From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:52482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1415116AbgJYKQt (ORCPT ); Sun, 25 Oct 2020 06:16:49 -0400 From: Mike Rapoport Subject: [PATCH 2/4] PM: hibernate: improve robustness of mapping pages in the direct map Date: Sun, 25 Oct 2020 12:15:53 +0200 Message-Id: <20201025101555.3057-3-rppt@kernel.org> In-Reply-To: <20201025101555.3057-1-rppt@kernel.org> References: <20201025101555.3057-1-rppt@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-ID: To: Andrew Morton Cc: Albert Ou , Andy Lutomirski , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Christian Borntraeger , Christoph Lameter , "David S. Miller" , Dave Hansen , David Hildenbrand , David Rientjes , "Edgecombe, Rick P" , "H. Peter Anvin" , Heiko Carstens , Ingo Molnar , Joonsoo Kim , "Kirill A. Shutemov" , Len Brown , Michael Ellerman , Mike Rapoport , Mike Rapoport , Palmer Dabbelt , Paul Mackerras , Paul Walmsley , Pavel Machek , Pekka Enberg , Peter Zijlstra , "Rafael J. Wysocki" , Thomas Gleixner , Vasily Gorbik , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, x86@kernel.org From: Mike Rapoport When DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP is enabled a page may be not present in the direct map and has to be explicitly mapped before it could be copied. On arm64 it is possible that a page would be removed from the direct map using set_direct_map_invalid_noflush() but __kernel_map_pages() will refuse to map this page back if DEBUG_PAGEALLOC is disabled. Explicitly use set_direct_map_{default,invalid}_noflush() for ARCH_HAS_SET_DIRECT_MAP case and debug_pagealloc_map_pages() for DEBUG_PAGEALLOC case. While on that, rename kernel_map_pages() to hibernate_map_page() and drop numpages parameter. Signed-off-by: Mike Rapoport --- kernel/power/snapshot.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index fa499466f645..ecb7b32ce77c 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -76,16 +76,25 @@ static inline void hibernate_restore_protect_page(void *page_address) {} static inline void hibernate_restore_unprotect_page(void *page_address) {} #endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ -#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) -static inline void -kernel_map_pages(struct page *page, int numpages, int enable) +static inline void hibernate_map_page(struct page *page, int enable) { - __kernel_map_pages(page, numpages, enable); + if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { + unsigned long addr = (unsigned long)page_address(page); + int ret; + + if (enable) + ret = set_direct_map_default_noflush(page); + else + ret = set_direct_map_invalid_noflush(page); + + if (WARN_ON(ret)) + return; + + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + } else { + debug_pagealloc_map_pages(page, 1, enable); + } } -#else -static inline void -kernel_map_pages(struct page *page, int numpages, int enable) {} -#endif static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); @@ -1366,9 +1375,9 @@ static void safe_copy_page(void *dst, struct page *s_page) if (kernel_page_present(s_page)) { do_copy_page(dst, page_address(s_page)); } else { - kernel_map_pages(s_page, 1, 1); + hibernate_map_page(s_page, 1); do_copy_page(dst, page_address(s_page)); - kernel_map_pages(s_page, 1, 0); + hibernate_map_page(s_page, 0); } } -- 2.28.0