linux/kernel
Linus Torvalds 614cb2751d tracing: Limit the shooting in the foot of tp_printk
The "tp_printk" option redirects the trace event output to printk at boot
 up. This is useful when a machine crashes before boot where the trace events
 can not be retrieved by the in kernel ring buffer. But it can be "dangerous"
 because trace events can be located in high frequency locations such as
 interrupts and the scheduler, where a printk can slow it down that it live
 locks the machine (because by the time the printk finishes, the next event
 is triggered). Thus tp_printk must be used with care.
 
 It was discovered that the filter logic to trace events does not apply to
 the tp_printk events. This can cause a surprise and live lock when the user
 expects it to be filtered to limit the amount of events printed to the
 console when in fact it still prints everything.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCYRwL+RQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qkRHAP9gvTYH1es9l4V5SNFEQ7+GEwknsaq7
 B5q4znVKQKgajQD/cd5Cm/alTIbxXdrQ9nxJ7lfffrvk46iqAb9PRX9vhAQ=
 =8QxT
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Limit the shooting in the foot of tp_printk

  The "tp_printk" option redirects the trace event output to printk at
  boot up. This is useful when a machine crashes before boot where the
  trace events can not be retrieved by the in kernel ring buffer. But it
  can be "dangerous" because trace events can be located in high
  frequency locations such as interrupts and the scheduler, where a
  printk can slow it down that it live locks the machine (because by the
  time the printk finishes, the next event is triggered). Thus tp_printk
  must be used with care.

  It was discovered that the filter logic to trace events does not apply
  to the tp_printk events. This can cause a surprise and live lock when
  the user expects it to be filtered to limit the amount of events
  printed to the console when in fact it still prints everything"

* tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Apply trace filters on all output channels
2021-08-17 09:47:18 -10:00
..
bpf bpf, core: Fix kernel-doc notation 2021-08-10 13:09:28 +02:00
cgroup cgroup: rstat: fix A-A deadlock on 32bit around u64_stats_sync 2021-07-27 13:12:20 -10:00
configs drivers/char: remove /dev/kmem for good 2021-05-07 00:26:34 -07:00
debug kernel: debug: Fix unreachable code in gdb_serial_stub() 2021-07-12 11:03:35 -05:00
dma dma-mapping: handle vmalloc addresses in dma_common_{mmap,get_sgtable} 2021-07-16 11:30:26 +02:00
entry tick/nohz: Only check for RCU deferred wakeup on user/guest entry when needed 2021-05-31 10:14:49 +02:00
events perf: Refactor permissions check into perf_check_permission() 2021-07-16 18:46:38 +02:00
gcov Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTR 2021-06-22 11:07:18 -07:00
irq genirq/msi: Ensure deactivation on teardown 2021-08-10 15:55:19 +02:00
kcsan Merge branch 'kcsan.2021.05.18a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 2021-07-04 12:29:16 -07:00
livepatch Livepatching changes for 5.13 2021-04-27 18:14:38 -07:00
locking locking/rtmutex: Use the correct rtmutex debugging config option 2021-08-10 08:21:52 +02:00
power PM: hibernate: disable when there are active secretmem users 2021-07-08 11:48:21 -07:00
printk printk changes for 5.14 2021-06-29 12:07:18 -07:00
rcu rcu: Fix pr_info() formats and values in show_rcu_gp_kthreads() 2021-07-06 15:53:12 -07:00
sched sched/rt: Fix double enqueue caused by rt_effective_prio 2021-08-04 15:16:31 +02:00
time timers: Move clearing of base::timer_running under base:: Lock 2021-07-27 20:57:44 +02:00
trace tracing: Limit the shooting in the foot of tp_printk 2021-08-17 09:47:18 -10:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
acct.c kernel/acct.c: use #elif instead of #end and #elif 2020-12-15 22:46:15 -08:00
async.c kernel/async.c: remove async_unregister_domain() 2021-05-07 00:26:33 -07:00
audit_fsnotify.c audit_alloc_mark(): don't open-code ERR_CAST() 2021-02-23 10:25:27 -05:00
audit_tree.c audit: Use list_move instead of list_del/list_add 2021-06-08 22:18:35 -04:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit.c lsm: separate security_task_getsecid() into subjective and objective variants 2021-03-22 15:23:32 -04:00
audit.h audit: remove trailing spaces and tabs 2021-06-10 20:59:05 -04:00
auditfilter.c lsm: separate security_task_getsecid() into subjective and objective variants 2021-03-22 15:23:32 -04:00
auditsc.c audit: remove trailing spaces and tabs 2021-06-10 20:59:05 -04:00
backtracetest.c
bounds.c
capability.c capability: handle idmapped mounts 2021-01-24 14:27:16 +01:00
cfi.c add support for Clang CFI 2021-04-08 16:04:20 -07:00
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c A fix for the CPU hotplug and cpusets interaction: 2021-06-29 12:23:02 -07:00
crash_core.c kdump: use vmlinux_build_id to simplify 2021-07-08 11:48:22 -07:00
crash_dump.c
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-06-28 20:39:26 -07:00
delayacct.c delayacct: Add sysctl to enable at runtime 2021-05-12 11:43:25 +02:00
dma.c
exec_domain.c
exit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-06-28 20:39:26 -07:00
extable.c
fail_function.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
fork.c Merge branch 'akpm' (patches from Andrew) 2021-06-29 17:29:11 -07:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
futex.c Locking changes for this cycle: 2021-06-28 11:45:29 -07:00
gen_kheaders.sh kbuild: clean up ${quiet} checks in shell scripts 2021-05-27 04:01:50 +09:00
groups.c groups: simplify struct group_info allocation 2021-02-26 09:41:03 -08:00
hung_task.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
iomem.c
irq_work.c irq_work: Make irq_work_queue() NMI-safe again 2021-06-10 10:00:08 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c module: add printk formats to add module build ID to stacktraces 2021-07-08 11:48:22 -07:00
kcmp.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt sched/core: Disable CONFIG_SCHED_CORE by default 2021-06-28 22:43:05 +02:00
kcov.c kernel: make kcov_common_handle consider the current context 2020-11-02 18:00:20 -08:00
kexec_core.c kernel.h: split out panic and oops helpers 2021-07-01 11:06:04 -07:00
kexec_elf.c
kexec_file.c kernel: kexec_file: fix error return code of kexec_calculate_store_digests() 2021-05-07 00:26:32 -07:00
kexec_internal.h kexec: move machine_kexec_post_load() to public interface 2021-02-22 12:33:26 +00:00
kexec.c
kheaders.c
kmod.c modules: add CONFIG_MODPROBE_PATH 2021-05-07 00:26:33 -07:00
kprobes.c Locking fixes: 2021-07-11 11:06:09 -07:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2021-06-29 17:29:11 -07:00
latencytop.c
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-02 00:43:35 +09:00
module_signature.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
module_signing.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
module-internal.h
module.c module: add printk formats to add module build ID to stacktraces 2021-07-08 11:48:22 -07:00
notifier.c
nsproxy.c fixes-v5.11 2020-12-14 16:40:27 -08:00
padata.c
panic.c kernel.h: split out panic and oops helpers 2021-07-01 11:06:04 -07:00
params.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
pid_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
pid.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
profile.c kernel: Initialize cpumask before parsing 2021-04-10 13:35:54 +02:00
ptrace.c sched: Change task_struct::state 2021-06-18 11:43:09 +02:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c reboot: Add hardware protection power-off 2021-06-21 13:08:36 +01:00
regset.c
relay.c relay: allow the use of const callback structs 2020-12-15 22:46:18 -08:00
resource_kunit.c resource: provide meaningful MODULE_LICENSE() in test suite 2020-11-25 18:52:35 +01:00
resource.c kernel/resource: fix return code check in __request_free_mem_region 2021-05-14 19:41:32 -07:00
rseq.c rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs() 2021-04-14 18:04:09 +02:00
scftorture.c scftorture: Avoid false-positive warnings in scftorture_invoker() 2021-07-06 12:37:55 -07:00
scs.c scs: switch to vmapped shadow stacks 2020-12-01 10:30:28 +00:00
seccomp.c seccomp: Fix setting loaded filter count during TSYNC 2021-08-11 11:48:28 -07:00
signal.c Fix UCOUNT_RLIMIT_SIGPENDING counter leak 2021-07-08 11:43:24 -07:00
smp.c smp: Fix smp_call_function_single_async prototype 2021-05-06 15:33:49 +02:00
smpboot.c smpboot: fix duplicate and misplaced inlining directive 2021-07-25 11:06:37 -07:00
smpboot.h
softirq.c sched: Introduce task_is_running() 2021-06-18 11:43:07 +02:00
stackleak.c
stacktrace.c
static_call.c static_call: Fix static_call_text_reserved() vs __init 2021-07-05 10:46:33 +02:00
stop_machine.c stop_machine: Add caller debug info to queue_stop_cpus_work 2021-03-23 16:01:58 +01:00
sys_ni.c mm: introduce memfd_secret system call to create "secret" memory areas 2021-07-08 11:48:21 -07:00
sys.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-06-28 20:39:26 -07:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
task_work.c kasan: record task_work_add() call stack 2021-04-30 11:20:42 -07:00
taskstats.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
test_kprobes.c
torture.c torture: Replace torture_init_begin string with %s 2021-03-08 14:22:28 -08:00
tracepoint.c tracepoint: Use rcu get state and cond sync for static call updates 2021-08-06 10:54:41 -04:00
tsacct.c
ucount.c ucounts: add missing data type changes 2021-08-09 15:45:02 -05:00
uid16.c
uid16.h
umh.c kernel/umh.c: fix some spelling mistakes 2021-05-07 00:26:34 -07:00
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-06-28 20:39:26 -07:00
user-return-notifier.c
user.c Reimplement RLIMIT_MEMLOCK on top of ucounts 2021-04-30 14:14:02 -05:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c watch_queue: rectify kernel-doc for init_watch() 2021-01-26 11:16:34 +00:00
watchdog_hld.c
watchdog.c kernel: watchdog: modify the explanation related to watchdog thread 2021-06-29 10:53:46 -07:00
workqueue_internal.h
workqueue.c workqueue: fix UAF in pwq_unbound_release_workfn() 2021-07-21 06:42:31 -10:00