| Message ID | 1340390174-7493-2-git-send-email-coreyb@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On 06/22/2012 12:36 PM, Corey Bryant wrote: > This sets the close-on-exec flag for the file descriptor received > via SCM_RIGHTS. > > Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com> > --- > v4 > -This patch is new in v4 (eblake@redhat.com) > > qemu-char.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/qemu-char.c b/qemu-char.c > index c2aaaee..f890113 100644 > --- a/qemu-char.c > +++ b/qemu-char.c > @@ -2263,7 +2263,7 @@ static ssize_t tcp_chr_recv(CharDriverState *chr, char *buf, size_t len) > msg.msg_control = &msg_control; > msg.msg_controllen = sizeof(msg_control); > > - ret = recvmsg(s->fd, &msg, 0); > + ret = recvmsg(s->fd, &msg, MSG_CMSG_CLOEXEC); MSG_CMSG_CLOEXEC is not (yet) in POSIX (although it has been proposed for addition); therefore, at the moment, it only exists on Linux and Cygwin. Does this need to have conditional code to allow compilation on BSD, such as: #ifndef MSG_CMSG_CLOEXEC # define MSG_CMSG_CLOEXEC 0 #endif as well as fallback code that sets FD_CLOEXEC manually via fcntl() when MSG_CMSG_CLOEXEC is missing?
On Fri, Jun 22, 2012 at 01:31:17PM -0600, Eric Blake wrote: > On 06/22/2012 12:36 PM, Corey Bryant wrote: > > This sets the close-on-exec flag for the file descriptor received > > via SCM_RIGHTS. > > > > Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com> > > --- > > v4 > > -This patch is new in v4 (eblake@redhat.com) > > > > qemu-char.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/qemu-char.c b/qemu-char.c > > index c2aaaee..f890113 100644 > > --- a/qemu-char.c > > +++ b/qemu-char.c > > @@ -2263,7 +2263,7 @@ static ssize_t tcp_chr_recv(CharDriverState *chr, char *buf, size_t len) > > msg.msg_control = &msg_control; > > msg.msg_controllen = sizeof(msg_control); > > > > - ret = recvmsg(s->fd, &msg, 0); > > + ret = recvmsg(s->fd, &msg, MSG_CMSG_CLOEXEC); > > MSG_CMSG_CLOEXEC is not (yet) in POSIX (although it has been proposed > for addition); therefore, at the moment, it only exists on Linux and > Cygwin. Does this need to have conditional code to allow compilation on > BSD, such as: > > #ifndef MSG_CMSG_CLOEXEC > # define MSG_CMSG_CLOEXEC 0 > #endif > > as well as fallback code that sets FD_CLOEXEC manually via fcntl() when > MSG_CMSG_CLOEXEC is missing? Good point. I think the answer is yes. Just like qemu_open() we can wrap "recvmsg(2) with fd" so that platforms with MSG_CMSG_CLOEXEC use that flag and other platforms use qemu_set_cloexec(). Stefan
On 06/25/2012 05:16 AM, Stefan Hajnoczi wrote: > On Fri, Jun 22, 2012 at 01:31:17PM -0600, Eric Blake wrote: >> On 06/22/2012 12:36 PM, Corey Bryant wrote: >>> This sets the close-on-exec flag for the file descriptor received >>> via SCM_RIGHTS. >>> >>> Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com> >>> --- >>> v4 >>> -This patch is new in v4 (eblake@redhat.com) >>> >>> qemu-char.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/qemu-char.c b/qemu-char.c >>> index c2aaaee..f890113 100644 >>> --- a/qemu-char.c >>> +++ b/qemu-char.c >>> @@ -2263,7 +2263,7 @@ static ssize_t tcp_chr_recv(CharDriverState *chr, char *buf, size_t len) >>> msg.msg_control = &msg_control; >>> msg.msg_controllen = sizeof(msg_control); >>> >>> - ret = recvmsg(s->fd, &msg, 0); >>> + ret = recvmsg(s->fd, &msg, MSG_CMSG_CLOEXEC); >> >> MSG_CMSG_CLOEXEC is not (yet) in POSIX (although it has been proposed >> for addition); therefore, at the moment, it only exists on Linux and >> Cygwin. Does this need to have conditional code to allow compilation on >> BSD, such as: >> >> #ifndef MSG_CMSG_CLOEXEC >> # define MSG_CMSG_CLOEXEC 0 >> #endif >> >> as well as fallback code that sets FD_CLOEXEC manually via fcntl() when >> MSG_CMSG_CLOEXEC is missing? > > Good point. I think the answer is yes. Just like qemu_open() we can > wrap "recvmsg(2) with fd" so that platforms with MSG_CMSG_CLOEXEC use > that flag and other platforms use qemu_set_cloexec(). > > Stefan > Thanks for pointing this out. I'll make the updates in v5.
diff --git a/qemu-char.c b/qemu-char.c index c2aaaee..f890113 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2263,7 +2263,7 @@ static ssize_t tcp_chr_recv(CharDriverState *chr, char *buf, size_t len) msg.msg_control = &msg_control; msg.msg_controllen = sizeof(msg_control); - ret = recvmsg(s->fd, &msg, 0); + ret = recvmsg(s->fd, &msg, MSG_CMSG_CLOEXEC); if (ret > 0 && s->is_unix) unix_process_msgfd(chr, &msg);
This sets the close-on-exec flag for the file descriptor received via SCM_RIGHTS. Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com> --- v4 -This patch is new in v4 (eblake@redhat.com) qemu-char.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)