+++ b/arch/arm/include/asm/checksum.h
@@ -38,16 +38,16 @@ __wsum csum_partial(const void *buff, int len, __wsum sum);
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len);

-__wsum
+__wsum_fault
csum_partial_copy_from_user(const void __user *src, void *dst, int len);

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
#define _HAVE_ARCH_CSUM_AND_COPY
static inline
-__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
if (!access_ok(src, len))
- return 0;
+ return -1;

return csum_partial_copy_from_user(src, dst, len);
}
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 82e96ac83684..d076a5c8556f 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -14,7 +14,7 @@
#include <linux/io.h>
#include <linux/arm-smccc.h>

-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/ftrace.h>

/*
diff --git a/arch/arm/lib/csumpartialcopygeneric.S b/arch/arm/lib/csumpartialcopygeneric.S
index 0fd5c10e90a7..5db935eaf165 100644
--- a/arch/arm/lib/csumpartialcopygeneric.S
+++ b/arch/arm/lib/csumpartialcopygeneric.S
@@ -86,7 +86,7 @@ sum .req r3

FN_ENTRY
save_regs
- mov sum, #-1
+ mov sum, #0

cmp len, #8 @ Ensure that we have at least
blo .Lless8 @ 8 bytes to copy.
@@ -160,6 +160,7 @@ FN_ENTRY
ldr sum, [sp, #0] @ dst
tst sum, #1
movne r0, r0, ror #8
+ mov r1, #0
load_regs

.Lsrc_not_aligned:
diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S
index 6928781e6bee..f273c9667914 100644
--- a/arch/arm/lib/csumpartialcopyuser.S
+++ b/arch/arm/lib/csumpartialcopyuser.S
@@ -73,11 +73,11 @@
#include "csumpartialcopygeneric.S"

/*
- * We report fault by returning 0 csum - impossible in normal case, since
- * we start with 0xffffffff for initial sum.
+ * We report fault by returning ~0ULL csum
*/
.pushsection .text.fixup,"ax"
.align 4
-9001: mov r0, #0
+9001: mov r0, #-1
+ mov r1, #-1
load_regs
.popsection
diff --git a/arch/ia64/include/asm/asm-prototypes.h b/arch/ia64/include/asm/asm-prototypes.h
index a96689447a74..41d23ab53ff4 100644
--- a/arch/ia64/include/asm/asm-prototypes.h
+++ b/arch/ia64/include/asm/asm-prototypes.h
@@ -3,7 +3,7 @@
#define _ASM_IA64_ASM_PROTOTYPES_H

#include <asm/cacheflush.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/esi.h>
#include <asm/ftrace.h>
#include <asm/page.h>
diff --git a/arch/m68k/include/asm/checksum.h b/arch/m68k/include/asm/checksum.h
index 692e7b6cc042..2adef06feeb3 100644
--- a/arch/m68k/include/asm/checksum.h
+++ b/arch/m68k/include/asm/checksum.h
@@ -32,7 +32,7 @@ __wsum csum_partial(const void *buff, int len, __wsum sum);

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
#define _HAVE_ARCH_CSUM_AND_COPY
-extern __wsum csum_and_copy_from_user(const void __user *src,
+extern __wsum_fault csum_and_copy_from_user(const void __user *src,
void *dst,
int len);

diff --git a/arch/m68k/lib/checksum.c b/arch/m68k/lib/checksum.c
index 5acb821849d3..4fed9070e976 100644
--- a/arch/m68k/lib/checksum.c
+++ b/arch/m68k/lib/checksum.c
@@ -128,7 +128,7 @@ EXPORT_SYMBOL(csum_partial);
* copy from user space while checksumming, with exception handling.
*/

-__wsum
+__wsum_fault
csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
/*
@@ -137,7 +137,7 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
* code.
*/
unsigned long tmp1, tmp2;
- __wsum sum = ~0U;
+ __wsum sum = 0;

__asm__("movel %2,%4\n\t"
"btst #1,%4\n\t" /* Check alignment */
@@ -240,7 +240,7 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
".even\n"
/* If any exception occurs, return 0 */
"90:\t"
- "clrl %0\n"
+ "moveq #1,%5\n"
"jra 7b\n"
".previous\n"
".section __ex_table,\"a\"\n"
@@ -262,7 +262,7 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
: "0" (sum), "1" (len), "2" (src), "3" (dst)
);

- return sum;
+ return tmp2 ? CSUM_FAULT : to_wsum_fault(sum);
}


diff --git a/arch/microblaze/kernel/microblaze_ksyms.c b/arch/microblaze/kernel/microblaze_ksyms.c
index c892e173ec99..e5858b15cd37 100644
--- a/arch/microblaze/kernel/microblaze_ksyms.c
+++ b/arch/microblaze/kernel/microblaze_ksyms.c
@@ -10,7 +10,7 @@
#include <linux/in6.h>
#include <linux/syscalls.h>

