linux-kernel - [PATCH v2 25/52] m68k: apollo: Replace set but not used variable by READ

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: <d0299797d6bf747eca2da998c6c6256485a9f52e.1694613528.git.geert@linux-m68k.org>
Date:   Wed, 13 Sep 2023 16:08:15 +0200
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     linux-m68k@...ts.linux-m68k.org
Cc:     Arnd Bergmann <arnd@...db.de>, Finn Thain <fthain@...ux-m68k.org>,
        Michael Schmitz <schmitzmic@...il.com>,
        Philip Blundell <philb@....org>,
        Greg Ungerer <gerg@...ux-m68k.org>,
        Joshua Thompson <funaho@...ai.org>,
        Sam Creasey <sammy@...my.net>,
        Laurent Vivier <laurent@...ier.eu>,
        linux-kernel@...r.kernel.org,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Subject: [PATCH v2 25/52] m68k: apollo: Replace set but not used variable by READ_ONCE()

When building with W=1:

    arch/m68k/apollo/config.c: In function ‘dn_timer_int’:
    arch/m68k/apollo/config.c:171:32: warning: variable ‘x’ set but not used [-Wunused-but-set-variable]
      149 |         volatile unsigned char x;
	  |                                ^

Fix this by using READ_ONCE(), and removing the variable.
As READ_ONCE() casts to volatile internally, remove the existing cast.
Deduplicate the remaining casts by introducing an intermediary.

Signed-off-by: Geert Uytterhoeven <geert@...ux-m68k.org>
Acked-by: Arnd Bergmann <arnd@...db.de>
---
v2:
  - Add Acked-by,
  - Remove volatile and dedup casts, as suggested by Finn.
---
 arch/m68k/apollo/config.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/m68k/apollo/config.c b/arch/m68k/apollo/config.c
index 0e6801eecbaf6361..7afefb0191504d4e 100644
--- a/arch/m68k/apollo/config.c
+++ b/arch/m68k/apollo/config.c
@@ -146,13 +146,13 @@ void __init config_apollo(void)
 
 irqreturn_t dn_timer_int(int irq, void *dev_id)
 {
-	volatile unsigned char x;
+	unsigned char *at = (unsigned char *)apollo_timer;
 
 	legacy_timer_tick(1);
 	timer_heartbeat();
 
-	x = *(volatile unsigned char *)(apollo_timer + 3);
-	x = *(volatile unsigned char *)(apollo_timer + 5);
+	READ_ONCE(*(at + 3));
+	READ_ONCE(*(at + 5));
 
 	return IRQ_HANDLED;
 }
-- 
2.34.1