diff options
| -rw-r--r-- | kernel/printk.c | 105 |
1 files changed, 61 insertions, 44 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index 915a8be10b5f..32462d2b364a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1264,13 +1264,13 @@ asmlinkage int vprintk_emit(int facility, int level, const char *fmt, va_list args) { static int recursion_bug; - static char buf[LOG_LINE_MAX]; - static size_t buflen; - static int buflevel; + static char cont_buf[LOG_LINE_MAX]; + static size_t cont_len; + static int cont_level; + static struct task_struct *cont_task; static char textbuf[LOG_LINE_MAX]; - static struct task_struct *cont; char *text = textbuf; - size_t textlen; + size_t text_len; unsigned long flags; int this_cpu; bool newline = false; @@ -1320,15 +1320,15 @@ asmlinkage int vprintk_emit(int facility, int level, * The printf needs to come first; we need the syslog * prefix which might be passed-in as a parameter. */ - textlen = vscnprintf(text, sizeof(textbuf), fmt, args); + text_len = vscnprintf(text, sizeof(textbuf), fmt, args); /* mark and strip a trailing newline */ - if (textlen && text[textlen-1] == '\n') { - textlen--; + if (text_len && text[text_len-1] == '\n') { + text_len--; newline = true; } - /* strip syslog prefix and extract log level or flags */ + /* strip syslog prefix and extract log level or control flags */ if (text[0] == '<' && text[1] && text[2] == '>') { switch (text[1]) { case '0' ... '7': @@ -1338,49 +1338,67 @@ asmlinkage int vprintk_emit(int facility, int level, prefix = true; case 'c': /* KERN_CONT */ text += 3; - textlen -= 3; + text_len -= 3; } } - if (buflen && (prefix || dict || cont != current)) { - /* flush existing buffer */ - log_store(facility, buflevel, NULL, 0, buf, buflen); - printed_len += buflen; - buflen = 0; - } + if (level == -1) + level = default_message_loglevel; - if (buflen == 0) { - /* remember level for first message in the buffer */ - if (level == -1) - buflevel = default_message_loglevel; - else - buflevel = level; + if (dict) { + prefix = true; + newline = true; } - if (buflen || !newline) { - /* append to existing buffer, or buffer until next message */ - if (buflen + textlen > sizeof(buf)) - textlen = sizeof(buf) - buflen; - memcpy(buf + buflen, text, textlen); - buflen += textlen; - } + if (!newline) { + if (cont_len && (prefix || cont_task != current)) { + /* + * Flush earlier buffer, which is either from a + * different thread, or when we got a new prefix. + */ + log_store(facility, cont_level, NULL, 0, cont_buf, cont_len); + cont_len = 0; + } - if (newline) { - /* end of line; flush buffer */ - if (buflen) { - log_store(facility, buflevel, - dict, dictlen, buf, buflen); - printed_len += buflen; - buflen = 0; - } else { - log_store(facility, buflevel, - dict, dictlen, text, textlen); - printed_len += textlen; + if (!cont_len) { + cont_level = level; + cont_task = current; } - cont = NULL; + + /* buffer or append to earlier buffer from the same thread */ + if (cont_len + text_len > sizeof(cont_buf)) + text_len = sizeof(cont_buf) - cont_len; + memcpy(cont_buf + cont_len, text, text_len); + cont_len += text_len; } else { - /* remember thread which filled the buffer */ - cont = current; + if (cont_len && cont_task == current) { + if (prefix) { + /* + * New prefix from the same thread; flush. We + * either got no earlier newline, or we race + * with an interrupt. + */ + log_store(facility, cont_level, + NULL, 0, cont_buf, cont_len); + cont_len = 0; + } + + /* append to the earlier buffer and flush */ + if (cont_len + text_len > sizeof(cont_buf)) + text_len = sizeof(cont_buf) - cont_len; + memcpy(cont_buf + cont_len, text, text_len); + cont_len += text_len; + log_store(facility, cont_level, + NULL, 0, cont_buf, cont_len); + cont_len = 0; + cont_task = NULL; + printed_len = cont_len; + } else { + /* ordinary single and terminated line */ + log_store(facility, level, + dict, dictlen, text, text_len); + printed_len = text_len; + } } /* @@ -1470,7 +1488,6 @@ EXPORT_SYMBOL(printk); #define LOG_LINE_MAX 0 static struct log *log_from_idx(u32 idx) { return NULL; } static u32 log_next(u32 idx) { return 0; } -static char *log_text(const struct log *msg) { return NULL; } static void call_console_drivers(int level, const char *text, size_t len) {} static size_t msg_print_text(const struct log *msg, bool syslog, char *buf, size_t size) { return 0; } |