From d43ff430f434d862db59582c0f1f02382a678036 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 25 Jun 2015 15:01:24 -0700 Subject: printk: guard the amount written per line by devkmsg_read() This patchset updates netconsole so that it can emit messages with the same header as used in /dev/kmsg which gives neconsole receiver full log information which enables things like structured logging and detection of lost messages. This patch (of 7): devkmsg_read() uses 8k buffer and assumes that the formatted output message won't overrun which seems safe given LOG_LINE_MAX, the current use of dict and the escaping method being used; however, we're planning to use devkmsg formatting wider and accounting for the buffer size properly isn't that complicated. This patch defines CONSOLE_EXT_LOG_MAX as 8192 and updates devkmsg_read() so that it limits output accordingly. Signed-off-by: Tejun Heo Cc: David Miller Cc: Kay Sievers Reviewed-by: Petr Mladek Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/printk.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/printk.h') diff --git a/include/linux/printk.h b/include/linux/printk.h index 9b30871c9149..58b1fec40d37 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -30,6 +30,8 @@ static inline const char *printk_skip_level(const char *buffer) return buffer; } +#define CONSOLE_EXT_LOG_MAX 8192 + /* printk's without a loglevel use this.. */ #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT -- cgit v1.2.3