diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0027-printk-Coordinate-direct-printing-in-panic.patch (renamed from debian/patches-rt/0031-printk-Coordinate-direct-printing-in-panic.patch) | 79 |
1 files changed, 54 insertions, 25 deletions
diff --git a/debian/patches-rt/0031-printk-Coordinate-direct-printing-in-panic.patch b/debian/patches-rt/0027-printk-Coordinate-direct-printing-in-panic.patch index 6f26bf7fc6..4893dd463f 100644 --- a/debian/patches-rt/0031-printk-Coordinate-direct-printing-in-panic.patch +++ b/debian/patches-rt/0027-printk-Coordinate-direct-printing-in-panic.patch @@ -1,7 +1,7 @@ From: John Ogness <john.ogness@linutronix.de> Date: Wed, 22 Nov 2023 11:56:58 +0000 -Subject: [PATCH 31/50] printk: Coordinate direct printing in panic -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.7/older/patches-6.7-rt6.tar.xz +Subject: [PATCH 27/48] printk: Coordinate direct printing in panic +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz Perform printing by nbcon consoles on the panic CPU from the printk() caller context in order to get panic messages printed @@ -20,33 +20,57 @@ from the printk() caller context). Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- - include/linux/printk.h | 2 + + include/linux/printk.h | 5 +++ kernel/panic.c | 2 + - kernel/printk/printk.c | 53 ++++++++++++++++++++++++++++++++++++++++++------- - 3 files changed, 50 insertions(+), 7 deletions(-) + kernel/printk/printk.c | 62 ++++++++++++++++++++++++++++++++++++++++++------- + 3 files changed, 61 insertions(+), 8 deletions(-) --- a/include/linux/printk.h +++ b/include/linux/printk.h -@@ -782,3 +782,5 @@ static inline void print_hex_dump_debug( - print_hex_dump_debug(prefix_str, prefix_type, 16, 1, buf, len, true) +@@ -195,6 +195,7 @@ void show_regs_print_info(const char *lo + extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold; + extern asmlinkage void dump_stack(void) __cold; + void printk_trigger_flush(void); ++void printk_legacy_allow_panic_sync(void); + extern void nbcon_driver_acquire(struct console *con); + extern void nbcon_driver_release(struct console *con); + void nbcon_atomic_flush_unsafe(void); +@@ -278,6 +279,10 @@ static inline void printk_trigger_flush( + { + } - #endif ++static inline void printk_legacy_allow_panic_sync(void) ++{ ++} + -+void printk_legacy_allow_panic_sync(void); + static inline void nbcon_driver_acquire(struct console *con) + { + } --- a/kernel/panic.c +++ b/kernel/panic.c -@@ -370,6 +370,8 @@ void panic(const char *fmt, ...) - */ - atomic_notifier_call_chain(&panic_notifier_list, 0, buf); +@@ -364,6 +364,8 @@ void panic(const char *fmt, ...) + + panic_other_cpus_shutdown(_crash_kexec_post_notifiers); + printk_legacy_allow_panic_sync(); + - panic_print_sys_info(false); - - kmsg_dump(KMSG_DUMP_PANIC); + /* + * Run any panic handlers, including those that might need to + * add information to the kmsg dump output. --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c -@@ -2329,12 +2329,23 @@ int vprintk_store(int facility, int leve +@@ -471,7 +471,9 @@ static DEFINE_MUTEX(syslog_lock); + static bool have_legacy_console; + + /* +- * Specifies if an nbcon console is registered. ++ * Specifies if an nbcon console is registered. If nbcon consoles are present, ++ * synchronous printing of legacy consoles will not occur during panic until ++ * the backtrace has been stored to the ringbuffer. + */ + static bool have_nbcon_console; + +@@ -2335,12 +2337,29 @@ int vprintk_store(int facility, int leve return ret; } @@ -54,11 +78,17 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> + +/* + * This acts as a one-way switch to allow legacy consoles to print from -+ * the printk() caller context on a panic CPU. ++ * the printk() caller context on a panic CPU. It also attempts to flush ++ * the legacy consoles in this context. + */ +void printk_legacy_allow_panic_sync(void) +{ + legacy_allow_panic_sync = true; ++ ++ if (printing_via_unlock && !in_nmi()) { ++ if (console_trylock()) ++ console_unlock(); ++ } +} + asmlinkage int vprintk_emit(int facility, int level, @@ -71,7 +101,7 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> /* Suppress unimportant messages after panic happens */ if (unlikely(suppress_printk)) -@@ -2350,15 +2361,43 @@ asmlinkage int vprintk_emit(int facility +@@ -2356,15 +2375,42 @@ asmlinkage int vprintk_emit(int facility if (level == LOGLEVEL_SCHED) { level = LOGLEVEL_DEFAULT; @@ -86,7 +116,7 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> - /* If called from the scheduler, we can not call up(). */ - if (!in_sched && printing_via_unlock) { -+ if (!have_boot_console && have_nbcon_console) { ++ if (have_nbcon_console && !have_boot_console) { + bool is_panic_context = this_cpu_in_panic(); + + /* @@ -105,20 +135,19 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> + * + * - When this CPU is in panic. + * -+ * Note that if boot consoles are registered, the -+ * console_lock/console_unlock dance must be relied upon -+ * instead because nbcon consoles cannot print simultaneously -+ * with boot consoles. ++ * Note that if boot consoles are registered, the console ++ * lock/unlock dance must be relied upon instead because nbcon ++ * consoles cannot print simultaneously with boot consoles. + */ + if (is_panic_context) -+ nbcon_atomic_flush_all(); ++ nbcon_atomic_flush_pending(); + } + + if (do_trylock_unlock) { /* * The caller may be holding system-critical or * timing-sensitive locks. Disable preemption during -@@ -2378,10 +2417,10 @@ asmlinkage int vprintk_emit(int facility +@@ -2384,10 +2430,10 @@ asmlinkage int vprintk_emit(int facility preempt_enable(); } |