linux/arch/x86/mm
Andrey Ryabinin 146fbb7669 x86/mm/ptdump: Fix soft lockup in page table walker
CONFIG_KASAN=y needs a lot of virtual memory mapped for its shadow.
In that case ptdump_walk_pgd_level_core() takes a lot of time to
walk across all page tables and doing this without
a rescheduling causes soft lockups:

 NMI watchdog: BUG: soft lockup - CPU#3 stuck for 23s! [swapper/0:1]
 ...
 Call Trace:
  ptdump_walk_pgd_level_core+0x40c/0x550
  ptdump_walk_pgd_level_checkwx+0x17/0x20
  mark_rodata_ro+0x13b/0x150
  kernel_init+0x2f/0x120
  ret_from_fork+0x2c/0x40

I guess that this issue might arise even without KASAN on huge machines
with several terabytes of RAM.

Stick cond_resched() in pgd loop to fix this.

Reported-by: Tobias Regnery <tobias.regnery@gmail.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Alexander Potapenko <glider@google.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170210095405.31802-1-aryabinin@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-10 11:00:23 +01:00
..
kmemcheck x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
amdtopology.c x86/mm/numa: Open code function early_get_boot_cpu_id() 2016-08-15 08:51:54 +02:00
debug_pagetables.c
dump_pagetables.c x86/mm/ptdump: Fix soft lockup in page table walker 2017-02-10 11:00:23 +01:00
extable.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
fault.c x86/mm: Drop unused argument 'removed' from sync_global_pgds() 2016-12-15 12:46:07 +01:00
gup.c mm: replace get_user_pages_unlocked() write/force parameters with gup_flags 2016-10-18 14:13:37 -07:00
highmem_32.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
hugetlbpage.c x86: mm: use hugetlb_bad_size() 2016-05-19 19:12:14 -07:00
ident_map.c x86/power/64: Always create temporary identity mapping correctly 2016-08-08 22:04:30 +02:00
init_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
init_64.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
init.c x86/e820: Use much less memory for e820/e820_saved, save up to 120k 2016-09-21 15:02:12 +02:00
iomap_32.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
ioremap.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
kasan_init_64.c kasan: add newline to messages 2016-07-15 14:54:27 +09:00
kaslr.c kconfig.h: remove config_enabled() macro 2016-10-27 18:43:43 -07:00
kmmio.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
Makefile x86/mm: Implement ASLR for kernel memory regions 2016-07-08 17:33:46 +02:00
mm_internal.h
mmap.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-15 10:45:39 -07:00
mmio-mod.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
mpx.c x86/mpx: Use compatible types in comparison to fix sparse error 2017-01-14 09:32:06 +01:00
numa_32.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
numa_64.c
numa_emulation.c
numa_internal.h
numa.c ACPI/NUMA: Do not map pxm to node when NUMA is turned off 2016-12-15 11:32:32 +01:00
pageattr-test.c
pageattr.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pat_internal.h
pat_rbtree.c x86: Clean up various simple wrapper functions 2016-09-13 20:42:58 +02:00
pat.c x86/pat, mm: Make track_pfn_insert() return void 2016-11-09 21:36:07 +01:00
pf_in.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
pf_in.h
pgtable_32.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
pgtable.c arch: x86: charge page tables to kmemcg 2016-07-26 16:19:19 -07:00
physaddr.c x86/mm: Audit and remove any unnecessary uses of module.h 2016-07-14 13:04:20 +02:00
physaddr.h
pkeys.c x86/fpu: Finish excising 'eagerfpu' 2016-10-18 09:56:03 +02:00
setup_nx.c Revert "x86/mm/32: Set NX in __supported_pte_mask before enabling paging" 2016-04-26 19:52:57 +02:00
srat.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
testmmiotrace.c
tlb.c x86/mm/64: Enable vmapped stacks (CONFIG_HAVE_ARCH_VMAP_STACK=y) 2016-08-24 12:11:42 +02:00