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[23.128.96.18]) by mx.google.com with ESMTP id w13si10704457edc.122.2021.02.08.01.00.55; Mon, 08 Feb 2021 01:01:19 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=DtKMmjBQ; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231260AbhBHJAT (ORCPT + 99 others); Mon, 8 Feb 2021 04:00:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:43336 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230155AbhBHIwd (ORCPT ); Mon, 8 Feb 2021 03:52:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8D61364EA3; Mon, 8 Feb 2021 08:50:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612774235; bh=/oLvYE09U2h83dGe9bhwIStTT4PzFzLjoBHxUn7Lnik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DtKMmjBQDGpRq7Uu95LBig01b9MovrzCHmZkRIqrWWCcD7iCsHPCfSrCUW/ZuKUrs 9AktXmpn1oBkTf4+HJT/IMOnqWvj3l++UfZpg3qTeZI7ZrqyyAhOEaQXSpihNhm0q/ 3W8i/ogIugzEOR+0UzWZJ2+0EOdNzCM2z/d/444CHiYUYZzGXLzVPJ9wjL6PqPp672 l+71bl/bgCCahtucF/97tod13D0QI4hBtpDFedT7LN0vFtQkrpr/i1fI+13dmIIR2R dexIPYuUOcPqu1QkKe1p3QFmPq5I/LBx9tD0cmzuik1Z3CnhXr2h6WLo+LtVXiMzdV 34Ep12yzF0EBQ== From: Mike Rapoport To: Andrew Morton Cc: Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Michal Hocko , Mike Rapoport , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shakeel Butt , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer , Palmer Dabbelt Subject: [PATCH v17 05/10] set_memory: allow querying whether set_direct_map_*() is actually enabled Date: Mon, 8 Feb 2021 10:49:15 +0200 Message-Id: <20210208084920.2884-6-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210208084920.2884-1-rppt@kernel.org> References: <20210208084920.2884-1-rppt@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Rapoport On arm64, set_direct_map_*() functions may return 0 without actually changing the linear map. This behaviour can be controlled using kernel parameters, so we need a way to determine at runtime whether calls to set_direct_map_invalid_noflush() and set_direct_map_default_noflush() have any effect. Extend set_memory API with can_set_direct_map() function that allows checking if calling set_direct_map_*() will actually change the page table, replace several occurrences of open coded checks in arm64 with the new function and provide a generic stub for architectures that always modify page tables upon calls to set_direct_map APIs. Signed-off-by: Mike Rapoport Reviewed-by: Catalin Marinas Reviewed-by: David Hildenbrand Cc: Alexander Viro Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christopher Lameter Cc: Dan Williams Cc: Dave Hansen Cc: Elena Reshetova Cc: Hagen Paul Pfeifer Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: James Bottomley Cc: "Kirill A. Shutemov" Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael Kerrisk Cc: Palmer Dabbelt Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Rick Edgecombe Cc: Roman Gushchin Cc: Shakeel Butt Cc: Shuah Khan Cc: Thomas Gleixner Cc: Tycho Andersen Cc: Will Deacon --- arch/arm64/include/asm/Kbuild | 1 - arch/arm64/include/asm/cacheflush.h | 6 ------ arch/arm64/include/asm/set_memory.h | 17 +++++++++++++++++ arch/arm64/kernel/machine_kexec.c | 1 + arch/arm64/mm/mmu.c | 6 +++--- arch/arm64/mm/pageattr.c | 13 +++++++++---- include/linux/set_memory.h | 12 ++++++++++++ 7 files changed, 42 insertions(+), 14 deletions(-) create mode 100644 arch/arm64/include/asm/set_memory.h diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 07ac208edc89..73aa25843f65 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -3,5 +3,4 @@ generic-y += early_ioremap.h generic-y += mcs_spinlock.h generic-y += qrwlock.h generic-y += qspinlock.h -generic-y += set_memory.h generic-y += user.h diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index d3598419a284..b1bdf83a73db 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -136,12 +136,6 @@ static __always_inline void __flush_icache_all(void) dsb(ish); } -int set_memory_valid(unsigned long addr, int numpages, int enable); - -int set_direct_map_invalid_noflush(struct page *page, int numpages); -int set_direct_map_default_noflush(struct page *page, int numpages); -bool kernel_page_present(struct page *page); - #include #endif /* __ASM_CACHEFLUSH_H */ diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h new file mode 100644 index 000000000000..ecb6b0f449ab --- /dev/null +++ b/arch/arm64/include/asm/set_memory.