Waiman Long
d682b596d9
locking/qspinlock: Handle > 4 slowpath nesting levels ...
Four queue nodes per CPU are allocated to enable up to 4 nesting levels
using the per-CPU nodes. Nested NMIs are possible in some architectures.
Still it is very unlikely that we will ever hit more than 4 nested
levels with contention in the slowpath.
When that rare condition happens, however, it is likely that the system
will hang or crash shortly after that. It is not good and we need to
handle this exception case.
This is done by spinning directly on the lock using repeated trylock.
This alternative code path should only be used when there is nested
NMIs. Assuming that the locks used by those NMI handlers will not be
heavily contended, a simple TAS locking should work out.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: James Morse <james.morse@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: SRINIVAS <srinivas.eeda@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Link: https://lkml.kernel.org/r/1548798828-16156-2-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 09:03:29 +01:00
bpf: fix inner map masking to prevent oob under speculation
2019-01-18 15:19:56 -08:00
Merge branch 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2018-12-29 10:57:20 -08:00
kvm_config: add CONFIG_VIRTIO_MENU
2018-10-24 20:55:56 -04:00
kdb: use bool for binary state indicators
2018-12-30 08:31:52 +00:00
swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exit
2019-01-16 09:59:17 -05:00
perf core: Fix perf_proc_update_handler() bug
2019-01-18 11:10:38 -03:00
genirq/irqdesc: Fix double increment in alloc_descs()
2019-01-18 00:43:09 +01:00
livepatch: Replace synchronize_sched() with synchronize_rcu()
2018-12-01 12:38:50 -08:00
locking/qspinlock: Handle > 4 slowpath nesting levels
2019-02-04 09:03:29 +01:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
rcutorture: Don't do busted forward-progress testing
2018-12-01 12:45:42 -08:00
sched/wake_q: Reduce reference counting for special users
2019-02-04 09:03:28 +01:00
posix-cpu-timers: Unbreak timer rearming
2019-01-15 16:34:37 +01:00
tracing/kprobes: Fix NULL pointer dereference in trace_kprobe_create()
2019-01-15 11:33:45 -05:00
audit: remove duplicated include from audit.c
2018-12-14 12:09:30 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
kbuild: fix kernel/bounds.c 'W=1' warning
2018-10-31 08:54:14 -07:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
Linux 5.0-rc5
2019-02-04 08:57:24 +01:00
kernel/crash_core.c: print timestamp using time64_t
2018-08-22 10:52:47 -07:00
cred: export get_task_cred().
2018-12-19 13:52:44 -05:00
delayacct: track delays from thrashing cache pages
2018-10-26 16:26:32 -07:00
kernel/exit.c: release ptraced tasks before zap_pid_ns_processes
2019-02-01 15:46:23 -08:00
kernel/fail_function.c: remove meaningless null pointer check before debugfs_remove_recursive
2018-10-31 08:54:12 -07:00
Merge branch 'akpm' (patches from Andrew)
2019-01-08 18:58:29 -08:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
sched/wake_q: Reduce reference counting for special users
2019-02-04 09:03:28 +01:00
kernel/hung_task.c: break RCU locks based on jiffies
2019-01-04 13:13:45 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
kallsyms: reduce size a little on 64-bit
2018-09-10 22:54:33 +09:00
kconfig: warn no new line at end of file
2018-12-15 17:44:35 +09:00
kernel/kcov.c: mark write_comp_data() as notrace
2019-01-04 13:13:47 -08:00
kexec: add call to LSM hook in original kexec_load syscall
2018-07-16 12:31:57 -07:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
kexec_file: kexec_walk_memblock() only walks a dedicated region at kdump
2018-12-06 14:38:50 +00:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 14:45:18 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
kbuild: change filechk to surround the given command with { }
2019-01-06 09:46:51 +09:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
modsign: use all trusted keys to verify module signature
2018-11-07 14:41:41 +01:00
padata: clean an indentation issue, remove extraneous space
2018-11-16 14:11:04 +08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
Fix failure path in alloc_pid()
2018-12-28 12:42:30 -08:00
signal: Use group_send_sig_info to kill all processes in a pid namespace
2018-09-16 16:08:25 +02:00
mm: remove include/linux/bootmem.h
2018-10-31 08:54:16 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
kernel/reboot.c: export pm_power_off_prepare
2018-09-11 16:13:24 +01:00
kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable
2018-12-28 12:11:49 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
seccomp: fix UAF in user-trap code
2019-01-15 09:43:12 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM
2019-01-30 19:27:00 +01:00
smpboot: Remove cpumask from the API
2018-07-03 09:20:44 +02:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-10-25 11:43:47 -07:00
stackleak: Mark stackleak_track_stack() as notrace
2018-12-05 19:31:44 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
kernel/sys.c: Clarify that UNAME26 does not generate unique versions anymore
2019-01-14 10:38:03 +12:00
y2038: socket: Add compat_sys_recvmmsg_time64
2018-12-18 16:13:04 +01:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
torture: Remove unnecessary "ret" variables
2018-12-01 12:45:35 -08:00
tracing: Replace synchronize_sched() and call_rcu_sched()
2018-11-27 09:21:41 -08:00
umh: add exit routine for UMH process
2019-01-11 18:05:40 -08:00
smp,cpumask: introduce on_each_cpu_cond_mask
2018-10-09 16:51:11 +02:00
userns: use irqsave variant of refcount_dec_and_lock()
2018-08-22 10:52:47 -07:00
userns: also map extents in the reverse map to kernel IDs
2018-11-07 23:51:16 -06:00
sys: don't hold uts_sem while accessing userspace memory
2018-08-11 02:05:53 -05:00
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
psi: fix aggregation idle shut-off
2019-02-01 15:46:23 -08:00
psi: fix aggregation idle shut-off
2019-02-01 15:46:23 -08:00
d682b596d9