truss

[Anton Yuzhaninov]

On Mon, 19 Sep 2011 15:58:02 +0300, Mikolaj Golub wrote:
 AY>> ktrace -i for truss sleep 5
 AY>> http://dl.dropbox.com/u/8798217/tmp/truss_ktrace2.txt
MG> 
MG> Although ptrace(PT_TRACE_ME,0,0,0) returned 0 the process did not stop after
MG> execve() and wait4() in parent (which was actually waiting for this stop)
MG> returned only after the child exit. No I idea why so far :-).
MG> 

As I understand SIGTRAP used to stop child process after execve(), but
this signal ignored:

citrin:~> sleep 300 &
citrin:~> procstat -i 1991 | fgrep TRAP
 1991 sleep            TRAP     -I-

Under FreeBSD 8, where ptrace works for me, this signal is not ignored:
x:~> sleep 300 &
x:~> procstat -i 78716 | fgrep TRAP
78716 sleep            TRAP     ---

-- 
 Anton Yuzhaninov