tracing: add trace_bprintk()
Impact: add a generic printk() for tracing, like trace_printk()
trace_bprintk() uses the infrastructure to record events on ring_buffer.
[ fweisbec@gmail.com: ported to latest -tip, made it work if
!CONFIG_MODULES, never free the format strings from modules
because we can't keep track of them and conditionnaly create
the ftrace format strings section (reported by Steven Rostedt) ]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0add6b2..48ade31 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -69,6 +69,14 @@
#define FTRACE_EVENTS()
#endif
+#ifdef CONFIG_TRACING
+#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \
+ *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
+ VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
+#else
+#define TRACE_PRINTKS()
+#endif
+
/* .data section */
#define DATA_DATA \
*(.data) \
@@ -100,6 +108,7 @@
*(__vermagic) /* Kernel version magic */ \
*(__markers_strings) /* Markers: strings */ \
*(__tracepoints_strings)/* Tracepoints: strings */ \
+ TRACE_PRINTKS() \
} \
\
.rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \