Re: [Libguestfs] [nbdkit PATCH] data: don't ignore SIGPIPE

On Fri, Jan 13, 2023 at 05:57:35AM +0000, Thomas Weißschuh wrote: > If all of the requested data has been read, the call to popen_close will > close the scripts output pipe and on the next write a SIGPIPE is > delivered. > When the scripts inherited signalhandler is ignoring the singal, it > won't be aborted by default. s/scripts/script's/2 > > This happens in the test suite, as make 4.4 seems to ignore this signal. > Therefore the executed scripts never stop and the testsuite never > finishes. That's a bug in make: https://savannah.gnu.org/bugs/index.php?63307 but one we may indeed need to work around (along with every other impacted program).

> --- > plugins/data/format.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/plugins/data/format.c b/plugins/data/format.c > index 3667ead6790f..2319ea09475c 100644 > --- a/plugins/data/format.c > +++ b/plugins/data/format.c > @@ -40,6 +40,7 @@ > #include <stdarg.h> > #include <string.h> > #include <assert.h> > +#include <signal.h> > > #define NBDKIT_API_VERSION 2 > #include <nbdkit-plugin.h> > @@ -1951,6 +1952,9 @@ store_script_len (struct allocator *a, >    char buf[BUFSIZ]; >    size_t n; > > +  /* Restore SIGPIPE back to SIG_DFL, since shell can't undo SIG_IGN */ > +  signal (SIGPIPE, SIG_DFL); > + >    pp = popen (script, "r"); >    if (pp == NULL) { >      nbdkit_error ("popen: %m"); ACK from my end, even if make ends up fixing their regression. -- Eric Blake, Principal Software Engineer Red Hat, Inc.           +1-919-301-3266 Virtualization:  qemu.org | libvirt.org