Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8639a847 authored by Atsushi Kumagai's avatar Atsushi Kumagai Committed by Linus Torvalds
Browse files

kexec: update VMCOREINFO for compound_order/dtor 



makedumpfile refers page.lru.next to get the order of compound pages for
page filtering.

However, now the order is stored in page.compound_order, hence
VMCOREINFO should be updated to export the offset of
page.compound_order.

The fact is, page.compound_order was introduced already in kernel 4.0,
but the offset of it was the same as page.lru.next until kernel 4.3, so
this was not actual problem.

The above can be said also for page.lru.prev and page.compound_dtor,
it's necessary to detect hugetlbfs pages.  Further, the content was
changed from direct address to the ID which means dtor.

The problem is that unnecessary hugepages won't be removed from a dump
file in kernels 4.4.x and later.  This means that extra disk space would
be consumed.  It's a problem, but not critical.

Signed-off-by: default avatarAtsushi Kumagai <ats-kumagai@wm.jp.nec.com>
Acked-by: default avatarDave Young <dyoung@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b75a2bf8

kernel/kexec_core.c

+4 −2
Original line number Original line Diff line number Diff line
@@ -1415,6 +1415,8 @@ static int __init crash_save_vmcoreinfo_init(void) 
	VMCOREINFO_OFFSET(page, lru);

	VMCOREINFO_OFFSET(page, lru);

	VMCOREINFO_OFFSET(page, _mapcount);

	VMCOREINFO_OFFSET(page, _mapcount);

	VMCOREINFO_OFFSET(page, private);

	VMCOREINFO_OFFSET(page, private);

	VMCOREINFO_OFFSET(page, compound_dtor);

	VMCOREINFO_OFFSET(page, compound_order);

	VMCOREINFO_OFFSET(pglist_data, node_zones);

	VMCOREINFO_OFFSET(pglist_data, node_zones);

	VMCOREINFO_OFFSET(pglist_data, nr_zones);

	VMCOREINFO_OFFSET(pglist_data, nr_zones);

#ifdef CONFIG_FLAT_NODE_MEM_MAP

#ifdef CONFIG_FLAT_NODE_MEM_MAP
@@ -1447,8 +1449,8 @@ static int __init crash_save_vmcoreinfo_init(void) 
#ifdef CONFIG_X86

#ifdef CONFIG_X86

	VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);

	VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);

#endif

#endif

#ifdef CONFIG_HUGETLBFS

#ifdef CONFIG_HUGETLB_PAGE

	VMCOREINFO_SYMBOL(free_huge_page);

	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);

#endif

#endif





	arch_crash_save_vmcoreinfo();

	arch_crash_save_vmcoreinfo();