-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/cacheflush.h>
#include <linux/io.h>
#include <asm/page.h>
diff --git a/arch/mips/include/asm/asm-prototypes.h b/arch/mips/include/asm/asm-prototypes.h
index 8e8fc38b0941..44fd0c30fd73 100644
--- a/arch/mips/include/asm/asm-prototypes.h
+++ b/arch/mips/include/asm/asm-prototypes.h
@@ -1,11 +1,11 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm/checksum.h>
#include <asm/page.h>
#include <asm/fpu.h>
#include <asm-generic/asm-prototypes.h>
#include <linux/uaccess.h>
#include <asm/ftrace.h>
#include <asm/mmu_context.h>
+#include <net/checksum.h>

extern void clear_page_cpu(void *page);
extern void copy_page_cpu(void *to, void *from);
diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index 4044eaf989ac..3dfe9eca4adc 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -34,16 +34,16 @@
*/
__wsum csum_partial(const void *buff, int len, __wsum sum);

-__wsum __csum_partial_copy_from_user(const void __user *src, void *dst, int len);
-__wsum __csum_partial_copy_to_user(const void *src, void __user *dst, int len);
+__wsum_fault __csum_partial_copy_from_user(const void __user *src, void *dst, int len);
+__wsum_fault __csum_partial_copy_to_user(const void *src, void __user *dst, int len);

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
-__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
might_fault();
if (!access_ok(src, len))
- return 0;
+ return CSUM_FAULT;
return __csum_partial_copy_from_user(src, dst, len);
}

@@ -52,11 +52,11 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
*/
#define HAVE_CSUM_COPY_USER
static inline
-__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
+__wsum_fault csum_and_copy_to_user(const void *src, void __user *dst, int len)
{
might_fault();
if (!access_ok(dst, len))
- return 0;
+ return CSUM_FAULT;
return __csum_partial_copy_to_user(src, dst, len);
}

@@ -65,10 +65,10 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
* we have just one address space, so this is identical to the above)
*/
#define _HAVE_ARCH_CSUM_AND_COPY
-__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len);
+__wsum_fault __csum_partial_copy_nocheck(const void *src, void *dst, int len);
static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return __csum_partial_copy_nocheck(src, dst, len);
+ return from_wsum_fault(__csum_partial_copy_nocheck(src, dst, len));
}

/*
diff --git a/arch/mips/lib/csum_partial.S b/arch/mips/lib/csum_partial.S
index 3d2ff4118d79..b0cda2950f4e 100644
--- a/arch/mips/lib/csum_partial.S
+++ b/arch/mips/lib/csum_partial.S
@@ -437,7 +437,7 @@ EXPORT_SYMBOL(csum_partial)

.macro __BUILD_CSUM_PARTIAL_COPY_USER mode, from, to

- li sum, -1
+ move sum, zero
move odd, zero
/*
* Note: dst & src may be unaligned, len may be 0
@@ -723,6 +723,9 @@ EXPORT_SYMBOL(csum_partial)
1:
#endif
.set pop
+#ifndef CONFIG_64BIT
+ move v1, zero
+#endif
.set reorder
jr ra
.set noreorder
@@ -730,8 +733,11 @@ EXPORT_SYMBOL(csum_partial)

.set noreorder
.L_exc:
+#ifndef CONFIG_64BIT
+ li v1, -1
+#endif
jr ra
- li v0, 0
+ li v0, -1

FEXPORT(__csum_partial_copy_nocheck)
EXPORT_SYMBOL(__csum_partial_copy_nocheck)
diff --git a/arch/openrisc/kernel/or32_ksyms.c b/arch/openrisc/kernel/or32_ksyms.c
index 212e5f85004c..a56dea4411ab 100644
--- a/arch/openrisc/kernel/or32_ksyms.c
+++ b/arch/openrisc/kernel/or32_ksyms.c
@@ -22,7 +22,7 @@

#include <asm/processor.h>
#include <linux/uaccess.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/io.h>
#include <asm/hardirq.h>
#include <asm/delay.h>
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 274bce76f5da..c283183e5a81 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -11,7 +11,7 @@

#include <linux/threads.h>
#include <asm/cacheflush.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <linux/uaccess.h>
#include <asm/epapr_hcalls.h>
#include <asm/dcr.h>
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h
index 4b573a3b7e17..b68184dfac00 100644
--- a/arch/powerpc/include/asm/checksum.h
+++ b/arch/powerpc/include/asm/checksum.h
@@ -18,18 +18,18 @@
* Like csum_partial, this must be called with even lengths,
* except for the last fragment.
*/
-extern __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+extern __wsum_fault csum_partial_copy_generic(const void *src, void *dst, int len);

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
-extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
+extern __wsum_fault csum_and_copy_from_user(const void __user *src, void *dst,
int len);
#define HAVE_CSUM_COPY_USER
-extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
+extern __wsum_fault csum_and_copy_to_user(const void *src, void __user *dst,
int len);

#define _HAVE_ARCH_CSUM_AND_COPY
#define csum_partial_copy_nocheck(src, dst, len) \
- csum_partial_copy_generic((src), (dst), (len))
+ from_wsum_fault(csum_partial_copy_generic((src), (dst), (len)))


/*
diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index cd00b9bdd772..03f63f36aeba 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -122,7 +122,7 @@ LG_CACHELINE_BYTES = L1_CACHE_SHIFT
CACHELINE_MASK = (L1_CACHE_BYTES-1)

