From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 7AB7D10967 for ; Fri, 13 Oct 2023 09:06:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MO4lwK5u" Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0ECE495; Fri, 13 Oct 2023 02:06:43 -0700 (PDT) Received: by mail-ej1-x636.google.com with SMTP id a640c23a62f3a-9936b3d0286so309924266b.0; Fri, 13 Oct 2023 02:06:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697188001; x=1697792801; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=SYCXmUlUlbkeZWXSKQCOfZubKeGAvOpPkTEQglD2zzw=; b=MO4lwK5uxQrSjcQpT1uWzKPFcLAE3SwhNrVWPl9FYG8b+Bz0uoD+aQlLIs7UsFgwhz uHRFGMhGDRuTLIY1LLRoO3IhSa6mUh7LZct3/22gxPf5AvQim7wFtNlGu9ZHcXH3THzd UyStCf71qGxtygxe0vepjXTA9f34gvUiFhH25L5u3VP4hFjy3//FhTSWUEhNUxoNJXr2 oMsJT0jTphBUKURgTG6CK5BuUmd28TyqObVjadELpXoiPHXnl6zvnNoml/l0o/EA+7Wd 8nGhtRzHGPQyddZ3TxmTV1+VhqiYJy0FKqUnMO//mAzI2oLInXICEsVvoAY9l4T8XsQ5 hQGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697188001; x=1697792801; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=SYCXmUlUlbkeZWXSKQCOfZubKeGAvOpPkTEQglD2zzw=; b=mS0CR/8jDBqQXRhQ4mK85taU+mAa1FjH/f+iL4oqefPRczyto52YLV1Hi5jD1ShxqM E2EIQF57H/uVebRxYAxRlo+g+2+xkCXxttjwkQl+V82jtza9lkiCfNp0WAqV2P0sZfUU SYgaHxgzMHF0x868X19uZOt1z6BribwFQq2dLwu3Hsv5YXVik1387amSSnu8/pc3I+dQ 08rE4Rz+HyDBb3EGqVmxrEH8ZsC/NlNXsAcNZrTZfJaOLl6iamDYI0WAiYndjhp8OSi0 Cfr33g27cpE71rRxZkYi/bqVcADzuYqfkPCW+zQjKeALH3ys1goXBe7pq1uYizkhGsG5 9JDQ== X-Gm-Message-State: AOJu0YxuL1rwxFouon8Fmql1ErvWi6+ZXHOcMFThkg2ii/tQJR8/+VJM MCOX0jMeARcNCsPjbdAlHKU= X-Google-Smtp-Source: AGHT+IEVhYLxqSknJcU+xVT4VirzpyubA3VLnZK5A7fsOp0vNRceduxO+T0cVRzCujNZeWy7luf/2w== X-Received: by 2002:a17:906:31cc:b0:9ae:56da:6068 with SMTP id f12-20020a17090631cc00b009ae56da6068mr15949758ejf.57.1697188000823; Fri, 13 Oct 2023 02:06:40 -0700 (PDT) Received: from gmail.com (1F2EF405.nat.pool.telekom.hu. [31.46.244.5]) by smtp.gmail.com with ESMTPSA id lc11-20020a170906f90b00b009b9aa8fffdasm12051982ejb.131.2023.10.13.02.06.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Oct 2023 02:06:39 -0700 (PDT) Sender: Ingo Molnar Date: Fri, 13 Oct 2023 11:06:37 +0200 From: Ingo Molnar To: Dan Carpenter Cc: Sandipan Das , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Thomas Gleixner , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Uros Bizjak Subject: Re: [PATCH] perf/x86/amd/uncore: fix error codes in amd_uncore_init() Message-ID: References: <0c973a20-e10c-4989-b7d9-86cb0f522718@kadam.mountain> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0c973a20-e10c-4989-b7d9-86cb0f522718@kadam.mountain> X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net * Dan Carpenter wrote: > On Fri, Oct 13, 2023 at 09:30:46AM +0200, Ingo Molnar wrote: > > > Ugh, why on Earth didn't GCC warn about this? The bad pattern is pretty > > simple & obvious once pointed out ... compilers should have no trouble > > realizing that 'ret' is returned uninitialized in some of these control > > paths. Yet not a peep from the compiler ... > > We disabled that warning years ago (5?) because GCC had too many false > positives. GCC had some pretty bogus notions about 'possible' uninitialized use that encouraged some bad code patterns, but in this case there's readily provable uninitialized use, that a compiler should warn about. Is it possible to disable just the unreliable, probabilistic part of GCC's uninitialized variables warnings? Thanks, Ingo