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s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MPLZOT/4bCsndxaWJtW6FhRuUjguIqCFp5N2dwDtYQ8=; b=YJ40Om8ooeECPyarO+NRadlTHoiG41QAQotfhhJzaOthNj+N5mE5DktPrXFysf5leJ DPPUosgBNHTktRSo92QwcTlERBcWPLhhh5jg6/doLFq+jni7klgZRaLHZgfC8q3X0n6M F4d5Bl2ZeEOW8iZ8XWW0u3jxPqzW0hfq6K+xM4dST/ceCl/ZbDe+iHpxx+ArC4e2Ixtw zi7Njn4FISB2gghyLUhwPpgvoH+YX3eykxGViHXGJd3+YC+FM2Rlu8pPDHRF9rrtS+hI Mf7wHRxmIGEtULDLDtzwSCum3o/+Q4XL3FMrrA9lPhHwe/bkYowb8WBTbKcrrlNpJUa3 xWog== X-Gm-Message-State: AOAM533WOl1dVH3J1ttCQ4vcpWC9LwvvBLMuKBU73Np9ozRNGXQH8BWZ N7MczWTKzWtygCh6GLChgaBVBYE+o7X7zwfvYqs= X-Google-Smtp-Source: ABdhPJziTNSuHWTzq2vssLq+q8Fk3g0gJzv6ZAQGOSjz3d+G2JKB1FM3MjsolLLYpNir2cIK2vJaKIQ5Hqvq0FlOkQ0= X-Received: by 2002:a05:651c:11c7:: with SMTP id z7mr899332ljo.29.1591231838573; Wed, 03 Jun 2020 17:50:38 -0700 (PDT) MIME-Version: 1.0 References: <20200603233203.1695403-1-keescook@chromium.org> <20200603233203.1695403-11-keescook@chromium.org> In-Reply-To: <20200603233203.1695403-11-keescook@chromium.org> From: Miguel Ojeda Date: Thu, 4 Jun 2020 02:50:27 +0200 Message-ID: Subject: Re: [PATCH 10/10] compiler: Remove uninitialized_var() macro To: Kees Cook Cc: linux-kernel , Linus Torvalds , Alexander Potapenko , Joe Perches , Andy Whitcroft , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, b43-dev@lists.infradead.org, Network Development , linux-wireless , linux-ide@vger.kernel.org, linux-clk@vger.kernel.org, linux-spi@vger.kernel.org, Linux-MM , clang-built-linux Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 736161814B0CC X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Kees, On Thu, Jun 4, 2020 at 1:32 AM Kees Cook wrote: > > Using uninitialized_var() is dangerous as it papers over real bugs[1] > (or can in the future), and suppresses unrelated compiler warnings > (e.g. "unused variable"). If the compiler thinks it is uninitialized, > either simply initialize the variable or make compiler changes. > > As recommended[2] by[3] Linus[4], remove the macro. > > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ > [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ > [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ > [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ > > Suggested-by: Linus Torvalds > Signed-off-by: Kees Cook > --- +1, one less trick split between `compiler*` files. Reviewed-by: Miguel Ojeda Cheers, Miguel