diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 8 | ||||
| -rw-r--r-- | Documentation/admin-guide/serial-console.rst | 4 | ||||
| -rw-r--r-- | drivers/gpu/drm/clients/drm_log.c | 4 | ||||
| -rw-r--r-- | drivers/tty/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 6 | ||||
| -rw-r--r-- | include/linux/console.h | 8 | ||||
| -rw-r--r-- | kernel/kexec_core.c | 4 | ||||
| -rw-r--r-- | kernel/power/hibernate.c | 16 | ||||
| -rw-r--r-- | kernel/power/suspend.c | 8 | ||||
| -rw-r--r-- | kernel/printk/internal.h | 1 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 55 | ||||
| -rw-r--r-- | kernel/printk/printk_ringbuffer.c | 13 | ||||
| -rw-r--r-- | tools/power/pm-graph/config/custom-timeline-functions.cfg | 4 | ||||
| -rwxr-xr-x | tools/power/pm-graph/sleepgraph.py | 6 |
14 files changed, 110 insertions, 46 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index e062e6270c2a..5e351ac52cca 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5020,6 +5020,14 @@ Format: <bool> default: 0 (auto_verbose is enabled) + printk.debug_non_panic_cpus= + Allows storing messages from non-panic CPUs into + the printk log buffer during panic(). They are + flushed to consoles by the panic-CPU on + a best-effort basis. + Format: <bool> (1/Y/y=enable, 0/N/n=disable) + Default: disabled + printk.devkmsg={on,off,ratelimit} Control writing to /dev/kmsg. on - unlimited logging to /dev/kmsg from userspace diff --git a/Documentation/admin-guide/serial-console.rst b/Documentation/admin-guide/serial-console.rst index a3dfc2c66e01..1609e7479249 100644 --- a/Documentation/admin-guide/serial-console.rst +++ b/Documentation/admin-guide/serial-console.rst @@ -78,7 +78,9 @@ If no console device is specified, the first device found capable of acting as a system console will be used. At this time, the system first looks for a VGA card and then for a serial port. So if you don't have a VGA card in your system the first serial port will automatically -become the console. +become the console, unless the kernel is configured with the +CONFIG_NULL_TTY_DEFAULT_CONSOLE option, then it will default to using the +ttynull device. You will need to create a new device to use ``/dev/console``. The official ``/dev/console`` is now character device 5,1. diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c index 379850c83e51..d239f1e3c456 100644 --- a/drivers/gpu/drm/clients/drm_log.c +++ b/drivers/gpu/drm/clients/drm_log.c @@ -323,7 +323,7 @@ static int drm_log_client_suspend(struct drm_client_dev *client, bool _console_l { struct drm_log *dlog = client_to_drm_log(client); - console_stop(&dlog->con); + console_suspend(&dlog->con); return 0; } @@ -332,7 +332,7 @@ static int drm_log_client_resume(struct drm_client_dev *client, bool _console_lo { struct drm_log *dlog = client_to_drm_log(client); - console_start(&dlog->con); + console_resume(&dlog->con); return 0; } diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig index 63a494d36a1f..7fb81bbaee60 100644 --- a/drivers/tty/Kconfig +++ b/drivers/tty/Kconfig @@ -383,7 +383,24 @@ config NULL_TTY available or desired. In order to use this driver, you should redirect the console to this - TTY, or boot the kernel with console=ttynull. + TTY, boot the kernel with console=ttynull, or enable + NULL_TTY_DEFAULT_CONSOLE. + + If unsure, say N. + +config NULL_TTY_DEFAULT_CONSOLE + bool "Support for console on ttynull" + depends on NULL_TTY=y && !VT_CONSOLE + help + Say Y here if you want the NULL TTY to be used as a /dev/console + device by default. + + For example, it might be useful to prevent a VT-less kernel from + writing the system log to a random device connected to the serial + port. + + Another console driver still might get preferred via the command + line, SPCR, or the device tree. If unsure, say N. diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 92f7e752f862..d46650e578e5 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2426,10 +2426,10 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) } /* - * Disable the console device before suspending. + * Suspend the console device before suspending the port. */ if (uart_console(uport)) - console_stop(uport->cons); + console_suspend(uport->cons); uart_change_pm(state, UART_PM_STATE_OFF); @@ -2484,7 +2484,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) uart_port_unlock_irq(uport); } if (console_suspend_enabled) - console_start(uport->cons); + console_resume(uport->cons); } if (tty_port_suspended(port)) { diff --git a/include/linux/console.h b/include/linux/console.h index eba367bf605d..8f10d0a85bb4 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -633,8 +633,8 @@ extern void console_conditional_schedule(void); extern void console_unblank(void); extern void console_flush_on_panic(enum con_flush_mode mode); extern struct tty_driver *console_device(int *); -extern void console_stop(struct console *); -extern void console_start(struct console *); +extern void console_suspend(struct console *); +extern void console_resume(struct console *); extern int is_console_locked(void); extern int braille_register_console(struct console *, int index, char *console_options, char *braille_options); @@ -648,8 +648,8 @@ static inline void console_sysfs_notify(void) extern bool console_suspend_enabled; /* Suspend and resume console messages over PM events */ -extern void suspend_console(void); -extern void resume_console(void); +extern void console_suspend_all(void); +extern void console_resume_all(void); int mda_console_init(void); diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index c0bdc1686154..c22ad51c4317 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1013,7 +1013,7 @@ int kernel_kexec(void) error = -EBUSY; goto Restore_console; } - suspend_console(); + console_suspend_all(); error = dpm_suspend_start(PMSG_FREEZE); if (error) goto Resume_console; @@ -1072,7 +1072,7 @@ int kernel_kexec(void) Resume_devices: dpm_resume_end(PMSG_RESTORE); Resume_console: - resume_console(); + console_resume_all(); thaw_processes(); Restore_console: pm_restore_console(); diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index b129ed1d25a8..50ec26ea696b 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -411,7 +411,7 @@ int hibernation_snapshot(int platform_mode) goto Thaw; } - suspend_console(); + console_suspend_all(); pm_restrict_gfp_mask(); error = dpm_suspend(PMSG_FREEZE); @@ -437,7 +437,7 @@ int hibernation_snapshot(int platform_mode) if (error || !in_suspend) pm_restore_gfp_mask(); - resume_console(); + console_resume_all(); dpm_complete(msg); Close: @@ -547,7 +547,7 @@ int hibernation_restore(int platform_mode) int error; pm_prepare_console(); - suspend_console(); + console_suspend_all(); pm_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_QUIESCE); if (!error) { @@ -561,7 +561,7 @@ int hibernation_restore(int platform_mode) } dpm_resume_end(PMSG_RECOVER); pm_restore_gfp_mask(); - resume_console(); + console_resume_all(); pm_restore_console(); return error; } @@ -586,7 +586,7 @@ int hibernation_platform_enter(void) goto Close; entering_platform_hibernation = true; - suspend_console(); + console_suspend_all(); error = dpm_suspend_start(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) @@ -639,7 +639,7 @@ int hibernation_platform_enter(void) Resume_devices: entering_platform_hibernation = false; dpm_resume_end(PMSG_RESTORE); - resume_console(); + console_resume_all(); Close: hibernation_ops->end(); @@ -901,7 +901,7 @@ int hibernate_quiet_exec(int (*func)(void *data), void *data) if (error) goto dpm_complete; - suspend_console(); + console_suspend_all(); error = dpm_suspend(PMSG_FREEZE); if (error) @@ -925,7 +925,7 @@ skip: dpm_resume: dpm_resume(PMSG_THAW); - resume_console(); + console_resume_all(); dpm_complete: dpm_complete(PMSG_THAW); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 