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-rw-r--r--kernel/kexec_core.c4
-rw-r--r--kernel/power/hibernate.c16
-rw-r--r--kernel/power/suspend.c8
-rw-r--r--kernel/printk/internal.h1
-rw-r--r--kernel/printk/printk.c55
-rw-r--r--kernel/printk/printk_ringbuffer.c13
6 files changed, 67 insertions, 30 deletions
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;
+ }
}
}
generated by cgit v1.2.3 (git 2.0.4) at 2026-01-06 21:56:36 +0000