Files
i2som-imx-linux/include/linux
Steven Rostedt (Red Hat) 3debb0a9dd tracing: Fix trace_printk() to print when not using bprintk()
The trace_printk() code will allocate extra buffers if the compile detects
that a trace_printk() is used. To do this, the format of the trace_printk()
is saved to the __trace_printk_fmt section, and if that section is bigger
than zero, the buffers are allocated (along with a message that this has
happened).

If trace_printk() uses a format that is not a constant, and thus something
not guaranteed to be around when the print happens, the compiler optimizes
the fmt out, as it is not used, and the __trace_printk_fmt section is not
filled. This means the kernel will not allocate the special buffers needed
for the trace_printk() and the trace_printk() will not write anything to the
tracing buffer.

Adding a "__used" to the variable in the __trace_printk_fmt section will
keep it around, even though it is set to NULL. This will keep the string
from being printed in the debugfs/tracing/printk_formats section as it is
not needed.

Reported-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 07d777fe8c "tracing: Add percpu buffers for trace_printk()"
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-22 18:02:40 -04:00
..
2016-01-05 18:04:58 +01:00
2016-02-11 10:07:18 -05:00
2016-01-08 01:12:06 +01:00
2016-01-15 17:56:32 -08:00
2016-01-20 17:09:18 -08:00
2016-01-15 17:56:32 -08:00
2016-01-15 17:56:32 -08:00
2016-01-15 17:56:32 -08:00
2016-02-03 08:28:43 -08:00
2016-02-03 08:28:43 -08:00
2016-02-08 15:20:01 -05:00
2016-01-22 17:02:18 -08:00
2016-02-11 18:35:48 -08:00
2016-02-11 18:35:48 -08:00
2016-01-07 14:31:27 -05:00
2016-01-10 22:13:15 -05:00
2016-01-04 16:11:11 -05:00
2016-02-09 04:28:06 -05:00
2016-01-04 10:20:19 -05:00
2016-01-15 22:34:39 +01:00
2016-01-12 20:47:02 +02:00
2016-01-15 17:56:32 -08:00
2016-01-14 16:00:49 -08:00