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
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
type which is a String type that has no -s limitations applied to it.
Change most Strings in the code to Names and add a few extra syscalls,
namely munmap, read, rename and symlink. This was enough to facilitate
following file descriptor allocations in the code more easily and
getting a hint at what's being read/written from/to files. More
syscalls should really be added.
While here, fix an off-by-one bug in the buffer truncation code and
add a fflush so that truss's output reflects the syscall that the
program is stuck in.
Sponsored by: Sophos/Activestate
MFC after: 2 weeks
