If a driver/subsystem tries to do an allocation after memblocks have
been freed and the memory handed to the buddy allocator, it will not
actually be legal to use that allocation - the buddy allocator owns the
memory. This is handled by the memblocks function which does allocations
and returns virtual addresses by printing a warning and doing a kmalloc
instead. However, the physical allocation function does not to do this
check - callers of the physical alloc function are unprotected against
mis-use.
Improve the error catching here by moving the check into the physical
allocation function which is used by the virtual addr allocation
function.
Signed-off-by: James Gowans <jgowans@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Alex Graf <graf@xxxxxxxxx>
---
mm/memblock.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/mm/memblock.c b/mm/memblock.c
index d09136e040d3..dd4f237dc1fc 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1457,6 +1457,17 @@ phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
align = SMP_CACHE_BYTES;
}
+ /*
+ * Detect any accidental use of these APIs after slab is ready, as at
+ * this moment memblock may be deinitialized already and its
+ * internal data may be destroyed (after execution of memblock_free_all)
+ */
+ if (WARN_ON_ONCE(slab_is_available())) {
+ void *vaddr = kzalloc_node(size, GFP_NOWAIT, nid);
+
+ return vaddr ? virt_to_phys(vaddr) : 0;
+ }
+
again:
found = memblock_find_in_range_node(size, align, start, end, nid,
flags);
@@ -1576,13 +1587,6 @@ static void * __init memblock_alloc_internal(
{
phys_addr_t alloc;
- /*
- * Detect any accidental use of these APIs after slab is ready, as at
- * this moment memblock may be deinitialized already and its
- * internal data may be destroyed (after execution of memblock_free_all)
- */
- if (WARN_ON_ONCE(slab_is_available()))
- return kzalloc_node(size, GFP_NOWAIT, nid);
if (max_addr > memblock.current_limit)
max_addr = memblock.current_limit;
--
2.34.1
