On Sat, 5 May 2018 11:38:03 +0900 Masami Hiramatsu mhiramat@kernel.org wrote:
On Fri, 4 May 2018 12:06:42 -0400 Steven Rostedt rostedt@goodmis.org wrote:
On Sat, 5 May 2018 00:48:28 +0900 Masami Hiramatsu mhiramat@kernel.org wrote:
So the syntax will be
p[:EVENT] SYM[(CAST)|+OFFS] [FETCHARG]
And here is an example;
p:myevent vfs_read(void *file, char *buf, size_t count, void *pos) $arg1 $arg2
If we do this, why bother with $arg1 $arg2?
User may want to trace only some of them. :)
OK, now I think it is a time to introduce new unified interface for dynamic events, tracefs/dynamic_events and make uprobe_events and kprobe_events as symbolic-links to the new interface file.
Actually, there is no reason we split those 2 interfaces, since both have similar, but very clear syntax differences.
o Uprobe event definition p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) -:[GRP/]EVENT : Clear uprobe or uretprobe event
o Kprobe event definition p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe r[MAXACTIVE][:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe -:[GRP/]EVENT : Clear a probe
At first, it is clear that those can share the parser. 2nd, it is easy to distinguish those, because Uprobe event must require the PATH which starts with '/', on the other hand, Kprobe event must NOT start with '/'. (both SYM and MOD will start with alphabet or '_', of course MEMADDR will start with digits)
If we can merge those to unified dynamic_events interface, I think 'f[:[GRP/]EVENT] SYM(CAST)' is also acceptable, since it is no more only for kprobe/uprobe. We can directly add some other dynamic events via dynamic_events interface. ;)
Thank you,