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From: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
To: linux-kernel@vger.kernel.org
Cc: sparclinux@vger.kernel.org,
	Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>,
	Andreas Larsson <andreas@gaisler.com>,
	John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
	Anthony Yznaga <anthony.yznaga@oracle.com>
Subject: [PATCH 2/4] sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III
Date: Tue, 26 Aug 2025 18:03:04 +0200	[thread overview]
Message-ID: <20250826160312.2070-3-kernel@mkarcher.dialup.fu-berlin.de> (raw)
In-Reply-To: <20250826160312.2070-1-kernel@mkarcher.dialup.fu-berlin.de>

Based on a finding by Anthony Yznaga that the UltraSPARC III copy_from_user
returns invalid values breaking other parts of the kernel in case of a
fault, while the generic implementation is correct.

Fixes: ee841d0aff64 ("sparc64: Convert U3copy_{from,to}_user to accurate exception reporting.")
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
---
 arch/sparc/lib/U3memcpy.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/sparc/lib/U3memcpy.S b/arch/sparc/lib/U3memcpy.S
index 9248d59c734c..bace3a18f836 100644
--- a/arch/sparc/lib/U3memcpy.S
+++ b/arch/sparc/lib/U3memcpy.S
@@ -267,6 +267,7 @@ FUNC_NAME:	/* %o0=dst, %o1=src, %o2=len */
 	faligndata	%f10, %f12, %f26
 	EX_LD_FP(LOAD(ldd, %o1 + 0x040, %f0), U3_retl_o2)
 
+	and		%o2, 0x3f, %o2
 	subcc		GLOBAL_SPARE, 0x80, GLOBAL_SPARE
 	add		%o1, 0x40, %o1
 	bgu,pt		%XCC, 1f
@@ -336,7 +337,6 @@ FUNC_NAME:	/* %o0=dst, %o1=src, %o2=len */
 	 * Also notice how this code is careful not to perform a
 	 * load past the end of the src buffer.
 	 */
-	and		%o2, 0x3f, %o2
 	andcc		%o2, 0x38, %g2
 	be,pn		%XCC, 2f
 	 subcc		%g2, 0x8, %g2
-- 
2.50.1


  parent reply	other threads:[~2025-08-26 16:03 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-26 16:03 Fix accurate exception reporting in SPARC assembly Michael Karcher
2025-08-26 16:03 ` [PATCH 1/4] sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC Michael Karcher
2025-08-29 10:53   ` John Paul Adrian Glaubitz
2025-09-02 16:33   ` Rene Rebe
2025-09-03 22:05   ` Jonathan Pallant
2025-08-26 16:03 ` Michael Karcher [this message]
2025-08-27  6:34   ` [PATCH 2/4] sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III John Paul Adrian Glaubitz
2025-08-28 15:53   ` John Paul Adrian Glaubitz
2025-08-30  1:57   ` Anthony Yznaga
2025-08-30  8:35     ` Michael Karcher
2025-09-04 14:05       ` Andreas Larsson
2025-09-04 14:14         ` Michael Karcher
2025-09-02 16:38   ` Rene Rebe
2025-08-26 16:03 ` [PATCH 3/4] sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara Michael Karcher
2025-08-29 21:44   ` John Paul Adrian Glaubitz
2025-09-02 16:40   ` Rene Rebe
2025-09-02 16:47     ` John Paul Adrian Glaubitz
2025-09-02 16:51       ` Rene Rebe
2025-09-02 16:53         ` John Paul Adrian Glaubitz
2025-09-02 17:04           ` Rene Rebe
2025-09-02 17:11             ` John Paul Adrian Glaubitz
2025-09-02 21:51           ` René Rebe
2025-09-05  8:04       ` Andreas Larsson
2025-09-05  9:02         ` John Paul Adrian Glaubitz
2025-09-04 18:36   ` Magnus Lindholm
2025-09-05  3:36     ` Ken Link
     [not found]     ` <CAPZdOsbQYRV=6D1Y62BZw2QH24tx0-+26n0yyG_YutvrocygiQ@mail.gmail.com>
2025-09-05  6:36       ` John Paul Adrian Glaubitz
2025-09-08  4:32   ` Ethan Hawke
2025-08-26 16:03 ` [PATCH 4/4] sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara 4 Michael Karcher
2025-08-27  6:37   ` John Paul Adrian Glaubitz
2025-08-28 20:21   ` John Paul Adrian Glaubitz
2025-08-29 13:24     ` Michael Karcher
2025-09-04 13:49 ` Fix accurate exception reporting in SPARC assembly Andreas Larsson
2025-09-04 17:21   ` John Paul Adrian Glaubitz

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