_GLOBAL(csum_partial_copy_generic)
- li r12,-1
+ li r12,0
addic r0,r0,0 /* clear carry */
addi r6,r4,-4
neg r0,r4
@@ -233,12 +233,14 @@ _GLOBAL(csum_partial_copy_generic)
slwi r0,r0,8
adde r12,r12,r0
66: addze r3,r12
+ li r4,0
beqlr+ cr7
rlwinm r3,r3,8,0,31 /* odd destination address: rotate one byte */
blr

fault:
- li r3,0
+ li r3,-1
+ li r4,-1
blr

EX_TABLE(70b, fault);
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S
index d53d8f09a2c2..3bbfeb98d256 100644
--- a/arch/powerpc/lib/checksum_64.S
+++ b/arch/powerpc/lib/checksum_64.S
@@ -208,7 +208,7 @@ EXPORT_SYMBOL(__csum_partial)
* csum_partial_copy_generic(r3=src, r4=dst, r5=len)
*/
_GLOBAL(csum_partial_copy_generic)
- li r6,-1
+ li r6,0
addic r0,r6,0 /* clear carry */

srdi. r6,r5,3 /* less than 8 bytes? */
@@ -406,7 +406,7 @@ dstnr; stb r6,0(r4)
ld r16,STK_REG(R16)(r1)
addi r1,r1,STACKFRAMESIZE
.Lerror_nr:
- li r3,0
+ li r3,-1
blr

EXPORT_SYMBOL(csum_partial_copy_generic)
diff --git a/arch/powerpc/lib/checksum_wrappers.c b/arch/powerpc/lib/checksum_wrappers.c
index 1a14c8780278..a23482b9f3f0 100644
--- a/arch/powerpc/lib/checksum_wrappers.c
+++ b/arch/powerpc/lib/checksum_wrappers.c
@@ -8,16 +8,16 @@
#include <linux/export.h>
#include <linux/compiler.h>
#include <linux/types.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <linux/uaccess.h>

-__wsum csum_and_copy_from_user(const void __user *src, void *dst,
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst,
int len)
{
- __wsum csum;
+ __wsum_fault csum;

if (unlikely(!user_read_access_begin(src, len)))
- return 0;
+ return CSUM_FAULT;

csum = csum_partial_copy_generic((void __force *)src, dst, len);

@@ -25,12 +25,12 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst,
return csum;
}

-__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
+__wsum_fault csum_and_copy_to_user(const void *src, void __user *dst, int len)
{
- __wsum csum;
+ __wsum_fault csum;

if (unlikely(!user_write_access_begin(dst, len)))
- return 0;
+ return CSUM_FAULT;

csum = csum_partial_copy_generic(src, (void __force *)dst, len);

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 05e51666db03..9bfd434d31e6 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -28,7 +28,7 @@
#include <asm/cpcmd.h>
#include <asm/ebcdic.h>
#include <asm/sclp.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/debug.h>
#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c
index 6e1824141b29..44447e3fef84 100644
--- a/arch/s390/kernel/os_info.c
+++ b/arch/s390/kernel/os_info.c
@@ -12,7 +12,7 @@
#include <linux/crash_dump.h>
#include <linux/kernel.h>
#include <linux/slab.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
#include <asm/maccess.h>
diff --git a/arch/sh/include/asm/checksum_32.h b/arch/sh/include/asm/checksum_32.h
index 2b5fa75b4651..94464451fd08 100644
--- a/arch/sh/include/asm/checksum_32.h
+++ b/arch/sh/include/asm/checksum_32.h
@@ -31,7 +31,7 @@ asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
* better 64-bit) boundary
*/

-asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+asmlinkage __wsum_fault csum_partial_copy_generic(const void *src, void *dst, int len);

#define _HAVE_ARCH_CSUM_AND_COPY
/*
@@ -44,15 +44,15 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len)
static inline
__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return csum_partial_copy_generic(src, dst, len);
+ return from_wsum_fault(csum_partial_copy_generic(src, dst, len));
}

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
-__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
if (!access_ok(src, len))
- return 0;
+ return CSUM_FAULT;
return csum_partial_copy_generic((__force const void *)src, dst, len);
}

@@ -193,12 +193,12 @@ static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
-static inline __wsum csum_and_copy_to_user(const void *src,
+static inline __wsum_fault csum_and_copy_to_user(const void *src,
void __user *dst,
int len)
{
if (!access_ok(dst, len))
- return 0;
+ return CSUM_FAULT;
return csum_partial_copy_generic(src, (__force void *)dst, len);
}
#endif /* __ASM_SH_CHECKSUM_H */
diff --git a/arch/sh/kernel/sh_ksyms_32.c b/arch/sh/kernel/sh_ksyms_32.c
index 5858936cb431..ce9d5547ac74 100644
--- a/arch/sh/kernel/sh_ksyms_32.c
+++ b/arch/sh/kernel/sh_ksyms_32.c
@@ -4,7 +4,7 @@
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/mm.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/sections.h>

