From patchwork Wed Feb 26 06:35:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russell Currey X-Patchwork-Id: 11405373 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 20A0F14BC for ; Wed, 26 Feb 2020 06:37:16 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 7DC9C206E2 for ; Wed, 26 Feb 2020 06:37:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=russell.cc header.i=@russell.cc header.b="fzJATGDo"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="qRtBUCWh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DC9C206E2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=russell.cc Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17950-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 17888 invoked by uid 550); 26 Feb 2020 06:36:46 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 17792 invoked from network); 26 Feb 2020 06:36:45 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=russell.cc; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; s=fm1; bh=kp8u9qL5i5T1m QUU2K/sNa+O6ICOZSqNmkNONM8HCIA=; b=fzJATGDokN1+R+MlmNqqa13I3oLTq OkzLJ7lhs5ghIs1tFaMk0ljnYHBPpfoygjxDUDw97FJBJJSPGdkoQN8W2VqM3MF+ OINrLWpgpgBYy6LmdnpU0fz49+qlnDJAgq3BVz1PjdFt0mFr6gl31d4t1O70PZXC Tfcv5P5ApNbE3EIoNF+udZYV9TNFgdgir2EdR0/Lj6dDWBNpP1j7h71LArZRnoRY G33RK5MNlC9z4HFpa+S/CoUSbd1I4PxoxawB8SZM8eBDi3N7kSOHRLTkSdli3Qb2 N5biH5UpTcG3FRdM/laciMGA4S6wgpZ8fLoNPYW/WnlWd6+LkAjFiU6Qw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; bh=kp8u9qL5i5T1mQUU2K/sNa+O6ICOZSqNmkNONM8HCIA=; b=qRtBUCWh 6sRn7gRUKt9JnHKqRL1rmrGS6E2TgS5qT0MvRFBnqqPnneowNTCpNcHbDyaVfpxx uRB+jwq8dM+q/20vhRIHcOBN6IQfk35vxx6WBqw8LJyV9GX2sC0ohsgEjbcqs2E0 mjdw3YEnBaLh1RpKYLeKXX7Y3E34Xx9WyMmrH84Sw8fGftD+BxNm5wjcHD+5IOVc oICmk7iNicWKTfSOubPkNyItxPx4j5RPkwgNB/wHCVUkXcWvF/iDu/fugQFHUOh8 5R/oXt6+S6RjwZ/ZK+C4LOFGXZm8Bv8L5n7A83gjCyY75katBdLbGCqeKtNrm8Fz QJa5Qi4B2JI1tw== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrleefgdelkecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenfg hrlhcuvffnffculddutddmnecujfgurhephffvufffkffojghfggfgsedtkeertdertddt necuhfhrohhmpeftuhhsshgvlhhlucevuhhrrhgvhicuoehruhhstghurhesrhhushhsvg hllhdrtggtqeenucfkphepuddvvddrleelrdekvddruddtnecuvehluhhsthgvrhfuihii vgepheenucfrrghrrghmpehmrghilhhfrhhomheprhhushgtuhhrsehruhhsshgvlhhlrd gttg X-ME-Proxy: From: Russell Currey To: linuxppc-dev@lists.ozlabs.org Cc: jniethe5@gmail.com, Christophe Leroy , joel@jms.id.au, mpe@ellerman.id.au, ajd@linux.ibm.com, dja@axtens.net, npiggin@gmail.com, kernel-hardening@lists.openwall.com, kbuild test robot , Russell Currey Subject: [PATCH v5 6/8] powerpc/mm: implement set_memory_attr() Date: Wed, 26 Feb 2020 17:35:49 +1100 Message-Id: <20200226063551.65363-7-ruscur@russell.cc> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200226063551.65363-1-ruscur@russell.cc> References: <20200226063551.65363-1-ruscur@russell.cc> MIME-Version: 1.0 From: Christophe Leroy In addition to the set_memory_xx() functions which allows to change the memory attributes of not (yet) used memory regions, implement a set_memory_attr() function to: - set the final memory protection after init on currently used kernel regions. - enable/disable kernel memory regions in the scope of DEBUG_PAGEALLOC. Unlike the set_memory_xx() which can act in three step as the regions are unused, this function must modify 'on the fly' as the kernel is executing from them. At the moment only PPC32 will use it and changing page attributes on the fly is not an issue. Signed-off-by: Christophe Leroy Reported-by: kbuild test robot [ruscur: cast "data" to unsigned long instead of int] Signed-off-by: Russell Currey --- v4: cast "data" to unsigned long instead of int arch/powerpc/include/asm/set_memory.h | 2 ++ arch/powerpc/mm/pageattr.c | 33 +++++++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/arch/powerpc/include/asm/set_memory.h b/arch/powerpc/include/asm/set_memory.h index 64011ea444b4..b040094f7920 100644 --- a/arch/powerpc/include/asm/set_memory.h +++ b/arch/powerpc/include/asm/set_memory.h @@ -29,4 +29,6 @@ static inline int set_memory_x(unsigned long addr, int numpages) return change_memory_attr(addr, numpages, SET_MEMORY_X); } +int set_memory_attr(unsigned long addr, int numpages, pgprot_t prot); + #endif diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c index 2b573768a7f7..ee6b5e3b7604 100644 --- a/arch/powerpc/mm/pageattr.c +++ b/arch/powerpc/mm/pageattr.c @@ -72,3 +72,36 @@ int change_memory_attr(unsigned long addr, int numpages, long action) return apply_to_page_range(&init_mm, start, sz, change_page_attr, (void *)action); } + +/* + * Set the attributes of a page: + * + * This function is used by PPC32 at the end of init to set final kernel memory + * protection. It includes changing the maping of the page it is executing from + * and data pages it is using. + */ +static int set_page_attr(pte_t *ptep, unsigned long addr, void *data) +{ + pgprot_t prot = __pgprot((unsigned long)data); + + spin_lock(&init_mm.page_table_lock); + + set_pte_at(&init_mm, addr, ptep, pte_modify(*ptep, prot)); + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + + spin_unlock(&init_mm.page_table_lock); + + return 0; +} + +int set_memory_attr(unsigned long addr, int numpages, pgprot_t prot) +{ + unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE); + unsigned long sz = numpages * PAGE_SIZE; + + if (!numpages) + return 0; + + return apply_to_page_range(&init_mm, start, sz, set_page_attr, + (void *)pgprot_val(prot)); +}