From nobody Tue Dec 16 11:05:15 2025 Received: from 009.lax.mailroute.net (009.lax.mailroute.net [199.89.1.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CAA751A9B58 for ; Thu, 6 Feb 2025 17:52:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738864356; cv=none; b=BqGpU4nKbg+CpTi40e3O0yG90E1EQkS8X2eTrM2rB2/fJRpW7YjDrtQi+oKf7Lfffz+QbO014NJ1gOu6jB8JONdChQA5v3p7Gy9Srz8HkWLlQ0SENk0qbXX1OxUzLYpFGA+JTvN6zflaF58HCWmEJvsJoohJwZQPy3C+9TbCrWU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738864356; c=relaxed/simple; bh=X3PlgX1yhKWIGV9xSdmzqvAcuP9HYUcLj0zeHJXqWTM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JbGrVFDQmEc4C/alxxbnzedr5vL79YqdFNKntaH8r4e+t+8Xy4e7s5OkMR2/fdQm1Tw4S5G22SLvPgAyNIW+GR1D/CoXnMR27nXIa3AqXkvhnTsvxluzoJ9f/LUAMKa6ZL3Y8idTuQdpUj9jMX5+NanLAeIDoRvCyapjwW5uFMw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=1eSk//BV; arc=none smtp.client-ip=199.89.1.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="1eSk//BV" Received: from localhost (localhost [127.0.0.1]) by 009.lax.mailroute.net (Postfix) with ESMTP id 4Ypl761y0gzlgTv0; Thu, 6 Feb 2025 17:52:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:mime-version:references:in-reply-to :x-mailer:message-id:date:date:subject:subject:from:from :received:received; s=mr01; t=1738864349; x=1741456350; bh=5zMoU NTxpBgVXmePaZw+7Qp6Z4XsLeU81MF8a5Spoo4=; b=1eSk//BVs3veS8aPqwAoP m8KOeTpzD3FDtssrPKs94nILk/y29fejr+jtSX0HS0z43Iww81A2/HlSL0oSQxg8 WxPUtPKPcAEB5/Uy8ssUfff9spy8CsCAAQj/Q1mwYvzCfWpQTZPcxzqOpIre+fcj 48cv09OOYT03eoQnHNqZm5ZWzXipsmSf4nzrTV3O5FHFgmZZdaauaRhviUa6gE7A F0Y7pGQVWtSUp6MYyOTDyQAjj/cfyj32WUtGGgP7ku41+ArcOjwucCk77rT4EllI 0Vt+2ft3jk2v22kQlQ1pbafH1LeG+aECGAvDS7Vh9eOntknlvOJgwW+xJ01ek0v2 g== X-Virus-Scanned: by MailRoute Received: from 009.lax.mailroute.net ([127.0.0.1]) by localhost (009.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id BW0B7O4JKL3T; Thu, 6 Feb 2025 17:52:29 +0000 (UTC) Received: from bvanassche.mtv.corp.google.com (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 009.lax.mailroute.net (Postfix) with ESMTPSA id 4Ypl6y5BLFzlgTy5; Thu, 6 Feb 2025 17:52:26 +0000 (UTC) From: Bart Van Assche To: Peter Zijlstra Cc: Will Deacon , Christoph Hellwig , Greg Kroah-Hartman , Marco Elver , Nick Desaulniers , Nathan Chancellor , Kees Cook , Jann Horn , linux-kernel@vger.kernel.org, Bart Van Assche , Sean Anderson , Tomi Valkeinen Subject: [PATCH RFC 24/33] drm: zynqmp_dp: Fix a deadlock in zynqmp_dp_ignore_hpd_set() Date: Thu, 6 Feb 2025 09:51:05 -0800 Message-ID: <20250206175114.1974171-25-bvanassche@acm.org> X-Mailer: git-send-email 2.48.1.502.g6dc24dfdaf-goog In-Reply-To: <20250206175114.1974171-1-bvanassche@acm.org> References: <20250206175114.1974171-1-bvanassche@acm.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Instead of attempting the same mutex twice, lock and unlock it. This bug has been detected by the Clang thread-safety analyzer. Cc: Sean Anderson Cc: Tomi Valkeinen Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance = testing") Signed-off-by: Bart Van Assche Reviewed-by: Sean Anderson --- drivers/gpu/drm/xlnx/zynqmp_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp= _dp.c index 979f6d3239ba..189a08cdc73c 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -2295,7 +2295,7 @@ static int zynqmp_dp_ignore_hpd_set(void *data, u64 v= al) =20 mutex_lock(&dp->lock); dp->ignore_hpd =3D val; - mutex_lock(&dp->lock); + mutex_unlock(&dp->lock); return 0; } =20