From 8f1d26d0e59b9676587c54578f976709b625d6e9 Mon Sep 17 00:00:00 2001 From: Atsushi Kumagai Date: Wed, 30 Jul 2014 16:08:39 -0700 Subject: kexec: export free_huge_page to VMCOREINFO PG_head_mask was added into VMCOREINFO to filter huge pages in b3acc56bfe1 ("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 Acked-by: Baoquan He Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 1 + kernel/kexec.c | 2 ++ mm/hugetlb.c | 2 +- 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 255cd5cc075..a23c096b308 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -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); diff --git a/kernel/kexec.c b/kernel/kexec.c index 369f41a9412..23a088fec3c 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -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(); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 9221c02ed9e..7a0a73d2fcf 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -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 -- cgit v1.2.3