From cc44c17baf7f3f833d36b2f2a1edb1cc0b6f2cc4 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 11 Jul 2020 00:12:07 -0400
Subject: [PATCH] csum_partial_copy_nocheck(): drop the last argument

It's always 0.  Note that we theoretically could use ~0U as well -
result will be the same modulo 0xffff, _if_ the damn thing did the
right thing for any value of initial sum; later we'll make use of
that when convenient.

However, unlike csum_and_copy_..._user(), there are instances that
did not work for arbitrary initial sums; c6x is one such.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/alpha/include/asm/checksum.h    | 2 +-
 arch/alpha/lib/csum_partial_copy.c   | 4 ++--
 arch/arm/include/asm/checksum.h      | 2 +-
 arch/arm/lib/csumpartialcopy.S       | 5 +++--
 arch/c6x/include/asm/checksum.h      | 2 +-
 arch/c6x/lib/csum_64plus.S           | 4 +---
 arch/m68k/include/asm/checksum.h     | 3 +--
 arch/m68k/lib/checksum.c             | 3 ++-
 arch/mips/include/asm/checksum.h     | 7 +++++--
 arch/mips/lib/csum_partial.S         | 4 ++--
 arch/powerpc/include/asm/checksum.h  | 4 ++--
 arch/sh/include/asm/checksum_32.h    | 5 ++---
 arch/sparc/include/asm/checksum_32.h | 4 ++--
 arch/sparc/include/asm/checksum_64.h | 8 ++++++--
 arch/sparc/lib/csum_copy.S           | 2 +-
 arch/x86/include/asm/checksum_32.h   | 5 ++---
 arch/x86/include/asm/checksum_64.h   | 3 +--
 arch/x86/lib/csum-wrappers_64.c      | 4 ++--
 arch/xtensa/include/asm/checksum.h   | 5 ++---
 drivers/net/ethernet/3com/typhoon.c  | 3 +--
 include/net/checksum.h               | 4 ++--
 lib/iov_iter.c                       | 2 +-
 net/core/skbuff.c                    | 4 ++--
 net/ipv4/icmp.c                      | 2 +-
 net/ipv4/ip_output.c                 | 2 +-
 net/ipv4/raw.c                       | 2 +-
 net/ipv6/raw.c                       | 2 +-
 27 files changed, 49 insertions(+), 48 deletions(-)

diff --git a/arch/alpha/include/asm/checksum.h b/arch/alpha/include/asm/checksum.h
index 7e8e4fa4362d..84f9faea864a 100644
--- a/arch/alpha/include/asm/checksum.h
+++ b/arch/alpha/include/asm/checksum.h
@@ -45,7 +45,7 @@ extern __wsum csum_partial(const void *buff, int len, __wsum sum);
 #define _HAVE_ARCH_CSUM_AND_COPY
 __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *errp);
 
-__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
+__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 af1dad74e933..f363dc89fcbe 100644
--- a/arch/alpha/lib/csum_partial_copy.c
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -372,13 +372,13 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len,
 EXPORT_SYMBOL(csum_and_copy_from_user);
 
 __wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
 	__wsum checksum;
 	mm_segment_t oldfs = get_fs();
 	set_fs(KERNEL_DS);
 	checksum = csum_and_copy_from_user((__force const void __user *)src,
-						dst, len, sum, NULL);
+						dst, len, 0, NULL);
 	set_fs(oldfs);
 	return checksum;
 }
diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
index 53f769508540..7612b2bd4e9b 100644
--- a/arch/arm/include/asm/checksum.h
+++ b/arch/arm/include/asm/checksum.h
@@ -35,7 +35,7 @@ __wsum csum_partial(const void *buff, int len, __wsum sum);
  */
 
 __wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
+csum_partial_copy_nocheck(const void *src, void *dst, int len);
 
 __wsum
 csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);
diff --git a/arch/arm/lib/csumpartialcopy.S b/arch/arm/lib/csumpartialcopy.S
index 184d97254a7a..aab914fbc86b 100644
--- a/arch/arm/lib/csumpartialcopy.S
+++ b/arch/arm/lib/csumpartialcopy.S
@@ -9,13 +9,14 @@
 
 		.text
 
-/* Function: __u32 csum_partial_copy_nocheck(const char *src, char *dst, int len, __u32 sum)
- * Params  : r0 = src, r1 = dst, r2 = len, r3 = checksum
+/* Function: __u32 csum_partial_copy_nocheck(const char *src, char *dst, int len)
+ * Params  : r0 = src, r1 = dst, r2 = len
  * Returns : r0 = new checksum
  */
 
