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From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, James Hogan <james.hogan@imgtec.com>,
	linux-metag@vger.kernel.org
Subject: [PATCH 3.16 132/178] metag/usercopy: Set flags before ADDZ
Date: Sun, 16 Jul 2017 14:56:46 +0100	[thread overview]
Message-ID: <lsq.1500213406.254080623@decadent.org.uk> (raw)
In-Reply-To: <lsq.1500213404.466735591@decadent.org.uk>

3.16.46-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: James Hogan <james.hogan@imgtec.com>

commit fd40eee1290ad7add7aa665e3ce6b0f9fe9734b4 upstream.

The fixup code for the copy_to_user rapf loops reads TXStatus.LSM_STEP
to decide how far to rewind the source pointer. There is a special case
for the last execution of an MGETL/MGETD, since it leaves LSM_STEP=0
even though the number of MGETLs/MGETDs attempted was 4. This uses ADDZ
which is conditional upon the Z condition flag, but the AND instruction
which masked the TXStatus.LSM_STEP field didn't set the condition flags
based on the result.

Fix that now by using ANDS which does set the flags, and also marking
the condition codes as clobbered by the inline assembly.

Fixes: 373cd784d0fc ("metag: Memory handling")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 arch/metag/lib/usercopy.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/arch/metag/lib/usercopy.c
+++ b/arch/metag/lib/usercopy.c
@@ -315,7 +315,7 @@
 		"	.previous\n"					\
 		: "=r" (to), "=r" (from), "=r" (ret), "=d" (n)		\
 		: "0" (to), "1" (from), "2" (ret), "3" (n)		\
-		: "D1Ar1", "D0Ar2", "memory")
+		: "D1Ar1", "D0Ar2", "cc", "memory")
 
 /*	rewind 'to' and 'from'  pointers when a fault occurs
  *
@@ -341,7 +341,7 @@
 #define __asm_copy_to_user_64bit_rapf_loop(to,	from, ret, n, id)\
 	__asm_copy_user_64bit_rapf_loop(to, from, ret, n, id,		\
 		"LSR	D0Ar2, D0Ar2, #8\n"				\
-		"AND	D0Ar2, D0Ar2, #0x7\n"				\
+		"ANDS	D0Ar2, D0Ar2, #0x7\n"				\
 		"ADDZ	D0Ar2, D0Ar2, #4\n"				\
 		"SUB	D0Ar2, D0Ar2, #1\n"				\
 		"MOV	D1Ar1, #4\n"					\
@@ -486,7 +486,7 @@
 		"	.previous\n"					\
 		: "=r" (to), "=r" (from), "=r" (ret), "=d" (n)		\
 		: "0" (to), "1" (from), "2" (ret), "3" (n)		\
-		: "D1Ar1", "D0Ar2", "memory")
+		: "D1Ar1", "D0Ar2", "cc", "memory")
 
 /*	rewind 'to' and 'from'  pointers when a fault occurs
  *
@@ -512,7 +512,7 @@
 #define __asm_copy_to_user_32bit_rapf_loop(to, from, ret, n, id)\
 	__asm_copy_user_32bit_rapf_loop(to, from, ret, n, id,		\
 		"LSR	D0Ar2, D0Ar2, #8\n"				\
-		"AND	D0Ar2, D0Ar2, #0x7\n"				\
+		"ANDS	D0Ar2, D0Ar2, #0x7\n"				\
 		"ADDZ	D0Ar2, D0Ar2, #4\n"				\
 		"SUB	D0Ar2, D0Ar2, #1\n"				\
 		"MOV	D1Ar1, #4\n"					\


      parent reply	other threads:[~2017-07-16 13:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <lsq.1500213404.466735591@decadent.org.uk>
2017-07-16 13:56 ` [PATCH 3.16 134/178] metag/usercopy: Add missing fixups Ben Hutchings
2017-07-16 13:56 ` [PATCH 3.16 128/178] metag/usercopy: Drop unused macros Ben Hutchings
2017-07-16 13:56 ` [PATCH 3.16 130/178] metag/usercopy: Add early abort to copy_to_user Ben Hutchings
2017-07-16 13:56 ` [PATCH 3.16 129/178] metag/usercopy: Fix alignment error checking Ben Hutchings
2017-07-16 13:56 ` [PATCH 3.16 131/178] metag/usercopy: Zero rest of buffer from copy_from_user Ben Hutchings
2017-07-16 13:56 ` [PATCH 3.16 133/178] metag/usercopy: Fix src fixup in from user rapf loops Ben Hutchings
2017-07-16 13:56 ` Ben Hutchings [this message]

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