Re: CVS commit: src/tests/lib/libc/sys

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Thu, May 14, 2020 at 07:21:35PM +0000, Kamil Rytarowski wrote:
> Module Name:	src
> Committed By:	kamil
> Date:		Thu May 14 19:21:35 UTC 2020
> 
> Modified Files:
> 	src/tests/lib/libc/sys: t_ptrace_fork_wait.h
> 
> Log Message:
> Ignore interception of the SIGCHLD signals.
> 
> SIGCHLD once blocked is discarded by the kernel as it has the
> SA_IGNORE property. During the fork(2) operation all signals can be
> shortly blocked and missed (unless there is a registered signal
> handler in the traced child). This leads to a race in this test if
> there would be an intention to catch SIGCHLD.

This doesn't sound right. sigprocmask and pthread_sigmask shouldn't
affect whether the signal handler is called, only when. Temporarily
masking a signal is different from setting it to SIG_IGN.

Joerg