Pid with Systrace

[sammerry]

Hey, I'm looking into using hstrace for a utility im working on but strugling tracing both parent and child processes. It seems like coupling pid with syscall in the crossbeam_chanel as a touple would keep things clearer when collecting calls from parent and child processes. You could simply forward each child into a central channel or chain iterators into a single match.

Is there an easier way to do this?

[sammerry]

nevermind, looks like TraceOutput contains Pid so simply calling .iter() on it should get what i need. Still having trouble joining multiple crossbeam_channels into one.
https://github.com/blaind/hstrace/blob/master/src/trace/hstrace_impl.rs#L78

Is there any chance that hstrace will support child processes in the future?
https://github.com/blaind/hstrace/blob/master/src/trace/hstrace_impl.rs#L200

[blaind]

Hi! This repo was more of a PoC/WIP, so not being actively developed.

If I remember correctly, https://github.com/blaind/hstrace/blob/master/src/trace/hstrace_impl.rs#L200 comment was added for future performance improvements where each thread could be traced in separate thread.

Forks are already detected. Added an example, check out https://github.com/blaind/hstrace/blob/master/examples/05_trace_child.rs

Output (notice the increasing pid after clone):

TRACE: pid=16430, call=Swapoff vars=["/tmp/__nonexistant"] out=Some(Err(EPERM))
TRACE: pid=16430, call=Mmap vars=[NULL, 1052672, 3, 34, 4294967295, 0] out=Some(Ok(0x7f192ad57000))
TRACE: pid=16430, call=Clone vars=[] out=Some(Ok(16431))
TRACE: pid=16431, call=Readlink vars=["/tmp/link_src_child_1", 0x7f192ae56ef0, 256] out=Some(Err(ENOENT))
TRACE: pid=16431, call=Mmap vars=[NULL, 1052672, 3, 34, 4294967295, 0] out=Some(Ok(0x7f192ac56000))
TRACE: pid=16431, call=Clone vars=[] out=Some(Ok(16432))
TRACE: pid=16432, call=Readlink vars=["/tmp/link_src_child_2", NULL, 256] out=Some(Err(ENOENT))
TRACE: pid=16431, call=Wait4 vars=[https://git.io/Jv49L] out=None
TRACE: pid=16431, call=Munmap vars=[0x7f192ac56000, 1052672] out=Some(Ok(0))
TRACE: pid=16430, call=Wait4 vars=[https://git.io/Jv49L] out=None
TRACE: pid=16430, call=Munmap vars=[0x7f192ad57000, 1052672] out=Some(Ok(0))
TRACE: pid=16430, call=ExitGroup vars=[0] out=None
TRACE: pid=16432, call=Exit vars=[https://git.io/Jv49L] out=None
TRACE: pid=16431, call=Exit vars=[https://git.io/Jv49L] out=None

[sammerry]

Thanks! that example helps a lot.

I don't have a lot of time at the moment, but really like the premise of the project and would like to help move it out of PoC if you have a list of missing features of things that need work.