tracing/fastboot: get the initcall name before it disappears

After some initcall traces, some initcall names may be inconsistent.
That's because these functions will disappear from the .init section
and also their name from the symbols table.

So we have to copy the name of the function in a buffer large enough
during the trace appending. It is not costly for the ring_buffer because
the number of initcall entries is commonly not really large.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 4455490d91bd..e672e51c40a9 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -7,6 +7,7 @@
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/kallsyms.h>
 
 extern int ftrace_enabled;
 extern int
@@ -213,7 +214,7 @@ ftrace_init_module(unsigned long *start, unsigned long *end) { }
 
 struct boot_trace {
         pid_t                   caller;
-        initcall_t              func;
+        char                    func[KSYM_NAME_LEN];
         int                     result;
         unsigned long long      duration;
         ktime_t                 calltime;
@@ -221,10 +222,10 @@ struct boot_trace {
 };
 
 #ifdef CONFIG_BOOT_TRACER
-extern void trace_boot(struct boot_trace *it);
+extern void trace_boot(struct boot_trace *it, initcall_t fn);
 extern void start_boot_trace(void);
 #else
-static inline void trace_boot(struct boot_trace *it) { }
+static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
 static inline void start_boot_trace(void) { }
 #endif