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mm: Fix devm_memremap_pages() collision handling 

If devm_memremap_pages() detects a collision while adding entries
to the radix-tree, we call pgmap_radix_release(). Unfortunately,
the function removes *all* entries for the range -- including the
entries that caused the collision in the first place.

Modify pgmap_radix_release() to take an additional argument to
indicate where to stop, so that only newly added entries are removed
from the tree.

Cc: <stable@vger.kernel.org>
Fixes: 9476df7d80 ("mm: introduce find_dev_pagemap()")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
hifive-unleashed-5.1
Jan H. Schönherr 2018-01-19 16:26:33 -08:00 committed by Dan Williams
parent 10a0cd6e49
commit 77dd66a3c6
1 changed files with 7 additions and 4 deletions
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11
kernel/memremap.c
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@ -241,13 +241,16 @@ int device_private_entry_fault(struct vm_area_struct *vma,
EXPORT_SYMBOL(device_private_entry_fault);
#endif /* CONFIG_DEVICE_PRIVATE */
static void pgmap_radix_release(struct resource *res)
static void pgmap_radix_release(struct resource *res, unsigned long end_pgoff)
{
unsigned long pgoff, order;
mutex_lock(&pgmap_lock);
foreach_order_pgoff(res, order, pgoff)
foreach_order_pgoff(res, order, pgoff) {
if (pgoff >= end_pgoff)
break;
radix_tree_delete(&pgmap_radix, PHYS_PFN(res->start) + pgoff);
}
mutex_unlock(&pgmap_lock);
synchronize_rcu();
@ -302,7 +305,7 @@ static void devm_memremap_pages_release(void *data)
mem_hotplug_done();
untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
pgmap_radix_release(res);
pgmap_radix_release(res, -1);
dev_WARN_ONCE(dev, pgmap->altmap.alloc,
"%s: failed to free all reserved pages\n", __func__);
}
@ -418,7 +421,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
err_pfn_remap:
err_radix:
pgmap_radix_release(res);
pgmap_radix_release(res, pgoff);
devres_free(pgmap);
return ERR_PTR(error);
}