When truss is detaching from very active process it is possible to
hang on waitpid(2) in restore_proc() forever, because
ptrace(PT_SYSCALL) must be called before detaching, to allow the
debugging process to continue execution. Also when truss called with
'-c' argument, it does not print anything after detach, because it
immediately exits from restore_proc().
To fix these two problems make detaching deferred, but then it is
impossible to detach from a process which does not do any system call.
To fix this issue use sigaction(2) instead of signal(3) to disable
SA_RESTART flag for waitpid(2) that makes it non-restartable. Remove
global variable child_pid, because now detaching is handled in context
where child's pid is known.
Reported by: mjg
Tested by: mjg, swills
Approved by: kib (mentor)
MFC after: 2 weeks
Using a separate process group here is bad, since (for example) job
control in the TTY layer prevents interaction with the TTY, causing the
child process to hang.
Mentioned on: current@
MFC after: 2 weeks
- Fix logic handling execve(). We will not be able to
obtain information otherwise.
- truss coredump [1].
- truss does not work against itself [2].
PR: bin/58970 [1], bin/45193 [2]
Submitted by: Howard Su
Approved by: re (kensmith)
rename, __getcwd, shutdown, getrlimit, setrlimit, _umtx_lock, _umtx_unlock,
pathconf, truncate, ftruncate, kill
- Decode more arguments of open, mprot, *stat, and fcntl.
- Convert all constant-macro and bitfield decoding to lookup tables; much
cleaner than previous code.
- Print the timestamp of process exit and signal reception when -d or -D are in
use
- Try six times with 1/2 second delay to debug the child
PR: bin/52190 (updated)
Submitted by: Dan Nelson <dnelson@allantgroup.com>
Approved by: alfred
depend on namespace pollution in <signal.h>. (truss shouldn't be
using timevals anyway, since it was implemented long after timevals
were obsoleted by timespecs.)
to wake up any processes waiting via PIOCWAIT on process exit, and truss
needs to be more aware that a process may actually disappear while it's
waiting.
Reviewed by: Paul Saab <ps@yahoo-inc.com>
execvp() in the child branch of a vfork(). Changed to use fork()
instead.
Some of these (mv, find, apply, xargs) might benefit greatly from
being rewritten to use vfork() properly.
PR: Loosely related to bin/8252
Approved by: jkh and bde
Correct usage: one of {-p pid, command} is required.
Open output file when command line is fully analyzed: incorrect `truss -o f'
command does not create an empty file anymore.
change from
ioctl(fd, PIOC<foo>, &i);
to
ioctl(fd, PIOC<foo>, i);
This is going from the _IOW to _IO ioctl macro. The kernel, procctl, and
truss must be in synch for it all to work (not doing so will get errors about
inappropriate ioctl's, fortunately). Hopefully I didn't forget anything :).
said process will not have its event mask cleared (and be restarted) on
the last close of a procfs/mem file for that pid. This reduces the chance
that a truss-monitored process will be left hanging with these bits set
and nobody looking for it.
This is the least-tested change of all of these, I'm afraid.
