work around wrong kernel type for sem_nsems member of struct semid_ds

[musl] / src / ipc / semget.c

diff --git a/src/ipc/semget.c b/src/ipc/semget.c
index 2dcf6ea..c4a559d 100644 (file)
--- a/src/ipc/semget.c
+++ b/src/ipc/semget.c
@@ -1,12 +1,19 @@
 #include <sys/sem.h>
+#include <limits.h>
+#include <errno.h>
 #include "syscall.h"
 #include "ipc.h"
 
 int semget(key_t key, int n, int fl)
 {
-#ifdef __NR_semget
-       return syscall3(__NR_semget, key, n, fl);
+       /* The kernel uses the wrong type for the sem_nsems member
+        * of struct semid_ds, and thus might not check that the
+        * n fits in the correct (per POSIX) userspace type, so
+        * we have to check here. */
+       if (n > USHRT_MAX) return __syscall_ret(-EINVAL);
+#ifdef SYS_semget
+       return syscall(SYS_semget, key, n, fl);
 #else
-       return syscall4(__NR_ipc, IPCOP_semget, key, n, fl);
+       return syscall(SYS_ipc, IPCOP_semget, key, n, fl);
 #endif
 }