On 04.02.2017 13:19, Tanu Kaskinen wrote: > Clang didn't like the variable length array: > > pulsecore/iochannel.c:358:17: error: fields must have a constant size: > 'variable length array in structure' extension will never be supported > uint8_t data[CMSG_SPACE(sizeof(int) * nfd)]; > ^ > > Commit 451d1d6762 introduced the variable length array in order to have > the correct value in msg_controllen. This patch reverts that commit and > uses a different way to achieve the same goal. > > BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=99458 > --- > src/pulsecore/iochannel.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/src/pulsecore/iochannel.c b/src/pulsecore/iochannel.c > index 8ace297ff..897337522 100644 > --- a/src/pulsecore/iochannel.c > +++ b/src/pulsecore/iochannel.c > @@ -355,7 +355,7 @@ ssize_t pa_iochannel_write_with_fds(pa_iochannel*io, const void*data, size_t l, > struct iovec iov; > union { > struct cmsghdr hdr; > - uint8_t data[CMSG_SPACE(sizeof(int) * nfd)]; > + uint8_t data[CMSG_SPACE(sizeof(int) * MAX_ANCIL_DATA_FDS)]; > } cmsg; > > pa_assert(io); > @@ -382,7 +382,13 @@ ssize_t pa_iochannel_write_with_fds(pa_iochannel*io, const void*data, size_t l, > mh.msg_iov = &iov; > mh.msg_iovlen = 1; > mh.msg_control = &cmsg; > - mh.msg_controllen = sizeof(cmsg); > + > + /* If we followed the example on the cmsg man page, we'd use > + * sizeof(cmsg.data) here, but if nfd < MAX_ANCIL_DATA_FDS, then the data > + * buffer is larger than needed, and the kernel doesn't like it if we set > + * msg_controllen to a larger than necessary value. The commit message for > + * commit 451d1d6762 contains a longer explanation. */ > + mh.msg_controllen = CMSG_SPACE(sizeof(int) * nfd); > > if ((r = sendmsg(io->ofd, &mh, MSG_NOSIGNAL)) >= 0) { > io->writable = io->hungup = false; Looks OK to me. Someone is complaining on IRC about that bug, so maybe you should push it soon.