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _ASM_ARM64_SET_MEMORY_H +#define _ASM_ARM64_SET_MEMORY_H + +#include + +bool can_set_direct_map(void); +#define can_set_direct_map can_set_direct_map + +int set_memory_valid(unsigned long addr, int numpages, int enable); + +int set_direct_map_invalid_noflush(struct page *page, int numpages); +int set_direct_map_default_noflush(struct page *page, int numpages); +bool kernel_page_present(struct page *page); + +#endif /* _ASM_ARM64_SET_MEMORY_H */ diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index a0b144cfaea7..0cbc50c4fa5a 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 9445eb77e3da..bd8521637120 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -492,7 +493,7 @@ static void __init map_mem(pgd_t *pgdp) int flags = 0; u64 i; - if (rodata_full || crash_mem_map || debug_pagealloc_enabled()) + if (can_set_direct_map() || crash_mem_map) flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; /* @@ -1470,8 +1471,7 @@ int arch_add_memory(int nid, u64 start, u64 size, * KFENCE requires linear map to be mapped at page granularity, so that * it is possible to protect/unprotect single pages in the KFENCE pool. */ - if (rodata_full || debug_pagealloc_enabled() || - IS_ENABLED(CONFIG_KFENCE)) + if (can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE)) flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index b53ef37bf95a..d505172265b0 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -19,6 +19,11 @@ struct page_change_data { bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED); +bool can_set_direct_map(void) +{ + return rodata_full || debug_pagealloc_enabled(); +} + static int change_page_range(pte_t *ptep, unsigned long addr, void *data) { struct page_change_data *cdata = data; @@ -156,7 +161,7 @@ int set_direct_map_invalid_noflush(struct page *page, int numpages) }; unsigned long size = PAGE_SIZE * numpages; - if (!debug_pagealloc_enabled() && !rodata_full) + if (!can_set_direct_map()) return 0; return apply_to_page_range(&init_mm, @@ -172,7 +177,7 @@ int set_direct_map_default_noflush(struct page *page, int numpages) }; unsigned long size = PAGE_SIZE * numpages; - if (!debug_pagealloc_enabled() && !rodata_full) + if (!can_set_direct_map()) return 0; return apply_to_page_range(&init_mm, @@ -183,7 +188,7 @@ int set_direct_map_default_noflush(struct page *page, int numpages) #ifdef CONFIG_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) { - if (!debug_pagealloc_enabled() && !rodata_full) + if (!can_set_direct_map()) return; set_memory_valid((unsigned long)page_address(page), numpages, enable); @@ -208,7 +213,7 @@ bool kernel_page_present(struct page *page) pte_t *ptep; unsigned long addr = (unsigned long)page_address(page); - if (!debug_pagealloc_enabled() && !rodata_full) + if (!can_set_direct_map()) return true; pgdp = pgd_offset_k(addr); diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h index c650f82db813..7b4b6626032d 100644 --- a/include/linux/set_memory.h +++ b/include/linux/set_memory.h @@ -28,7 +28,19 @@ static inline bool kernel_page_present(struct page *page) { return true; } +#else /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */ +/* + * Some architectures, e.g. ARM64 can disable direct map modifications at + * boot time. Let them overrive this query. + */ +#ifndef can_set_direct_map +static inline bool can_set_direct_map(void) +{ + return true; +} +#define can_set_direct_map can_set_direct_map #endif +#endif /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */ #ifndef set_mce_nospec static inline int set_mce_nospec(unsigned long pfn, bool unmap) -- 2.28.0