Re: [PATCH v3 2/4] PM: hibernate: make direct map manipulations more explicit
From: Mike Rapoport <rppt@kernel.org>
Date: 2020-11-03 12:14:07
Also in:
linux-mm, linux-pm, linux-riscv, linux-s390, linuxppc-dev, lkml, sparclinux
On Tue, Nov 03, 2020 at 02:08:16PM +0300, Kirill A. Shutemov wrote:
On Sun, Nov 01, 2020 at 07:08:13PM +0200, Mike Rapoport wrote:quoted
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 46b1804c1ddf..054c8cce4236 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c@@ -76,6 +76,32 @@ 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 */ +static inline void hibernate_map_page(struct page *page, int enable) +{ + if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { + unsigned long addr = (unsigned long)page_address(page); + int ret; + + /* + * This should not fail because remapping a page here means + * that we only update protection bits in an existing PTE. + * It is still worth to have WARN_ON() here if something + * changes and this will no longer be the case. + */ + if (enable) + ret = set_direct_map_default_noflush(page); + else + ret = set_direct_map_invalid_noflush(page); + + if (WARN_ON(ret))_ONCE?
I've changed it to pr_warn() after David said people enable panic on warn in production kernels.
quoted
+ return; + + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + } else { + debug_pagealloc_map_pages(page, 1, enable); + } +} + static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *);-- Kirill A. Shutemov
-- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel