Issue a prctl to let the kernel accept tagged pointers in syscall arguments.
This is a no-op (kernel returns -EINVAL) if the kernel doesn't understand
the prctl.
Bug: 144799191
Change-Id: I8708e92e31d7a60b2847ae2bc242e46dafb77680
diff --git a/libc/bionic/libc_init_common.cpp b/libc/bionic/libc_init_common.cpp
index b6a9ed2..542c4a5 100644
--- a/libc/bionic/libc_init_common.cpp
+++ b/libc/bionic/libc_init_common.cpp
@@ -103,6 +103,14 @@
__system_properties_init(); // Requires 'environ'.
__libc_init_fdsan(); // Requires system properties (for debug.fdsan).
+
+ // Allow the kernel to accept tagged pointers in syscall arguments. This is a no-op (kernel
+ // returns -EINVAL) if the kernel doesn't understand the prctl.
+#if defined(__aarch64__)
+#define PR_SET_TAGGED_ADDR_CTRL 55
+#define PR_TAGGED_ADDR_ENABLE (1UL << 0)
+ prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0);
+#endif
}
void __libc_init_fork_handler() {