6fae1e0a331c..8eaec4ab121d 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -508,7 +508,7 @@ int suspend_devices_and_enter(suspend_state_t state) if (error) goto Close; - suspend_console(); + console_suspend_all(); suspend_test_start(); error = dpm_suspend_start(PMSG_SUSPEND); if (error) { @@ -527,9 +527,9 @@ int suspend_devices_and_enter(suspend_state_t state) suspend_test_start(); dpm_resume_end(PMSG_RESUME); suspend_test_finish("resume devices"); - trace_suspend_resume(TPS("resume_console"), state, true); - resume_console(); - trace_suspend_resume(TPS("resume_console"), state, false); + trace_suspend_resume(TPS("console_resume_all"), state, true); + console_resume_all(); + trace_suspend_resume(TPS("console_resume_all"), state, false); Close: platform_resume_end(state); diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index a91bdf802967..48a24e7b309d 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -64,6 +64,7 @@ struct dev_printk_info; extern struct printk_ringbuffer *prb; extern bool printk_kthreads_running; +extern bool debug_non_panic_cpus; __printf(4, 0) int vprintk_store(int facility, int level, diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 057db78876cd..1eea80d0648e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2375,6 +2375,22 @@ void printk_legacy_allow_panic_sync(void) } } +bool __read_mostly debug_non_panic_cpus; + +#ifdef CONFIG_PRINTK_CALLER +static int __init debug_non_panic_cpus_setup(char *str) +{ + debug_non_panic_cpus = true; + pr_info("allow messages from non-panic CPUs in panic()\n"); + + return 0; +} +early_param("debug_non_panic_cpus", debug_non_panic_cpus_setup); +module_param(debug_non_panic_cpus, bool, 0644); +MODULE_PARM_DESC(debug_non_panic_cpus, + "allow messages from non-panic CPUs in panic()"); +#endif + asmlinkage int vprintk_emit(int facility, int level, const struct dev_printk_info *dev_info, const char *fmt, va_list args) @@ -2391,7 +2407,9 @@ asmlinkage int vprintk_emit(int facility, int level, * non-panic CPUs are generating any messages, they will be * silently dropped. */ - if (other_cpu_in_panic() && !panic_triggering_all_cpu_backtrace) + if (other_cpu_in_panic() && + !debug_non_panic_cpus && + !panic_triggering_all_cpu_backtrace) return 0; printk_get_console_flush_type(&ft); @@ -2731,11 +2749,11 @@ module_param_named(console_no_auto_verbose, printk_console_no_auto_verbose, bool MODULE_PARM_DESC(console_no_auto_verbose, "Disable console loglevel raise to highest on oops/panic/etc"); /** - * suspend_console - suspend the console subsystem + * console_suspend_all - suspend the console subsystem * * This disables printk() while we go into suspend states */ -void suspend_console(void) +void console_suspend_all(void) { struct console *con; @@ -2758,7 +2776,7 @@ void suspend_console(void) synchronize_srcu(&console_srcu); } -void resume_console(void) +void console_resume_all(void) { struct console_flush_type ft; struct console *con; @@ -3340,7 +3358,12 @@ void console_unblank(void) */ cookie = console_srcu_read_lock(); for_each_console_srcu(c) { - if ((console_srcu_read_flags(c) & CON_ENABLED) && c->unblank) { + short flags = console_srcu_read_flags(c); + + if (flags & CON_SUSPENDED) + continue; + + if ((flags & CON_ENABLED) && c->unblank) { found_unblank = true; break; } @@ -3377,7 +3400,12 @@ void console_unblank(void) cookie = console_srcu_read_lock(); for_each_console_srcu(c) { - if ((console_srcu_read_flags(c) & CON_ENABLED) && c->unblank) + short flags = console_srcu_read_flags(c); + + if (flags & CON_SUSPENDED) + continue; + + if ((flags & CON_ENABLED) && c->unblank) c->unblank(); } console_srcu_read_unlock(cookie); @@ -3495,10 +3523,10 @@ struct tty_driver *console_device(int *index) /* * Prevent further output on the passed console device so that (for example) - * serial drivers can disable console output before suspending a port, and can + * serial