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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH 06/18] alpha: propagate the calling convention changes down to csum_partial_copy.c helpers
Date: Tue, 21 Jul 2020 21:25:37 +0100	[thread overview]
Message-ID: <20200721202549.4150745-6-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200721202549.4150745-1-viro@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

get rid of set_fs() in csum_partial_copy_nocheck(), while we are at it -
just take the part of csum_and_copy_from_user() sans the access_ok() check
into a helper function and have csum_partial_copy_nocheck() call that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/alpha/lib/csum_partial_copy.c | 157 ++++++++++++++++---------------------
 1 file changed, 69 insertions(+), 88 deletions(-)

diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c
index 3c0e89c39ddb..dc68efbe9367 100644
--- a/arch/alpha/lib/csum_partial_copy.c
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -39,12 +39,11 @@ __asm__ __volatile__("insql %1,%2,%0":"=r" (z):"r" (x),"r" (y))
 #define insqh(x,y,z) \
 __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
 
-
-#define __get_user_u(x,ptr)				\
+#define __get_word(insn,x,ptr)				\
 ({							\
 	long __guu_err;					\
 	__asm__ __volatile__(				\
-	"1:	ldq_u %0,%2\n"				\
+	"1:	"#insn" %0,%2\n"			\
 	"2:\n"						\
 	EXC(1b,2b,%0,%1)				\
 		: "=r"(x), "=r"(__guu_err)		\
@@ -52,19 +51,6 @@ __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
 	__guu_err;					\
 })
 
-#define __put_user_u(x,ptr)				\
-({							\
-	long __puu_err;					\
-	__asm__ __volatile__(				\
-	"1:	stq_u %2,%1\n"				\
-	"2:\n"						\
-	EXC(1b,2b,$31,%0)				\
-		: "=r"(__puu_err)			\
-		: "m"(__m(addr)), "rJ"(x), "0"(0));	\
-	__puu_err;					\
-})
-
-
 static inline unsigned short from64to16(unsigned long x)
 {
 	/* Using extract instructions is a bit more efficient
@@ -95,15 +81,15 @@ static inline unsigned short from64to16(unsigned long x)
  */
 static inline unsigned long
 csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
-			 long len, unsigned long checksum,
-			 int *errp)
+			 long len)
 {
+	unsigned long checksum = ~0U;
 	unsigned long carry = 0;
-	int err = 0;
 
 	while (len >= 0) {
 		unsigned long word;
-		err |= __get_user(word, src);
+		if (__get_word(ldq, word, src))
+			return 0;
 		checksum += carry;
 		src++;
 		checksum += word;
@@ -116,7 +102,8 @@ csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
 	checksum += carry;
 	if (len) {
 		unsigned long word, tmp;
-		err |= __get_user(word, src);
+		if (__get_word(ldq, word, src))
+			return 0;
 		tmp = *dst;
 		mskql(word, len, word);
 		checksum += word;
@@ -125,7 +112,6 @@ csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
 		*dst = word | tmp;
 		checksum += carry;
 	}
-	if (err && errp) *errp = err;
 	return checksum;
 }
 
@@ -137,20 +123,21 @@ static inline unsigned long
 csum_partial_cfu_dest_aligned(const unsigned long __user *src,
 			      unsigned long *dst,
 			      unsigned long soff,
-			      long len, unsigned long checksum,
-			      int *errp)
+			      long len)
 {
 	unsigned long first;
 	unsigned long word, carry;
 	unsigned long lastsrc = 7+len+(unsigned long)src;
-	int err = 0;
+	unsigned long checksum = ~0U;
 
-	err |= __get_user_u(first,src);
+	if (__get_word(ldq_u, first,src))
+		return 0;
 	carry = 0;
 	while (len >= 0) {
 		unsigned long second;
 
-		err |= __get_user_u(second, src+1);
+		if (__get_word(ldq_u, second, src+1))
+			return 0;
 		extql(first, soff, word);
 		len -= 8;
 		src++;
@@ -168,7 +155,8 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
 	if (len) {
 		unsigned long tmp;
 		unsigned long second;
-		err |= __get_user_u(second, lastsrc);
+		if (__get_word(ldq_u, second, lastsrc))
+			return 0;
 		tmp = *dst;
 		extql(first, soff, word);
 		extqh(second, soff, first);
@@ -180,7 +168,6 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
 		*dst = word | tmp;
 		checksum += carry;
 	}
-	if (err && errp) *errp = err;
 	return checksum;
 }
 
