Re: [PATCH v3 10/10] run-command: block signals between fork and execve

[Eric Wong]

Brandon Williams <bmw...@google.com> wrote:
> On 04/14, Brandon Williams wrote:
> >             /*
> > +            * restore default signal handlers here, in case
> > +            * we catch a signal right before execve below
> > +            */
> > +           for (sig = 1; sig < NSIG; sig++) {
> > +                   sighandler_t old = signal(sig, SIG_DFL);
> 
> So sighandler_t doesn't work on macOS.  Is there a more portable lib
> that needs to be included for this to work?

Oops, maybe this works (only tested on GNU/Linux):

--- a/run-command.c
+++ b/run-command.c
@@ -675,7 +675,7 @@ int start_command(struct child_process *cmd)
                 * we catch a signal right before execve below
                 */
                for (sig = 1; sig < NSIG; sig++) {
-                       sighandler_t old = signal(sig, SIG_DFL);
+                       void (*old)(int) = signal(sig, SIG_DFL);
 
                        /* ignored signals get reset to SIG_DFL on execve */
                        if (old == SIG_IGN)

Otherwise, maybe just casting to 'void *' is OK:

                        void *old = (void *)signal(sig, SIG_DFL);

                        if (old == (void *)SIG_IGN)
                                ...



void *old = signal(sig, SIG_DFL);