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Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , tony.luck@intel.com, npmccallum@redhat.com, brijesh.ksingh@gmail.com Subject: Re: [PATCH Part1 RFC v4 15/36] x86/mm: Add support to validate memory when changing C-bit To: Borislav Petkov References: <20210707181506.30489-1-brijesh.singh@amd.com> <20210707181506.30489-16-brijesh.singh@amd.com> <162d75ca-f0ec-bb7e-bb47-70060772a52c@amd.com> From: Brijesh Singh Message-ID: Date: Tue, 17 Aug 2021 13:18:44 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SA9PR03CA0030.namprd03.prod.outlook.com (2603:10b6:806:20::35) To SN6PR12MB2718.namprd12.prod.outlook.com (2603:10b6:805:6f::22) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [10.236.31.95] (165.204.77.1) by SA9PR03CA0030.namprd03.prod.outlook.com (2603:10b6:806:20::35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4436.19 via Frontend Transport; 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>>> >>> Make that error message more distinctive so that *if* it happens, one >>> can pinpoint the place in the code where the panic comes from. >>> >> >> Now I am running checkpatch and notice that it complain about the message >> too. I can add a BUG() or WARN() to get the stack trace before the crashing. > > checkpatch complains because there's a kmalloc before it and if it > fails, the mm core will issue a warning so there's no need for a warning > here. > > But in this case, you want to panic and checkpatch doesn't see that so > you can ignore it here and leave the panic message but make it more > distinctive so one can find it by grepping. IOW, something like > > if (!desc) > panic("SEV-SNP: Failed to allocame memory for PSC descriptor"); > Got it, I will update the message accordingly. thanks