Linus Torvalds 7218974aba mm: suppress mm fault logging if fatal signal already pending ... [ Upstream commit 5f0bc0b042fc77ff70e14c790abdec960cde4ec1 ] Commit eda0047296a1 ("mm: make the page fault mmap locking killable") intentionally made it much easier to trigger the "page fault fails because a fatal signal is pending" situation, by having the mmap locking fail early in that case. We have long aborted page faults in other fatal cases when the actual IO for a page is interrupted by SIGKILL - which is particularly useful for the traditional case of NFS hanging due to network issues, but local filesystems could cause it too if you happened to get the SIGKILL while waiting for a page to be faulted in (eg lock_folio_maybe_drop_mmap()). So aborting the page fault wasn't a new condition - but it now triggers earlier, before we even get to 'handle_mm_fault()'. And as a result the error doesn't go through our 'fault_signal_pending()' logic, and doesn't get filtered away there. Normally you'd never even notice, because if a fatal signal is pending, the new SIGSEGV we send ends up being ignored anyway. But it turns out that there is one very noticeable exception: if you enable 'show_unhandled_signals', the aborted page fault will be logged in the kernel messages, and you'll get a scary line looking something like this in your logs: pverados[2183248]: segfault at 55e5a00f9ae0 ip 000055e5a00f9ae0 sp 00007ffc0720bea8 error 14 in perl[55e5a00d4000+195000] likely on CPU 10 (core 4, socket 0) which is rather misleading. It's not really a segfault at all, it's just "the thread was killed before the page fault completed, so we aborted the page fault". Fix this by just making it clear that a pending fatal signal means that any new signal coming in after that is implicitly handled. This will avoid the misleading logging, since now the signal isn't 'unhandled' any more. Reported-and-tested-by: Fiona Ebner <f.ebner@proxmox.com> Tested-by: Thomas Lamprecht <t.lamprecht@proxmox.com> Link: https://lore.kernel.org/lkml/8d063a26-43f5-0bb7-3203-c6a04dc159f8@proxmox.com/ Acked-by: Oleg Nesterov <oleg@redhat.com> Fixes: eda0047296a1 ("mm: make the page fault mmap locking killable") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-08-03 10:24:01 +02:00
..
bpf	bpf: aggressively forget precise markings during state checkpointing	2023-07-27 08:50:51 +02:00
cgroup	sched/psi: use kernfs polling functions for PSI trigger polling	2023-07-27 08:50:38 +02:00
configs	Kbuild: add Rust support	2022-09-28 09:02:20 +02:00
debug	mm: remove vmacache	2022-09-26 19:46:18 -07:00
dma	swiotlb: mark swiotlb_memblock_alloc() as __init	2023-07-23 13:49:50 +02:00
entry	entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up	2023-03-30 12:49:13 +02:00
events	perf/core: Fix hardlockup failure caused by perf throttle	2023-05-11 23:03:31 +09:00
futex	futex: Fix futex_waitv() hrtimer debug object leak on kcalloc error	2023-01-04 11:28:58 +01:00
gcov	gcov: add support for checksum field	2022-12-31 13:33:11 +01:00
irq	x86/pci/xen: populate MSI sysfs entries	2023-05-30 14:03:22 +01:00
kcsan	kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures	2023-07-19 16:21:37 +02:00
livepatch	Livepatching changes for 6.1	2022-10-10 11:36:19 -07:00
locking	locking/rwsem: Add __always_inline annotation to __down_read_common() and inlined callers	2023-05-17 11:53:57 +02:00
module	module: Don't wait for GOING modules	2023-02-01 08:34:37 +01:00
power	PM: QoS: Restore support for default value on frequency QoS	2023-07-23 13:49:45 +02:00
printk	kernel/printk/index.c: fix memory leak with using debugfs_lookup()	2023-03-11 13:55:32 +01:00
rcu	rcu: Mark additional concurrent load from ->cpu_no_qs.b.exp	2023-07-27 08:50:33 +02:00
sched	sched/psi: use kernfs polling functions for PSI trigger polling	2023-07-27 08:50:38 +02:00
