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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SOwCMPM2O4ZOlwd3DBrA7iEvzDojcSJWVcNWTrD2V3A=; b=qqfsbbw5wVbxlxpoOQZy6dF/hmp2bpx1nn1pUH6i+hfxsyKX5EbN++nY2gCsHxEG1b vXNHNjAJ9CXCkX2mn57QpYVSr7TCU41PnNKvJsttfZcG2HCg9CZFFkIdrA7WN7oCZeUG cBfWA5r5jrGh0zqUaOskHNOqk/e61JNyVXh4HdFCNt9txVryY6Zi+V75/By5KwEsr8jA wZbUwP3q/TKsBr2Xblf1wi2TmWvo9ix96HkfiPNLtAssw9juCcUPEiOrCVV9m5p134ZA y6tOiLyFLNXTSekjr6WQbrGnBpLw+GsGB9uBoTQVNQHMXgva0EXznUHYuDjWINL/4jha yWqw== X-Gm-Message-State: APjAAAUejueY7dYARBFoqVxqQ6RUmKQ5eoMcREF/suGo1KjF4fJe7j4J 17PlK/LHt/+k+ZggSnViFRIF48qANoTKyiSg54cuvA== X-Google-Smtp-Source: APXvYqwitHy/uW9BgFO85xlL31gu4CkfssJm5Y58pk3pu/OFECEhzo8ZcmTg1xeRhUyxbxF5+qEX2qRHXCg/5F+6CB8= X-Received: by 2002:a67:ed8b:: with SMTP id d11mr3107850vsp.104.1572036693631; Fri, 25 Oct 2019 13:51:33 -0700 (PDT) MIME-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> <20191024225132.13410-1-samitolvanen@google.com> <20191024225132.13410-6-samitolvanen@google.com> In-Reply-To: From: Sami Tolvanen Date: Fri, 25 Oct 2019 13:51:22 -0700 Message-ID: Subject: Re: [PATCH v2 05/17] add support for Clang's Shadow Call Stack (SCS) To: Nick Desaulniers X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191025_135139_182683_62A5D845 X-CRM114-Status: GOOD ( 11.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Kees Cook , Ard Biesheuvel , Masahiro Yamada , Catalin Marinas , Jann Horn , LKML , Steven Rostedt , Miguel Ojeda , Masami Hiramatsu , clang-built-linux , Kernel Hardening , Laura Abbott , Will Deacon , Dave Martin , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Oct 25, 2019 at 9:22 AM Nick Desaulniers wrote: > > +static void scs_free(void *s) > > +{ > > + int i; > > + > > + for (i = 0; i < SCS_CACHE_SIZE; i++) { > > + if (this_cpu_cmpxchg(scs_cache[i], 0, s) != 0) > > + continue; > > + > > + return; > > + } > > prefer: > > for ...: > if foo() == 0: > return > > to: > > for ...: > if foo() != 0: > continue > return This was essentially copied from free_thread_stack in kernel/fork.c, but I agree, your way is cleaner. I'll change this in the next version. Thanks! Sami _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel