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authorDavid Hildenbrand <david@redhat.com>2021-06-04 20:01:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-05 08:58:11 -0700
commit928130532e19f2f920840e41bd6b1cae742ea63b (patch)
tree1ba2746cbc3b1ed74bd28225fc3ff0b6adced4f2
parentbac9c6fa1f929213bbd0ac9cdf21e8e2f0916828 (diff)
downloadandroid-dev-928130532e19f2f920840e41bd6b1cae742ea63b.tar.gz
drivers/base/memory: fix trying offlining memory blocks with memory holes on aarch64
offline_pages() properly checks for memory holes and bails out. However, we do a page_zone(pfn_to_page(start_pfn)) before calling offline_pages() when offlining a memory block. We should not unconditionally call page_zone(pfn_to_page(start_pfn)) on aarch64 in offlining code, otherwise we can trigger a BUG when hitting a memory hole: kernel BUG at include/linux/mm.h:1383! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: loop processor efivarfs ip_tables x_tables ext4 mbcache jbd2 dm_mod igb nvme i2c_algo_bit mlx5_core i2c_core nvme_core firmware_class CPU: 13 PID: 1694 Comm: ranbug Not tainted 5.12.0-next-20210524+ #4 Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.6 06/28/2020 pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) pc : memory_subsys_offline+0x1f8/0x250 lr : memory_subsys_offline+0x1f8/0x250 Call trace: memory_subsys_offline+0x1f8/0x250 device_offline+0x154/0x1d8 online_store+0xa4/0x118 dev_attr_store+0x44/0x78 sysfs_kf_write+0xe8/0x138 kernfs_fop_write_iter+0x26c/0x3d0 new_sync_write+0x2bc/0x4f8 vfs_write+0x718/0xc88 ksys_write+0xf8/0x1e0 __arm64_sys_write+0x74/0xa8 invoke_syscall.constprop.0+0x78/0x1e8 do_el0_svc+0xe4/0x298 el0_svc+0x20/0x30 el0_sync_handler+0xb0/0xb8 el0_sync+0x178/0x180 Kernel panic - not syncing: Oops - BUG: Fatal exception SMP: stopping secondary CPUs Kernel Offset: disabled CPU features: 0x00000251,20000846 Memory Limit: none If nr_vmemmap_pages is set, we know that we are dealing with hotplugged memory that doesn't have any holes. So call page_zone(pfn_to_page(start_pfn)) only when really necessary -- when nr_vmemmap_pages is set and we actually adjust the present pages. Link: https://lkml.kernel.org/r/20210526075226.5572-1-david@redhat.com Fixes: a08a2ae34613 ("mm,memory_hotplug: allocate memmap from the added memory range") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Qian Cai (QUIC) <quic_qiancai@quicinc.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/base/memory.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b31b3af5c490..d5ffaab3cb61 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -218,14 +218,14 @@ static int memory_block_offline(struct memory_block *mem)
struct zone *zone;
int ret;
- zone = page_zone(pfn_to_page(start_pfn));
-
/*
* Unaccount before offlining, such that unpopulated zone and kthreads
* can properly be torn down in offline_pages().
*/
- if (nr_vmemmap_pages)
+ if (nr_vmemmap_pages) {
+ zone = page_zone(pfn_to_page(start_pfn));
adjust_present_page_count(zone, -nr_vmemmap_pages);
+ }
ret = offline_pages(start_pfn + nr_vmemmap_pages,
nr_pages - nr_vmemmap_pages);