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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=JchjGYZl0wqUOrU5YQvGeZV5DROtdtYOgYQQhEiIskY=; b=K8le81swJDw/DIdoH6yGzhJJZMxmzvRlDnaHaJmkbLQMroRJXRE8XiKSKvj3jNh5l7 1hf5a3YaTK9wkjof209pY0TbVGEltibohdcHrmWXVZwVIKOaYWpBnD+tBIrkrBX4L9dv hPqjtdibJ1RmiQyc9L1amH3dGZTHJKoP36hNn3MnseZpEhzxO055YkwXGhhMIlDmgv5F 1mArAQW2AIzxdtXinVjLahSDpPCq9wu9nGWPfe4iLsHAb141uhw7jKuvQcaaz3uVeYd1 MaKD2O8muYLh7a4zqdzN4LvUNJFwgTODOAsU83l0wj4vkl1hbjY6Qqao8HOXEZGWrTaD vNpA== X-Gm-Message-State: AOAM531OaRmSfPui7TRir3GVCs1kkfXiffo1DqbQN1QwNKMT/qknZiAs MXZ7VzfjTeSj0YtyTW3WfqdhsIY5vrKO2H7g4JbqfQ== X-Google-Smtp-Source: ABdhPJy7InXrusPAFFTJ9/oFSaSF0Eic2jn49VfP7aR0w5k1vGP4KYsGIQVm0HirYrhRu0SFvISfn3kdwUp620gXyHY= X-Received: by 2002:a63:f00d:: with SMTP id k13mr6167247pgh.263.1591300583418; Thu, 04 Jun 2020 12:56:23 -0700 (PDT) MIME-Version: 1.0 References: <20200603233203.1695403-1-keescook@chromium.org> <20200603233203.1695403-3-keescook@chromium.org> In-Reply-To: <20200603233203.1695403-3-keescook@chromium.org> From: Nick Desaulniers Date: Thu, 4 Jun 2020 12:56:11 -0700 Message-ID: Subject: Re: [PATCH 02/10] drbd: 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 Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 3EBFA10064AA7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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 initialize this variable to NULL. > > [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: a29728463b25 ("drbd: Backport the "events2" command") > --- > drivers/block/drbd/drbd_state.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c > index eeaa3b49b264..0067d328f0b5 100644 > --- a/drivers/block/drbd/drbd_state.c > +++ b/drivers/block/drbd/drbd_state.c > @@ -1604,7 +1604,7 @@ static void broadcast_state_change(struct drbd_state_change *state_change) > unsigned int n_device, n_connection, n_peer_device, n_peer_devices; > void (*last_func)(struct sk_buff *, unsigned int, void *, > enum drbd_notification_type) = NULL; > - void *uninitialized_var(last_arg); > + void *last_arg = NULL; > > #define HAS_CHANGED(state) ((state)[OLD] != (state)[NEW]) > #define FINAL_STATE_CHANGE(type) \ > -- > 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/20200603233203.1695403-3-keescook%40chromium.org. -- Thanks, ~Nick Desaulniers