From patchwork Mon May 12 08:45:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Xin Li \(Intel\)" X-Patchwork-Id: 889638 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 7F1B7259CB8; Mon, 12 May 2025 08:46:46 +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=1747039607; cv=none; b=CidgXhzMVtGpoKpTgsCLxCYFQL0sDNgIfsDHktDbsNjOS1KJ8DGnRA3lb0Z5TeTaXqhoPzAVYNH++fxf1BumneSHKX1X3Vojuey7AEQy5AEPPOviBeReJe323c746XsKFuu9TJFlUYqwgNk5aiXV4/rWj3uSEGH5M78Ke9D3yqc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747039607; c=relaxed/simple; bh=7rbfKiTxV4TmgxsREEclgvq00JGTvcvzpLtxrb7oD+4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VpXelDSqlDRtmdEf9ywPBDy1CsLDd0OuanTk92guqk7n6oyhn07HS7dpmDjiqMc7MRrvvI7E3dnx7ylperK+L4lt4NsLcVPd2WQG3g/PpAsqlV3txv+oFArB5HnRb2DIu+f7cdvWQGO74tPw6b+HgRw2MpOPyFIORMX/gjeBxS8= 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=bmWYvnwx; 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="bmWYvnwx" 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 54C8jqc61586901 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 12 May 2025 01:46:01 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 54C8jqc61586901 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025042001; t=1747039562; bh=r60JlXTos4KUiP7BNV4Mubm1J2LcZX1eO8iTOKbeekU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bmWYvnwxTU0pVJW4u5KvyhR8cTc1ILbP2oLLV6/74QxSidvlgisrmNIxqhqDAWxKZ TfRpxdQFxnaY6yhrR7m4LAqjzS1vvDMK3xmikiuu/o0qUX54thQc2j1Gjq2HQ4VNwr rQKjxAF2qcQOahokDI2/tvLM1hf8YVHZ+abqqiF51/1wliz8hXeqPJdAFOMveLB42B DSKDUbp1sv3q/sTl5Z8xcEzVErSlNqGYT1F1PLCScIypX4jxPqjgttEGM9q3tH7Gdv i3o5hUvLakD4MvXrM6mRnnF2KzfqtpiDMAQ8pAj28Y0O3oXTU0l3ue3PDx/tGmMrY1 Snn6b8NY550AQ== 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, rafael@kernel.org, lenb@kernel.org Subject: [PATCH v1 2/3] x86/xen/msr: Fix uninitialized symbol 'err' Date: Mon, 12 May 2025 01:45:51 -0700 Message-ID: <20250512084552.1586883-3-xin@zytor.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250512084552.1586883-1-xin@zytor.com> References: <20250512084552.1586883-1-xin@zytor.com> 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(). Because xen_read_msr_safe() is essentially a wrapper of xen_do_read_msr(), the latter should be responsible for initializing the value of *err to 0. Thus initialize *err to 0 in xen_do_read_msr(). Fixes: 502ad6e5a619 ("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) --- arch/x86/xen/enlighten_pv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 3be38350f044..01f1d441347e 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1091,6 +1091,9 @@ static u64 xen_do_read_msr(u32 msr, int *err) { u64 val = 0; /* Avoid uninitialized value for safe variant. */ + if (err) + *err = 0; + if (pmu_msr_chk_emulated(msr, &val, true)) return val; @@ -1162,7 +1165,7 @@ 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;