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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 v2 10/20] m68k: get rid of zeroing destination on error in csum_and_copy_from_user()
Date: Fri, 24 Jul 2020 02:25:36 +0100	[thread overview]
Message-ID: <20200724012546.302155-10-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200724012546.302155-1-viro@ZenIV.linux.org.uk>

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

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/m68k/lib/checksum.c | 79 +++++++++---------------------------------------
 1 file changed, 15 insertions(+), 64 deletions(-)

diff --git a/arch/m68k/lib/checksum.c b/arch/m68k/lib/checksum.c
index 3aeca261f622..7e6afeae6217 100644
--- a/arch/m68k/lib/checksum.c
+++ b/arch/m68k/lib/checksum.c
@@ -236,82 +236,33 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
 		"clrl %5\n\t"
 		"addxl %5,%0\n\t"	/* add X bit */
 	     "7:\t"
-		"clrl %5\n"		/* no error - clear return value */
-	     "8:\n"
 		".section .fixup,\"ax\"\n"
 		".even\n"
-		/* If any exception occurs zero out the rest.
-		   Similarities with the code above are intentional :-) */
+		/* If any exception occurs, return 0 */
 	     "90:\t"
-		"clrw %3@+\n\t"
-		"movel %1,%4\n\t"
-		"lsrl #5,%1\n\t"
-		"jeq 1f\n\t"
-		"subql #1,%1\n"
-	     "91:\t"
-		"clrl %3@+\n"
-	     "92:\t"
-		"clrl %3@+\n"
-	     "93:\t"
-		"clrl %3@+\n"
-	     "94:\t"
-		"clrl %3@+\n"
-	     "95:\t"
-		"clrl %3@+\n"
-	     "96:\t"
-		"clrl %3@+\n"
-	     "97:\t"
-		"clrl %3@+\n"
-	     "98:\t"
-		"clrl %3@+\n\t"
-		"dbra %1,91b\n\t"
-		"clrw %1\n\t"
-		"subql #1,%1\n\t"
-		"jcc 91b\n"
-	     "1:\t"
-		"movel %4,%1\n\t"
-		"andw #0x1c,%4\n\t"
-		"jeq 1f\n\t"
-		"lsrw #2,%4\n\t"
-		"subqw #1,%4\n"
-	     "99:\t"
-		"clrl %3@+\n\t"
-		"dbra %4,99b\n\t"
-	     "1:\t"
-		"andw #3,%1\n\t"
-		"jeq 9f\n"
-	     "100:\t"
-		"clrw %3@+\n\t"
-		"tstw %1\n\t"
-		"jeq 9f\n"
-	     "101:\t"
-		"clrb %3@+\n"
-	     "9:\t"
-#define STR(X) STR1(X)
-#define STR1(X) #X
-		"moveq #-" STR(EFAULT) ",%5\n\t"
-		"jra 8b\n"
+		"clrl %0\n"
+		"jra 7b\n"
 		".previous\n"
 		".section __ex_table,\"a\"\n"
 		".long 10b,90b\n"
-		".long 11b,91b\n"
-		".long 12b,92b\n"
-		".long 13b,93b\n"
-		".long 14b,94b\n"
-		".long 15b,95b\n"
-		".long 16b,96b\n"
-		".long 17b,97b\n"
-		".long 18b,98b\n"
-		".long 19b,99b\n"
-		".long 20b,100b\n"
-		".long 21b,101b\n"
+		".long 11b,90b\n"
+		".long 12b,90b\n"
+		".long 13b,90b\n"
+		".long 14b,90b\n"
+		".long 15b,90b\n"
+		".long 16b,90b\n"
+		".long 17b,90b\n"
+		".long 18b,90b\n"
+		".long 19b,90b\n"
+		".long 20b,90b\n"
+		".long 21b,90b\n"
 		".previous"
 		: "=d" (sum), "=d" (len), "=a" (src), "=a" (dst),
 		  "=&d" (tmp1), "=d" (tmp2)
 		: "0" (sum), "1" (len), "2" (src), "3" (dst)
 	    );
 
-	return tmp2 ? 0 : sum;
+	return sum;
 }
 
 EXPORT_SYMBOL(csum_and_copy_from_user);
-- 
2.11.0

  parent reply	other threads:[~2020-07-24  1:25 UTC|newest]

Thread overview: 102+ 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     ` 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 20:25     ` 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
2020-07-21 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
2020-07-21 20:25   ` [PATCH 06/18] alpha: propagate the calling convention changes down to csum_partial_copy.c helpers Al Viro
2020-07-21 20:25     ` Al Viro
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     ` 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     ` 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
2020-07-21 20:25     ` 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     ` 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     ` 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
2020-07-21 20:25     ` 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     ` Al Viro
2020-07-21 20:25   ` [PATCH 18/18] ppc: propagate the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-21 20:25     ` 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       ` 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
2020-07-26  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  1:25       ` Al Viro
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       ` 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       ` 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     ` Al Viro [this message]
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       ` 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       ` 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       ` 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       ` 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       ` 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       ` 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       ` 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
2020-07-24  1:25       ` 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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