From patchwork Tue Jan 9 12:14:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 13514858 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (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 C6E8E381A5; Tue, 9 Jan 2024 12:15:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=csgroup.eu Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4T8VHT5y4Kz9v6s; Tue, 9 Jan 2024 13:15:01 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4MdGbzyeBSEE; Tue, 9 Jan 2024 13:15:01 +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 4T8VHT4pzsz9v2V; Tue, 9 Jan 2024 13:15:01 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9BC028B77D; Tue, 9 Jan 2024 13:15:01 +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 uBzJP-3JQq-L; Tue, 9 Jan 2024 13:15:01 +0100 (CET) Received: from PO20335.idsi0.si.c-s.fr (unknown [192.168.233.126]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 053088B77E; Tue, 9 Jan 2024 13:14:59 +0100 (CET) From: Christophe Leroy To: linux-hardening@vger.kernel.org, Russell King , Catalin Marinas , Will Deacon , Michael Ellerman , Nicholas Piggin , "Aneesh Kumar K.V" , "Naveen N. Rao" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Gerald Schaefer , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Kees Cook Cc: Christophe Leroy , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-mm@kvack.org, steven.price@arm.com, Phong Tran , mark.rutland@arm.com, Greg KH Subject: [PATCH 2/4] arm64, powerpc, riscv, s390, x86: Refactor CONFIG_DEBUG_WX Date: Tue, 9 Jan 2024 13:14:36 +0100 Message-ID: X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1704802473; l=11315; i=christophe.leroy@csgroup.eu; s=20211009; h=from:subject:message-id; bh=/7r2fv5UgWErZwlk5FNzmu53iFGklb0c7kTSXPgGEHM=; b=01YQqBwyJGJIDGN7KSgjPDE5jKTdPTeM7uAcHq541R/m2p25Tc/MpyxpccE0H4QHv8KYbJfkg EJojygb2mj9BPwL+zk+tkKOnjeyHzNiyrBGrSuwP4HGM+3QWJJwAGnV X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= All architectures using the core ptdump functionality also implement CONFIG_DEBUG_WX, and they all do it more or less the same way, with a function called debug_checkwx() that is called by mark_rodata_ro(), which is a substitute to ptdump_check_wx() when CONFIG_DEBUG_WX is set and a no-op otherwise. Refactor by centraly defining debug_checkwx() in linux/ptdump.h and call debug_checkwx() immediately after calling mark_rodata_ro() instead of calling it at the end of every mark_rodata_ro(). On x86_32, mark_rodata_ro() first checks __supported_pte_mask has _PAGE_NX before calling debug_checkwx(). Now the check is inside the callee ptdump_walk_pgd_level_checkwx(). On powerpc_64, mark_rodata_ro() bails out early before calling ptdump_check_wx() when the MMU doesn't have KERNEL_RO feature. The check is now also done in ptdump_check_wx() as it is called outside mark_rodata_ro(). Signed-off-by: Christophe Leroy Reviewed-by: Alexandre Ghiti --- arch/arm64/include/asm/ptdump.h | 7 ------- arch/arm64/mm/mmu.c | 2 -- arch/powerpc/mm/mmu_decl.h | 6 ------ arch/powerpc/mm/pgtable_32.c | 4 ---- arch/powerpc/mm/pgtable_64.c | 3 --- arch/powerpc/mm/ptdump/ptdump.c | 3 +++ arch/riscv/include/asm/ptdump.h | 22 ---------------------- arch/riscv/mm/init.c | 3 --- arch/riscv/mm/ptdump.c | 1 - arch/s390/include/asm/ptdump.h | 14 -------------- arch/s390/mm/dump_pagetables.c | 1 - arch/s390/mm/init.c | 2 -- arch/x86/include/asm/pgtable.h | 3 +-- arch/x86/mm/dump_pagetables.c | 3 +++ arch/x86/mm/init_32.c | 2 -- arch/x86/mm/init_64.c | 2 -- include/linux/ptdump.h | 7 +++++++ init/main.c | 2 ++ 18 files changed, 16 insertions(+), 71 deletions(-) delete mode 100644 arch/riscv/include/asm/ptdump.h delete mode 100644 arch/s390/include/asm/ptdump.h diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h index 581caac525b0..5b1701c76d1c 100644 --- a/arch/arm64/include/asm/ptdump.h +++ b/arch/arm64/include/asm/ptdump.h @@ -29,13 +29,6 @@ void __init ptdump_debugfs_register(struct ptdump_info *info, const char *name); static inline void ptdump_debugfs_register(struct ptdump_info *info, const char *name) { } #endif -void ptdump_check_wx(void); #endif /* CONFIG_PTDUMP_CORE */ -#ifdef CONFIG_DEBUG_WX -#define debug_checkwx() ptdump_check_wx() -#else -#define debug_checkwx() do { } while (0) -#endif - #endif /* __ASM_PTDUMP_H */ diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 15f6347d23b6..e011beb2e5e3 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -635,8 +635,6 @@ void mark_rodata_ro(void) section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata; update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, section_size, PAGE_KERNEL_RO); - - debug_checkwx(); } static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end, diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 72341b9fb552..90dcc2844056 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -171,12 +171,6 @@ static inline void mmu_mark_rodata_ro(void) { } void __init mmu_mapin_immr(void); #endif -#ifdef CONFIG_DEBUG_WX -void ptdump_check_wx(void); -#else -static inline void ptdump_check_wx(void) { } -#endif - static inline bool debug_pagealloc_enabled_or_kfence(void) { return IS_ENABLED(CONFIG_KFENCE) || debug_pagealloc_enabled(); diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index 5c02fd08d61e..12498017da8e 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -153,7 +153,6 @@ void mark_rodata_ro(void) if (v_block_mapped((unsigned long)_stext + 1)) { mmu_mark_rodata_ro(); - ptdump_check_wx(); return; } @@ -166,9 +165,6 @@ void mark_rodata_ro(void) PFN_DOWN((unsigned long)_stext); set_memory_ro((unsigned long)_stext, numpages); - - // mark_initmem_nx() should have already run by now - ptdump_check_wx(); } #endif diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index 5ac1fd30341b..1b366526f4f2 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -150,9 +150,6 @@ void mark_rodata_ro(void) radix__mark_rodata_ro(); else hash__mark_rodata_ro(); - - // mark_initmem_nx() should have already run by now - ptdump_check_wx(); } void mark_initmem_nx(void) diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index 2313053fe679..620d4917ebe8 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -343,6 +343,9 @@ void ptdump_check_wx(void) } }; + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !mmu_has_feature(MMU_FTR_KERNEL_RO)) + return; + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); if (st.wx_pages) diff --git a/arch/riscv/include/asm/ptdump.h b/arch/riscv/include/asm/ptdump.h deleted file mode 100644 index 3c9ea6dd5af7..000000000000 --- a/arch/riscv/include/asm/ptdump.h +++ /dev/null @@ -1,22 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Copyright (C) 2019 SiFive - */ - -#ifndef _ASM_RISCV_PTDUMP_H -#define _ASM_RISCV_PTDUMP_H - -void ptdump_check_wx(void); - -#ifdef CONFIG_DEBUG_WX -static inline void debug_checkwx(void) -{ - ptdump_check_wx(); -} -#else -static inline void debug_checkwx(void) -{ -} -#endif - -#endif /* _ASM_RISCV_PTDUMP_H */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 2e011cbddf3a..55c4deb1b332 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -29,7 +29,6 @@ #include #include #include -#include #include #include #include @@ -720,8 +719,6 @@ void mark_rodata_ro(void) if (IS_ENABLED(CONFIG_64BIT)) set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data), set_memory_ro); - - debug_checkwx(); } #else static __init pgprot_t pgprot_from_va(uintptr_t va) diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 657c27bc07a7..075265603313 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -9,7 +9,6 @@ #include #include -#include #include #include diff --git