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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=SpMt9swBFV/X7pJxY11yJxvoU/jl5TYZqkYEwxVo1zk=; b=YSSJiKbNeDWkwui4r3Pqo58HEySlJuUShKoJET8KiMZmAp6AqXVvLeuJMrwX2l6iMM Vt200YFlepsbfuWJprlquMqiLfApZlIU0N3+b3fIb+YO6mvWcMDhZXGTY89I+0etT+V3 cSWef1RsndgN/zlaGW/63wGWVVse7wKBMqSil4Z0ku6PO03SfolCkWlQcRsec2TycVJ6 /Fa+avt0Jvv20JvgZ328XXaOX4LejAGSqzlygG6xN1AHWJhHP5uxJvUWiU5IZEAkw/b2 jMrDIzHall0UJHl7QYr1a/o2iEU5kiA6Hk+saR+4/DmFM+G35J/VFlaaR2kPSSiH/h1A 6sSA== X-Gm-Message-State: APjAAAVhs/JHUVWRMrXbRQ3KoOwYuG40K6WaM2kggFqwpJd9iz93LRex SwuJsX+QuAQhcfd37BBz4S9rLedKkXUVJUAAMBmOVw== X-Google-Smtp-Source: APXvYqw74Dsa5tbwvZVY6ubm3mq6Ol0GpZBf3HyKWvRWHEbC8fAxc8l0X7gBK5dChGcDSWL/yjwxE6D5ZDxmwT29ntI= X-Received: by 2002:a67:ed8b:: with SMTP id d11mr3309159vsp.104.1572543748924; Thu, 31 Oct 2019 10:42:28 -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: Sami Tolvanen Date: Thu, 31 Oct 2019 10:42:17 -0700 Message-ID: Subject: Re: [PATCH v3 13/17] arm64: preserve x18 when CPU is suspended To: Nick Desaulniers X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191031_104230_749268_586AF1D5 X-CRM114-Status: GOOD ( 12.08 ) 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 Archived-At: List-Archive: On Thu, Oct 31, 2019 at 10:35 AM Nick Desaulniers wrote: > > 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. Sure, I'll add a comment in the next version. Sami _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel