Re: patches to actually use markers?
"Frank Ch. Eigler" <[email protected]> Fri, 16 Nov 2007 15:26:45 -0500
| Newsgroups | gmane.linux.systemtap,gmane.linux.kernel.tracing |
|---|---|
| Message-ID | <[email protected]> |
Hi - On Fri, Nov 16, 2007 at 03:10:15PM -0500, Mathieu Desnoyers wrote: > [...] > > How would this syscall specific function get ebx or the string, > > without ebx (or regs) being passed as marker arguments? > That's the idea : in the syscall specific function (not in > syscall_trace()), we add another marker that takes the syscall > specific arguments as parameter. I think we use the same approach > there. I see. Yes, per-systemcall markers would be welcome by our group, and ones not dependent on TIF_TRACE or whatnot even more so. But were trying not to get too optimistic. > What I was saying is that we can't extract the string from > syscall_trace() because we have no idea it is a string. If "we" is a marker callback function that is given the system call number, it can be taught. This is the sort of thing we do currently in systemtap script code based upon kprobes. - FChE