X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6d2010ae8f7a6078e10b361c6962983bab233e0f..7e41aa883dd258f888d0470250eead40a53ef1f5:/libsyscall/custom/errno.c

diff --git a/libsyscall/custom/errno.c b/libsyscall/custom/errno.c
index 58da2c114..86f754a65 100644
--- a/libsyscall/custom/errno.c
+++ b/libsyscall/custom/errno.c
@@ -26,4 +26,54 @@
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
+#include <TargetConditionals.h>
+#include <stddef.h>
+#include <stdint.h>
+#include "tsd.h"
+
+/*
+ * cerror takes the return value of the syscall, being non-zero, and
+ * stores it in errno. It needs to return -1 to indicate failure but
+ * 64-bit platforms need to ensure that possible 128-bit wide return
+ * values are also properly set.
+ */
+#ifdef __LP64__
+typedef unsigned __int128 cerror_return_t;
+#else
+typedef uint64_t cerror_return_t;
+#endif
+
+extern void _pthread_exit_if_canceled(int error);
+
+#undef errno
 int errno;
+
+int *
+__error(void)
+{
+	void *ptr = _os_tsd_get_direct(__TSD_ERRNO);
+	if (ptr != NULL) {
+		return (int*)ptr;
+	}
+	return &errno;
+}
+
+__attribute__((noinline))
+cerror_return_t
+cerror_nocancel(int err)
+{
+	errno = err;
+	int *tsderrno = (int*)_os_tsd_get_direct(__TSD_ERRNO);
+	if (tsderrno) {
+		*tsderrno = err;
+	}
+	return -1;
+}
+
+__attribute__((noinline))
+cerror_return_t
+cerror(int err)
+{
+	_pthread_exit_if_canceled(err);
+	return cerror_nocancel(err);
+}