linux-kernel - [PATCH] m68k: Fix invalid RMW

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-next>] [day] [month] [year] [list]

Date:   Sun, 25 Jul 2021 12:44:13 +0200
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Greg Ungerer <gerg@...inux.org>
Cc:     kernel test robot <lkp@...el.com>, Arnd Bergmann <arnd@...db.de>,
        linux-m68k@...ts.linux-m68k.org, linux-kernel@...r.kernel.org,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Subject: [PATCH] m68k: Fix invalid RMW_INSNS on CPUs that lack CAS

When enabling CONFIG_RMW_INSNS in e.g. a Coldfire build:

    {standard input}:3068: Error: invalid instruction for this architecture; needs 68020 or higher (68020 [68k, 68ec020], 68030 [68ec030], 68040 [68ec040], 68060 [68ec060]) -- statement `casl %d4,%d0,(%a6)' ignored

Fix this by (a) adding a new config symbol to track if support for any
CPU that lacks the CAS instruction is enabled, and (b) making
CONFIG_RMW_INSNS depend on the new symbol not being set.

Fixes: 0e152d80507b75c0 ("m68k: reorganize Kconfig options to improve mmu/non-mmu selections")
Reported-by: kernel test robot <lkp@...el.com>
Reported-by: Arnd Bergmann <arnd@...db.de>
Signed-off-by: Geert Uytterhoeven <geert@...ux-m68k.org>
---
 arch/m68k/Kconfig.cpu | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 29e946394fdb4017..277d61a094637ce3 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -26,6 +26,7 @@ config COLDFIRE
 	bool "Coldfire CPU family support"
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select CPU_HAS_NO_BITFIELDS
+	select CPU_HAS_NO_CAS
 	select CPU_HAS_NO_MULDIV64
 	select GENERIC_CSUM
 	select GPIOLIB
@@ -39,6 +40,7 @@ config M68000
 	bool
 	depends on !MMU
 	select CPU_HAS_NO_BITFIELDS
+	select CPU_HAS_NO_CAS
 	select CPU_HAS_NO_MULDIV64
 	select CPU_HAS_NO_UNALIGNED
 	select GENERIC_CSUM
@@ -54,6 +56,7 @@ config M68000
 config MCPU32
 	bool
 	select CPU_HAS_NO_BITFIELDS
+	select CPU_HAS_NO_CAS
 	select CPU_HAS_NO_UNALIGNED
 	select CPU_NO_EFFICIENT_FFS
 	help
@@ -383,7 +386,7 @@ config ADVANCED
 
 config RMW_INSNS
 	bool "Use read-modify-write instructions"
-	depends on ADVANCED
+	depends on ADVANCED && !CPU_HAS_NO_CAS
 	help
 	  This allows to use certain instructions that work with indivisible
 	  read-modify-write bus cycles. While this is faster than the
@@ -450,6 +453,9 @@ config M68K_L2_CACHE
 config CPU_HAS_NO_BITFIELDS
 	bool
 
+config CPU_HAS_NO_CAS
+	bool
+
 config CPU_HAS_NO_MULDIV64
 	bool
 
-- 
2.25.1