 		.macro	save_regs
 		stmfd	sp!, {r1, r4 - r8, lr}
+		mov	r3, #0
 		.endm
 
 		.macro	load_regs
diff --git a/arch/c6x/include/asm/checksum.h b/arch/c6x/include/asm/checksum.h
index fa31bdc186b2..934918def632 100644
--- a/arch/c6x/include/asm/checksum.h
+++ b/arch/c6x/include/asm/checksum.h
@@ -27,7 +27,7 @@ csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
 #define csum_tcpudp_nofold csum_tcpudp_nofold
 
 #define _HAVE_ARCH_CSUM_AND_COPY
-extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
+extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
 
 #include <asm-generic/checksum.h>
 
diff --git a/arch/c6x/lib/csum_64plus.S b/arch/c6x/lib/csum_64plus.S
index 9c07127485d1..57148866d8d3 100644
--- a/arch/c6x/lib/csum_64plus.S
+++ b/arch/c6x/lib/csum_64plus.S
@@ -24,7 +24,6 @@
 ENTRY(csum_partial_copy_nocheck)
 	MVC	.S2	ILC,B30
 
-	MV	.D1X	B6,A31		; given csum
 	ZERO	.D1	A9		; csum (a side)
 ||	ZERO	.D2	B9		; csum (b side)
 ||	SHRU	.S2X	A6,2,B5		; len / 4
@@ -144,8 +143,7 @@ L91:	SHRU	.S2X	A9,16,B4
 	SHRU	.S1	A9,16,A0
    [A0]	BNOP	.S1	L91,5
 
-L10:	ADD	.D1	A31,A9,A9
-	MV	.D1	A9,A4
+L10:	MV	.D1	A9,A4
 
 	BNOP	.S2	B3,4
 	MVC	.S2	B30,ILC
diff --git a/arch/m68k/include/asm/checksum.h b/arch/m68k/include/asm/checksum.h
index ab16881d84cb..d5e74c64b6cd 100644
--- a/arch/m68k/include/asm/checksum.h
+++ b/arch/m68k/include/asm/checksum.h
@@ -38,8 +38,7 @@ extern __wsum csum_and_copy_from_user(const void __user *src,
 						int *csum_err);
 
 extern __wsum csum_partial_copy_nocheck(const void *src,
-					      void *dst, int len,
-					      __wsum sum);
+					      void *dst, int len);
 
 /*
  *	This is a version of ip_fast_csum() optimized for IP headers,
diff --git a/arch/m68k/lib/checksum.c b/arch/m68k/lib/checksum.c
index 31797be9a3dc..86ddd2ee187d 100644
--- a/arch/m68k/lib/checksum.c
+++ b/arch/m68k/lib/checksum.c
@@ -324,9 +324,10 @@ EXPORT_SYMBOL(csum_and_copy_from_user);
  */
 
 __wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
 	unsigned long tmp1, tmp2;
+	__wsum sum = 0;
 	__asm__("movel %2,%4\n\t"
 		"btst #1,%4\n\t"	/* Check alignment */
 		"jeq 2f\n\t"
diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index abdf1086873d..ec3159dbc1b3 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -102,8 +102,11 @@ __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 sum);
+__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
+static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
+{
+	return __csum_partial_copy_nocheck(src, dst, len, 0);
+}
 
 /*
  *	Fold a partial checksum without adding pseudo headers
diff --git a/arch/mips/lib/csum_partial.S b/arch/mips/lib/csum_partial.S
index 87fda0713b84..8d70855b0914 100644
--- a/arch/mips/lib/csum_partial.S
+++ b/arch/mips/lib/csum_partial.S
@@ -462,8 +462,8 @@ EXPORT_SYMBOL(csum_partial)
 	lw	errptr, 16(sp)
 #endif
 	.if \__nocheck == 1
-	FEXPORT(csum_partial_copy_nocheck)
-	EXPORT_SYMBOL(csum_partial_copy_nocheck)
+	FEXPORT(__csum_partial_copy_nocheck)
+	EXPORT_SYMBOL(__csum_partial_copy_nocheck)
 	.endif
 	move	sum, zero
 	move	odd, zero
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h
index d75fc5bf8f37..64299785f639 100644
--- a/arch/powerpc/include/asm/checksum.h
+++ b/arch/powerpc/include/asm/checksum.h
@@ -30,8 +30,8 @@ extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
 				    int len, __wsum sum, int *err_ptr);
 
 #define _HAVE_ARCH_CSUM_AND_COPY
-#define csum_partial_copy_nocheck(src, dst, len, sum)   \
-        csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
+#define csum_partial_copy_nocheck(src, dst, len)   \
+        csum_partial_copy_generic((src), (dst), (len), 0, NULL, NULL)
 