drivers can suspend console output before suspending a port, and can * re-enable output afterwards. */ -void console_stop(struct console *console) +void console_suspend(struct console *console) { __pr_flush(console, 1000, true); console_list_lock(); @@ -3513,9 +3541,9 @@ void console_stop(struct console *console) */ synchronize_srcu(&console_srcu); } -EXPORT_SYMBOL(console_stop); +EXPORT_SYMBOL(console_suspend); -void console_start(struct console *console) +void console_resume(struct console *console) { struct console_flush_type ft; bool is_nbcon; @@ -3540,7 +3568,7 @@ void console_start(struct console *console) __pr_flush(console, 1000, true); } -EXPORT_SYMBOL(console_start); +EXPORT_SYMBOL(console_resume); #ifdef CONFIG_PRINTK static int unregister_console_locked(struct console *console); @@ -4275,6 +4303,11 @@ void __init console_init(void) initcall_t call; initcall_entry_t *ce; +#ifdef CONFIG_NULL_TTY_DEFAULT_CONSOLE + if (!console_set_on_cmdline) + add_preferred_console("ttynull", 0, NULL); +#endif + /* Setup the default TTY line discipline. */ n_tty_init(); diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c index 88e8f3a61922..d9fb053cff67 100644 --- a/kernel/printk/printk_ringbuffer.c +++ b/kernel/printk/printk_ringbuffer.c @@ -2133,9 +2133,9 @@ static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq, * there may be other finalized records beyond that * need to be printed for a panic situation. If this * is the panic CPU, skip this - * non-existent/non-finalized record unless it is - * at or beyond the head, in which case it is not - * possible to continue. + * non-existent/non-finalized record unless non-panic + * CPUs are still running and their debugging is + * explicitly enabled. * * Note that new messages printed on panic CPU are * finalized when we are here. The only exception @@ -2143,10 +2143,13 @@ static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq, * But it would have the sequence number returned * by "prb_next_reserve_seq() - 1". */ - if (this_cpu_in_panic() && ((*seq + 1) < prb_next_reserve_seq(rb))) + if (this_cpu_in_panic() && + (!debug_non_panic_cpus || legacy_allow_panic_sync) && + ((*seq + 1) < prb_next_reserve_seq(rb))) { (*seq)++; - else + } else { return false; + } } } diff --git a/tools/power/pm-graph/config/custom-timeline-functions.cfg b/tools/power/pm-graph/config/custom-timeline-functions.cfg index 4f80ad7d7275..0321b59518f3 100644 --- a/tools/power/pm-graph/config/custom-timeline-functions.cfg +++ b/tools/power/pm-graph/config/custom-timeline-functions.cfg @@ -122,13 +122,13 @@ freeze_processes: freeze_kernel_threads: pm_restrict_gfp_mask: acpi_suspend_begin: -suspend_console: +console_suspend_all: acpi_pm_prepare: syscore_suspend: arch_enable_nonboot_cpus_end: syscore_resume: acpi_pm_finish: -resume_console: +console_resume_all: acpi_pm_end: pm_restore_gfp_mask: thaw_processes: diff --git a/tools/power/pm-graph/sleepgraph.py b/tools/power/pm-graph/sleepgraph.py index 918eae58b0b4..e2261f33a082 100755 --- a/tools/power/pm-graph/sleepgraph.py +++ b/tools/power/pm-graph/sleepgraph.py @@ -210,13 +210,13 @@ class SystemValues: 'hibernate_preallocate_memory': {}, 'create_basic_memory_bitmaps': {}, 'swsusp_write': {}, - 'suspend_console': {}, + 'console_suspend_all': {}, 'acpi_pm_prepare': {}, 'syscore_suspend': {}, 'arch_enable_nonboot_cpus_end': {}, 'syscore_resume': {}, 'acpi_pm_finish': {}, - 'resume_console': {}, + 'console_resume_all': {}, 'acpi_pm_end': {}, 'pm_restore_gfp_mask': {}, 'thaw_processes': {}, @@ -3459,7 +3459,7 @@ def parseTraceLog(live=False): tracewatch = ['irq_wakeup'] if sysvals.usekprobes: tracewatch += ['sync_filesystems', 'freeze_processes', 'syscore_suspend', - 'syscore_resume', 'resume_console', 'thaw_processes', 'CPU_ON', + 'syscore_resume', 'console_resume_all', 'thaw_processes', 'CPU_ON', 'CPU_OFF', 'acpi_suspend'] # extract the callgraph and traceevent data |