Thomas Weißschuh
2023-Jan-13 05:57 UTC
[Libguestfs] [nbdkit PATCH] data: don't ignore SIGPIPE
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.
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.
---
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");
base-commit: 09a61a0a00d3036ebfbc2fbadb0ba3e10a778ff3
--
2.39.0
Richard W.M. Jones
2023-Jan-13 08:26 UTC
[Libguestfs] [nbdkit PATCH] data: don't ignore SIGPIPE
On Fri, Jan 13, 2023 at 05:57:35AM +0000, Thomas Wei?schuh 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. > > 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. > --- > 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"); > > base-commit: 09a61a0a00d3036ebfbc2fbadb0ba3e10a778ff3Thanks - pushed upstream in commit c0c31227198dbc7d26fd5955c18d0e2b27df3b84 Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html
On Fri, Jan 13, 2023 at 05:57:35AM +0000, Thomas Wei?schuh 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