From patchwork Sat May 17 16:57:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Xin Li X-Patchwork-Id: 890910 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 0E6001D514F; Sat, 17 May 2025 16:57:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747501070; cv=none; b=u6ny8G8xKR2WHWBj/OMEVA0yKaQjjmWgBc5Atdh3yZFLW8Zjyot+ePM4EcqhN2kvPLMs6OPcIBVcfWZS0WvD55R0SvRd0tFVXfDBQS8537fktqIt2KLoJ95Ily4L3VLti2zgZrzOJ1fS9kPr2XS8st14duawMEHy0miWnwljNWo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747501070; c=relaxed/simple; bh=ygzNzs7UaCvsP0sFN3SdSeG6G3cRl9r+gxrWvNu9d0o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=deWKE2H6L97QhXvS5hlBxDpiUbo7h4RfbyggJdaLK15e3ZmNpFMrTY8KO98N/nPJTmMfzCCf9lCPsEGQGwAloVlnYmR7i4ROkH4aeodWU1/aP1Zxwyo7gs3Qg1v5qRJa4WYnQrbo8kb+iMqmNe6RUz28l/VuEg+nrhIWDXScoLE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=OYWedsLY; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="OYWedsLY" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 54HGvDhh935399 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sat, 17 May 2025 09:57:18 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 54HGvDhh935399 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025042001; t=1747501039; bh=mKRkOm6YCP44COro/tUSTMPHIOXwpBJTdxPBtiGGv34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OYWedsLYqMQmUpWqc2lx996Ra0psIm3b5PKqU86NwNH25aNWyIThMqo2+aNRuDOug B1CY58kCLHBpWGBl0T1HxmhtWReeJMNs8rsPm9o1GG8t67JuTKpzymKrmieoahJOdS TOqO3IMnQj/CrXNe879Sjb1ZilZ2/j9XWTakmjs3koC7vrgSeL/nPPgUkb6zuBW+E2 bSVwKohXIIesXQ58FjFp9XJnUD25RKDb3oAyZD2kHGEN27x07cSde3P9HrdTNVUlKv gLCdquuKYcnBd0aCK3drY1Cst2OvRwLvdn/z9ZSeVsC564kEFulFyZbIaENPQ9nP+A k0KUjSx4wKMfA== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org Cc: tglx@linutronix.de, mingo@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, peterz@infradead.org, jgross@suse.com, boris.ostrovsky@oracle.com, dan.carpenter@linaro.org, rafael@kernel.org, lenb@kernel.org Subject: [PATCH v1A 2/3] x86/xen/msr: Fix uninitialized symbol 'err' Date: Sat, 17 May 2025 09:57:12 -0700 Message-ID: <20250517165713.935384-1-xin@zytor.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 xen_read_msr_safe() currently passes an uninitialized argument err to xen_do_read_msr(). But as xen_do_read_msr() may not set the argument, xen_read_msr_safe() could return err with an unpredictable value. To ensure correctness, initialize err to 0 (representing success) in xen_read_msr_safe(). Do the same in xen_read_msr(), even err is not used after being passed to xen_do_read_msr(). Fixes: d815da84fdd0 ("x86/msr: Change the function type of native_read_msr_safe()" Reported-by: Dan Carpenter Closes: https://lore.kernel.org/xen-devel/aBxNI_Q0-MhtBSZG@stanley.mountain/ Signed-off-by: Xin Li (Intel) --- Change in v1A: *) Drop setting err to 0 in xen_do_read_msr() initially and set err to 0 in all callers (Jürgen Groß). --- arch/x86/xen/enlighten_pv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 7f9ded1bc707..26bbaf4b7330 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1162,7 +1162,7 @@ static void xen_do_write_msr(u32 msr, u64 val, int *err) static int xen_read_msr_safe(u32 msr, u64 *val) { - int err; + int err = 0; *val = xen_do_read_msr(msr, &err); return err; @@ -1179,7 +1179,7 @@ static int xen_write_msr_safe(u32 msr, u64 val) static u64 xen_read_msr(u32 msr) { - int err; + int err = 0; return xen_do_read_msr(msr, xen_msr_safe ? &err : NULL); }