Commit b0da6408 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'printk-for-6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux 

Pull printk fix from Petr Mladek:

 - Do not block printk on non-panic CPUs when they are dumping
   backtraces

* tag 'printk-for-6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk/panic: Allow cpu backtraces to be written into ringbuffer during panic
parents 47ac09b9 bcc954c6

include/linux/panic.h

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ extern void oops_enter(void); 
extern void oops_exit(void);

extern bool oops_may_print(void);



extern bool panic_triggering_all_cpu_backtrace;

extern int panic_timeout;

extern unsigned long panic_print;

extern int panic_on_oops;

kernel/panic.c

+7 −1
Original line number Diff line number Diff line
@@ -64,6 +64,8 @@ unsigned long panic_on_taint; 
bool panic_on_taint_nousertaint = false;

static unsigned int warn_limit __read_mostly;



bool panic_triggering_all_cpu_backtrace;



int panic_timeout = CONFIG_PANIC_TIMEOUT;

EXPORT_SYMBOL_GPL(panic_timeout);
@@ -253,8 +255,12 @@ void check_panic_on_warn(const char *origin) 
 */

static void panic_other_cpus_shutdown(bool crash_kexec)

{

	if (panic_print & PANIC_PRINT_ALL_CPU_BT)

	if (panic_print & PANIC_PRINT_ALL_CPU_BT) {

		/* Temporary allow non-panic CPUs to write their backtraces. */

		panic_triggering_all_cpu_backtrace = true;

		trigger_all_cpu_backtrace();

		panic_triggering_all_cpu_backtrace = false;

	}



	/*

	 * Note that smp_send_stop() is the usual SMP shutdown function,

kernel/printk/printk.c

+1 −1
Original line number Diff line number Diff line
@@ -2316,7 +2316,7 @@ 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())

	if (other_cpu_in_panic() && !panic_triggering_all_cpu_backtrace)

		return 0;



	if (level == LOGLEVEL_SCHED) {