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884e370ea8
CON_PRINTBUFFER console registration requires us to do several preparation steps: - Rollback console_seq to replay logbuf messages which were already seen on other consoles; - Set exclusive_console flag so console_unlock() will ->write() logbuf messages only to the exclusive_console driver. The way we do it, however, is a bit racy logbuf_lock_irqsave(flags); console_seq = syslog_seq; console_idx = syslog_idx; logbuf_unlock_irqrestore(flags); << preemption enabled << irqs enabled exclusive_console = newcon; console_unlock(); We rollback console_seq under logbuf_lock with IRQs disabled, but we set exclusive_console with local IRQs enabled and logbuf unlocked. If the system oops-es or panic-s before we set exclusive_console - and given that we have IRQs and preemption enabled there is such a possibility - we will re-play all logbuf messages to every registered console, which may be a bit annoying and time consuming. Move exclusive_console assignment to the same IRQs-disabled and logbuf_lock-protected section where we rollback console_seq. Link: http://lkml.kernel.org/r/20180928095304.9972-1-sergey.senozhatsky@gmail.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> |
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| .. | ||
| bpf | ||
| cgroup | ||
| configs | ||
| debug | ||
| dma | ||
| events | ||
| gcov | ||
| irq | ||
| livepatch | ||
| locking | ||
| power | ||
| printk | ||
| rcu | ||
| sched | ||
| time | ||
| trace | ||
| .gitignore | ||
| acct.c | ||
| async.c | ||
| audit.c | ||
| audit.h | ||
| audit_fsnotify.c | ||
| audit_tree.c | ||
| audit_watch.c | ||
| auditfilter.c | ||
| auditsc.c | ||
| backtracetest.c | ||
| bounds.c | ||
| capability.c | ||
| compat.c | ||
| configs.c | ||
| context_tracking.c | ||
| cpu.c | ||
| cpu_pm.c | ||
| crash_core.c | ||
| crash_dump.c | ||
| cred.c | ||
| delayacct.c | ||
| dma.c | ||
| elfcore.c | ||
| exec_domain.c | ||
| exit.c | ||
| extable.c | ||
| fail_function.c | ||
| fork.c | ||
| freezer.c | ||
| futex.c | ||
| futex_compat.c | ||
| groups.c | ||
| hung_task.c | ||
| iomem.c | ||
| irq_work.c | ||
| jump_label.c | ||
| kallsyms.c | ||
| kcmp.c | ||
| Kconfig.freezer | ||
| Kconfig.hz | ||
| Kconfig.locks | ||
| Kconfig.preempt | ||
| kcov.c | ||
| kexec.c | ||
| kexec_core.c | ||
| kexec_file.c | ||
| kexec_internal.h | ||
| kmod.c | ||
| kprobes.c | ||
| ksysfs.c | ||
| kthread.c | ||
| latencytop.c | ||
| Makefile | ||
| memremap.c | ||
| module-internal.h | ||
| module.c | ||
| module_signing.c | ||
| notifier.c | ||
| nsproxy.c | ||
| padata.c | ||
| panic.c | ||
| params.c | ||
| pid.c | ||
| pid_namespace.c | ||
| profile.c | ||
| ptrace.c | ||
| range.c | ||
| reboot.c | ||
| relay.c | ||
| resource.c | ||
| rseq.c | ||
| seccomp.c | ||
| signal.c | ||
| smp.c | ||
| smpboot.c | ||
| smpboot.h | ||
| softirq.c | ||
| stacktrace.c | ||
| stop_machine.c | ||
| sys.c | ||
| sys_ni.c | ||
| sysctl.c | ||
| sysctl_binary.c | ||
| task_work.c | ||
| taskstats.c | ||
| test_kprobes.c | ||
| torture.c | ||
| tracepoint.c | ||
| tsacct.c | ||
| ucount.c | ||
| uid16.c | ||
| uid16.h | ||
| umh.c | ||
| up.c | ||
| user-return-notifier.c | ||
| user.c | ||
| user_namespace.c | ||
| utsname.c | ||
| utsname_sysctl.c | ||
| watchdog.c | ||
| watchdog_hld.c | ||
| workqueue.c | ||
| workqueue_internal.h | ||