a/arch/s390/include/asm/ptdump.h b/arch/s390/include/asm/ptdump.h deleted file mode 100644 index f960b2896606..000000000000 --- a/arch/s390/include/asm/ptdump.h +++ /dev/null @@ -1,14 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -#ifndef _ASM_S390_PTDUMP_H -#define _ASM_S390_PTDUMP_H - -void ptdump_check_wx(void); - -static inline void debug_checkwx(void) -{ - if (IS_ENABLED(CONFIG_DEBUG_WX)) - ptdump_check_wx(); -} - -#endif /* _ASM_S390_PTDUMP_H */ diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index d37a8f607b71..8dcb4e0c71bd 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -6,7 +6,6 @@ #include #include #include -#include #include #include #include diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 43e612bc2bcd..d2e5eff9d1de 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -37,7 +37,6 @@ #include #include #include -#include #include #include #include @@ -109,7 +108,6 @@ void mark_rodata_ro(void) __set_memory_ro(__start_ro_after_init, __end_ro_after_init); pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); - debug_checkwx(); } int set_memory_encrypted(unsigned long vaddr, int numpages) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 57bab91bbf50..036ce63f3b95 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -32,6 +32,7 @@ void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm); void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm, bool user); void ptdump_walk_pgd_level_checkwx(void); +#define ptdump_check_wx() ptdump_walk_pgd_level_checkwx() void ptdump_walk_user_pgd_level_checkwx(void); /* @@ -41,10 +42,8 @@ void ptdump_walk_user_pgd_level_checkwx(void); #define pgprot_decrypted(prot) __pgprot(cc_mkdec(pgprot_val(prot))) #ifdef CONFIG_DEBUG_WX -#define debug_checkwx() ptdump_walk_pgd_level_checkwx() #define debug_checkwx_user() ptdump_walk_user_pgd_level_checkwx() #else -#define debug_checkwx() do { } while (0) #define debug_checkwx_user() do { } while (0) #endif diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index e1b599ecbbc2..0008524eebe9 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -433,6 +433,9 @@ void ptdump_walk_user_pgd_level_checkwx(void) void ptdump_walk_pgd_level_checkwx(void) { + if (!(__supported_pte_mask & _PAGE_NX)) + return; + ptdump_walk_pgd_level_core(NULL, &init_mm, INIT_PGD, true, false); } diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index b63403d7179d..5c736b707cae 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -800,6 +800,4 @@ void mark_rodata_ro(void) set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); #endif mark_nxdata_nx(); - if (__supported_pte_mask & _PAGE_NX) - debug_checkwx(); } diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index a190aae8ceaf..16e248769338 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1412,8 +1412,6 @@ void mark_rodata_ro(void) (void *)text_end, (void *)rodata_start); free_kernel_image_pages("unused kernel image (rodata/data gap)", (void *)rodata_end, (void *)_sdata); - - debug_checkwx(); } /* diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h index 2a3a95586425..c10513739bf9 100644 --- a/include/linux/ptdump.h +++ b/include/linux/ptdump.h @@ -19,5 +19,12 @@ struct ptdump_state { }; void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd); +void ptdump_check_wx(void); + +static inline void debug_checkwx(void) +{ + if (IS_ENABLED(CONFIG_DEBUG_WX)) + ptdump_check_wx(); +} #endif /* _LINUX_PTDUMP_H */ diff --git a/init/main.c b/init/main.c index e24b0780fdff..749a9f8d2c9b 100644 --- a/init/main.c +++ b/init/main.c @@ -99,6 +99,7 @@ #include #include #include +#include #include #include @@ -1408,6 +1409,7 @@ static void mark_readonly(void) */ rcu_barrier(); mark_rodata_ro(); + debug_checkwx(); rodata_test(); } else pr_info("Kernel memory protection disabled.\n");