From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48JtmxBtmrETTPxV4JoqlBM6M6gYlxZYBOmrBG3yE69STw5ZIlAWnXuE7l9TRdQbWigyzUh ARC-Seal: i=1; a=rsa-sha256; t=1524505514; cv=none; d=google.com; s=arc-20160816; b=HKzf7TAkw+TgMbwbdqG3fb+4jhR0UEXwxWNCO1z4jUfq0tBzA8PcxfVAUpYPcFzAsx 18Ru59GllcgCtQJ5pkxE6wb32+MThqJfvYZbuy4igByhZ4SG36pQz6sIw7zNqevgSkL+ XLE8xa7x3jwbULUI4Y8CGJRYDVQ8G/5UIor0gXMlPmG5yrxPlpSNfPCCr1Uye5+0/EoV S8xRF81PPXKF51D7YtjYkCMNbRDpuONDn7KSJp6TdEswW1d0osawP7RafJRGhk2aOY9z ndWidtu9WflwvqfxqXjuOQpebxCcui4uSe3GhKPI4UTCI7/yVJzPmnHk0RyG7MEUg0rN 3YZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:arc-authentication-results; bh=D8EzFyPzjra5MgkjxCCubukBWI7H/uncvrHQx4CP86I=; b=1K0SVQtKUaYH/Wt6+2CpsEd/xfzh2apNQVPLlQwhkNnMESOyvYfz3hrzr+wtzbHhBs Zdp3JaU242YaArF33oZYX1X4UmCU9DYxhWNwkoHAy/eMxAwSMYbilxEwx0xXX9lm1OTr tEW0fGT/gGBCSAj54EeKFp0+t69BoYjn3UF4pjpGlpOmjQij6yvcKaFHcm270LdfPOhL LK6rLbVuwWljsGdY50ZbtRzrlg/hZcw1Z/PFWm0hw57NiRxaVUCYW2INpjS6s515bP1y +WvVS++2W5ejLtYj/3tVzJv/PnbmAgN8XecXcUIEojqlehs/K116mLnYZBQNGxY5HoyT eYEA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of jroedel@suse.de designates 195.135.220.15 as permitted sender) smtp.mailfrom=jroedel@suse.de Authentication-Results: mx.google.com; spf=pass (google.com: domain of jroedel@suse.de designates 195.135.220.15 as permitted sender) smtp.mailfrom=jroedel@suse.de Date: Mon, 23 Apr 2018 19:45:06 +0200 From: Joerg Roedel To: Linus Torvalds Cc: Joerg Roedel , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , the arch/x86 maintainers , Linux Kernel Mailing List , linux-mm , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , "Liguori, Anthony" , Daniel Gruss , Hugh Dickins , Kees Cook , Andrea Arcangeli , Waiman Long , Pavel Machek , "David H . Gutteridge" Subject: Re: [PATCH 00/37 v6] PTI support for x86-32 Message-ID: <20180423174506.mpbpnvfzv6fmpbzy@suse.de> References: <1524498460-25530-1-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170421 (1.8.2) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598552504711746562?= X-GMAIL-MSGID: =?utf-8?q?1598559894865525347?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Mon, Apr 23, 2018 at 09:45:38AM -0700, Linus Torvalds wrote: > Just one question: have you checked the page table setup for the > basics wrt the USER bit in particular? Just checked that and there are no pages with GLB and USR set, not even a vdso page. > No global pages should be marked PAGE_USER, with the possible > exception of that nasty old vsyscall page. The vsyscall page does not exist on plain 32 bit, no? All I could find there is the vdso page, and that has no compat mapping anymore in recent upstream kernels. To my understanding the vdso page is mapped into the user-space portion of the address space. At least that is what I found while looking at this, but I might have missed something. I actually ran into a vdso issue when porting these changes to 3.0 (where there still is a compat vdso mapping in the fixmap) so I checked my upstream code too, but didn't find the code to setup a vdso in the fixmap. > And it would be nice to verify that the page tables for kernel > mappings also don't have PAGE_USER on them, although again that > vsyscall page can cause problems. Checked that too, all USR mappings are below PAGE_OFFSET. Regards, Joerg