EXPORT_SYMBOL(memchr);
diff --git a/arch/sh/lib/checksum.S b/arch/sh/lib/checksum.S
index 3e07074e0098..2d624efc4c2d 100644
--- a/arch/sh/lib/checksum.S
+++ b/arch/sh/lib/checksum.S
@@ -193,7 +193,7 @@ unsigned int csum_partial_copy_generic (const char *src, char *dst, int len)
! r6: int LEN
!
ENTRY(csum_partial_copy_generic)
- mov #-1,r7
+ mov #0,r7
mov #3,r0 ! Check src and dest are equally aligned
mov r4,r1
and r0,r1
@@ -358,8 +358,10 @@ EXC( mov.b r0,@r5 )
.section .fixup, "ax"

6001:
+ mov #-1,r1
rts
- mov #0,r0
+ mov #-1,r0
.previous
+ mov #0,r1
rts
mov r7,r0
diff --git a/arch/sparc/include/asm/asm-prototypes.h b/arch/sparc/include/asm/asm-prototypes.h
index 4987c735ff56..e15661bf8b36 100644
--- a/arch/sparc/include/asm/asm-prototypes.h
+++ b/arch/sparc/include/asm/asm-prototypes.h
@@ -4,7 +4,7 @@
*/

#include <asm/xor.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/trap_block.h>
#include <linux/uaccess.h>
#include <asm/atomic.h>
diff --git a/arch/sparc/include/asm/checksum_32.h b/arch/sparc/include/asm/checksum_32.h
index ce11e0ad80c7..751b89d827aa 100644
--- a/arch/sparc/include/asm/checksum_32.h
+++ b/arch/sparc/include/asm/checksum_32.h
@@ -50,7 +50,7 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len)

__asm__ __volatile__ (
"call __csum_partial_copy_sparc_generic\n\t"
- " mov -1, %%g7\n"
+ " clr %%g7\n"
: "=&r" (ret), "=&r" (d), "=&r" (l)
: "0" (ret), "1" (d), "2" (l)
: "o2", "o3", "o4", "o5", "o7",
@@ -59,20 +59,50 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len)
return (__force __wsum)ret;
}

-static inline __wsum
+static inline __wsum_fault
csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
+ register unsigned int ret asm("o0") = (unsigned int)src;
+ register char *d asm("o1") = dst;
+ register int l asm("g1") = len; // used to return an error
+
if (unlikely(!access_ok(src, len)))
- return 0;
- return csum_partial_copy_nocheck((__force void *)src, dst, len);
+ return CSUM_FAULT;
+
+ __asm__ __volatile__ (
+ "call __csum_partial_copy_sparc_generic\n\t"
+ " clr %%g7\n"
+ : "=&r" (ret), "=&r" (d), "=&r" (l)
+ : "0" (ret), "1" (d), "2" (l)
+ : "o2", "o3", "o4", "o5", "o7",
+ "g2", "g3", "g4", "g5", "g7",
+ "memory", "cc");
+ if (unlikely(l < 0))
+ return CSUM_FAULT;
+ return to_wsum_fault((__force __wsum)ret);
}

-static inline __wsum
+static inline __u64
csum_and_copy_to_user(const void *src, void __user *dst, int len)
{
- if (!access_ok(dst, len))
- return 0;
- return csum_partial_copy_nocheck(src, (__force void *)dst, len);
+ register unsigned int ret asm("o0") = (unsigned int)src;
+ register char *d asm("o1") = (__force void *)dst;
+ register int l asm("g1") = len; // used to return an error
+
+ if (unlikely(!access_ok(dst, len)))
+ return CSUM_FAULT;
+
+ __asm__ __volatile__ (
+ "call __csum_partial_copy_sparc_generic\n\t"
+ " clr %%g7\n"
+ : "=&r" (ret), "=&r" (d), "=&r" (l)
+ : "0" (ret), "1" (d), "2" (l)
+ : "o2", "o3", "o4", "o5", "o7",
+ "g2", "g3", "g4", "g5", "g7",
+ "memory", "cc");
+ if (unlikely(l < 0))
+ return CSUM_FAULT;
+ return to_wsum_fault((__force __wsum)ret);
}

/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
diff --git a/arch/sparc/include/asm/checksum_64.h b/arch/sparc/include/asm/checksum_64.h
index d6b59461e064..0e3041ca384b 100644
--- a/arch/sparc/include/asm/checksum_64.h
+++ b/arch/sparc/include/asm/checksum_64.h
@@ -39,8 +39,8 @@ __wsum csum_partial(const void * buff, int len, __wsum sum);
* better 64-bit) boundary
*/
__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
-__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
-__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len);
+__wsum_fault csum_and_copy_to_user(const void *src, void __user *dst, int len);

