linux-user: emulate msgsnd(), msgrcv() and semtimedop()
When we have updated kernel headers to 5.2-rc1 we have introduced
new syscall numbers that can be not supported by older kernels
and fail with ENOSYS while the guest emulation succeeded before
because the syscalls were emulated with ipc().
This patch fixes the problem by using ipc() if the new syscall
returns ENOSYS.
Fixes: 86e636951ddc ("linux-user: fix __NR_semtimedop undeclared error")
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190529084804.25950-1-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index b187c12..e942049 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -762,50 +762,21 @@
safe_syscall4(int, clock_nanosleep, const clockid_t, clock, int, flags,
const struct timespec *, req, struct timespec *, rem)
#endif
-#if !defined(__NR_msgsnd) || !defined(__NR_msgrcv) || !defined(__NR_semtimedop)
-/* This host kernel architecture uses a single ipc syscall; fake up
- * wrappers for the sub-operations to hide this implementation detail.
- * Annoyingly we can't include linux/ipc.h to get the constant definitions
- * for the call parameter because some structs in there conflict with the
- * sys/ipc.h ones. So we just define them here, and rely on them being
- * the same for all host architectures.
- */
-#define Q_SEMTIMEDOP 4
-#define Q_MSGSND 11
-#define Q_MSGRCV 12
-#define Q_IPCCALL(VERSION, OP) ((VERSION) << 16 | (OP))
-
+#ifdef __NR_ipc
safe_syscall6(int, ipc, int, call, long, first, long, second, long, third,
void *, ptr, long, fifth)
#endif
#ifdef __NR_msgsnd
safe_syscall4(int, msgsnd, int, msgid, const void *, msgp, size_t, sz,
int, flags)
-#else
-static int safe_msgsnd(int msgid, const void *msgp, size_t sz, int flags)
-{
- return safe_ipc(Q_IPCCALL(0, Q_MSGSND), msgid, sz, flags, (void *)msgp, 0);
-}
#endif
#ifdef __NR_msgrcv
safe_syscall5(int, msgrcv, int, msgid, void *, msgp, size_t, sz,
long, msgtype, int, flags)
-#else
-static int safe_msgrcv(int msgid, void *msgp, size_t sz, long type, int flags)
-{
- return safe_ipc(Q_IPCCALL(1, Q_MSGRCV), msgid, sz, flags, msgp, type);
-}
#endif
#ifdef __NR_semtimedop
safe_syscall4(int, semtimedop, int, semid, struct sembuf *, tsops,
unsigned, nsops, const struct timespec *, timeout)
-#else
-static int safe_semtimedop(int semid, struct sembuf *tsops, unsigned nsops,
- const struct timespec *timeout)
-{
- return safe_ipc(Q_IPCCALL(0, Q_SEMTIMEDOP), semid, nsops, 0, tsops,
- (long)timeout);
-}
#endif
#if defined(TARGET_NR_mq_open) && defined(__NR_mq_open)
safe_syscall5(int, mq_timedsend, int, mqdes, const char *, msg_ptr,
@@ -3529,11 +3500,21 @@
static inline abi_long do_semop(int semid, abi_long ptr, unsigned nsops)
{
struct sembuf sops[nsops];
+ abi_long ret;
if (target_to_host_sembuf(sops, ptr, nsops))
return -TARGET_EFAULT;
- return get_errno(safe_semtimedop(semid, sops, nsops, NULL));
+ ret = -TARGET_ENOSYS;
+#ifdef __NR_semtimedop
+ ret = get_errno(safe_semtimedop(semid, sops, nsops, NULL));
+#endif
+#ifdef __NR_ipc
+ if (ret == -TARGET_ENOSYS) {
+ ret = get_errno(safe_ipc(IPCOP_semtimedop, semid, nsops, 0, sops, 0));
+ }
+#endif
+ return ret;
}
struct target_msqid_ds
@@ -3688,7 +3669,16 @@
}
host_mb->mtype = (abi_long) tswapal(target_mb->mtype);
memcpy(host_mb->mtext, target_mb->mtext, msgsz);
+ ret = -TARGET_ENOSYS;
+#ifdef __NR_msgsnd
ret = get_errno(safe_msgsnd(msqid, host_mb, msgsz, msgflg));
+#endif
+#ifdef __NR_ipc
+ if (ret == -TARGET_ENOSYS) {
+ ret = get_errno(safe_ipc(IPCOP_msgsnd, msqid, msgsz, msgflg,
+ host_mb, 0));
+ }
+#endif
g_free(host_mb);
unlock_user_struct(target_mb, msgp, 0);
@@ -3716,7 +3706,16 @@
ret = -TARGET_ENOMEM;
goto end;
}
+ ret = -TARGET_ENOSYS;
+#ifdef __NR_msgrcv
ret = get_errno(safe_msgrcv(msqid, host_mb, msgsz, msgtyp, msgflg));
+#endif
+#ifdef __NR_ipc
+ if (ret == -TARGET_ENOSYS) {
+ ret = get_errno(safe_ipc(IPCOP_CALL(1, IPCOP_msgrcv), msqid, msgsz,
+ msgflg, host_mb, msgtyp));
+ }
+#endif
if (ret > 0) {
abi_ulong target_mtext_addr = msgp + sizeof(abi_ulong);