time	tick/rcu: Fix bogus ratelimit condition	2023-07-19 16:20:59 +02:00
trace	tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails	2023-08-03 10:23:55 +02:00
.gitignore
acct.c	acct: fix potential integer overflow in encode_comp_t()	2022-12-31 13:32:58 +01:00
async.c
audit.c	audit: use time_after to compare time	2022-08-29 19:47:03 -04:00
audit.h	audit: remove selinux_audit_rule_update() declaration	2022-09-07 11:30:15 -04:00
audit_fsnotify.c	audit: fix potential double free on error path from fsnotify_add_inode_mark	2022-08-22 18:50:06 -04:00
audit_tree.c	audit: use fsnotify group lock helpers	2022-04-25 14:37:28 +02:00
audit_watch.c	audit_init_parent(): constify path	2022-09-01 17:39:30 -04:00
auditfilter.c
auditsc.c	audit/stable-6.1 PR 20221003	2022-10-04 11:05:43 -07:00
backtracetest.c
bounds.c	mm: multi-gen LRU: minimal implementation	2022-09-26 19:46:09 -07:00
capability.c
cfi.c	cfi: Switch to -fsanitize=kcfi	2022-09-26 10:13:13 -07:00
compat.c	sched_getaffinity: don't assume 'cpumask_size()' is fully initialized	2023-04-06 12:10:40 +02:00
configs.c
context_tracking.c	context_tracking: Fix noinstr vs KASAN	2023-03-10 09:33:45 +01:00
cpu.c	cpu/hotplug: Do not bail-out in DYING/STARTING sections	2022-12-31 13:31:59 +01:00
cpu_pm.c	context_tracking: Take IRQ eqs entrypoints over RCU	2022-07-05 13:32:59 -07:00
crash_core.c	vmcoreinfo: add kallsyms_num_syms symbol	2022-08-28 14:02:44 -07:00
crash_dump.c
cred.c
delayacct.c	delayacct: support re-entrance detection of thrashing accounting	2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c	exit: Detect and fix irq disabled state in oops	2023-03-10 09:33:45 +01:00
extable.c	context_tracking: Take NMI eqs entrypoints over RCU	2022-07-05 13:32:59 -07:00
fail_function.c	kernel/fail_function: fix memory leak with using debugfs_lookup()	2023-03-11 13:55:39 +01:00
fork.c	bpf: Fix UAF in task local storage	2023-06-14 11:15:16 +02:00
freezer.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
gen_kheaders.sh	kbuild: build init/built-in.a just once	2022-09-29 04:40:15 +09:00
groups.c	security: Add LSM hook to setgroups() syscall	2022-07-15 18:21:49 +00:00
hung_task.c	sched: Fix more TASK_state comparisons	2022-09-30 16:50:39 +02:00
iomem.c
irq_work.c	irq_work: use kasan_record_aux_stack_noalloc() record callstack	2022-04-15 14:49:55 -07:00
jump_label.c	jump_label: make initial NOP patching the special case	2022-06-24 09:48:55 +02:00
kallsyms.c	kallsyms: strip LTO-only suffixes from promoted global functions	2023-07-27 08:50:39 +02:00
kallsyms_internal.h	kallsyms: Improve the performance of kallsyms_lookup_name()	2023-07-27 08:50:39 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt	Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels"	2022-03-31 10:36:55 +02:00
kcov.c	kcov: kmsan: unpoison area->list in kcov_remote_area_put()	2022-10-03 14:03:23 -07:00
kexec.c	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kexec_core.c	kexec: fix a memory leak in crash_shrink_memory()	2023-07-19 16:21:08 +02:00
kexec_elf.c
kexec_file.c	kexec: support purgatories with .text.hot sections	2023-06-21 16:00:55 +02:00
kexec_internal.h	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kheaders.c	kheaders: Use array declaration instead of char	2023-05-11 23:03:02 +09:00
kmod.c
kprobes.c	kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list	2023-03-10 09:34:27 +01:00
ksysfs.c	kexec: turn all kexec_mutex acquisitions into trylocks	2022-09-11 21:55:06 -07:00
kthread.c	signal: break out of wait loops on kthread_stop()	2022-10-09 16:01:59 -07:00
latencytop.c	latencytop: use the last element of latency_record of system	2022-09-11 21:55:12 -07:00
Makefile	cfi: Fix CFI failure with KASAN	2022-12-31 13:33:08 +01:00
module_signature.c
notifier.c	notifier: Add blocking/atomic_notifier_chain_register_unique_prio()	2022-05-19 19:30:30 +02:00