/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
* the majority of the time.
diff --git a/arch/sparc/lib/checksum_32.S b/arch/sparc/lib/checksum_32.S
index 84ad709cbecb..546968db199d 100644
--- a/arch/sparc/lib/checksum_32.S
+++ b/arch/sparc/lib/checksum_32.S
@@ -453,5 +453,5 @@ ccslow: cmp %g1, 0
* we only bother with faults on loads... */

cc_fault:
- ret
- clr %o0
+ retl
+ mov -1, %g1
diff --git a/arch/sparc/lib/csum_copy.S b/arch/sparc/lib/csum_copy.S
index f968e83bc93b..9312d51367d3 100644
--- a/arch/sparc/lib/csum_copy.S
+++ b/arch/sparc/lib/csum_copy.S
@@ -71,7 +71,7 @@
FUNC_NAME: /* %o0=src, %o1=dst, %o2=len */
LOAD(prefetch, %o0 + 0x000, #n_reads)
xor %o0, %o1, %g1
- mov -1, %o3
+ clr %o3
clr %o4
andcc %g1, 0x3, %g0
bne,pn %icc, 95f
diff --git a/arch/sparc/lib/csum_copy_from_user.S b/arch/sparc/lib/csum_copy_from_user.S
index b0ba8d4dd439..d74241692f0f 100644
--- a/arch/sparc/lib/csum_copy_from_user.S
+++ b/arch/sparc/lib/csum_copy_from_user.S
@@ -9,7 +9,7 @@
.section .fixup, "ax"; \
.align 4; \
99: retl; \
- mov 0, %o0; \
+ mov -1, %o0; \
.section __ex_table,"a";\
.align 4; \
.word 98b, 99b; \
diff --git a/arch/sparc/lib/csum_copy_to_user.S b/arch/sparc/lib/csum_copy_to_user.S
index 91ba36dbf7d2..2878a933d7ab 100644
--- a/arch/sparc/lib/csum_copy_to_user.S
+++ b/arch/sparc/lib/csum_copy_to_user.S
@@ -9,7 +9,7 @@
.section .fixup,"ax"; \
.align 4; \
99: retl; \
- mov 0, %o0; \
+ mov -1, %o0; \
.section __ex_table,"a";\
.align 4; \
.word 98b, 99b; \
diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
index b1a98fa38828..655e25745349 100644
--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -4,7 +4,7 @@
#include <linux/pgtable.h>
#include <asm/string.h>
#include <asm/page.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/mce.h>

#include <asm-generic/asm-prototypes.h>
diff --git a/arch/x86/include/asm/checksum_32.h b/arch/x86/include/asm/checksum_32.h
index 17da95387997..65ca3448e83d 100644
--- a/arch/x86/include/asm/checksum_32.h
+++ b/arch/x86/include/asm/checksum_32.h
@@ -27,7 +27,7 @@ asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
* better 64-bit) boundary
*/

-asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+asmlinkage __wsum_fault csum_partial_copy_generic(const void *src, void *dst, int len);

/*
* Note: when you get a NULL pointer exception here this means someone
@@ -38,17 +38,17 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len)
*/
static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return csum_partial_copy_generic(src, dst, len);
+ return from_wsum_fault(csum_partial_copy_generic(src, dst, len));
}

-static inline __wsum csum_and_copy_from_user(const void __user *src,
+static inline __wsum_fault csum_and_copy_from_user(const void __user *src,
void *dst, int len)
{
- __wsum ret;
+ __wsum_fault ret;

might_sleep();
if (!user_access_begin(src, len))
- return 0;
+ return CSUM_FAULT;
ret = csum_partial_copy_generic((__force void *)src, dst, len);
user_access_end();

@@ -168,15 +168,15 @@ static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
/*
* Copy and checksum to user
*/
-static inline __wsum csum_and_copy_to_user(const void *src,
+static inline __wsum_fault csum_and_copy_to_user(const void *src,
void __user *dst,
int len)
{
- __wsum ret;
+ __wsum_fault ret;

might_sleep();
if (!user_access_begin(dst, len))
- return 0;
+ return CSUM_FAULT;

ret = csum_partial_copy_generic(src, (__force void *)dst, len);
user_access_end();
diff --git a/arch/x86/include/asm/checksum_64.h b/arch/x86/include/asm/checksum_64.h
index 4d4a47a3a8ab..23c56eef8e47 100644
--- a/arch/x86/include/asm/checksum_64.h
+++ b/arch/x86/include/asm/checksum_64.h
@@ -129,10 +129,10 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
extern __wsum csum_partial(const void *buff, int len, __wsum sum);

/* Do not call this directly. Use the wrappers below */
-extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+extern __visible __wsum_fault csum_partial_copy_generic(const void *src, void *dst, int len);

-extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
-extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
+extern __wsum_fault csum_and_copy_from_user(const void __user *src, void *dst, int len);
+extern __wsum_fault csum_and_copy_to_user(const void *src, void __user *dst, int len);
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);

/**
diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index 23318c338db0..ab58a528d846 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -262,7 +262,7 @@ unsigned int csum_partial_copy_generic (const char *src, char *dst,

#define EXC(y...) \
9999: y; \
- _ASM_EXTABLE_TYPE(9999b, 7f, EX_TYPE_UACCESS | EX_FLAG_CLEAR_AX)
+ _ASM_EXTABLE_TYPE(9999b, 9f, EX_TYPE_UACCESS)

#ifndef CONFIG_X86_USE_PPRO_CHECKSUM

@@ -278,7 +278,7 @@ SYM_FUNC_START(csum_partial_copy_generic)
movl ARGBASE+4(%esp),%esi # src
movl ARGBASE+8(%esp),%edi # dst

