linux-kernel - [PATCH v2 5/5] sparc: fix accurate exception reporting in copy_{from,to}

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250904-memcpy_series-v2-5-9806dd1784e7@mkarcher.dialup.fu-berlin.de>
Date: Thu, 04 Sep 2025 20:53:55 +0200
From: Michael Karcher <kernel@...rcher.dialup.fu-berlin.de>
To: Andreas Larsson <andreas@...sler.com>, 
 Babu Moger <babu.moger@...cle.com>
Cc: sparclinux@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Michael Karcher <kernel@...rcher.dialup.fu-berlin.de>, 
 John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>, 
 Anthony Yznaga <anthony.yznaga@...cle.com>
Subject: [PATCH v2 5/5] sparc: fix accurate exception reporting in
 copy_{from,to}_user for M7

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from                                               the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a couple of bad
calculations. This will fix the return value of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

Fixes: 34060b8fffa7 ("arch/sparc: Add accurate exception reporting in M7memcpy")

Tested-by: John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>
Signed-off-by: Michael Karcher <kernel@...rcher.dialup.fu-berlin.de>
---
 arch/sparc/lib/M7memcpy.S     | 20 ++++++++++----------
 arch/sparc/lib/Memcpy_utils.S |  9 +++++++++
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/arch/sparc/lib/M7memcpy.S b/arch/sparc/lib/M7memcpy.S
index cbd42ea7c3f7c25a369536eaf8d0b28a808ae5ba..99357bfa8e82ad7cf15dfd04117c89b905082f5b 100644
--- a/arch/sparc/lib/M7memcpy.S
+++ b/arch/sparc/lib/M7memcpy.S
@@ -696,16 +696,16 @@ FUNC_NAME:
 	EX_LD_FP(LOAD(ldd, %o4+40, %f26), memcpy_retl_o2_plus_o5_plus_40)
 	faligndata %f24, %f26, %f10
 	EX_ST_FP(STORE(std, %f6, %o0+24), memcpy_retl_o2_plus_o5_plus_40)
-	EX_LD_FP(LOAD(ldd, %o4+48, %f28), memcpy_retl_o2_plus_o5_plus_40)
+	EX_LD_FP(LOAD(ldd, %o4+48, %f28), memcpy_retl_o2_plus_o5_plus_32)
 	faligndata %f26, %f28, %f12
-	EX_ST_FP(STORE(std, %f8, %o0+32), memcpy_retl_o2_plus_o5_plus_40)
+	EX_ST_FP(STORE(std, %f8, %o0+32), memcpy_retl_o2_plus_o5_plus_32)
 	add	%o4, 64, %o4
-	EX_LD_FP(LOAD(ldd, %o4-8, %f30), memcpy_retl_o2_plus_o5_plus_40)
+	EX_LD_FP(LOAD(ldd, %o4-8, %f30), memcpy_retl_o2_plus_o5_plus_24)
 	faligndata %f28, %f30, %f14
-	EX_ST_FP(STORE(std, %f10, %o0+40), memcpy_retl_o2_plus_o5_plus_40)
-	EX_ST_FP(STORE(std, %f12, %o0+48), memcpy_retl_o2_plus_o5_plus_40)
+	EX_ST_FP(STORE(std, %f10, %o0+40), memcpy_retl_o2_plus_o5_plus_24)
+	EX_ST_FP(STORE(std, %f12, %o0+48), memcpy_retl_o2_plus_o5_plus_16)
 	add	%o0, 64, %o0
-	EX_ST_FP(STORE(std, %f14, %o0-8), memcpy_retl_o2_plus_o5_plus_40)
+	EX_ST_FP(STORE(std, %f14, %o0-8), memcpy_retl_o2_plus_o5_plus_8)
 	fsrc2	%f30, %f14
 	bgu,pt	%xcc, .Lunalign_sloop
 	 prefetch [%o4 + (8 * BLOCK_SIZE)], 20
@@ -728,7 +728,7 @@ FUNC_NAME:
 	add	%o4, 8, %o4
 	faligndata %f0, %f2, %f16
 	subcc	%o5, 8, %o5
-	EX_ST_FP(STORE(std, %f16, %o0), memcpy_retl_o2_plus_o5)
+	EX_ST_FP(STORE(std, %f16, %o0), memcpy_retl_o2_plus_o5_plus_8)
 	fsrc2	%f2, %f0
 	bgu,pt	%xcc, .Lunalign_by8
 	 add	%o0, 8, %o0
@@ -772,7 +772,7 @@ FUNC_NAME:
 	subcc	%o5, 0x20, %o5
 	EX_ST(STORE(stx, %o3, %o0 + 0x00), memcpy_retl_o2_plus_o5_plus_32)
 	EX_ST(STORE(stx, %g2, %o0 + 0x08), memcpy_retl_o2_plus_o5_plus_24)
-	EX_ST(STORE(stx, %g7, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_24)
+	EX_ST(STORE(stx, %g7, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_16)
 	EX_ST(STORE(stx, %o4, %o0 + 0x18), memcpy_retl_o2_plus_o5_plus_8)
 	bne,pt	%xcc, 1b
 	 add	%o0, 0x20, %o0
@@ -804,12 +804,12 @@ FUNC_NAME:
 	brz,pt	%o3, 2f
 	 sub	%o2, %o3, %o2
 
-1:	EX_LD(LOAD(ldub, %o1 + 0x00, %g2), memcpy_retl_o2_plus_g1)
+1:	EX_LD(LOAD(ldub, %o1 + 0x00, %g2), memcpy_retl_o2_plus_o3)
 	add	%o1, 1, %o1
 	subcc	%o3, 1, %o3
 	add	%o0, 1, %o0
 	bne,pt	%xcc, 1b
-	 EX_ST(STORE(stb, %g2, %o0 - 0x01), memcpy_retl_o2_plus_g1_plus_1)
+	 EX_ST(STORE(stb, %g2, %o0 - 0x01), memcpy_retl_o2_plus_o3_plus_1)
 2:
 	and	%o1, 0x7, %o3
 	brz,pn	%o3, .Lmedium_noprefetch_cp
diff --git a/arch/sparc/lib/Memcpy_utils.S b/arch/sparc/lib/Memcpy_utils.S
index 64fbac28b3db18864b0d067acaee0d7898feec7a..207343367bb2daa41a70398e20ef271116423b38 100644
--- a/arch/sparc/lib/Memcpy_utils.S
+++ b/arch/sparc/lib/Memcpy_utils.S
@@ -137,6 +137,15 @@ ENTRY(memcpy_retl_o2_plus_63_8)
 	ba,pt	%xcc, __restore_asi
 	 add	%o2, 8, %o0
 ENDPROC(memcpy_retl_o2_plus_63_8)
+ENTRY(memcpy_retl_o2_plus_o3)
+	ba,pt	%xcc, __restore_asi
+	 add	%o2, %o3, %o0
+ENDPROC(memcpy_retl_o2_plus_o3)
+ENTRY(memcpy_retl_o2_plus_o3_plus_1)
+	add	%o3, 1, %o3
+	ba,pt	%xcc, __restore_asi
+	 add	%o2, %o3, %o0
+ENDPROC(memcpy_retl_o2_plus_o3_plus_1)
 ENTRY(memcpy_retl_o2_plus_o5)
 	ba,pt	%xcc, __restore_asi
 	 add	%o2, %o5, %o0

-- 
2.50.1