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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=BN0NA5oXxaJmgloA0bV1VuRl7DweslwGb9BXC5tlSZI=; b=AEYHubHeVg88ObpTpRE+qOA9RngXqEQBdO4sOGAC/NFbjj2g6aQrrm7rFfLYqYNC9X cNtL1bpLUuzpwEEg3dkf1HMFoQjbuerKNsCyWJIQ7jj1cikEByNcHsjRY6gWJBQd/mb8 JrY6eQ+3NoOl/sXt+DWEfPf59MDUgSd9SPZEfhyxPe5ZRZqt9lS74v9fm43lGJFtHEOU bx5I0btpNDamg7RLV5LQp4Q602oP/2guNyjqt+EgbBYcgmB3rOFmQ9tOqftmUvf/fBLN hIR1BjGh+xVDAInzyChjQhgPBUhb2arVdQoPoT8SlFczGfqHGWySllgDmmZPZCqi7dSF r6HQ== X-Gm-Message-State: AOAM533Tuewon7ld8rpIkf/zYwUeCnUQwJHthwJQEH6NxmXB3CTfLHNq /AgfuIkhmNmTgX8BJbojdiO9QV7bjdwaXK3vKWsujw== X-Google-Smtp-Source: ABdhPJzSzKsiHc4z7LwcmpkgMu0NbAbDQYhYcnmTB/97B33m/EUjE6lKfBun6ZCLEkmHQ8gJwyD1p9mb5gkpJj8C3R0= X-Received: by 2002:a17:902:724a:: with SMTP id c10mr6119344pll.223.1591298968901; Thu, 04 Jun 2020 12:29:28 -0700 (PDT) MIME-Version: 1.0 References: <20200603233203.1695403-1-keescook@chromium.org> <20200603233203.1695403-6-keescook@chromium.org> In-Reply-To: <20200603233203.1695403-6-keescook@chromium.org> From: Nick Desaulniers Date: Thu, 4 Jun 2020 12:29:17 -0700 Message-ID: Subject: Re: [PATCH 05/10] ide: Remove uninitialized_var() usage To: Kees Cook Cc: LKML , Linus Torvalds , Miguel Ojeda , 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 Memory Management List , clang-built-linux , Sebastian Andrzej Siewior Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: B5BA41803F9A5 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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: On Wed, Jun 3, 2020 at 4:32 PM 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 a precursor > to removing[2] this[3] macro[4], just remove this variable since it was > actually unused: > > drivers/ide/ide-taskfile.c:232:34: warning: unused variable 'flags' [-Wunused-variable] > unsigned long uninitialized_var(flags); > ^ > > [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/ > > Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers Fixes ce1e518190ea ("ide: don't disable interrupts during kmap_atomic()") > --- > drivers/ide/ide-taskfile.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c > index aab6a10435b6..a26f85ab58a9 100644 > --- a/drivers/ide/ide-taskfile.c > +++ b/drivers/ide/ide-taskfile.c > @@ -229,7 +229,6 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd, > ide_hwif_t *hwif = drive->hwif; > struct scatterlist *sg = hwif->sg_table; > struct scatterlist *cursg = cmd->cursg; > - unsigned long uninitialized_var(flags); > struct page *page; > unsigned int offset; > u8 *buf; > -- > 2.25.1 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200603233203.1695403-6-keescook%40chromium.org. -- Thanks, ~Nick Desaulniers