From: Tetsuo Handa Date: Tue, 11 Dec 2018 09:49:05 +0000 (+0900) Subject: printk: Remove print_prefix() calls with NULL buffer. X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=07c17732bd687567802aaa5fa5c101c2776565d1;p=openwrt%2Fstaging%2Fblogic.git printk: Remove print_prefix() calls with NULL buffer. We can save lines/size by removing print_prefix() with buf == NULL. This patch makes no functional change. Link: http://lkml.kernel.org/r/1544521745-11925-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp To: Steven Rostedt Cc: linux-kernel@vger.kernel.org Signed-off-by: Tetsuo Handa Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek --- diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index c7d217764db3..91db332ccf4d 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1228,13 +1228,15 @@ static inline void boot_delay_msec(int level) static bool printk_time = IS_ENABLED(CONFIG_PRINTK_TIME); module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR); +static size_t print_syslog(unsigned int level, char *buf) +{ + return sprintf(buf, "<%u>", level); +} + static size_t print_time(u64 ts, char *buf) { unsigned long rem_nsec = do_div(ts, 1000000000); - if (!buf) - return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts); - return sprintf(buf, "[%5lu.%06lu] ", (unsigned long)ts, rem_nsec / 1000); } @@ -1243,24 +1245,11 @@ static size_t print_prefix(const struct printk_log *msg, bool syslog, bool time, char *buf) { size_t len = 0; - unsigned int prefix = (msg->facility << 3) | msg->level; - - if (syslog) { - if (buf) { - len += sprintf(buf, "<%u>", prefix); - } else { - len += 3; - if (prefix > 999) - len += 3; - else if (prefix > 99) - len += 2; - else if (prefix > 9) - len++; - } - } + if (syslog) + len = print_syslog((msg->facility << 3) | msg->level, buf); if (time) - len += print_time(msg->ts_nsec, buf ? buf + len : NULL); + len += print_time(msg->ts_nsec, buf + len); return len; } @@ -1270,6 +1259,8 @@ static size_t msg_print_text(const struct printk_log *msg, bool syslog, const char *text = log_text(msg); size_t text_size = msg->text_len; size_t len = 0; + char prefix[PREFIX_MAX]; + const size_t prefix_len = print_prefix(msg, syslog, time, prefix); do { const char *next = memchr(text, '\n', text_size); @@ -1284,19 +1275,17 @@ static size_t msg_print_text(const struct printk_log *msg, bool syslog, } if (buf) { - if (print_prefix(msg, syslog, time, NULL) + - text_len + 1 >= size - len) + if (prefix_len + text_len + 1 >= size - len) break; - len += print_prefix(msg, syslog, time, buf + len); + memcpy(buf + len, prefix, prefix_len); + len += prefix_len; memcpy(buf + len, text, text_len); len += text_len; buf[len++] = '\n'; } else { /* SYSLOG_ACTION_* buffer size only calculation */ - len += print_prefix(msg, syslog, time, NULL); - len += text_len; - len++; + len += prefix_len + text_len + 1; } text = next;