diff options
| -rw-r--r-- | drivers/tty/serial/earlycon.c | 23 | ||||
| -rw-r--r-- | drivers/tty/sysrq.c | 18 | ||||
| -rw-r--r-- | include/linux/printk.h | 11 | ||||
| -rw-r--r-- | init/main.c | 5 | ||||
| -rw-r--r-- | kernel/printk/internal.h | 3 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 47 | ||||
| -rw-r--r-- | kernel/printk/printk_safe.c | 18 |
7 files changed, 102 insertions, 23 deletions
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index a5fbb6ed38ae..ab9af37f6cda 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -248,6 +248,29 @@ static int __init param_setup_earlycon(char *buf) } early_param("earlycon", param_setup_earlycon); +/* + * The `console` parameter is overloaded. It's handled here as an early param + * and in `printk.c` as a late param. It's possible to specify an early + * `bootconsole` using `earlycon=uartXXXX` (handled above), or via + * the `console=uartXXX` alias. See the comment in `8250_early.c`. + */ +static int __init param_setup_earlycon_console_alias(char *buf) +{ + /* + * A plain `console` parameter must not enable the SPCR `bootconsole` + * like a plain `earlycon` does. + * + * A `console=` parameter that specifies an empty value is used to + * disable the `console`, not the `earlycon` `bootconsole`. The + * disabling of the `console` is handled by `printk.c`. + */ + if (!buf || !buf[0]) + return 0; + + return param_setup_earlycon(buf); +} +early_param("console", param_setup_earlycon_console_alias); + #ifdef CONFIG_OF_EARLY_FLATTREE int __init of_setup_earlycon(const struct earlycon_id *match, diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 930b04e3d148..f85ce02e4725 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -583,7 +583,6 @@ static void __sysrq_put_key_op(u8 key, const struct sysrq_key_op *op_p) void __handle_sysrq(u8 key, bool check_mask) { const struct sysrq_key_op *op_p; - int orig_log_level; int orig_suppress_printk; int i; @@ -593,13 +592,12 @@ void __handle_sysrq(u8 key, bool check_mask) rcu_sysrq_start(); rcu_read_lock(); /* - * Raise the apparent loglevel to maximum so that the sysrq header - * is shown to provide the user with positive feedback. We do not - * simply emit this at KERN_EMERG as that would change message - * routing in the consumers of /proc/kmsg. + * Enter in the force_console context so that sysrq header is shown to + * provide the user with positive feedback. We do not simply emit this + * at KERN_EMERG as that would change message routing in the consumers + * of /proc/kmsg. */ - orig_log_level = console_loglevel; - console_loglevel = CONSOLE_LOGLEVEL_DEFAULT; + printk_force_console_enter(); op_p = __sysrq_get_key_op(key); if (op_p) { @@ -609,11 +607,11 @@ void __handle_sysrq(u8 key, bool check_mask) */ if (!check_mask || sysrq_on_mask(op_p->enable_mask)) { pr_info("%s\n", op_p->action_msg); - console_loglevel = orig_log_level; + printk_force_console_exit(); op_p->handler(key); } else { pr_info("This sysrq operation is disabled.\n"); - console_loglevel = orig_log_level; + printk_force_console_exit(); } } else { pr_info("HELP : "); @@ -631,7 +629,7 @@ void __handle_sysrq(u8 key, bool check_mask) } } pr_cont("\n"); - console_loglevel = orig_log_level; + printk_force_console_exit(); } rcu_read_unlock(); rcu_sysrq_end(); diff --git a/include/linux/printk.h b/include/linux/printk.h index eca9bb2ee637..4217a9f412b2 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -166,6 +166,9 @@ __printf(1, 2) __cold int _printk_deferred(const char *fmt, ...); extern void __printk_deferred_enter(void); extern void __printk_deferred_exit(void); +extern void printk_force_console_enter(void); +extern void printk_force_console_exit(void); + /* * The printk_deferred_enter/exit macros are available only as a hack for * some code paths that need to defer all printk console printing. Interrupts @@ -229,6 +232,14 @@ static inline void printk_deferred_exit(void) { } +static inline void printk_force_console_enter(void) +{ +} + +static inline void printk_force_console_exit(void) +{ +} + static inline int printk_ratelimit(void) { return 0; diff --git a/init/main.c b/init/main.c index c4778edae797..00fac1170294 100644 --- a/init/main.c +++ b/init/main.c @@ -754,10 +754,7 @@ static int __init do_early_param(char *param, char *val, const struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { - if ((p->early && parameq(param, p->str)) || - (strcmp(param, "console") == 0 && - strcmp(p->str, "earlycon") == 0) - ) { + if (p->early && parameq(param, p->str)) { if (p->setup_func(val) != 0) pr_warn("Malformed early option '%s'\n", param); } diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 3fcb48502adb..c6bb47666aef 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -53,6 +53,8 @@ int