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From: Stefan Agner <stefan@agner.ch>
To: linux@armlinux.org.uk, ard.biesheuvel@linaro.org, arnd@arndb.de
Cc: nicolas.pitre@linaro.org, marc.zyngier@arm.com,
	behanw@converseincode.com, keescook@chromium.org,
	Bernhard.Rosenkranzer@linaro.org, mka@chromium.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Stefan Agner <stefan@agner.ch>
Subject: [PATCH 1/5] bus: arm-cci: use asm unreachable
Date: Wed, 21 Mar 2018 00:02:02 +0100	[thread overview]
Message-ID: <20180320230206.25289-2-stefan@agner.ch> (raw)
In-Reply-To: <20180320230206.25289-1-stefan@agner.ch>

Mixing asm and C code is not recommended in a naked function by
gcc and leads to an error when using clang:
  drivers/bus/arm-cci.c:2107:2: error: non-ASM statement in naked
  function is not supported
        unreachable();
        ^

Instead of using the unreachable() macro use the assember variant
ASM_UNREACHABLE.  This will no longer emit __builtin_unreachable(),
but since the function is naked and its return type is void it seems
not to have aversive effects.

Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 drivers/bus/arm-cci.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 5426c04fe24b..ee9da86fec47 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -2084,6 +2084,7 @@ asmlinkage void __naked cci_enable_port_for_self(void)
 
 "	mov	r0, #0 \n"
 "	bx	lr \n"
+	ASM_UNREACHABLE
 
 "	.align	2 \n"
 "5:	.word	cpu_port - . \n"
@@ -2103,8 +2104,6 @@ asmlinkage void __naked cci_enable_port_for_self(void)
 	[sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)),
 	[sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)),
 	[offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) );
-
-	unreachable();
 }
 
 /**
-- 
2.16.2

  reply	other threads:[~2018-03-20 23:02 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-20 23:02 [PATCH 0/5] ARM: clang support Stefan Agner
2018-03-20 23:02 ` Stefan Agner [this message]
2018-03-20 23:30   ` [PATCH 1/5] bus: arm-cci: use asm unreachable Russell King - ARM Linux
2018-03-21  8:22     ` Stefan Agner
2018-03-20 23:02 ` [PATCH 2/5] efi/libstub/arm: add support for building with clang Stefan Agner
2018-03-20 23:02 ` [PATCH 3/5] ARM: trusted_foundations: do not use naked function Stefan Agner
2018-03-20 23:13   ` Russell King - ARM Linux
2018-03-21  8:41     ` Stefan Agner
2018-03-21 12:13   ` Robin Murphy
2018-03-21 14:09     ` Stefan Agner
2018-03-21 15:26       ` Dmitry Osipenko
2018-03-21 16:40         ` Stephen Warren
2018-03-21 17:16           ` Robin Murphy
2018-03-21 21:41             ` Stefan Agner
2018-03-22 11:48               ` Robin Murphy
2018-03-22 12:43                 ` Stefan Agner
2018-03-22 14:03                   ` Dmitry Osipenko
2018-03-20 23:02 ` [PATCH 4/5] ARM: drop no-thumb-interwork in EABI mode Stefan Agner
2018-03-20 23:02 ` [PATCH 5/5] ARM: add support for building ARM kernel with clang Stefan Agner
2018-03-20 23:18   ` Russell King - ARM Linux
2018-03-21  0:20     ` Matthias Kaehlcke
2018-03-21  9:03       ` Stefan Agner
2018-03-25 13:24     ` Stefan Agner

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