diff options
Diffstat (limited to 'kernel/printk')
| -rw-r--r-- | kernel/printk/nmi.c | 83 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 49 |
2 files changed, 66 insertions, 66 deletions
diff --git a/kernel/printk/nmi.c b/kernel/printk/nmi.c index 16bab471c7e2..f011aaef583c 100644 --- a/kernel/printk/nmi.c +++ b/kernel/printk/nmi.c @@ -67,7 +67,8 @@ static int vprintk_nmi(const char *fmt, va_list args) again: len = atomic_read(&s->len); - if (len >= sizeof(s->buffer)) { + /* The trailing '\0' is not counted into len. */ + if (len >= sizeof(s->buffer) - 1) { atomic_inc(&nmi_message_lost); return 0; } @@ -79,7 +80,7 @@ again: if (!len) smp_rmb(); - add = vsnprintf(s->buffer + len, sizeof(s->buffer) - len, fmt, args); + add = vscnprintf(s->buffer + len, sizeof(s->buffer) - len, fmt, args); /* * Do it once again if the buffer has been flushed in the meantime. @@ -113,16 +114,51 @@ static void printk_nmi_flush_line(const char *text, int len) } -/* - * printk one line from the temporary buffer from @start index until - * and including the @end index. - */ -static void printk_nmi_flush_seq_line(struct nmi_seq_buf *s, - int start, int end) +/* printk part of the temporary buffer line by line */ +static int printk_nmi_flush_buffer(const char *start, size_t len) { - const char *buf = s->buffer + start; + const char *c, *end; + bool header; + + c = start; + end = start + len; + header = true; + + /* Print line by line. */ + while (c < end) { + if (*c == '\n') { + printk_nmi_flush_line(start, c - start + 1); + start = ++c; + header = true; + continue; + } + + /* Handle continuous lines or missing new line. */ + if ((c + 1 < end) && printk_get_level(c)) { + if (header) { + c = printk_skip_level(c); + continue; + } + + printk_nmi_flush_line(start, c - start); + start = c++; + header = true; + continue; + } + + header = false; + c++; + } - printk_nmi_flush_line(buf, (end - start) + 1); + /* Check if there was a partial line. Ignore pure header. */ + if (start < end && !header) { + static const char newline[] = KERN_CONT "\n"; + + printk_nmi_flush_line(start, end - start); + printk_nmi_flush_line(newline, strlen(newline)); + } + + return len; } /* @@ -135,8 +171,8 @@ static void __printk_nmi_flush(struct irq_work *work) __RAW_SPIN_LOCK_INITIALIZER(read_lock); struct nmi_seq_buf *s = container_of(work, struct nmi_seq_buf, work); unsigned long flags; - size_t len, size; - int i, last_i; + size_t len; + int i; /* * The lock has two functions. First, one reader has to flush all @@ -154,12 +190,14 @@ more: /* * This is just a paranoid check that nobody has manipulated * the buffer an unexpected way. If we printed something then - * @len must only increase. + * @len must only increase. Also it should never overflow the + * buffer size. */ - if (i && i >= len) { + if ((i && i >= len) || len > sizeof(s->buffer)) { const char *msg = "printk_nmi_flush: internal error\n"; printk_nmi_flush_line(msg, strlen(msg)); + len = 0; } if (!len) @@ -167,22 +205,7 @@ more: /* Make sure that data has been written up to the @len */ smp_rmb(); - - size = min(len, sizeof(s->buffer)); - last_i = i; - - /* Print line by line. */ - for (; i < size; i++) { - if (s->buffer[i] == '\n') { - printk_nmi_flush_seq_line(s, last_i, i); - last_i = i + 1; - } - } - /* Check if there was a partial line. */ - if (last_i < size) { - printk_nmi_flush_seq_line(s, last_i, size - 1); - printk_nmi_flush_line("\n", strlen("\n")); - } + i += printk_nmi_flush_buffer(s->buffer + i, len - i); /* * Check that nothing has got added in the meantime and truncate diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index de08fc90baaf..577f2288d19f 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -253,17 +253,6 @@ static int preferred_console = -1; int console_set_on_cmdline; EXPORT_SYMBOL(console_set_on_cmdline); -#ifdef CONFIG_OF -static bool of_specified_console; - -void console_set_by_of(void) -{ - of_specified_console = true; -} -#else -# define of_specified_console false -#endif - /* Flag: console code may call schedule() */ static int console_may_schedule; @@ -794,8 +783,6 