Commit-ID: 95100358491abaa2e9a5483811370059bbca4645 Gitweb: http://git.kernel.org/tip/95100358491abaa2e9a5483811370059bbca4645 Author: Johannes Berg <johannes.berg@xxxxxxxxx> AuthorDate: Thu, 24 Nov 2011 20:03:08 +0100 Committer: Steven Rostedt <rostedt@xxxxxxxxxxx> CommitDate: Mon, 13 Feb 2012 13:46:05 -0500 printk/tracing: Add console output tracing Add a printk.console trace point to record any printk messages into the trace, regardless of the current console loglevel. This can help correlate (existing) printk debugging with other tracing. Link: http://lkml.kernel.org/r/1322161388.5366.54.camel@xxxxxxxxxxxxxxxxxxxxx Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- include/trace/events/printk.h | 41 +++++++++++++++++++++++++++++++++++++++++ kernel/printk.c | 5 +++++ 2 files changed, 46 insertions(+), 0 deletions(-) diff --git a/include/trace/events/printk.h b/include/trace/events/printk.h new file mode 100644 index 0000000..94ec79c --- /dev/null +++ b/include/trace/events/printk.h @@ -0,0 +1,41 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM printk + +#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PRINTK_H + +#include <linux/tracepoint.h> + +TRACE_EVENT_CONDITION(console, + TP_PROTO(const char *log_buf, unsigned start, unsigned end, + unsigned log_buf_len), + + TP_ARGS(log_buf, start, end, log_buf_len), + + TP_CONDITION(start != end), + + TP_STRUCT__entry( + __dynamic_array(char, msg, end - start + 1) + ), + + TP_fast_assign( + if ((start & (log_buf_len - 1)) > (end & (log_buf_len - 1))) { + memcpy(__get_dynamic_array(msg), + log_buf + (start & (log_buf_len - 1)), + log_buf_len - (start & (log_buf_len - 1))); + memcpy((char *)__get_dynamic_array(msg) + + log_buf_len - (start & (log_buf_len - 1)), + log_buf, end & (log_buf_len - 1)); + } else + memcpy(__get_dynamic_array(msg), + log_buf + (start & (log_buf_len - 1)), + end - start); + ((char *)__get_dynamic_array(msg))[end - start] = 0; + ), + + TP_printk("%s", __get_str(msg)) +); +#endif /* _TRACE_PRINTK_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/kernel/printk.c b/kernel/printk.c index 13c0a11..cb8a6bd 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -44,6 +44,9 @@ #include <asm/uaccess.h> +#define CREATE_TRACE_POINTS +#include <trace/events/printk.h> + /* * Architectures can override it: */ @@ -542,6 +545,8 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to" static void _call_console_drivers(unsigned start, unsigned end, int msg_log_level) { + trace_console(&LOG_BUF(0), start, end, log_buf_len); + if ((msg_log_level < console_loglevel || ignore_loglevel) && console_drivers && start != end) { if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) { -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html