 
 /*
diff --git a/arch/sh/include/asm/checksum_32.h b/arch/sh/include/asm/checksum_32.h
index 87269642d78d..e8bf84d3b843 100644
--- a/arch/sh/include/asm/checksum_32.h
+++ b/arch/sh/include/asm/checksum_32.h
@@ -43,10 +43,9 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
  *	access_ok().
  */
 static inline
-__wsum csum_partial_copy_nocheck(const void *src, void *dst,
-				 int len, __wsum sum)
+__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
-	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+	return csum_partial_copy_generic(src, dst, len, 0, NULL, NULL);
 }
 
 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
diff --git a/arch/sparc/include/asm/checksum_32.h b/arch/sparc/include/asm/checksum_32.h
index 479a0b812af5..d21d114436ba 100644
--- a/arch/sparc/include/asm/checksum_32.h
+++ b/arch/sparc/include/asm/checksum_32.h
@@ -42,7 +42,7 @@ __wsum csum_partial(const void *buff, int len, __wsum sum);
 unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
 
 static inline __wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
 	register unsigned int ret asm("o0") = (unsigned int)src;
 	register char *d asm("o1") = dst;
@@ -52,7 +52,7 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
 		"call __csum_partial_copy_sparc_generic\n\t"
 		" mov %6, %%g7\n"
 	: "=&r" (ret), "=&r" (d), "=&r" (l)
-	: "0" (ret), "1" (d), "2" (l), "r" (sum)
+	: "0" (ret), "1" (d), "2" (l), "r" (0)
 	: "o2", "o3", "o4", "o5", "o7",
 	  "g2", "g3", "g4", "g5", "g7",
 	  "memory", "cc");
diff --git a/arch/sparc/include/asm/checksum_64.h b/arch/sparc/include/asm/checksum_64.h
index 0fa4433f5662..7aebdbe3ac96 100644
--- a/arch/sparc/include/asm/checksum_64.h
+++ b/arch/sparc/include/asm/checksum_64.h
@@ -38,8 +38,12 @@ __wsum csum_partial(const void * buff, int len, __wsum sum);
  * here even more important to align src and dst on a 32-bit (or even
  * better 64-bit) boundary
  */
-__wsum csum_partial_copy_nocheck(const void *src, void *dst,
-				 int len, __wsum sum);
+__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
+
+static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
+{
+	return __csum_partial_copy_nocheck(src, dst, len, 0);
+}
 
 long __csum_partial_copy_from_user(const void __user *src,
 				   void *dst, int len,
diff --git a/arch/sparc/lib/csum_copy.S b/arch/sparc/lib/csum_copy.S
index 26c644ba3ecb..72c900d21b12 100644
--- a/arch/sparc/lib/csum_copy.S
+++ b/arch/sparc/lib/csum_copy.S
@@ -33,7 +33,7 @@
 #endif
 
 #ifndef FUNC_NAME
-#define FUNC_NAME	csum_partial_copy_nocheck
+#define FUNC_NAME	__csum_partial_copy_nocheck
 #endif
 
 	.register	%g2, #scratch
diff --git a/arch/x86/include/asm/checksum_32.h b/arch/x86/include/asm/checksum_32.h
index 11624c8a9d8d..137a3033edcc 100644
--- a/arch/x86/include/asm/checksum_32.h
+++ b/arch/x86/include/asm/checksum_32.h
@@ -38,10 +38,9 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
  *	If you use these functions directly please don't forget the
  *	access_ok().
  */
-static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst,
-					       int len, __wsum sum)
+static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
-	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+	return csum_partial_copy_generic(src, dst, len, 0, NULL, NULL);
 }
 
 static inline __wsum csum_and_copy_from_user(const void __user *src,
diff --git a/arch/x86/include/asm/checksum_64.h b/arch/x86/include/asm/checksum_64.h
index 0a289b87e872..5339f5dfc776 100644
--- a/arch/x86/include/asm/checksum_64.h
+++ b/arch/x86/include/asm/checksum_64.h
@@ -139,8 +139,7 @@ extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
 					  int len, __wsum isum, int *errp);
 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
 					int len, __wsum isum, int *errp);
-extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
-					int len, __wsum sum);
+extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
 
