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From: Vineet Gupta <vineet.gupta@linux.dev>
To: "Thomas Gleixner" <tglx@kernel.org>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Borislav Petkov" <bp@alien8.de>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	x86@kernel.org, "Peter Zijlstra" <peterz@infradead.org>,
	"Juri Lelli" <juri.lelli@redhat.com>,
	"Vincent Guittot" <vincent.guittot@linaro.org>,
	"Joerg Roedel (AMD)" <joro@8bytes.org>,
	"Will Deacon" <will@kernel.org>,
	"Jani Nikula" <jani.nikula@linux.intel.com>,
	"Joonas Lahtinen" <joonas.lahtinen@linux.intel.com>,
	"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
	"Tvrtko Ursulin" <tursulin@ursulin.net>,
	"David Airlie" <airlied@gmail.com>,
	"Simona Vetter" <simona@ffwll.ch>,
	"Matthew Brost" <matthew.brost@intel.com>,
	"Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Vineet Gupta <vineet.gupta@linux.dev>,
	Robin Murphy <robin.murphy@arm.com>,
	iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] iommupt: Make PT_SUPPORTED_FEATURE() return 0 or 1
Date: Wed,  4 Nov 2026 08:07:20 -0800	[thread overview]
Message-ID: <20261104160722.1637541-4-vineet.gupta@linux.dev> (raw)
In-Reply-To: <20261104160722.1637541-1-vineet.gupta@linux.dev>

GCC 17 adds -Wconstant-logical-operand to -Wall. It warns when an operand
of && or || folds to a constant other than 0 or 1. PT_SUPPORTED_FEATURE()
returns the raw feature bit, and the fvalog2_*() helpers use it as an &&
operand. The build fails with CONFIG_WERROR=y:

  drivers/iommu/generic_pt/fmt/../pt_defs.h:255:51: error: use of logical '&&' with constant operand '2' [-Werror=constant-logical-operand]

clang has the same warning, but it checks only a constant right operand.

Compare the masked value against 0. All users test the result as a truth
value, so the behaviour does not change.

Signed-off-by: Vineet Gupta <vineet.gupta@linux.dev>
---
 drivers/iommu/generic_pt/pt_defs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/generic_pt/pt_defs.h b/drivers/iommu/generic_pt/pt_defs.h
index 707b3b0282fa..51a9c1c5fcc9 100644
--- a/drivers/iommu/generic_pt/pt_defs.h
+++ b/drivers/iommu/generic_pt/pt_defs.h
@@ -200,7 +200,7 @@ static inline bool pt_table_install32(struct pt_state *pts, u32 table_entry)
 	return ret;
 }
 
-#define PT_SUPPORTED_FEATURE(feature_nr) (PT_SUPPORTED_FEATURES & BIT(feature_nr))
+#define PT_SUPPORTED_FEATURE(feature_nr) ((PT_SUPPORTED_FEATURES & BIT(feature_nr)) != 0)
 
 static __always_inline bool pt_feature(const struct pt_common *common,
 			      unsigned int feature_nr)
-- 
2.53.0-Meta


  parent reply	other threads:[~2026-11-04 16:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-04 16:07 [PATCH 0/4] Fix the x86 defconfig build with GCC 17 Vineet Gupta
2026-11-04 16:07 ` [PATCH 1/4] x86/cpufeatures: Make {REQUIRED,DISABLED}_MASK_BIT_SET() return 0 or 1 Vineet Gupta
2026-11-04 16:07 ` [PATCH 2/4] wait: Make ___wait_is_interruptible() " Vineet Gupta
2026-11-04 16:07 ` Vineet Gupta [this message]
2026-11-04 16:07 ` [PATCH 4/4] drm/i915: Avoid -Wconstant-logical-operand with GCC 17 Vineet Gupta
2026-11-04 16:27 ` [PATCH 0/4] Fix the x86 defconfig build " Borislav Petkov
2026-11-04 18:05   ` Vineet Gupta
2026-11-04 21:18     ` Borislav Petkov

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