devkmsg_sysctl_set_loglvl(const struct ctl_table *table, int write, /* Flags for a single printk record. */ enum printk_info_flags { + /* always show on console, ignore console_loglevel */ + LOG_FORCE_CON = 1, LOG_NEWLINE = 2, /* text ended with a newline */ LOG_CONT = 8, /* text is a fragment of a continuation line */ }; @@ -90,6 +92,7 @@ bool printk_percpu_data_ready(void); void defer_console_output(void); bool is_printk_legacy_deferred(void); +bool is_printk_force_console(void); u16 printk_parse_prefix(const char *text, int *level, enum printk_info_flags *flags); diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 19911c8fa7b6..80910bc3470c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1157,6 +1157,17 @@ static unsigned int __init add_to_rb(struct printk_ringbuffer *rb, static char setup_text_buf[PRINTKRB_RECORD_MAX] __initdata; +static void print_log_buf_usage_stats(void) +{ + unsigned int descs_count = log_buf_len >> PRB_AVGBITS; + size_t meta_data_size; + + meta_data_size = descs_count * (sizeof(struct prb_desc) + sizeof(struct printk_info)); + + pr_info("log buffer data + meta data: %u + %zu = %zu bytes\n", + log_buf_len, meta_data_size, log_buf_len + meta_data_size); +} + void __init setup_log_buf(int early) { struct printk_info *new_infos; @@ -1186,20 +1197,25 @@ void __init setup_log_buf(int early) if (!early && !new_log_buf_len) log_buf_add_cpu(); - if (!new_log_buf_len) + if (!new_log_buf_len) { + /* Show the memory stats only once. */ + if (!early) + goto out; + return; + } new_descs_count = new_log_buf_len >> PRB_AVGBITS; if (new_descs_count == 0) { pr_err("new_log_buf_len: %lu too small\n", new_log_buf_len); - return; + goto out; } new_log_buf = memblock_alloc(new_log_buf_len, LOG_ALIGN); if (unlikely(!new_log_buf)) { pr_err("log_buf_len: %lu text bytes not available\n", new_log_buf_len); - return; + goto out; } new_descs_size = new_descs_count * sizeof(struct prb_desc); @@ -1262,7 +1278,7 @@ void __init setup_log_buf(int early) prb_next_seq(&printk_rb_static) - seq); } - pr_info("log_buf_len: %u bytes\n", log_buf_len); + print_log_buf_usage_stats(); pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); return; @@ -1271,6 +1287,8 @@ err_free_descs: memblock_free(new_descs, new_descs_size); err_free_log_buf: memblock_free(new_log_buf, new_log_buf_len); +out: + print_log_buf_usage_stats(); } static bool __read_mostly ignore_loglevel; @@ -1320,11 +1338,11 @@ static void boot_delay_msec(int level) { unsigned long long k; unsigned long timeout; + bool suppress = !is_printk_force_console() && + suppress_message_printing(level); - if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING) - || suppress_message_printing(level)) { + if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING) || suppress) return; - } k = (unsigned long long)loops_per_msec * boot_delay; @@ -2274,6 +2292,9 @@ int vprintk_store(int facility, int level, if (dev_info) flags |= LOG_NEWLINE; + if (is_printk_force_console()) + flags |= LOG_FORCE_CON; + if (flags & LOG_CONT) { prb_rec_init_wr(&r, reserve_size); if (prb_reserve_in_last(&e, prb, &r, caller_id, PRINTKRB_RECORD_MAX)) { @@ -2281,6 +2302,9 @@ int vprintk_store(int facility, int level, facility, &flags, fmt, args); r.info->text_len += text_len; + if (flags & LOG_FORCE_CON) + r.info->flags |= LOG_FORCE_CON; + if (flags & LOG_NEWLINE) { r.info->flags |= LOG_NEWLINE; prb_final_commit(&e); @@ -2948,6 +2972,7 @@ bool printk_get_next_message(struct printk_message *pmsg, u64 seq, struct printk_info info; struct printk_record r; size_t len = 0; + bool force_con; /* * Formatting extended messages requires a separate buffer, so use the @@ -2966,9 +2991,13 @@ bool printk_get_next_message(struct printk_message *pmsg, u64 seq, pmsg->seq = r.info->seq; pmsg->dropped = r.info->seq - seq; + force_con = r.info->flags & LOG_FORCE_CON; - /* Skip record that has level above the console loglevel. */ - if (may_suppress && suppress_message_printing(r.info->level)) + /* + * Skip records that are not forced to be printed on consoles and that + * has level above the console loglevel. + */ + if (!force_con && may_suppress && suppress_message_printing(r.info->level)) goto out; if (is_extended) { diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 2b35a9d3919d..6f94418d53ff 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -12,6 +12,24 @@ #include "internal.h" +/* Context where printk messages are never suppressed */ +static atomic_t force_con; + +void printk_force_console_enter(void) +{ + atomic_inc(&force_con); +} + +void printk_force_console_exit(void) +{ + atomic_dec(&force_con); +} + +bool is_printk_force_console(void) +{ + return atomic_read(&force_con); +} + static DEFINE_PER_CPU(int, printk_context); /* Can be preempted by NMI. */ |