@@ -191,18 +178,18 @@ static inline unsigned long
 csum_partial_cfu_src_aligned(const unsigned long __user *src,
 			     unsigned long *dst,
 			     unsigned long doff,
-			     long len, unsigned long checksum,
-			     unsigned long partial_dest,
-			     int *errp)
+			     long len,
+			     unsigned long partial_dest)
 {
 	unsigned long carry = 0;
 	unsigned long word;
 	unsigned long second_dest;
-	int err = 0;
+	unsigned long checksum = ~0U;
 
 	mskql(partial_dest, doff, partial_dest);
 	while (len >= 0) {
-		err |= __get_user(word, src);
+		if (__get_word(ldq, word, src))
+			return 0;
 		len -= 8;
 		insql(word, doff, second_dest);
 		checksum += carry;
@@ -216,7 +203,8 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
 	len += 8;
 	if (len) {
 		checksum += carry;
-		err |= __get_user(word, src);
+		if (__get_word(ldq, word, src))
+			return 0;
 		mskql(word, len, word);
 		len -= 8;
 		checksum += word;
@@ -237,7 +225,6 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
 	stq_u(partial_dest | second_dest, dst);
 out:
 	checksum += carry;
-	if (err && errp) *errp = err;
 	return checksum;
 }
 
@@ -249,23 +236,23 @@ static inline unsigned long
 csum_partial_cfu_unaligned(const unsigned long __user * src,
 			   unsigned long * dst,
 			   unsigned long soff, unsigned long doff,
-			   long len, unsigned long checksum,
-			   unsigned long partial_dest,
-			   int *errp)
+			   long len, unsigned long partial_dest)
 {
 	unsigned long carry = 0;
 	unsigned long first;
 	unsigned long lastsrc;
-	int err = 0;
+	unsigned long checksum = ~0U;
 
-	err |= __get_user_u(first, src);
+	if (__get_word(ldq_u, first, src))
+		return 0;
 	lastsrc = 7+len+(unsigned long)src;
 	mskql(partial_dest, doff, partial_dest);
 	while (len >= 0) {
 		unsigned long second, word;
 		unsigned long second_dest;
 
-		err |= __get_user_u(second, src+1);
+		if (__get_word(ldq_u, second, src+1))
+			return 0;
 		extql(first, soff, word);
 		checksum += carry;
 		len -= 8;
@@ -286,7 +273,8 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
 		unsigned long second, word;
 		unsigned long second_dest;
 
-		err |= __get_user_u(second, lastsrc);
+		if (__get_word(ldq_u, second, lastsrc))
+			return 0;
 		extql(first, soff, word);
 		extqh(second, soff, first);
 		word |= first;
@@ -307,7 +295,8 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
 		unsigned long second, word;
 		unsigned long second_dest;
 
-		err |= __get_user_u(second, lastsrc);
+		if (__get_word(ldq_u, second, lastsrc))
+			return 0;
 		extql(first, soff, word);
 		extqh(second, soff, first);
 		word |= first;
@@ -320,63 +309,55 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
 		stq_u(partial_dest | word | second_dest, dst);
 		checksum += carry;
 	}
-	if (err && errp) *errp = err;
 	return checksum;
 }
 
