From: Stefan Hajnoczi <stefa...@redhat.com> Date: Tue, 12 Sep 2017 17:34:35 +0100
> This patch fixes the following compiler errors when userspace > applications use the vm_sockets.h header: > > include/uapi/linux/vm_sockets.h:148:32: error: invalid application of > ‘sizeof’ to incomplete type ‘struct sockaddr’ > unsigned char svm_zero[sizeof(struct sockaddr) - > ^~~~~~ > include/uapi/linux/vm_sockets.h:149:18: error: ‘sa_family_t’ undeclared > here (not in a function) > sizeof(sa_family_t) - > ^~~~~~~~~~~ > > Two issues: > 1. In the kernel struct sockaddr comes in via <linux/socket.h> but in > userspace <sys/socket.h> is required. > 2. struct sockaddr_vm has a __kernel_sa_family_t field so let's be > consistent and use the same type for the sizeof(sa_family_t) > calculation. > > Currently userspace applications work around this broken header by first > including <sys/socket.h>. In the kernel there is no compiler error > because <linux/socket.h> provides everything. It's worth fixing the > header file though. > > Cc: Jorgen Hansen <jhan...@vmware.com> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > include/uapi/linux/vm_sockets.h | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/uapi/linux/vm_sockets.h b/include/uapi/linux/vm_sockets.h > index b4ed5d895699..4ae5c625ac56 100644 > --- a/include/uapi/linux/vm_sockets.h > +++ b/include/uapi/linux/vm_sockets.h > @@ -18,6 +18,10 @@ > > #include <linux/socket.h> > > +#ifndef __KERNEL__ > +#include <sys/socket.h> /* struct sockaddr */ > +#endif > + There is no precedence whatsoever to include sys/socket.h in _any_ UAPI header file provided by the kernel. __kernel_sa_family_t is what should be used in UAPI headers, only non-UAPI headers can use plain sa_family_t. So that is the correct fix for this problem. Thank you.
