From a763677343c2f19b78f795a187e2b2fb442d0ee4 Mon Sep 17 00:00:00 2001 From: Marcin Niesluchowski Date: Thu, 2 Jul 2015 16:54:51 +0200 Subject: [PATCH] printk: add one function for storing log in proper format Preparation commit for future changes purpose. Separate code responsible for storing log message in proper format from operations on consoles by putting it in another function. Change-Id: I6d744bb83f8dd0e4ae5afe05bd082092e28082a9 Signed-off-by: Marcin Niesluchowski --- kernel/printk/printk.c | 183 ++++++++++++++++++++++------------------- 1 file changed, 98 insertions(+), 85 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 7a35de3e1b32..3b9f85fa4152 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -586,6 +586,102 @@ static size_t cont_print_text(char *text, size_t size) return textlen; } +static int log_format_and_store(int facility, int level, + const char *dict, size_t dictlen, + const char *fmt, va_list args) +{ + static char textbuf[LOG_LINE_MAX]; + char *text = textbuf; + size_t text_len = 0; + enum log_flags lflags = 0; + int printed_len = 0; + + /* + * The printf needs to come first; we need the syslog + * prefix which might be passed-in as a parameter. + */ + text_len = vscnprintf(text, sizeof(textbuf), fmt, args); + + /* mark and strip a trailing newline */ + if (text_len && text[text_len-1] == '\n') { + text_len--; + lflags |= LOG_NEWLINE; + } + + /* strip kernel syslog prefix and extract log level or control flags */ + if (facility == 0) { + int kern_level = printk_get_level(text); + + if (kern_level) { + const char *end_of_header = printk_skip_level(text); + + switch (kern_level) { + case '0' ... '7': + if (level == LOGLEVEL_DEFAULT) + level = kern_level - '0'; + /* fallthrough */ + case 'd': /* KERN_DEFAULT */ + lflags |= LOG_PREFIX; + } + /* + * No need to check length here because vscnprintf + * put '\0' at the end of the string. Only valid and + * newly printed level is detected. + */ + text_len -= end_of_header - text; + text = (char *)end_of_header; + } + } + + if (level == LOGLEVEL_DEFAULT) + level = default_message_loglevel; + + if (dict) + lflags |= LOG_PREFIX|LOG_NEWLINE; + + if (!(lflags & LOG_NEWLINE)) { + /* + * Flush the conflicting buffer. An earlier newline was missing, + * or another task also prints continuation lines. + */ + if (cont.len && (lflags & LOG_PREFIX || cont.owner != current)) + cont_flush(LOG_NEWLINE); + + /* buffer line if possible, otherwise store it right away */ + if (cont_add(facility, level, text, text_len)) + printed_len += text_len; + else + printed_len += log_store(facility, level, + lflags | LOG_CONT, 0, + dict, dictlen, text, text_len); + } else { + bool stored = false; + + /* + * If an earlier newline was missing and it was the same task, + * either merge it with the current buffer and flush, or if + * there was a race with interrupts (prefix == true) then just + * flush it out and store this line separately. + * If the preceding printk was from a different task and missed + * a newline, flush and append the newline. + */ + if (cont.len) { + if (cont.owner == current && !(lflags & LOG_PREFIX)) + stored = cont_add(facility, level, text, + text_len); + cont_flush(LOG_NEWLINE); + } + + if (stored) + printed_len += text_len; + else + printed_len += log_store(facility, level, + lflags, 0, dict, dictlen, + text, text_len); + } + return printed_len; +} + int dmesg_restrict = IS_ENABLED(CONFIG_SECURITY_DMESG_RESTRICT); static int syslog_action_restricted(int type) @@ -1626,10 +1722,6 @@ asmlinkage int vprintk_emit(int facility, int level, const char *fmt, va_list args) { static int recursion_bug; - static char textbuf[LOG_LINE_MAX]; - char *text = textbuf; - size_t text_len = 0; - enum log_flags lflags = 0; unsigned long flags; int this_cpu; int printed_len = 0; @@ -1683,87 +1775,8 @@ asmlinkage int vprintk_emit(int facility, int level, strlen(recursion_msg)); } - /* - * The printf needs to come first; we need the syslog - * prefix which might be passed-in as a parameter. - */ - text_len = vscnprintf(text, sizeof(textbuf), fmt, args); - - /* mark and strip a trailing newline */ - if (text_len && text[text_len-1] == '\n') { - text_len--; - lflags |= LOG_NEWLINE; - } - - /* strip kernel syslog prefix and extract log level or control flags */ - if (facility == 0) { - int kern_level = printk_get_level(text); - - if (kern_level) { - const char *end_of_header = printk_skip_level(text); - switch (kern_level) { - case '0' ... '7': - if (level == LOGLEVEL_DEFAULT) - level = kern_level - '0'; - /* fallthrough */ - case 'd': /* KERN_DEFAULT */ - lflags |= LOG_PREFIX; - } - /* - * No need to check length here because vscnprintf - * put '\0' at the end of the string. Only valid and - * newly printed level is detected. - */ - text_len -= end_of_header - text; - text = (char *)end_of_header; - } - } - - if (level == LOGLEVEL_DEFAULT) - level = default_message_loglevel; - - if (dict) - lflags |= LOG_PREFIX|LOG_NEWLINE; - - if (!(lflags & LOG_NEWLINE)) { - /* - * Flush the conflicting buffer. An earlier newline was missing, - * or another task also prints continuation lines. - */ - if (cont.len && (lflags & LOG_PREFIX || cont.owner != current)) - cont_flush(LOG_NEWLINE); - - /* buffer line if possible, otherwise store it right away */ - if (cont_add(facility, level, text, text_len)) - printed_len += text_len; - else - printed_len += log_store(facility, level, - lflags | LOG_CONT, 0, - dict, dictlen, text, text_len); - } else { - bool stored = false; - - /* - * If an earlier newline was missing and it was the same task, - * either merge it with the current buffer and flush, or if - * there was a race with interrupts (prefix == true) then just - * flush it out and store this line separately. - * If the preceding printk was from a different task and missed - * a newline, flush and append the newline. - */ - if (cont.len) { - if (cont.owner == current && !(lflags & LOG_PREFIX)) - stored = cont_add(facility, level, text, - text_len); - cont_flush(LOG_NEWLINE); - } - - if (stored) - printed_len += text_len; - else - printed_len += log_store(facility, level, lflags, 0, - dict, dictlen, text, text_len); - } + printed_len += log_format_and_store(facility, level, dict, dictlen, + fmt, args); logbuf_cpu = UINT_MAX; raw_spin_unlock(&logbuf_lock); -- 2.34.1