Tracing Syscalls under Fedora 9

[Martin Süßkraut]

>> On Fri, Jun 06, 2008 at 04:38:34PM +0200, Martin Süßkraut wrote:
>> > has the tracing of system calls changed in utrace between Fedora 8 and 9?
>> For some reason the only way to trace the syscall is to trace also
>> UTRACE_EVENT(SIGNAL_TERM)
>> or CORE.
>>
>> I added an empty report_signal function and now it works.
>
> Martin told me by an E-mail message that the change proposed above solved
> his problem. This is for the people on the ML concerned with the same
> trouble.
While tracing signals I found some interesting behavior:

When a signal is reported, that is ignored and interrupts a syscall A.
The callbacks report_syscall_enter and report_syscall_exit are called
twice for A. The first report_syscall_exit shows that A failed with
ERESTARTNOINTR. Interestingly, if A's arguments were manipulated in
the first report_syscall_enter, the manipulations are visible in the
second report_syscall_enter.

Is this behavior by purpose (e.g. for ptrace)?

Best Regards,
      Martin