linux/arch/x86
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
..
boot x86/boot: Add missing declaration of string functions 2017-01-09 11:53:05 +01:00
configs
crypto crypto: aesni - Fix failure when built-in with modular pcbc 2016-12-30 18:20:45 +08:00
entry x86/entry: Fix the end of the stack for newly forked tasks 2017-01-12 09:28:29 +01:00
events perf/x86/intel/uncore: Make package handling more robust 2017-02-01 08:37:27 +01:00
ia32 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
include x86/CPU/AMD: Bring back Compute Unit ID 2017-02-05 12:18:45 +01:00
kernel x86/tsc: Make the TSC ADJUST sanitizing work for tsc_reliable 2017-02-10 09:47:17 +01:00
kvm KVM: x86: fix fixing of hypercalls 2017-01-17 15:06:05 +01:00
lguest clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
lib Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm x86/mm/ptdump: Fix soft lockup in page table walker 2017-02-10 11:00:23 +01:00
net bpf: change back to orig prog on too many passes 2017-01-08 17:00:18 -05:00
oprofile
pci x86/PCI: Ignore _CRS on Supermicro X8DTH-i/6/iF/6F 2017-01-11 09:11:15 -06:00
platform x86/efi: Always map the first physical page into the EFI pagetables 2017-01-28 09:18:56 +01:00
power Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-18 13:59:10 -08:00
purgatory
ras
realmode
tools x86/tools: Fix gcc-7 warning in relocs.c 2016-12-19 11:50:24 +01:00
um Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
video
xen Merge branch 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2017-01-06 10:53:21 -08:00
.gitignore
Kbuild
Kconfig Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
Kconfig.cpu
Kconfig.debug
Makefile
Makefile.um
Makefile_32.cpu