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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=6vxne2J2U+zueRlGB+uihx88K5obGcz7JfVVNIfE6MI=; b=QgAqrYmcARLKfIJZF1ix89Yl7jAMLwf355O0jEfF3DiXKSVexIOFZ4eGlEcJf2OlHH /6zqBpn6g8AeiT4XNBrRQW59WI+89TBg1mtDS4fiMJlGRCgnfY0ElHs/VzTD4HV97d/W LaAkLfmJl4h5VgQ8UKu5cFfp3BUvaZuCpKS6U9Rd4o8Z/6FHiI8kvJaMUobMaoUj82Q6 JShFXvjKxdAOQmr6srA2QP/7yyWlhAAVBBvLvCRFVzAZNoiIZItsM23kpZ7LNSsnWZxr fuOKe8NJMwo+Jh61M9YG5GmM6fLekAO1PDI2ROP87UqTRliQsJpbSR5AAahZM873vq3w PsdQ== X-Gm-Message-State: APjAAAWBfD2J+yKWxaRNwJ8faMl3i11sahttY/3+gNhTXxotm0fWLZuv Zt2p13+B5UpZbhhuNdd4RXtpbgUF5dlDJjHbbNRxAg== X-Google-Smtp-Source: APXvYqz/lhCOKKkE7+XVjZtp5lyRajdclaBkyDSosLmDck7GxCYMMFfzkg348/A5b/zQnTjld0uu3Efy3NYsSqb59C8= X-Received: by 2002:a17:90a:1f4b:: with SMTP id y11mr8889337pjy.123.1572543304777; Thu, 31 Oct 2019 10:35:04 -0700 (PDT) MIME-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> <20191031164637.48901-1-samitolvanen@google.com> <20191031164637.48901-14-samitolvanen@google.com> In-Reply-To: From: Nick Desaulniers Date: Thu, 31 Oct 2019 10:34:53 -0700 Message-ID: Subject: Re: [PATCH v3 13/17] arm64: preserve x18 when CPU is suspended To: Sami Tolvanen X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191031_103506_121598_CEB73155 X-CRM114-Status: GOOD ( 11.28 ) 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 Thu, Oct 31, 2019 at 10:27 AM Sami Tolvanen wrote: > > On Thu, Oct 31, 2019 at 10:18 AM Nick Desaulniers > wrote: > > > +#ifdef CONFIG_SHADOW_CALL_STACK > > > + ldr x18, [x0, #96] > > > + str xzr, [x0, #96] > > > > How come we zero out x0+#96, but not for other offsets? Is this str necessary? > > It clears the shadow stack pointer from the sleep state buffer, which > is not strictly speaking necessary, but leaves one fewer place to find > it. That sounds like a good idea. Consider adding comments or to the commit message so that the str doesn't get removed accidentally in the future. Reviewed-by: Nick Desaulniers -- Thanks, ~Nick Desaulniers _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel