How to a detect process is running in system call or not?

[nisarg]

Hello All,

I have two running processes A and B. After some time, process B stops (SIGSTOP) the process A.

Now, process B wants to determine that - " when the process A was stopped (SIGSTOP), was it (process A) executing some system call or not? "

And if the process A was in system call, then in which system call was it executing?

Remember : process B is working via kernel-module.

Thank you and wishing your reply...

from,
Nisarg

[Lakshmipathi]

Just guessing here,may be generate a core dump of process and find whether the process was in kernel mode or not using the dump.
another guess,time command provides user time and system time --- is possible to retrieve something from there?

no more guesses....I hope someone comes with better reply than this

[matt_kleviar]

get the stack trace of the process A
and scan it.
you can see whether process was in kernel mode :
and if it was then get the symbol (of course which was must be telling which system call you were in)