On Fri, 29 Nov 2019 09:25:15 +0100
David Marchand <david.march...@redhat.com> wrote:
> On Wed, Nov 27, 2019 at 11:32 PM Stephen Hemminger
> <step...@networkplumber.org> wrote:
> >
> > Valgrind reports that eal interrupt thread is calling epoll_ctl
> > with uninitialized data. Trivial to fix by initializing it.
> >
> > Fixes: af75078fece3 ("first public release")
> > Cc: sta...@dpdk.org
> > Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
> > ---
> > lib/librte_eal/linux/eal/eal_interrupts.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/lib/librte_eal/linux/eal/eal_interrupts.c
> > b/lib/librte_eal/linux/eal/eal_interrupts.c
> > index 1955324d3045..2cd537ba4492 100644
> > --- a/lib/librte_eal/linux/eal/eal_interrupts.c
> > +++ b/lib/librte_eal/linux/eal/eal_interrupts.c
> > @@ -1045,7 +1045,7 @@ eal_intr_handle_interrupts(int pfd, unsigned totalfds)
> > static __attribute__((noreturn)) void *
> > eal_intr_thread_main(__rte_unused void *arg)
> > {
> > - struct epoll_event ev;
> > + struct epoll_event ev = { };
> >
> > /* host thread, never break out */
> > for (;;) {
>
> typedef union epoll_data
> {
> void *ptr;
> int fd;
> uint32_t u32;
> uint64_t u64;
> } epoll_data_t;
>
> struct epoll_event
> {
> uint32_t events; /* Epoll events */
> epoll_data_t data; /* User data variable */
> } __EPOLL_PACKED;
>
>
> static __attribute__((noreturn)) void *
> eal_intr_thread_main(__rte_unused void *arg)
> {
> struct epoll_event ev;
> [...]
> ev.events = EPOLLIN | EPOLLPRI | EPOLLRDHUP |
> EPOLLHUP;
> ev.data.fd = src->intr_handle.fd;
> [...]
> if (epoll_ctl(pfd, EPOLL_CTL_ADD,
> src->intr_handle.fd, &ev) < 0){
>
> So the uninitialised part is because we only set an int in the union.
> False positive from valgrind, but the fix is quite simple.
>
> Acked-by: David Marchand <david.march...@redhat.com>
Agreed it is a false positive because the kernel is not going to care about
the unused bits in the union. But I wanted to make the application
run clean under valgrind. Otherwise, it is hard to find the real warnings
in surrounding noise.