-__wsum
-csum_and_copy_from_user(const void __user *src, void *dst, int len)
+static __wsum __csum_and_copy(const void __user *src, void *dst, int len)
 {
-	unsigned long checksum = ~0U;
 	unsigned long soff = 7 & (unsigned long) src;
 	unsigned long doff = 7 & (unsigned long) dst;
-	int err = 0;
-
-	if (len) {
-		if (!access_ok(src, len))
-			return 0;
-		if (!doff) {
-			if (!soff)
-				checksum = csum_partial_cfu_aligned(
-					(const unsigned long __user *) src,
-					(unsigned long *) dst,
-					len-8, checksum, &err);
-			else
-				checksum = csum_partial_cfu_dest_aligned(
-					(const unsigned long __user *) src,
-					(unsigned long *) dst,
-					soff, len-8, checksum, &err);
-		} else {
-			unsigned long partial_dest;
-			ldq_u(partial_dest, dst);
-			if (!soff)
-				checksum = csum_partial_cfu_src_aligned(
-					(const unsigned long __user *) src,
-					(unsigned long *) dst,
-					doff, len-8, checksum,
-					partial_dest, &err);
-			else
-				checksum = csum_partial_cfu_unaligned(
-					(const unsigned long __user *) src,
-					(unsigned long *) dst,
-					soff, doff, len-8, checksum,
-					partial_dest, &err);
-		}
-		checksum = err ? 0 : from64to16 (checksum);
+	unsigned long checksum;
+
+	if (!doff) {
+		if (!soff)
+			checksum = csum_partial_cfu_aligned(
+				(const unsigned long __user *) src,
+				(unsigned long *) dst, len-8);
+		else
+			checksum = csum_partial_cfu_dest_aligned(
+				(const unsigned long __user *) src,
+				(unsigned long *) dst,
+				soff, len-8);
+	} else {
+		unsigned long partial_dest;
+		ldq_u(partial_dest, dst);
+		if (!soff)
+			checksum = csum_partial_cfu_src_aligned(
+				(const unsigned long __user *) src,
+				(unsigned long *) dst,
+				doff, len-8, partial_dest);
+		else
+			checksum = csum_partial_cfu_unaligned(
+				(const unsigned long __user *) src,
+				(unsigned long *) dst,
+				soff, doff, len-8, partial_dest);
 	}
-	return (__force __wsum)checksum;
+	return (__force __wsum)from64to16 (checksum);
+}
+
+__wsum
+csum_and_copy_from_user(const void __user *src, void *dst, int len)
+{
+	if (!access_ok(src, len))
+		return 0;
+	return __csum_and_copy(src, dst, len);
 }
 EXPORT_SYMBOL(csum_and_copy_from_user);
 
 __wsum
 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,
+	return __csum_and_copy((__force const void __user *)src,
 						dst, len);
-	set_fs(oldfs);
-	return checksum;
 }
 EXPORT_SYMBOL(csum_partial_copy_nocheck);
-- 
2.11.0


  parent reply	other threads:[~2020-07-21 20:25 UTC|newest]