 /**
  * ip_compute_csum - Compute an 16bit IP checksum.
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
index ee63d7576fd2..245f929a1c2c 100644
--- a/arch/x86/lib/csum-wrappers_64.c
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -129,9 +129,9 @@ EXPORT_SYMBOL(csum_and_copy_to_user);
  * Returns an 32bit unfolded checksum of the buffer.
  */
 __wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
-	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+	return csum_partial_copy_generic(src, dst, len, 0, NULL, NULL);
 }
 EXPORT_SYMBOL(csum_partial_copy_nocheck);
 
diff --git a/arch/xtensa/include/asm/checksum.h b/arch/xtensa/include/asm/checksum.h
index 0c879099977f..dc09448935bf 100644
--- a/arch/xtensa/include/asm/checksum.h
+++ b/arch/xtensa/include/asm/checksum.h
@@ -47,10 +47,9 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
  *	passed in an incorrect kernel address to one of these functions.
  */
 static inline
-__wsum csum_partial_copy_nocheck(const void *src, void *dst,
-					int len, __wsum sum)
+__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
-	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+	return csum_partial_copy_generic(src, dst, len, 0, NULL, NULL);
 }
 
 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
diff --git a/drivers/net/ethernet/3com/typhoon.c b/drivers/net/ethernet/3com/typhoon.c
index d3b30bacc94e..049cc0158a64 100644
--- a/drivers/net/ethernet/3com/typhoon.c
+++ b/drivers/net/ethernet/3com/typhoon.c
@@ -1419,8 +1419,7 @@ typhoon_download_firmware(struct typhoon *tp)
 			 * the checksum, we can do this once, at the end.
 			 */
 			csum = csum_fold(csum_partial_copy_nocheck(image_data,
-								   dpage, len,
-								   0));
+								   dpage, len));
 
 			iowrite32(len, ioaddr + TYPHOON_REG_BOOT_LENGTH);
 			iowrite32(le16_to_cpu((__force __le16)csum),
diff --git a/include/net/checksum.h b/include/net/checksum.h
index db9d02b5f88a..1029191986e3 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -49,10 +49,10 @@ static __inline__ __wsum csum_and_copy_to_user
 
 #ifndef _HAVE_ARCH_CSUM_AND_COPY
 static inline __wsum
-csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+csum_partial_copy_nocheck(const void *src, void *dst, int len)
 {
 	memcpy(dst, src, len);
-	return csum_partial(dst, len, sum);
+	return csum_partial(dst, len, 0);
 }
 #endif
 
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5e40786c8f12..84f3a9156684 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -581,7 +581,7 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes,
 static __wsum csum_and_memcpy(void *to, const void *from, size_t len,
 			      __wsum sum, size_t off)
 {
-	__wsum next = csum_partial_copy_nocheck(from, to, len, 0);
+	__wsum next = csum_partial_copy_nocheck(from, to, len);
 	return csum_block_add(sum, next, off);
 }
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6e806da2913e..48dd4757b898 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2736,7 +2736,7 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
 		if (copy > len)
 			copy = len;
 		csum = csum_partial_copy_nocheck(skb->data + offset, to,
-						 copy, 0);
+						 copy);
 		if ((len -= copy) == 0)
 			return csum;
 		offset += copy;
@@ -2766,7 +2766,7 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
 				vaddr = kmap_atomic(p);
 				csum2 = csum_partial_copy_nocheck(vaddr + p_off,
 								  to + copied,
-								  p_len, 0);
+								  p_len);
 				kunmap_atomic(vaddr);
 				csum = csum_block_add(csum, csum2, pos);
 				pos += p_len;
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index e23dd5fc2e73..bdaaee52c41b 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -381,7 +381,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
 
 		csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
 						 (char *)icmph,
-						 icmp_param->head_len, 0);
+						 icmp_param->head_len);
 		skb_queue_walk(&sk->sk_write_queue, skb1) {
 			csum = csum_add(csum, skb1->csum);
 		}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 5bd059853376..bd79ea3e8c44 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1648,7 +1648,7 @@ static int ip_reply_glue_bits(void *dptr, char *to, int offset,
 {
 	__wsum csum;
 
-	csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0);
+	csum = csum_partial_copy_nocheck(dptr+offset, to, len);
 	skb->csum = csum_block_add(skb->csum, csum, odd);
 	return 0;
 }
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 6fd4330287c2..79392154c30a 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -478,7 +478,7 @@ static int raw_getfrag(void *from, char *to, int offset, int len, int odd,
 			skb->csum = csum_block_add(
 				skb->csum,
 				csum_partial_copy_nocheck(rfv->hdr.c + offset,
-							  to, copy, 0),
+							  to, copy),
 				odd);
 
 		odd = 0;
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 874f01cd7aec..6e4ab80a3b94 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -746,7 +746,7 @@ static int raw6_getfrag(void *from, char *to, int offset, int len, int odd,
 			skb->csum = csum_block_add(
 				skb->csum,
 				csum_partial_copy_nocheck(rfv->c + offset,
-							  to, copy, 0),
+							  to, copy),
 				odd);
 
 		odd = 0;