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Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Randy Dunlap , "Ravi V . Shankar" , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, Yu-cheng Yu Subject: Re: [PATCH v2 17/39] mm: Fixup places that call pte_mkwrite() directly Message-ID: References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-18-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220929222936.14584-18-rick.p.edgecombe@intel.com> ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=FI8zrVaV; spf=none (imf06.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1665762752; a=rsa-sha256; cv=none; b=KXAohiNxPo5pDaSOkt51IlSCmF/yAFZ8DLxJsuD1VKsXvdsk66pLbBXyKaifcI69wVfjSe MQTBW8IYkDiljtZwyVlflfmK9ywJfAulqqpGvfEoV4TYULnT504VTuh15PQIB4HxFjShAg gEYUiTY4PB4H4Db0suryoc6fUDnYfMo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1665762752; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=uURYEhJNF/y4ef2ytvd2xFiDhwfWuIdCXYX1RDrMcEU=; b=8OC+K5HIY/QdzrCLH39RrNYmn6+staTCTVf+hNpa96VMyIXBZwpCsE/PvgTx3EcB/gQlHG SONdnZbUSIvUk4m/FGhVh8tNI6xzzrV4CnyYm1kLnzToNODvoOzeCimFJYCblideEeMKXz BTGoy1zQVGRf97DdE5r/5bT3LFZA7lg= X-Rspamd-Server: rspam05 X-Rspam-User: Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=FI8zrVaV; spf=none (imf06.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none X-Stat-Signature: jkt9dqsxn56yst5g8yyqe9cjt68da14w X-Rspamd-Queue-Id: 830D018001F X-HE-Tag: 1665762751-374404 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 Thu, Sep 29, 2022 at 03:29:14PM -0700, Rick Edgecombe wrote: > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > index 7327b2573f7c..b49372c7de41 100644 > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -63,6 +63,7 @@ int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, > int ret; > pte_t _dst_pte, *dst_pte; > bool writable = dst_vma->vm_flags & VM_WRITE; > + bool shstk = dst_vma->vm_flags & VM_SHADOW_STACK; > bool vm_shared = dst_vma->vm_flags & VM_SHARED; > bool page_in_cache = page->mapping; > spinlock_t *ptl; > @@ -83,9 +84,12 @@ int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, > writable = false; > } > > - if (writable) > - _dst_pte = pte_mkwrite(_dst_pte); > - else > + if (writable) { > + if (shstk) > + _dst_pte = pte_mkwrite_shstk(_dst_pte); > + else > + _dst_pte = pte_mkwrite(_dst_pte); > + } else > /* > * We need this to make sure write bit removed; as mk_pte() > * could return a pte with write bit set. Urgh.. that's unfortunate. But yeah, I don't see a way to make that pretty either.