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Commit 5a982cbc authored by Yinghai Lu's avatar Yinghai Lu Committed by Linus Torvalds
Browse files

mm: fix boundary checking in free_bootmem_core 



With numa enabled, some callers could have a range of memory on one node
but try to free that on other node.  This can cause some pages to be
freed wrongly.

For example: when we try to allocate 128g boot ram early for
gart/swiotlb, and free that range later so gart/swiotlb can get some
range afterwards.

With this patch, we don't need to care which node holds the range, just
loop to call free_bootmem_node for all online nodes.

This patch makes free_bootmem_core() more robust by trimming the sidx
and eidx according the ram range that the node has.

And make the free_bootmem_core handle this out of range case.  We could
use bdata_list to make sure the range can be freed for sure.  So next
time, we don't need to loop online nodes and could use free_bootmem
directly.

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Tested-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2875fb65

mm/bootmem.c

+19 −6
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ static int __init reserve_bootmem_core(bootmem_data_t *bdata, 
	BUG_ON(!size);

	BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);

	BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);

	BUG_ON(addr < bdata->node_boot_start);



	sidx = PFN_DOWN(addr - bdata->node_boot_start);

	eidx = PFN_UP(addr + size - bdata->node_boot_start);
@@ -156,21 +157,31 @@ static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr, 
	unsigned long sidx, eidx;

	unsigned long i;



	BUG_ON(!size);



	/* out range */

	if (addr + size < bdata->node_boot_start ||

		PFN_DOWN(addr) > bdata->node_low_pfn)

		return;

	/*

	 * round down end of usable mem, partially free pages are

	 * considered reserved.

	 */

	BUG_ON(!size);

	BUG_ON(PFN_DOWN(addr + size) > bdata->node_low_pfn);



	if (addr < bdata->last_success)

	if (addr >= bdata->node_boot_start && addr < bdata->last_success)

		bdata->last_success = addr;



	/*

	 * Round up the beginning of the address.

	 * Round up to index to the range.

	 */

	if (PFN_UP(addr) > PFN_DOWN(bdata->node_boot_start))

		sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);

	else

		sidx = 0;



	eidx = PFN_DOWN(addr + size - bdata->node_boot_start);

	if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))

		eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);



	for (i = sidx; i < eidx; i++) {

		if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
@@ -421,7 +432,9 @@ int __init reserve_bootmem(unsigned long addr, unsigned long size, 


void __init free_bootmem(unsigned long addr, unsigned long size)

{

	free_bootmem_core(NODE_DATA(0)->bdata, addr, size);

	bootmem_data_t *bdata;

	list_for_each_entry(bdata, &bdata_list, list)

		free_bootmem_core(bdata, addr, size);

}



unsigned long __init free_all_bootmem(void)