- movl $-1, %eax # sum
+ xorl %eax,%eax # sum
testl $2, %edi # Check alignment.
jz 2f # Jump if alignment is ok.
subl $2, %ecx # Alignment uses up two bytes.
@@ -357,12 +357,17 @@ EXC( movb %cl, (%edi) )
6: addl %ecx, %eax
adcl $0, %eax
7:
-
+ xorl %edx, %edx
+8:
popl %ebx
popl %esi
popl %edi
popl %ecx # equivalent to addl $4,%esp
RET
+9:
+ movl $-1,%eax
+ movl $-1,%edx
+ jmp 8b
SYM_FUNC_END(csum_partial_copy_generic)

#else
@@ -388,7 +393,7 @@ SYM_FUNC_START(csum_partial_copy_generic)
movl ARGBASE+4(%esp),%esi #src
movl ARGBASE+8(%esp),%edi #dst
movl ARGBASE+12(%esp),%ecx #len
- movl $-1, %eax #sum
+ xorl %eax, %eax #sum
# movl %ecx, %edx
movl %ecx, %ebx
movl %esi, %edx
@@ -430,11 +435,16 @@ EXC( movb %dl, (%edi) )
6: addl %edx, %eax
adcl $0, %eax
7:
-
+ xorl %edx, %edx
+8:
popl %esi
popl %edi
popl %ebx
RET
+9:
+ movl $-1,%eax
+ movl $-1,%edx
+ jmp 8b
SYM_FUNC_END(csum_partial_copy_generic)

#undef ROUND
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S
index d9e16a2cf285..084181030dd3 100644
--- a/arch/x86/lib/csum-copy_64.S
+++ b/arch/x86/lib/csum-copy_64.S
@@ -44,7 +44,7 @@ SYM_FUNC_START(csum_partial_copy_generic)
movq %r13, 3*8(%rsp)
movq %r15, 4*8(%rsp)

- movl $-1, %eax
+ xorl %eax, %eax
xorl %r9d, %r9d
movl %edx, %ecx
cmpl $8, %ecx
@@ -249,8 +249,8 @@ SYM_FUNC_START(csum_partial_copy_generic)
roll $8, %eax
jmp .Lout

- /* Exception: just return 0 */
+ /* Exception: just return -1 */
.Lfault:
- xorl %eax, %eax
+ movq -1, %rax
jmp .Lout
SYM_FUNC_END(csum_partial_copy_generic)
diff --git a/arch/x86/lib/csum-partial_64.c b/arch/x86/lib/csum-partial_64.c
index cea25ca8b8cf..5e877592a7b3 100644
--- a/arch/x86/lib/csum-partial_64.c
+++ b/arch/x86/lib/csum-partial_64.c
@@ -8,7 +8,7 @@

#include <linux/compiler.h>
#include <linux/export.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/word-at-a-time.h>

static inline unsigned short from32to16(unsigned a)
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
index 145f9a0bde29..e90ac389a013 100644
--- a/arch/x86/lib/csum-wrappers_64.c
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -4,7 +4,7 @@
*
* Wrappers of assembly checksum functions for x86-64.
*/
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <asm/smap.h>
@@ -14,20 +14,18 @@
* @src: source address (user space)
* @dst: destination address
* @len: number of bytes to be copied.
- * @isum: initial sum that is added into the result (32bit unfolded)
- * @errp: set to -EFAULT for an bad source address.
*
- * Returns an 32bit unfolded checksum of the buffer.
+ * Returns an 32bit unfolded checksum of the buffer or -1ULL on error
* src and dst are best aligned to 64bits.
*/
-__wsum
+__wsum_fault
csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
- __wsum sum;
+ __wsum_fault sum;

might_sleep();
if (!user_access_begin(src, len))
- return 0;
+ return CSUM_FAULT;
sum = csum_partial_copy_generic((__force const void *)src, dst, len);
user_access_end();
return sum;
@@ -38,20 +36,18 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
* @src: source address
* @dst: destination address (user space)
* @len: number of bytes to be copied.
- * @isum: initial sum that is added into the result (32bit unfolded)
- * @errp: set to -EFAULT for an bad destination address.
*
- * Returns an 32bit unfolded checksum of the buffer.
+ * Returns an 32bit unfolded checksum of the buffer or -1ULL on error
* src and dst are best aligned to 64bits.
*/
-__wsum
+__wsum_fault
csum_and_copy_to_user(const void *src, void __user *dst, int len)
{
- __wsum sum;
+ __wsum_fault sum;

might_sleep();
if (!user_access_begin(dst, len))
- return 0;
+ return CSUM_FAULT;
sum = csum_partial_copy_generic(src, (void __force *)dst, len);
user_access_end();
return sum;
@@ -62,14 +58,13 @@ csum_and_copy_to_user(const void *src, void __user *dst, int len)
* @src: source address
* @dst: destination address
* @len: number of bytes to be copied.
- * @sum: initial sum that is added into the result (32bit unfolded)
*
* Returns an 32bit unfolded checksum of the buffer.
*/
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return csum_partial_copy_generic(src, dst, len);
+ return from_wsum_fault(csum_partial_copy_generic(src, dst, len));
}
EXPORT_SYMBOL(csum_partial_copy_nocheck);

diff --git a/arch/xtensa/include/asm/asm-prototypes.h b/arch/xtensa/include/asm/asm-prototypes.h
index b0da61812b85..b01b8170fafb 100644
--- a/arch/xtensa/include/asm/asm-prototypes.h
+++ b/arch/xtensa/include/asm/asm-prototypes.h
@@ -3,7 +3,7 @@
#define __ASM_PROTOTYPES_H

