From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Nathan Chancellor <natechancellor@gmail.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Sasha Levin <sashal@kernel.org>,
linux-acpi@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH AUTOSEL 4.14 18/37] ACPI: fix false-positive -Wuninitialized warning
Date: Fri, 26 Jul 2019 09:43:13 -0400 [thread overview]
Message-ID: <20190726134332.12626-18-sashal@kernel.org> (raw)
In-Reply-To: <20190726134332.12626-1-sashal@kernel.org>
From: Arnd Bergmann <arnd@arndb.de>
[ Upstream commit dfd6f9ad36368b8dbd5f5a2b2f0a4705ae69a323 ]
clang gets confused by an uninitialized variable in what looks
to it like a never executed code path:
arch/x86/kernel/acpi/boot.c:618:13: error: variable 'polarity' is uninitialized when used here [-Werror,-Wuninitialized]
polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
^~~~~~~~
arch/x86/kernel/acpi/boot.c:606:32: note: initialize the variable 'polarity' to silence this warning
int rc, irq, trigger, polarity;
^
= 0
arch/x86/kernel/acpi/boot.c:617:12: error: variable 'trigger' is uninitialized when used here [-Werror,-Wuninitialized]
trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
^~~~~~~
arch/x86/kernel/acpi/boot.c:606:22: note: initialize the variable 'trigger' to silence this warning
int rc, irq, trigger, polarity;
^
= 0
This is unfortunately a design decision in clang and won't be fixed.
Changing the acpi_get_override_irq() macro to an inline function
reliably avoids the issue.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/acpi.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 13c105121a18..d7a9700b9333 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -324,7 +324,10 @@ void acpi_set_irq_model(enum acpi_irq_model_id model,
#ifdef CONFIG_X86_IO_APIC
extern int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity);
#else
-#define acpi_get_override_irq(gsi, trigger, polarity) (-1)
+static inline int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity)
+{
+ return -1;
+}
#endif
/*
* This function undoes the effect of one call to acpi_register_gsi().
--
2.20.1
prev parent reply other threads:[~2019-07-26 13:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190726134332.12626-1-sashal@kernel.org>
2019-07-26 13:43 ` [PATCH AUTOSEL 4.14 15/37] ACPI: blacklist: fix clang warning for unused DMI table Sasha Levin
2019-07-26 13:43 ` Sasha Levin [this message]
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