From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4054C43441 for ; Wed, 28 Nov 2018 17:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B1642081B for ; Wed, 28 Nov 2018 17:21:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B1642081B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728909AbeK2EXe (ORCPT ); Wed, 28 Nov 2018 23:23:34 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:3700 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728223AbeK2EXe (ORCPT ); Wed, 28 Nov 2018 23:23:34 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 434nVs6Hpjz9vBmM; Wed, 28 Nov 2018 18:21:09 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id Lwq5dJxyfUWc; Wed, 28 Nov 2018 18:21:09 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 434nVs5dMWz9vBmL; Wed, 28 Nov 2018 18:21:09 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 4605C8B889; Wed, 28 Nov 2018 18:21:11 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id KmMk8aU_hg08; Wed, 28 Nov 2018 18:21:11 +0100 (CET) Received: from po14163vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.231.2]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 130038B888; Wed, 28 Nov 2018 18:21:11 +0100 (CET) Received: by po14163vm.idsi0.si.c-s.fr (Postfix, from userid 0) id DDF4769B1A; Wed, 28 Nov 2018 17:21:10 +0000 (UTC) Message-Id: <62fcfb8435c2f801d820eff469fd01e68c1b107d.1543425412.git.christophe.leroy@c-s.fr> From: Christophe Leroy Subject: [PATCH v3] powerpc/mm: add exec protection on powerpc 603 To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Wed, 28 Nov 2018 17:21:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The 603 doesn't have a HASH table, TLB misses are handled by software. It is then possible to generate page fault when _PAGE_EXEC is not set like in nohash/32. There is one "reserved" PTE bit available, this patch uses it for _PAGE_EXEC. In order to support it, set_pte_filter() and set_access_flags_filter() are made common, and the handling is made dependent on MMU_FTR_HPTE_TABLE Signed-off-by: Christophe Leroy --- v3: Included the _PAGE_EXEC flag in the existing test in TLB handler, no additional insns. v2: Amended commit log and removed #ifdef in pagetable dump arch/powerpc/include/asm/book3s/32/hash.h | 1 + arch/powerpc/include/asm/book3s/32/pgtable.h | 18 +++++++++--------- arch/powerpc/include/asm/cputable.h | 8 ++++---- arch/powerpc/kernel/head_32.S | 2 +- arch/powerpc/mm/dump_linuxpagetables-generic.c | 2 -- arch/powerpc/mm/pgtable.c | 20 +++++++++++--------- 6 files changed, 26 insertions(+), 25 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/hash.h b/arch/powerpc/include/asm/book3s/32/hash.h index f2892c7ab73e..2a0a467d2985 100644 --- a/arch/powerpc/include/asm/book3s/32/hash.h +++ b/arch/powerpc/include/asm/book3s/32/hash.h @@ -26,6 +26,7 @@ #define _PAGE_WRITETHRU 0x040 /* W: cache write-through */ #define _PAGE_DIRTY 0x080 /* C: page changed */ #define _PAGE_ACCESSED 0x100 /* R: page referenced */ +#define _PAGE_EXEC 0x200 /* software: exec allowed */ #define _PAGE_RW 0x400 /* software: user write access allowed */ #define _PAGE_SPECIAL 0x800 /* software: Special page */ diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h index b849b45429d5..6accf3e686af 100644 --- a/arch/powerpc/include/asm/book3s/32/pgtable.h +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h @@ -10,9 +10,9 @@ /* And here we include common definitions */ #define _PAGE_KERNEL_RO 0 -#define _PAGE_KERNEL_ROX 0 +#define _PAGE_KERNEL_ROX (_PAGE_EXEC) #define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW) -#define _PAGE_KERNEL_RWX (_PAGE_DIRTY | _PAGE_RW) +#define _PAGE_KERNEL_RWX (_PAGE_DIRTY | _PAGE_RW | _PAGE_EXEC) #define _PAGE_HPTEFLAGS _PAGE_HASHPTE @@ -66,11 +66,11 @@ static inline bool pte_user(pte_t pte) */ #define PAGE_NONE __pgprot(_PAGE_BASE) #define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW) -#define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW) +#define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC) #define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER) -#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER) +#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC) #define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_USER) -#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER) +#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC) /* Permission masks used for kernel mappings */ #define PAGE_KERNEL __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW) @@ -318,7 +318,7 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma, int psize) { unsigned long set = pte_val(entry) & - (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW); + (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC); pte_update(ptep, 0, set); @@ -384,7 +384,7 @@ static inline int pte_dirty(pte_t pte) { return !!(pte_val(pte) & _PAGE_DIRTY); static inline int pte_young(pte_t pte) { return !!(pte_val(pte) & _PAGE_ACCESSED); } static inline int pte_special(pte_t pte) { return !!