#include <asm/cacheflush.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/ftrace.h>
#include <asm/page.h>
#include <asm/string.h>
diff --git a/arch/xtensa/include/asm/checksum.h b/arch/xtensa/include/asm/checksum.h
index 44ec1d0b2a35..bf4ee4fd8f57 100644
--- a/arch/xtensa/include/asm/checksum.h
+++ b/arch/xtensa/include/asm/checksum.h
@@ -37,7 +37,7 @@ asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
* better 64-bit) boundary
*/

-asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+asmlinkage __wsum_fault csum_partial_copy_generic(const void *src, void *dst, int len);

#define _HAVE_ARCH_CSUM_AND_COPY
/*
@@ -47,16 +47,16 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len)
static inline
__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return csum_partial_copy_generic(src, dst, len);
+ return from_wsum_fault(csum_partial_copy_generic(src, dst, len));
}

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
-__wsum csum_and_copy_from_user(const void __user *src, void *dst,
+__wsum_fault csum_and_copy_from_user(const void __user *src, void *dst,
int len)
{
if (!access_ok(src, len))
- return 0;
+ return CSUM_FAULT;
return csum_partial_copy_generic((__force const void *)src, dst, len);
}

@@ -237,11 +237,11 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
-static __inline__ __wsum csum_and_copy_to_user(const void *src,
+static __inline__ __wsum_fault csum_and_copy_to_user(const void *src,
void __user *dst, int len)
{
if (!access_ok(dst, len))
- return 0;
+ return CSUM_FAULT;
return csum_partial_copy_generic(src, (__force void *)dst, len);
}
#endif
diff --git a/arch/xtensa/lib/checksum.S b/arch/xtensa/lib/checksum.S
index ffee6f94c8f8..71a70bed4618 100644
--- a/arch/xtensa/lib/checksum.S
+++ b/arch/xtensa/lib/checksum.S
@@ -192,7 +192,7 @@ unsigned int csum_partial_copy_generic (const char *src, char *dst, int len)
ENTRY(csum_partial_copy_generic)

abi_entry_default
- movi a5, -1
+ movi a5, 0
or a10, a2, a3

/* We optimize the following alignment tests for the 4-byte
@@ -311,6 +311,7 @@ EX(10f) s8i a9, a3, 0
ONES_ADD(a5, a9)
8:
mov a2, a5
+ movi a3, 0
abi_ret_default

5:
@@ -353,7 +354,8 @@ EXPORT_SYMBOL(csum_partial_copy_generic)
# Exception handler:
.section .fixup, "ax"
10:
- movi a2, 0
+ movi a2, -1
+ movi a3, -1
abi_ret_default

.previous
diff --git a/drivers/net/ethernet/brocade/bna/bnad.h b/drivers/net/ethernet/brocade/bna/bnad.h
index 627a93ce38ab..a3334ad8ecc8 100644
--- a/drivers/net/ethernet/brocade/bna/bnad.h
+++ b/drivers/net/ethernet/brocade/bna/bnad.h
@@ -19,8 +19,6 @@
#include <linux/firmware.h>
#include <linux/if_vlan.h>

-/* Fix for IA64 */
-#include <asm/checksum.h>
#include <net/ip6_checksum.h>

#include <net/ip.h>
diff --git a/drivers/net/ethernet/lantiq_etop.c b/drivers/net/ethernet/lantiq_etop.c
index f5961bdcc480..a6e88d673878 100644
--- a/drivers/net/ethernet/lantiq_etop.c
+++ b/drivers/net/ethernet/lantiq_etop.c
@@ -27,8 +27,6 @@
#include <linux/module.h>
#include <linux/property.h>

-#include <asm/checksum.h>
-
#include <lantiq_soc.h>
#include <xway_dma.h>
#include <lantiq_platform.h>
diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h
index 915aaf18c409..bef4cd73f06d 100644
--- a/drivers/net/vmxnet3/vmxnet3_int.h
+++ b/drivers/net/vmxnet3/vmxnet3_int.h
@@ -51,7 +51,6 @@
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/etherdevice.h>
-#include <asm/checksum.h>
#include <linux/if_vlan.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c
index bc3be0330f1d..bcbff216fa5f 100644
--- a/drivers/s390/char/zcore.c
+++ b/drivers/s390/char/zcore.c
@@ -27,7 +27,7 @@
#include <asm/debug.h>
#include <asm/processor.h>
#include <asm/irqflags.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <asm/os_info.h>
#include <asm/switch_to.h>
#include <asm/maccess.h>
diff --git a/include/net/checksum.h b/include/net/checksum.h
index 1338cb92c8e7..22c97902845d 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -16,8 +16,40 @@
#define _CHECKSUM_H

