We end up calling __add_memory() without the device hotplug lock held. (I used a local patch to assert in __add_memory() that the device_hotplug_lock is held - I might upstream that as well soon) [ 26.771684] create_memory_block_devices+0xa4/0x140 [ 26.772952] add_memory_resource+0xde/0x200 [ 26.773987] __add_memory+0x6e/0xa0 [ 26.775161] acpi_memory_device_add+0x149/0x2b0 [ 26.776263] acpi_bus_attach+0xf1/0x1f0 [ 26.777247] acpi_bus_attach+0x66/0x1f0 [ 26.778268] acpi_bus_attach+0x66/0x1f0 [ 26.779073] acpi_bus_attach+0x66/0x1f0 [ 26.780143] acpi_bus_scan+0x3e/0x90 [ 26.780844] acpi_scan_init+0x109/0x257 [ 26.781638] acpi_init+0x2ab/0x30d [ 26.782248] do_one_initcall+0x58/0x2cf [ 26.783181] kernel_init_freeable+0x1bd/0x247 [ 26.784345] kernel_init+0x5/0xf1 [ 26.785314] ret_from_fork+0x3a/0x50 So perform the locking just like in acpi_device_hotplug(). Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> --- drivers/acpi/scan.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 0e28270b0fd8..cbc9d64b48dd 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2204,7 +2204,9 @@ int __init acpi_scan_init(void) acpi_gpe_apply_masked_gpes(); acpi_update_all_gpes(); + lock_device_hotplug(); mutex_lock(&acpi_scan_lock); + /* * Enumerate devices in the ACPI namespace. */ @@ -2232,6 +2234,7 @@ int __init acpi_scan_init(void) out: mutex_unlock(&acpi_scan_lock); + unlock_device_hotplug(); return result; } -- 2.21.0
