Mikhail Zaslonko 4e8346d0be memory_hotplug: fix kernel_panic on offline page processing ... Within show_valid_zones() the function test_pages_in_a_zone() should be called for online memory blocks only. Otherwise it might lead to the VM_BUG_ON due to uninitialized struct pages (when CONFIG_DEBUG_VM_PGFLAGS kernel option is set): page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) ------------[ cut here ]------------ Call Trace: ([<000000000038f91e>] test_pages_in_a_zone+0xe6/0x168) [<0000000000923472>] show_valid_zones+0x5a/0x1a8 [<0000000000900284>] dev_attr_show+0x3c/0x78 [<000000000046f6f0>] sysfs_kf_seq_show+0xd0/0x150 [<00000000003ef662>] seq_read+0x212/0x4b8 [<00000000003bf202>] __vfs_read+0x3a/0x178 [<00000000003bf3ca>] vfs_read+0x8a/0x148 [<00000000003bfa3a>] ksys_read+0x62/0xb8 [<0000000000bc2220>] system_call+0xdc/0x2d8 That VM_BUG_ON was triggered by the page poisoning introduced in mm/sparse.c with the git commit d0dc12e86b ("mm/memory_hotplug: optimize memory hotplug"). With the same commit the new 'nid' field has been added to the struct memory_block in order to store and later on derive the node id for offline pages (instead of accessing struct page which might be uninitialized). But one reference to nid in show_valid_zones() function has been overlooked. Fixed with current commit. Also, nr_pages will not be used any more after test_pages_in_a_zone() call, do not update it. Link: http://lkml.kernel.org/r/20180828090539.41491-1-zaslonko@linux.ibm.com Fixes: d0dc12e86b ("mm/memory_hotplug: optimize memory hotplug") Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: <stable@vger.kernel.org> [4.17+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2018-09-04 16:45:02 -07:00
..
firmware_loader	mm: provide a fallback for PAGE_KERNEL_RO for architectures	2018-08-17 16:20:29 -07:00
power	PM / clk: signedness bug in of_pm_clk_add_clks()	2018-08-24 11:52:34 +02:00
regmap	regmap: Support non-incrementing registers	2018-08-09 11:15:06 +01:00
test
arch_topology.c
attribute_container.c
base.h
bus.c
cacheinfo.c
class.c
component.c
container.c
core.c	Driver core patches for 4.19-rc1	2018-08-18 11:44:53 -07:00
cpu.c
dd.c	Merge 4.18-rc7 into driver-core-next	2018-07-30 10:08:09 +02:00
devcon.c
devcoredump.c
devres.c
devtmpfs.c
driver.c
firmware.c
hypervisor.c
init.c
isa.c
Kconfig
Makefile
map.c
memory.c	memory_hotplug: fix kernel_panic on offline page processing	2018-09-04 16:45:02 -07:00
module.c
node.c	mm/memory_hotplug.c: drop unnecessary checks from register_mem_sect_under_node()	2018-08-17 16:20:29 -07:00
pinctrl.c
platform-msi.c
platform.c
property.c
soc.c
syscore.c
topology.c
transport_class.c