From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5E096FA1 for ; Mon, 3 Apr 2023 14:50:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CE9CC433EF; Mon, 3 Apr 2023 14:50:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680533443; bh=4a3ztiUrQ+f6Igs57SLsrvIjOa9ukdXV8dRBXD7oQPQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XWeBXmFVnE0lVi8qlHZbJAmsruG6atOAnrjRmmBoRcBQ/19opvr0mmmKr88pfG+ag YJ9meo/JiE93sCU222wkjlpKEU21IehcU+hgDou5sd7voqNhm/mRUJPmOO24mTaL3N duZgzcya472vDfkmAdvA4RMiF3bNb6cqDSmiefso= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Russell Currey , Benjamin Gray , Michael Ellerman Subject: [PATCH 6.2 156/187] powerpc/64s: Fix __pte_needs_flush() false positive warning Date: Mon, 3 Apr 2023 16:10:01 +0200 Message-Id: <20230403140421.220397605@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140416.015323160@linuxfoundation.org> References: <20230403140416.015323160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Benjamin Gray commit 1abce0580b89464546ae06abd5891ebec43c9470 upstream. Userspace PROT_NONE ptes set _PAGE_PRIVILEGED, triggering a false positive debug assertion that __pte_flags_need_flush() is not called on a kernel mapping. Detect when it is a userspace PROT_NONE page by checking the required bits of PAGE_NONE are set, and none of the RWX bits are set. pte_protnone() is insufficient here because it always returns 0 when CONFIG_NUMA_BALANCING=n. Fixes: b11931e9adc1 ("powerpc/64s: add pte_needs_flush and huge_pmd_needs_flush") Cc: stable@vger.kernel.org # v6.1+ Reported-by: Russell Currey Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20230302225947.81083-1-bgray@linux.ibm.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/book3s/64/tlbflush.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/arch/powerpc/include/asm/book3s/64/tlbflush.h +++ b/arch/powerpc/include/asm/book3s/64/tlbflush.h @@ -148,6 +148,11 @@ static inline void flush_tlb_fix_spuriou */ } +static inline bool __pte_protnone(unsigned long pte) +{ + return (pte & (pgprot_val(PAGE_NONE) | _PAGE_RWX)) == pgprot_val(PAGE_NONE); +} + static inline bool __pte_flags_need_flush(unsigned long oldval, unsigned long newval) { @@ -164,8 +169,8 @@ static inline bool __pte_flags_need_flus /* * We do not expect kernel mappings or non-PTEs or not-present PTEs. */ - VM_WARN_ON_ONCE(oldval & _PAGE_PRIVILEGED); - VM_WARN_ON_ONCE(newval & _PAGE_PRIVILEGED); + VM_WARN_ON_ONCE(!__pte_protnone(oldval) && oldval & _PAGE_PRIVILEGED); + VM_WARN_ON_ONCE(!__pte_protnone(newval) && newval & _PAGE_PRIVILEGED); VM_WARN_ON_ONCE(!(oldval & _PAGE_PTE)); VM_WARN_ON_ONCE(!(newval & _PAGE_PTE)); VM_WARN_ON_ONCE(!(oldval & _PAGE_PRESENT));