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21 20:24 [RFC][CFT][PATCHSET] saner calling conventions for csum-and-copy primitives Al Viro
2020-07-21 20:25 ` [PATCH 01/18] skb_copy_and_csum_bits(): don't bother with the last argument Al Viro
2020-07-21 20:25   ` [PATCH 02/18] icmp_push_reply(): reorder adding the checksum up Al Viro
2020-07-21 20:25   ` [PATCH 03/18] csum_partial_copy_nocheck(): drop the last argument Al Viro
2020-07-21 20:25   ` [PATCH 04/18] csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum Al Viro
2020-07-21 20:55     ` Linus Torvalds
2020-07-21 20:58       ` Linus Torvalds
2020-07-21 21:11         ` Al Viro
2020-07-21 21:16           ` Linus Torvalds
2020-07-25 17:54           ` Al Viro
2020-07-22  9:45       ` David Laight
2020-07-22  9:27     ` David Laight
2020-07-22 14:42       ` Al Viro
2020-07-22 15:22         ` David Laight
2020-07-22 15:54           ` Al Viro
2020-07-22 16:17             ` David Laight
2020-07-22 17:39               ` Al Viro
2020-07-23  8:29                 ` David Laight
2020-07-23 13:54                 ` David Laight
2020-07-23 14:30                   ` David Laight
2020-07-23 14:53                   ` Al Viro
2020-07-23 15:19                     ` David Laight
2020-07-23 15:21                     ` Al Viro
2020-07-23 15:36                       ` David Laight
2020-07-21 20:25   ` [PATCH 05/18] saner calling conventions for csum_and_copy_..._user() Al Viro
2020-07-21 20:25   ` Al Viro [this message]
2020-07-21 20:25   ` [PATCH 07/18] arm: propagate the calling convention changes down to csum_partial_copy_from_user() Al Viro
2020-07-21 20:25   ` [PATCH 08/18] m68k: get rid of zeroing destination on error in csum_and_copy_from_user() Al Viro
2020-07-21 20:25   ` [PATCH 09/18] sh: propage the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-21 20:25   ` [PATCH 10/18] i386: propagate " Al Viro
2020-07-21 20:25   ` [PATCH 11/18] sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic() Al Viro
2020-07-22  1:20     ` David Miller
2020-07-21 20:25   ` [PATCH 12/18] mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS Al Viro
2020-07-21 20:25   ` [PATCH 13/18] mips: __csum_partial_copy_kernel() has no users left Al Viro
2020-07-21 20:25   ` [PATCH 14/18] mips: propagate the calling convention change down into __csum_partial_copy_..._user() Al Viro
2020-07-21 20:25   ` [PATCH 15/18] xtensa: propagate the calling conventions change down into csum_partial_copy_generic() Al Viro
2020-07-22  8:56     ` Max Filippov
2020-07-21 20:25   ` [PATCH 16/18] sparc64: propagate the calling convention changes down to __csum_partial_copy_...() Al Viro
2020-07-22  1:21     ` David Miller
2020-07-21 20:25   ` [PATCH 17/18] amd64: switch csum_partial_copy_generic() to new calling conventions Al Viro
2020-07-21 20:25   ` [PATCH 18/18] ppc: propagate the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-24  1:25 ` [RFC][CFT][PATCHSET v2] saner calling conventions for csum-and-copy primitives Al Viro
2020-07-24  1:25   ` [PATCH v2 01/20] xtensa: fix access check in csum_and_copy_from_user Al Viro
2020-07-24  1:25     ` [PATCH v2 02/20] skb_copy_and_csum_bits(): don't bother with the last argument Al Viro
2020-07-24  1:25     ` [PATCH v2 03/20] icmp_push_reply(): reorder adding the checksum up Al Viro
2020-07-24  1:25     ` [PATCH v2 04/20] unify generic instances of csum_partial_copy_nocheck() Al Viro
2020-07-24  6:41       ` Christoph Hellwig
2020-07-24 12:19         ` Al Viro
2020-07-24 12:23           ` Christoph Hellwig
2020-07-24 12:30             ` Al Viro
2020-07-26  7:11               ` Christoph Hellwig
2020-07-27  3:58                 ` Al Viro
2020-07-24  1:25     ` [PATCH v2 05/20] csum_partial_copy_nocheck(): drop the last argument Al Viro
2020-07-24 12:21       ` kernel test robot
2020-07-24  1:25     ` [PATCH v2 06/20] csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum Al Viro
2020-07-24  1:25     ` [PATCH v2 07/20] saner calling conventions for csum_and_copy_..._user() Al Viro
2020-07-24  1:25     ` [PATCH v2 08/20] alpha: propagate the calling convention changes down to csum_partial_copy.c helpers Al Viro
2020-07-24  1:25     ` [PATCH v2 09/20] arm: propagate the calling convention changes down to csum_partial_copy_from_user() Al Viro
2020-07-24  1:25     ` [PATCH v2 10/20] m68k: get rid of zeroing destination on error in csum_and_copy_from_user() Al Viro
2020-07-24  1:25     ` [PATCH v2 11/20] sh: propage the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-24  1:25     ` [PATCH v2 12/20] i386: propagate " Al Viro
2020-07-24  1:25     ` [PATCH v2 13/20] sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic() Al Viro
2020-07-24  1:25     ` [PATCH v2 14/20] mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS Al Viro
2020-07-24  1:25     ` [PATCH v2 15/20] mips: __csum_partial_copy_kernel() has no users left Al Viro
2020-07-24  1:25     ` [PATCH v2 16/20] mips: propagate the calling convention change down into __csum_partial_copy_..._user() Al Viro
2020-07-24  1:25     ` [PATCH v2 17/20] xtensa: propagate the calling conventions change down into csum_partial_copy_generic() Al Viro
2020-07-24  1:25     ` [PATCH v2 18/20] sparc64: propagate the calling convention changes down to __csum_partial_copy_...() Al Viro
2020-07-24  1:25     ` [PATCH v2 19/20] amd64: switch csum_partial_copy_generic() to new calling conventions Al Viro
2020-07-24  1:25     ` [PATCH v2 20/20] ppc: propagate the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-10-14 22:26       ` Jason A. Donenfeld
2020-10-14 22:51         ` Linus Torvalds
2020-10-14 22:53           ` Linus Torvalds
2020-10-14 22:54             ` Jason A. Donenfeld
2020-10-14 22:53           ` Jason A. Donenfeld
2020-10-14 23:12           ` Al Viro
2020-10-14 23:02         ` [PATCH] powerpc32: don't adjust unmoved stack pointer in csum_partial_copy_generic() epilogue Jason A. Donenfeld
2020-10-14 23:05           ` Linus Torvalds

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