#include <linux/errno.h>
-#include <asm/types.h>
+#include <linux/bitops.h>
#include <asm/byteorder.h>
+
+typedef u64 __bitwise __wsum_fault;
+static inline __wsum_fault to_wsum_fault(__wsum v)
+{
+#if defined(CONFIG_64BIT) || defined(__LITTLE_ENDIAN__)
+ return (__force __wsum_fault)v;
+#else
+ return (__force __wsum_fault)((__force u64)v << 32);
+#endif
+}
+
+static inline __wsum_fault from_wsum_fault(__wsum v)
+{
+#if defined(CONFIG_64BIT) || defined(__LITTLE_ENDIAN__)
+ return (__force __wsum)v;
+#else
+ return (__force __wsum)((__force u64)v >> 32);
+#endif
+}
+
+static inline bool wsum_fault_check(__wsum_fault v)
+{
+#if defined(CONFIG_64BIT) || defined(__LITTLE_ENDIAN__)
+ return (__force s64)v < 0;
+#else
+ return (int)(__force u32)v < 0;
+#endif
+}
+
+#define CSUM_FAULT ((__force __wsum_fault)-1)
+
+
#include <asm/checksum.h>
#if !defined(_HAVE_ARCH_COPY_AND_CSUM_FROM_USER) || !defined(HAVE_CSUM_COPY_USER)
#include <linux/uaccess.h>
@@ -25,24 +57,24 @@

#ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static __always_inline
-__wsum csum_and_copy_from_user (const void __user *src, void *dst,
+__wsum_fault csum_and_copy_from_user (const void __user *src, void *dst,
int len)
{
if (copy_from_user(dst, src, len))
- return 0;
- return csum_partial(dst, len, ~0U);
+ return CSUM_FAULT;
+ return to_wsum_fault(csum_partial(dst, len, 0));
}
#endif

#ifndef HAVE_CSUM_COPY_USER
-static __always_inline __wsum csum_and_copy_to_user
+static __always_inline __wsum_fault csum_and_copy_to_user
(const void *src, void __user *dst, int len)
{
- __wsum sum = csum_partial(src, len, ~0U);
+ __wsum sum = csum_partial(src, len, 0);

if (copy_to_user(dst, src, len) == 0)
- return sum;
- return 0;
+ return to_wsum_fault(sum);
+ return CSUM_FAULT;
}
#endif

diff --git a/include/net/ip6_checksum.h b/include/net/ip6_checksum.h
index c8a96b888277..4666b9855263 100644
--- a/include/net/ip6_checksum.h
+++ b/include/net/ip6_checksum.h
@@ -25,7 +25,7 @@
#include <asm/types.h>
#include <asm/byteorder.h>
#include <net/ip.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>
#include <linux/in6.h>
#include <linux/tcp.h>
#include <linux/ipv6.h>
diff --git a/lib/checksum_kunit.c b/lib/checksum_kunit.c
index 0eed92b77ba3..971e7824893b 100644
--- a/lib/checksum_kunit.c
+++ b/lib/checksum_kunit.c
@@ -4,7 +4,7 @@
*/

#include <kunit/test.h>
-#include <asm/checksum.h>
+#include <net/checksum.h>

#define MAX_LEN 512
#define MAX_ALIGN 64
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 27234a820eeb..0da8f36ce341 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1184,15 +1184,16 @@ EXPORT_SYMBOL(iov_iter_get_pages_alloc2);
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
struct iov_iter *i)
{
- __wsum sum, next;
+ __wsum sum;
+ __wsum_fault next;
sum = *csum;
if (WARN_ON_ONCE(!i->data_source))
return 0;

iterate_and_advance(i, bytes, base, len, off, ({
next = csum_and_copy_from_user(base, addr + off, len);
- sum = csum_block_add(sum, next, off);
- next ? 0 : len;
+ sum = csum_block_add(sum, from_wsum_fault(next), off);
+ likely(!wsum_fault_check(next)) ? 0 : len;
}), ({
sum = csum_and_memcpy(addr + off, base, len, sum, off);
})
@@ -1206,7 +1207,8 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate,
struct iov_iter *i)
{
struct csum_state *csstate = _csstate;
- __wsum sum, next;
+ __wsum sum;
+ __wsum_fault next;

if (WARN_ON_ONCE(i->data_source))
return 0;
@@ -1222,8 +1224,8 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate,
sum = csum_shift(csstate->csum, csstate->off);
iterate_and_advance(i, bytes, base, len, off, ({
next = csum_and_copy_to_user(addr + off, base, len);
- sum = csum_block_add(sum, next, off);
- next ? 0 : len;
+ sum = csum_block_add(sum, from_wsum_fault(next), off);
+ likely(!wsum_fault_check(next)) ? 0 : len;
}), ({
sum = csum_and_memcpy(base, addr + off, len, sum, off);
})
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
index 377717045f8f..fce94af322ae 100644
--- a/net/ipv6/ip6_checksum.c
+++ b/net/ipv6/ip6_checksum.c
@@ -2,7 +2,7 @@
#include <net/ip.h>
#include <net/udp.h>
#include <net/udplite.h>
-#include <asm/checksum.h>
+#include <net/ip6_checksum.h>

#ifndef _HAVE_ARCH_IPV6_CSUM
__sum16 csum_ipv6_magic(const struct in6_addr *saddr,