Revision 924d8696751c4b9e58263bc82efdafcf875596a6 authored by James Morse on 16 August 2016, 09:46:38 UTC, committed by Rafael J. Wysocki on 16 August 2016, 11:16:36 UTC
rtree_next_node() walks the linked list of leaf nodes to find the next
block of pages in the struct memory_bitmap. If it walks off the end of
the list of nodes, it walks the list of memory zones to find the next
region of memory. If it walks off the end of the list of zones, it
returns false.
This leaves the struct bm_position's node and zone pointers pointing
at their respective struct list_heads in struct mem_zone_bm_rtree.
memory_bm_find_bit() uses struct bm_position's node and zone pointers
to avoid walking lists and trees if the next bit appears in the same
node/zone. It handles these values being stale.
Swap rtree_next_node()s 'step then test' to 'test-next then step',
this means if we reach the end of memory we return false and leave
the node and zone pointers as they were.
This fixes a panic on resume using AMD Seattle with 64K pages:
[ 6.868732] Freezing user space processes ... (elapsed 0.000 seconds) done.
[ 6.875753] Double checking all user space processes after OOM killer disable... (elapsed 0.000 seconds)
[ 6.896453] PM: Using 3 thread(s) for decompression.
[ 6.896453] PM: Loading and decompressing image data (5339 pages)...
[ 7.318890] PM: Image loading progress: 0%
[ 7.323395] Unable to handle kernel paging request at virtual address 00800040
[ 7.330611] pgd = ffff000008df0000
[ 7.334003] [00800040] *pgd=00000083fffe0003, *pud=00000083fffe0003, *pmd=00000083fffd0003, *pte=0000000000000000
[ 7.344266] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[ 7.349825] Modules linked in:
[ 7.352871] CPU: 2 PID: 1 Comm: swapper/0 Tainted: G W I 4.8.0-rc1 #4737
[ 7.360512] Hardware name: AMD Overdrive/Supercharger/Default string, BIOS ROD1002C 04/08/2016
[ 7.369109] task: ffff8003c0220000 task.stack: ffff8003c0280000
[ 7.375020] PC is at set_bit+0x18/0x30
[ 7.378758] LR is at memory_bm_set_bit+0x24/0x30
[ 7.383362] pc : [<ffff00000835bbc8>] lr : [<ffff0000080faf18>] pstate: 60000045
[ 7.390743] sp : ffff8003c0283b00
[ 7.473551]
[ 7.475031] Process swapper/0 (pid: 1, stack limit = 0xffff8003c0280020)
[ 7.481718] Stack: (0xffff8003c0283b00 to 0xffff8003c0284000)
[ 7.800075] Call trace:
[ 7.887097] [<ffff00000835bbc8>] set_bit+0x18/0x30
[ 7.891876] [<ffff0000080fb038>] duplicate_memory_bitmap.constprop.38+0x54/0x70
[ 7.899172] [<ffff0000080fcc40>] snapshot_write_next+0x22c/0x47c
[ 7.905166] [<ffff0000080fe1b4>] load_image_lzo+0x754/0xa88
[ 7.910725] [<ffff0000080ff0a8>] swsusp_read+0x144/0x230
[ 7.916025] [<ffff0000080fa338>] load_image_and_restore+0x58/0x90
[ 7.922105] [<ffff0000080fa660>] software_resume+0x2f0/0x338
[ 7.927752] [<ffff000008083350>] do_one_initcall+0x38/0x11c
[ 7.933314] [<ffff000008b40cc0>] kernel_init_freeable+0x14c/0x1ec
[ 7.939395] [<ffff0000087ce564>] kernel_init+0x10/0xfc
[ 7.944520] [<ffff000008082e90>] ret_from_fork+0x10/0x40
[ 7.949820] Code: d2800022 8b400c21 f9800031 9ac32043 (c85f7c22)
[ 7.955909] ---[ end trace 0024a5986e6ff323 ]---
[ 7.960529] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Here struct mem_zone_bm_rtree's start_pfn has been returned instead of
struct rtree_node's addr as the node/zone pointers are corrupt after
we walked off the end of the lists during mark_unsafe_pages().
This behaviour was exposed by commit 6dbecfd345a6 ("PM / hibernate:
Simplify mark_unsafe_pages()"), which caused mark_unsafe_pages() to call
duplicate_memory_bitmap(), which uses memory_bm_find_bit() after walking
off the end of the memory bitmap.
Fixes: 3a20cb177961 (PM / Hibernate: Implement position keeping in radix tree)
Signed-off-by: James Morse <james.morse@arm.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 parent 5d87f49
Kconfig
config SECURITY_SMACK
bool "Simplified Mandatory Access Control Kernel Support"
depends on NET
depends on INET
depends on SECURITY
select NETLABEL
select SECURITY_NETWORK
default n
help
This selects the Simplified Mandatory Access Control Kernel.
Smack is useful for sensitivity, integrity, and a variety
of other mandatory security schemes.
If you are unsure how to answer this question, answer N.
config SECURITY_SMACK_BRINGUP
bool "Reporting on access granted by Smack rules"
depends on SECURITY_SMACK
default n
help
Enable the bring-up ("b") access mode in Smack rules.
When access is granted by a rule with the "b" mode a
message about the access requested is generated. The
intention is that a process can be granted a wide set
of access initially with the bringup mode set on the
rules. The developer can use the information to
identify which rules are necessary and what accesses
may be inappropriate. The developer can reduce the
access rule set once the behavior is well understood.
This is a superior mechanism to the oft abused
"permissive" mode of other systems.
If you are unsure how to answer this question, answer N.
config SECURITY_SMACK_NETFILTER
bool "Packet marking using secmarks for netfilter"
depends on SECURITY_SMACK
depends on NETWORK_SECMARK
depends on NETFILTER
default n
help
This enables security marking of network packets using
Smack labels.
If you are unsure how to answer this question, answer N.
Computing file changes ...