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from) return ret; } -static void cont_flush(void); - static ssize_t devkmsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { @@ -811,7 +798,6 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf, if (ret) return ret; raw_spin_lock_irq(&logbuf_lock); - cont_flush(); while (user->seq == log_next_seq) { if (file->f_flags & O_NONBLOCK) { ret = -EAGAIN; @@ -874,7 +860,6 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence) return -ESPIPE; raw_spin_lock_irq(&logbuf_lock); - cont_flush(); switch (whence) { case SEEK_SET: /* the first record */ @@ -913,7 +898,6 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait) poll_wait(file, &log_wait, wait); raw_spin_lock_irq(&logbuf_lock); - cont_flush(); if (user->seq < log_next_seq) { /* return error when data has vanished underneath us */ if (user->seq < log_first_seq) @@ -1300,7 +1284,6 @@ static int syslog_print(char __user *buf, int size) size_t skip; raw_spin_lock_irq(&logbuf_lock); - cont_flush(); if (syslog_seq < log_first_seq) { /* messages are gone, move to first one */ syslog_seq = log_first_seq; @@ -1360,7 +1343,6 @@ static int syslog_print_all(char __user *buf, int size, bool clear) return -ENOMEM; raw_spin_lock_irq(&logbuf_lock); - cont_flush(); if (buf) { u64 next_seq; u64 seq; @@ -1522,7 +1504,6 @@ int do_syslog(int type, char __user *buf, int len, int source) /* Number of chars in the log buffer */ case SYSLOG_ACTION_SIZE_UNREAD: raw_spin_lock_irq(&logbuf_lock); - cont_flush(); if (syslog_seq < log_first_seq) { /* messages are gone, move to first one */ syslog_seq = log_first_seq; @@ -2185,27 +2166,20 @@ void resume_console(void) /** * console_cpu_notify - print deferred console messages after CPU hotplug - * @self: notifier struct - * @action: CPU hotplug event - * @hcpu: unused + * @cpu: unused * * If printk() is called from a CPU that is not online yet, the messages * will be spooled but will not show up on the console. This function is * called when a new CPU comes online (or fails to come up), and ensures * that any such output gets printed. */ -static int console_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - switch (action) { - case CPU_ONLINE: - case CPU_DEAD: - case CPU_DOWN_FAILED: - case CPU_UP_CANCELED: +static int console_cpu_notify(unsigned int cpu) +{ + if (!cpuhp_tasks_frozen) { console_lock(); console_unlock(); } - return NOTIFY_OK; + return 0; } /** @@ -2657,7 +2631,7 @@ void register_console(struct console *newcon) * didn't select a console we take the first one * that registers here. */ - if (preferred_console < 0 && !of_specified_console) { + if (preferred_console < 0) { if (newcon->index < 0) newcon->index = 0; if (newcon->setup == NULL || @@ -2843,6 +2817,7 @@ EXPORT_SYMBOL(unregister_console); static int __init printk_late_init(void) { struct console *con; + int ret; for_each_console(con) { if (!keep_bootcon && con->flags & CON_BOOT) { @@ -2857,7 +2832,12 @@ static int __init printk_late_init(void) unregister_console(con); } } - hotcpu_notifier(console_cpu_notify, 0); + ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL, + console_cpu_notify); + WARN_ON(ret < 0); + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online", + console_cpu_notify, NULL); + WARN_ON(ret < 0); return 0; } late_initcall(printk_late_init); @@ -3039,7 +3019,6 @@ void kmsg_dump(enum kmsg_dump_reason reason) dumper->active = true; raw_spin_lock_irqsave(&logbuf_lock, flags); - cont_flush(); dumper->cur_seq = clear_seq; dumper->cur_idx = clear_idx; dumper->next_seq = log_next_seq; @@ -3130,7 +3109,6 @@ bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog, bool ret; raw_spin_lock_irqsave(&logbuf_lock, flags); - cont_flush(); ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len); raw_spin_unlock_irqrestore(&logbuf_lock, flags); @@ -3173,7 +3151,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog, goto out; raw_spin_lock_irqsave(&logbuf_lock, flags); - cont_flush(); if (dumper->cur_seq < log_first_seq) { /* messages are gone, move to first available one */ dumper->cur_seq = log_first_seq; |
