[ Upstream commit 46e66dab85 ]
memory_group_register_static takes maximum number of pages as the argument
while dev_dax_kmem_probe passes total_len (in bytes) as the argument.
IIUC, I don't see any crash/panic impact as such. As,
memory_group_register_static just set the max_pages limit which is used in
auto_movable_zone_for_pfn to determine the zone.
which might cause these condition to behave differently,
This will be true always so jump will happen to kernel_zone
...
if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages))
goto kernel_zone;
...
kernel_zone:
return default_kernel_zone_for_pfn(nid, pfn, nr_pages);
Here, In below, zone_intersects compare range will be larger as nr_pages
will be higher (derived from total_len passed in dev_dax_kmem_probe).
...
static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn,
unsigned long nr_pages)
{
struct pglist_data *pgdat = NODE_DATA(nid);
int zid;
for (zid = 0; zid < ZONE_NORMAL; zid++) {
struct zone *zone = &pgdat->node_zones[zid];
if (zone_intersects(zone, start_pfn, nr_pages))
return zone;
}
return &pgdat->node_zones[ZONE_NORMAL];
}
Incorrect zone will be returned here, which in later time might cause bigger
problem.
Fixes: eedf634aac ("dax/kmem: use a single static memory group for a single probed unit")
Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com>
Link: https://lore.kernel.org/r/20230621155025.370672-1-tsahu@linux.ibm.com
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cd5bd4b713