kexec: export free_huge_page to VMCOREINFO (8f1d26d0) · Commits · 戴 / test

PG_head_mask was added into VMCOREINFO to filter huge pages in ("kexec: save PG_head_mask in VMCOREINFO"), but makedumpfile still need another symbol to filter *hugetlbfs* pages. If a user hope to filter user pages, makedumpfile tries to exclude them by checking the condition whether the page is anonymous, but hugetlbfs pages aren't anonymous while they also be user pages. We know it's possible to detect them in the same way as PageHuge(), so we need the start address of free_huge_page(): int PageHuge(struct page *page) { if (!PageCompound(page)) return 0; page = compound_head(page); return get_compound_page_dtor(page) == free_huge_page; } For that reason, this patch changes free_huge_page() into public to export it to VMCOREINFO. Signed-off-by:

Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Acked-by:

Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

include/linux/hugetlb.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -80,6 +80,7 @@ int dequeue_hwpoisoned_huge_page(struct page *page);
		bool isolate_huge_page(struct page page, struct list_head list);
		void putback_active_hugepage(struct page *page);
		bool is_hugepage_active(struct page *page);
		void free_huge_page(struct page *page);

		#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
		pte_t huge_pmd_share(struct mm_struct mm, unsigned long addr, pud_t *pud);

kernel/kexec.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@
		#include <linux/swap.h>
		#include <linux/syscore_ops.h>
		#include <linux/compiler.h>
		#include <linux/hugetlb.h>

		#include <asm/page.h>
		#include <asm/uaccess.h>
		@@ -1619,6 +1620,7 @@ static int __init crash_save_vmcoreinfo_init(void)
		#endif
		VMCOREINFO_NUMBER(PG_head_mask);
		VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
		VMCOREINFO_SYMBOL(free_huge_page);

		arch_crash_save_vmcoreinfo();
		update_vmcoreinfo_note();

mm/hugetlb.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -856,7 +856,7 @@ struct hstate *size_to_hstate(unsigned long size)
		return NULL;
		}

		static void free_huge_page(struct page *page)
		void free_huge_page(struct page *page)
		{
		/*
		* Can't pass hstate in here because it is called from the

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