4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jan H. Schönherr jschoenh@amazon.de
commit 77dd66a3c67c93ab401ccc15efff25578be281fd upstream.
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: 9476df7d80df ("mm: introduce find_dev_pagemap()") Signed-off-by: Jan H. Schönherr jschoenh@amazon.de Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/memremap.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -248,13 +248,16 @@ int device_private_entry_fault(struct vm 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(); @@ -309,7 +312,7 @@ static void devm_memremap_pages_release( 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 && pgmap->altmap->alloc, "%s: failed to free all reserved pages\n", __func__); } @@ -459,7 +462,7 @@ void *devm_memremap_pages(struct device 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(page_map); return ERR_PTR(error); }