linux-kernel - [PATCH] ARM: kexec: drop invalid assembly argument

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:   Wed,  5 Feb 2020 23:59:26 +0100
From:   Stefan Agner <stefan@...er.ch>
To:     linux@...linux.org.uk
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        clang-built-linux@...glegroups.com, Stefan Agner <stefan@...er.ch>
Subject: [PATCH] ARM: kexec: drop invalid assembly argument

The tst menomic has only a single #<const> argument in Thumb mode. There
is an ARM variant which allows to write #<const> as #<byte>, #<rot>
which probably is where the current syntax comes from.

It seems that binutils does not care about the additional parameter.
Clang however complains in Thumb2 mode:
arch/arm/kernel/relocate_kernel.S:28:12: error: too many operands for
instruction
 tst r3,#1,0
           ^

Drop the unnecessary parameter. This fixes building this file in Thumb2
mode with the Clang integrated assembler.

Link: https://github.com/ClangBuiltLinux/linux/issues/770
Signed-off-by: Stefan Agner <stefan@...er.ch>
---
 arch/arm/kernel/relocate_kernel.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S
index 7eaa2ae7aff5..72a08786e16e 100644
--- a/arch/arm/kernel/relocate_kernel.S
+++ b/arch/arm/kernel/relocate_kernel.S
@@ -25,26 +25,26 @@ ENTRY(relocate_new_kernel)
 	ldr	r3, [r0],#4
 
 	/* Is it a destination page. Put destination address to r4 */
-	tst	r3,#1,0
+	tst	r3,#1
 	beq	1f
 	bic	r4,r3,#1
 	b	0b
 1:
 	/* Is it an indirection page */
-	tst	r3,#2,0
+	tst	r3,#2
 	beq	1f
 	bic	r0,r3,#2
 	b	0b
 1:
 
 	/* are we done ? */
-	tst	r3,#4,0
+	tst	r3,#4
 	beq	1f
 	b	2f
 
 1:
 	/* is it source ? */
-	tst	r3,#8,0
+	tst	r3,#8
 	beq	0b
 	bic r3,r3,#8
 	mov r6,#1024
-- 
2.25.0