nsproxy.c	Revert "fs/exec: allow to unshare a time namespace on vfork+exec"	2022-09-13 10:38:43 -07:00
padata.c	padata: Fix list iterator in padata_do_serial()	2022-12-31 13:32:34 +01:00
panic.c	panic: fix the panic_print NMI backtrace setting	2023-03-10 09:34:25 +01:00
params.c
pid.c	gfs2: Add glockfd debugfs file	2022-06-29 13:07:16 +02:00
pid_namespace.c	rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()	2023-03-10 09:32:52 +01:00
profile.c	kernel/profile.c: simplify duplicated code in profile_setup()	2022-09-11 21:55:12 -07:00
ptrace.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
range.c
reboot.c	kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode	2022-10-04 15:59:36 +02:00
regset.c
relay.c	relayfs: fix out-of-bounds access in relay_file_read	2023-05-11 23:03:03 +09:00
resource.c	dax/kmem: Fix leak of memory-hotplug resources	2023-03-10 09:34:25 +01:00
resource_kunit.c
rseq.c	rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered	2022-11-14 09:58:32 +01:00
scftorture.c	scftorture: Fix distribution of short handler delays	2022-04-11 17:07:29 -07:00
scs.c	kasan, vmalloc: only tag normal vmalloc allocations	2022-03-24 19:06:48 -07:00
seccomp.c	seccomp: Add wait_killable semantic to seccomp user notifier	2022-05-03 14:11:58 -07:00
signal.c	mm: suppress mm fault logging if fatal signal already pending	2023-08-03 10:24:01 +02:00
smp.c	bitmap patches for v6.1-rc1	2022-10-10 12:49:34 -07:00
smpboot.c	smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death	2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c	context_tracking: Take IRQ eqs entrypoints over RCU	2022-07-05 13:32:59 -07:00
stackleak.c	stackleak: add on/off stack variants	2022-05-08 01:33:09 -07:00
stacktrace.c
static_call.c	static_call: Don't make __static_call_return0 static	2022-04-05 09:59:38 +02:00
static_call_inline.c	static_call: Don't make __static_call_return0 static	2022-04-05 09:59:38 +02:00
stop_machine.c	Scheduler changes in this cycle were:	2022-05-24 11:11:13 -07:00
sys.c	kernel/sys.c: fix and improve control flow in __sys_setres[ug]id()	2023-04-26 14:28:39 +02:00
sys_ni.c	kernel/sys_ni: add compat entry for fadvise64_64	2022-08-20 15:17:45 -07:00
sysctl-test.c	kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred}	2022-09-08 16:56:45 -07:00
sysctl.c	proc: proc_skip_spaces() shouldn't think it is working on C strings	2022-12-05 12:09:06 -08:00
task_work.c	task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run	2022-09-11 21:55:10 -07:00
taskstats.c	genetlink: start to validate reserved header bytes	2022-08-29 12:47:15 +01:00
torture.c	torture: Fix hang during kthread shutdown phase	2023-03-10 09:34:07 +01:00
tracepoint.c	tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming()	2022-09-26 13:01:18 -04:00
tsacct.c	taskstats: version 12 with thread group and exe info	2022-04-29 14:38:03 -07:00
ucount.c	ucounts: Split rlimit and ucount values and max values	2022-05-18 18:24:57 -05:00
uid16.c
uid16.h
umh.c	freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL	2023-02-22 12:59:50 +01:00
up.c
user-return-notifier.c
user.c
user_namespace.c	ucounts: Split rlimit and ucount values and max values	2022-10-09 16:24:05 -07:00
usermode_driver.c	blob_to_mnt(): kern_unmount() is needed to undo kern_mount()	2022-05-19 23:25:47 -04:00
utsname.c
utsname_sysctl.c	kernel/utsname_sysctl.c: Fix hostname polling	2022-10-23 12:01:01 -07:00
watch_queue.c	watch_queue: prevent dangling pipe pointer	2023-07-19 16:22:10 +02:00
watchdog.c	powerpc updates for 6.0	2022-08-06 16:38:17 -07:00
watchdog_hld.c	watchdog/perf: more properly prevent false positives with turbo modes	2023-07-19 16:21:08 +02:00
workqueue.c	workqueue: clean up WORK_* constant types, clarify masking	2023-07-23 13:49:19 +02:00
workqueue_internal.h