(pte_val(pte) & _PAGE_SPECIAL); } static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; } -static inline bool pte_exec(pte_t pte) { return true; } +static inline bool pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; } static inline int pte_present(pte_t pte) { @@ -451,7 +451,7 @@ static inline pte_t pte_wrprotect(pte_t pte) static inline pte_t pte_exprotect(pte_t pte) { - return pte; + return __pte(pte_val(pte) & ~_PAGE_EXEC); } static inline pte_t pte_mkclean(pte_t pte) @@ -466,7 +466,7 @@ static inline pte_t pte_mkold(pte_t pte) static inline pte_t pte_mkexec(pte_t pte) { - return pte; + return __pte(pte_val(pte) | _PAGE_EXEC); } static inline pte_t pte_mkpte(pte_t pte) diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h index 29f49a35d6ee..a0395ccbbe9e 100644 --- a/arch/powerpc/include/asm/cputable.h +++ b/arch/powerpc/include/asm/cputable.h @@ -296,7 +296,7 @@ static inline void cpu_feature_keys_init(void) { } #define CPU_FTRS_PPC601 (CPU_FTR_COMMON | CPU_FTR_601 | \ CPU_FTR_COHERENT_ICACHE | CPU_FTR_UNIFIED_ID_CACHE | CPU_FTR_USE_RTC) #define CPU_FTRS_603 (CPU_FTR_COMMON | CPU_FTR_MAYBE_CAN_DOZE | \ - CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_PPC_LE) + CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_PPC_LE | CPU_FTR_NOEXECUTE) #define CPU_FTRS_604 (CPU_FTR_COMMON | CPU_FTR_PPC_LE) #define CPU_FTRS_740_NOTAU (CPU_FTR_COMMON | \ CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_L2CR | \ @@ -367,15 +367,15 @@ static inline void cpu_feature_keys_init(void) { } CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_L2CR | CPU_FTR_ALTIVEC_COMP | \ CPU_FTR_SPEC7450 | CPU_FTR_NAP_DISABLE_L2_PR | \ CPU_FTR_PPC_LE | CPU_FTR_NEED_PAIRED_STWCX) -#define CPU_FTRS_82XX (CPU_FTR_COMMON | CPU_FTR_MAYBE_CAN_DOZE) +#define CPU_FTRS_82XX (CPU_FTR_COMMON | CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_NOEXECUTE) #define CPU_FTRS_G2_LE (CPU_FTR_COMMON | CPU_FTR_MAYBE_CAN_DOZE | \ CPU_FTR_MAYBE_CAN_NAP) #define CPU_FTRS_E300 (CPU_FTR_MAYBE_CAN_DOZE | \ CPU_FTR_MAYBE_CAN_NAP | \ - CPU_FTR_COMMON) + CPU_FTR_COMMON | CPU_FTR_NOEXECUTE) #define CPU_FTRS_E300C2 (CPU_FTR_MAYBE_CAN_DOZE | \ CPU_FTR_MAYBE_CAN_NAP | \ - CPU_FTR_COMMON | CPU_FTR_FPU_UNAVAILABLE) + CPU_FTR_COMMON | CPU_FTR_FPU_UNAVAILABLE | CPU_FTR_NOEXECUTE) #define CPU_FTRS_CLASSIC32 (CPU_FTR_COMMON) #define CPU_FTRS_8XX (CPU_FTR_NOEXECUTE) #define CPU_FTRS_40X (CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE) diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index 118c3b216e60..479017f6a992 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -499,7 +499,7 @@ InstructionTLBMiss: lis r1,PAGE_OFFSET@h /* check if kernel address */ cmplw 0,r1,r3 mfspr r2,SPRN_SPRG_THREAD - li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */ + li r1,_PAGE_USER|_PAGE_PRESENT|_PAGE_EXEC /* low addresses tested as user */ lwz r2,PGDIR(r2) bge- 112f mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */ diff --git a/arch/powerpc/mm/dump_linuxpagetables-generic.c b/arch/powerpc/mm/dump_linuxpagetables-generic.c index 1e3829ec1348..3fe98a0974c6 100644 --- a/arch/powerpc/mm/dump_linuxpagetables-generic.c +++ b/arch/powerpc/mm/dump_linuxpagetables-generic.c @@ -21,13 +21,11 @@ static const struct flag_info flag_array[] = { .set = "rw", .clear = "r ", }, { -#ifndef CONFIG_PPC_BOOK3S_32 .mask = _PAGE_EXEC, .val = _PAGE_EXEC, .set = " X ", .clear = " ", }, { -#endif .mask = _PAGE_PRESENT, .val = _PAGE_PRESENT, .set = "present", diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index 1e33dccbd176..d3d61d29b4f1 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -74,7 +74,7 @@ static struct page *maybe_pte_to_page(pte_t pte) * support falls into the same category. */ -static pte_t set_pte_filter(pte_t pte) +static pte_t set_pte_filter_hash(pte_t pte) { if (radix_enabled()) return pte; @@ -93,14 +93,12 @@ static pte_t set_pte_filter(pte_t pte) return pte; } -static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma, - int dirty) -{ - return pte; -} - #else /* CONFIG_PPC_BOOK3S */ +static pte_t set_pte_filter_hash(pte_t pte) { return pte; } + +#endif /* CONFIG_PPC_BOOK3S */ + /* Embedded type MMU with HW exec support. This is a bit more complicated * as we don't have two bits to spare for _PAGE_EXEC and _PAGE_HWEXEC so * instead we "filter out" the exec permission for non clean pages. @@ -109,6 +107,9 @@ static pte_t set_pte_filter(pte_t pte) { struct page *pg; + if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return set_pte_filter_hash(pte); + /* No exec permission in the first place, move on */ if (!pte_exec(pte) || !pte_looks_normal(pte)) return pte; @@ -138,6 +139,9 @@ static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma, { struct page *pg; + if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return pte; + /* So here, we only care about exec faults, as we use them * to recover lost _PAGE_EXEC and perform I$/D$ coherency * if necessary. Also if _PAGE_EXEC is already set, same deal, @@ -172,8 +176,6 @@ static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma, return pte_mkexec(pte); } -#endif /* CONFIG_PPC_BOOK3S */ - /* * set_pte stores a linux PTE into the linux page table. */ -- 2.13.3