Commit 26562c59 authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
Browse files

kcore: register vmemmap range 



Benjamin Herrenschmidt <benh@kernel.crashing.org> pointed out that vmemmap
range is not included in KCORE_RAM, KCORE_VMALLOC ....

This adds KCORE_VMEMMAP if SPARSEMEM_VMEMMAP is used.  By this, vmemmap
can be readable via /proc/kcore

Because it's not vmalloc area, vread/vwrite cannot be used.  But the range
is static against the memory layout, this patch handles vmemmap area by
the same scheme with physical memory.

This patch assumes SPARSEMEM_VMEMMAP range is not in VMALLOC range.  It's
correct now.

[akpm@linux-foundation.org: fix typo]
Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3089aa1b

fs/proc/kcore.c

+50 −2
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ static void free_kclist_ents(struct list_head *head) 
	}

}

/*

 * Replace all KCORE_RAM information with passed list.

 * Replace all KCORE_RAM/KCORE_VMEMMAP information with passed list.

 */

static void __kcore_update_ram(struct list_head *list)

{
@@ -113,7 +113,8 @@ static void __kcore_update_ram(struct list_head *list) 
	write_lock(&kclist_lock);

	if (kcore_need_update) {

		list_for_each_entry_safe(pos, tmp, &kclist_head, list) {

			if (pos->type == KCORE_RAM)

			if (pos->type == KCORE_RAM

				|| pos->type == KCORE_VMEMMAP)

				list_move(&pos->list, &garbage);

		}

		list_splice_tail(list, &kclist_head);
@@ -151,6 +152,47 @@ static int kcore_update_ram(void) 


#else /* !CONFIG_HIGHMEM */



#ifdef CONFIG_SPARSEMEM_VMEMMAP

/* calculate vmemmap's address from given system ram pfn and register it */

int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)

{

	unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT;

	unsigned long nr_pages = ent->size >> PAGE_SHIFT;

	unsigned long start, end;

	struct kcore_list *vmm, *tmp;





	start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK;

	end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1;

	end = ALIGN(end, PAGE_SIZE);

	/* overlap check (because we have to align page */

	list_for_each_entry(tmp, head, list) {

		if (tmp->type != KCORE_VMEMMAP)

			continue;

		if (start < tmp->addr + tmp->size)

			if (end > tmp->addr)

				end = tmp->addr;

	}

	if (start < end) {

		vmm = kmalloc(sizeof(*vmm), GFP_KERNEL);

		if (!vmm)

			return 0;

		vmm->addr = start;

		vmm->size = end - start;

		vmm->type = KCORE_VMEMMAP;

		list_add_tail(&vmm->list, head);

	}

	return 1;



}

#else

int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)

{

	return 1;

}



#endif



static int

kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)

{
@@ -181,6 +223,12 @@ kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg) 


	ent->type = KCORE_RAM;

	list_add_tail(&ent->list, head);



	if (!get_sparsemem_vmemmap_info(ent, head)) {

		list_del(&ent->list);

		goto free_out;

	}



	return 0;

free_out:

	kfree(ent);

include/linux/proc_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ enum kcore_type { 
	KCORE_TEXT,

	KCORE_VMALLOC,

	KCORE_RAM,

	KCORE_VMEMMAP,

	KCORE_OTHER,

};

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