treewide: Allow additional system calls for i386/i686

I haven't tested i386 for a long time (after playing with some
openSUSE i586 image a couple of years ago). It turns out that a number
of system calls we actually need were denied by the seccomp filter,
and not even basic functionality works.

Add some system calls that glibc started using with the 64-bit time
("t64") transition, see also:

  https://wiki.debian.org/ReleaseGoals/64bit-time

that is: clock_gettime64, timerfd_gettime64, fcntl64, and
recvmmsg_time64.

Add further system calls that are needed regardless of time_t width,
that is, mmap2 (valgrind profile only), _llseek and sigreturn (common
outside x86_64), and socketcall (same as s390x).

I validated this against an almost full run of the test suite, with
just a few selected tests skipped. Fixes needed to run most tests on
i386/i686, and other assorted fixes for tests, are included in
upcoming patches.

Reported-by: Uroš Knupleš <uros@knuples.net>
Analysed-by: Faidon Liambotis <paravoid@debian.org>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078981
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

Makefile

@@ -129,7 +129,7 @@ qrap: $(QRAP_SRCS) passt.h
 
 valgrind: EXTRA_SYSCALLS += rt_sigprocmask rt_sigtimedwait rt_sigaction	\
 			    rt_sigreturn getpid gettid kill clock_gettime mmap \
-			    munmap open unlink gettimeofday futex
+			    mmap2 munmap open unlink gettimeofday futex
 valgrind: FLAGS += -g -DVALGRIND
 valgrind: all
 

log.c

@@ -98,7 +98,7 @@ const char *logfile_prefix[] = {
  * @fd:		Log file descriptor
  * @now:	Current timestamp
  *
- * #syscalls lseek ppc64le:_llseek ppc64:_llseek arm:_llseek
+ * #syscalls lseek ppc64le:_llseek ppc64:_llseek arm:_llseek i686:_llseek
  */
 static void logfile_rotate_fallocate(int fd, const struct timespec *now)
 {

passt.c

@@ -191,11 +191,11 @@ void exit_handler(int signal)
  * Return: non-zero on failure
  *
  * #syscalls read write writev
- * #syscalls socket bind connect getsockopt setsockopt s390x:socketcall close
- * #syscalls recvfrom sendto shutdown
+ * #syscalls socket getsockopt setsockopt s390x:socketcall i686:socketcall close
+ * #syscalls bind connect recvfrom sendto shutdown
  * #syscalls arm:recv ppc64le:recv arm:send ppc64le:send
  * #syscalls accept4|accept listen epoll_ctl epoll_wait|epoll_pwait epoll_pwait
- * #syscalls clock_gettime arm:clock_gettime64
+ * #syscalls clock_gettime arm:clock_gettime64 i686:clock_gettime64
  */
 int main(int argc, char **argv)
 {

pasta.c

@@ -13,7 +13,7 @@
  *
  * #syscalls:pasta clone waitid exit exit_group rt_sigprocmask
  * #syscalls:pasta rt_sigreturn|sigreturn
- * #syscalls:pasta arm:sigreturn ppc64:sigreturn s390x:sigreturn
+ * #syscalls:pasta arm:sigreturn ppc64:sigreturn s390x:sigreturn i686:sigreturn
  */
 
 #include <sched.h>

tcp.c

@@ -2144,7 +2144,7 @@ cancel:
  * @c:		Execution context
  * @ref:	epoll reference of timer (not connection)
  *
- * #syscalls timerfd_gettime
+ * #syscalls timerfd_gettime i686:timerfd_gettime64
  */
 void tcp_timer_handler(struct ctx *c, union epoll_ref ref)
 {

tcp_splice.c

@@ -28,7 +28,7 @@
  * - FIN_SENT_0:		FIN (write shutdown) sent to accepted socket
  * - FIN_SENT_1:		FIN (write shutdown) sent to target socket
  *
- * #syscalls:pasta pipe2|pipe fcntl arm:fcntl64 ppc64:fcntl64
+ * #syscalls:pasta pipe2|pipe fcntl arm:fcntl64 ppc64:fcntl64 i686:fcntl64
  */
 
 #include <sched.h>

udp.c

@@ -460,7 +460,7 @@ static bool udp_sock_recverr(int s)
  * @events:	epoll events bitmap
  * @mmh		mmsghdr array to receive into
  *
- * #syscalls recvmmsg
+ * #syscalls recvmmsg i686:recvmmsg_time64
  */
 static int udp_sock_recv(const struct ctx *c, int s, uint32_t events,
 			 struct mmsghdr *mmh)

udp_flow.c

@@ -174,7 +174,7 @@ cancel:
  * @s_in:	Source socket address, filled in by recvmmsg()
  * @now:	Timestamp
  *
- * #syscalls fcntl
+ * #syscalls fcntl arm:fcntl64 ppc64:fcntl64 i686:fcntl64
  *
  * Return: sidx for the destination side of the flow for this packet, or
  *         FLOW_SIDX_NONE if we couldn't find or create a flow.