From 28300737d9bfa684aac372729e0148b22c4ded2b Mon Sep 17 00:00:00 2001
From: Apple <opensource@apple.com>
Date: Tue, 24 Mar 2020 21:32:37 +0000
Subject: [PATCH] Libc-1353.41.1.tar.gz

---
 os/assumes.c      | 22 ---------------------
 secure/chk_fail.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++
 sys/_libc_init.c  |  2 ++
 3 files changed, 51 insertions(+), 22 deletions(-)

diff --git a/os/assumes.c b/os/assumes.c
index 3f711f7..389fe17 100644
--- a/os/assumes.c
+++ b/os/assumes.c
@@ -63,8 +63,6 @@ typedef struct dl_info {
 #define OSX_ASSUMES_LOG_REDIRECT_SECT_NAME "__osx_log_func"
 #define os_atomic_cmpxchg(p, o, n) __sync_bool_compare_and_swap((p), (o), (n))
 
-static bool _os_should_abort_on_assumes = false;
-
 #if !TARGET_OS_DRIVERKIT
 static const char *
 _os_basename(const char *p)
@@ -127,34 +125,14 @@ _os_get_image_uuid(void *hdr, uuid_t uuid)
 }
 #endif
 
-static void
-_os_abort_on_assumes_once(void)
-{
-	/* Embedded boot-args can get pretty long. Let's just hope this is big
-	 * enough.
-	 */
-	char bootargs[2048];
-	size_t len = sizeof(bootargs) - 1;
-
-	if (sysctlbyname("kern.bootargs", bootargs, &len, NULL, 0) == 0) {
-		if (strnstr(bootargs, "-os_assumes_fatal", len)) {
-			_os_should_abort_on_assumes = true;
-		}
-	}
-}
-
 static bool
 _os_abort_on_assumes(void)
 {
-	static pthread_once_t once = PTHREAD_ONCE_INIT;
 	bool result = false;
 
 	if (getpid() != 1) {
 		if (getenv("OS_ASSUMES_FATAL")) {
 			result = true;
-		} else {
-			pthread_once(&once, _os_abort_on_assumes_once);
-			result = _os_should_abort_on_assumes;
 		}
 	} else {
 		if (getenv("OS_ASSUMES_FATAL_PID1")) {
diff --git a/secure/chk_fail.c b/secure/chk_fail.c
index 596ce44..9dc6c00 100644
--- a/secure/chk_fail.c
+++ b/secure/chk_fail.c
@@ -24,10 +24,59 @@
 #include <os/assumes.h>
 #include <stdint.h>
 #include <TargetConditionals.h>
+#include "crt_externs.h"
 
+#ifndef PR_13085474_CHECK
+#define PR_13085474_CHECK TARGET_OS_OSX
+#endif
+
+#if PR_13085474_CHECK
+/* Some shipped applications fail this check and were tested against
+ * versions of these functions that supported overlapping buffers.
+ *
+ * We would rather let such applications run, using the old memmove
+ * implementation, than abort() because they can't use the new
+ * implementation.
+ */
+
+#include <libkern/OSAtomic.h>
+#include <mach-o/dyld.h>
+#include <mach-o/dyld_priv.h>
+#if TARGET_OS_OSX
+#define START_VERSION dyld_platform_version_macOS_10_9
+#else
+#error "This platform should not build with PR_13085474_CHECK=1"
+#endif
+#endif /* !PR_13085474_CHECK */
+
+/* For PR_13085474_CHECK set, we initialize __chk_assert_no_overlap to
+ * 1 initially and then reset it to 0 if the main image of the process
+ * was linked earlier than 10.9.
+ *
+ * If PR_13085474_CHECK is zero, then we never do any sdk version checking
+ * and always do overlap checks.
+ */
 __attribute__ ((visibility ("hidden")))
 uint32_t __chk_assert_no_overlap = 1;
 
+#if PR_13085474_CHECK
+static bool
+__chk_assert_sdk_pre_start(const struct mach_header *mh) {
+  return (dyld_get_active_platform() == PLATFORM_MACOS &&
+      !dyld_sdk_at_least(mh, START_VERSION));
+}
+#endif
+
+__attribute__ ((visibility ("hidden")))
+void __chk_init(void) {
+#if PR_13085474_CHECK
+  if (__chk_assert_sdk_pre_start((const struct mach_header *)
+        _NSGetMachExecuteHeader())) {
+    __chk_assert_no_overlap = 0;
+  }
+#endif
+}
+
 __attribute__ ((visibility ("hidden")))
 __attribute__ ((noreturn))
 void
diff --git a/sys/_libc_init.c b/sys/_libc_init.c
index 54790ce..3f95640 100644
--- a/sys/_libc_init.c
+++ b/sys/_libc_init.c
@@ -41,6 +41,7 @@ extern void _arc4_init(void);
 extern void __atexit_init(void);
 extern void __confstr_init(const struct _libc_functions *funcs);
 extern void _init_clock_port(void);
+extern void __chk_init(void);
 extern void __xlocale_init(void);
 extern void __guard_setup(const char *apple[]);
 
@@ -55,6 +56,7 @@ _libc_initializer(const struct _libc_functions *funcs,
 	__confstr_init(funcs);
 	__atexit_init();
 	_init_clock_port();
+	__chk_init();
 	__xlocale_init();
 	__guard_setup(apple);
 }
-- 
2.47.2