tracing/kprobes: Support basic types on dynamic events

Support basic types of integer (u8, u16, u32, u64, s8, s16, s32, s64) in
kprobe tracer. With this patch, users can specify above basic types on
each arguments after ':'. If omitted, the argument type is set as
unsigned long (u32 or u64, arch-dependent).

 e.g.
  echo 'p account_system_time+0 hardirq_offset=%si:s32' > kprobe_events

  adds a probe recording hardirq_offset in signed-32bits value on the
  entry of account_system_time.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100412171708.3790.18599.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 14 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index bec2c973ff0c..3ebdb6bd2362 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -102,29 +102,17 @@ struct syscall_trace_exit {
         long                    ret;
 };
 
-struct kprobe_trace_entry {
+struct kprobe_trace_entry_head {
         struct trace_entry      ent;
         unsigned long           ip;
-        int                     nargs;
-        unsigned long           args[];
 };
 
-#define SIZEOF_KPROBE_TRACE_ENTRY(n)                    \
-        (offsetof(struct kprobe_trace_entry, args) +    \
-        (sizeof(unsigned long) * (n)))
-
-struct kretprobe_trace_entry {
+struct kretprobe_trace_entry_head {
         struct trace_entry      ent;
         unsigned long           func;
         unsigned long           ret_ip;
-        int                     nargs;
-        unsigned long           args[];
 };
 
-#define SIZEOF_KRETPROBE_TRACE_ENTRY(n)                 \
-        (offsetof(struct kretprobe_trace_entry, args) + \
-        (sizeof(unsigned long) * (n)))
-
 /*
  * trace_flag_type is an enumeration that holds different
  * states when a trace occurs. These are: