diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp
index 1ee67b87c2bbe823f32af9538b5570cc793c81a5..7bff121d3e931c7a17114879bff6cb14d3349c9c 100644
--- a/libunwind/src/UnwindCursor.hpp
+++ b/libunwind/src/UnwindCursor.hpp
@@ -2712,20 +2712,12 @@ bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
   // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
   const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
   // The PC might contain an invalid address if the unwind info is bad, so
-  // directly accessing it could cause a segfault. Use process_vm_readv to read
-  // the memory safely instead. process_vm_readv was added in Linux 3.2, and
-  // AArch64 supported was added in Linux 3.7, so the syscall is guaranteed to
-  // be present. Unfortunately, there are Linux AArch64 environments where the
-  // libc wrapper for the syscall might not be present (e.g. Android 5), so call
-  // the syscall directly instead.
-  uint32_t instructions[2];
-  struct iovec local_iov = {&instructions, sizeof instructions};
-  struct iovec remote_iov = {reinterpret_cast<void *>(pc), sizeof instructions};
-  long bytesRead =
-      syscall(SYS_process_vm_readv, getpid(), &local_iov, 1, &remote_iov, 1, 0);
+  // directly accessing it could cause a SIGSEGV.
+  if (!isReadableAddr(pc))
+    return false;
+  auto *instructions = reinterpret_cast<const uint32_t *>(pc);
   // Look for instructions: mov x8, #0x8b; svc #0x0
-  if (bytesRead != sizeof instructions || instructions[0] != 0xd2801168 ||
-      instructions[1] != 0xd4000001)
+  if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001)
     return false;
 
   _info = {};
diff --git a/llvm-build/build.py b/llvm-build/build.py
index db8cbed51934c03609ab44e2da17b0c931ff6e0f..9f9cb8cd635bfdbdf61d9d56e9581cd17bd6d573 100755
--- a/llvm-build/build.py
+++ b/llvm-build/build.py
@@ -709,20 +709,19 @@ class BuildUtils(object):
         return self.merge_out_path('third_party', 'ncurses', 'build', platform_triple, *args)
 
     def get_libxml2_version(self):
-        version_file = os.path.join(self.build_config.REPOROOT_DIR, 'third_party', 'libxml2', 'libxml2.spec')
-        if os.path.isfile(version_file):
-            pattern = r'Version:\s+(\d+\.\d+\.\d+)'
-            with open(version_file, 'r') as file:
-                lines = file.readlines()
-                VERSION = ''
-                for line in lines:
-                    if 'Version: ' in line:
-                        VERSION = re.search(pattern, line).group(1)
-                    if VERSION != '':
-                        return VERSION
-                return None
-
-        return None
+        #version_file = os.path.join(self.build_config.REPOROOT_DIR, 'third_party', 'libxml2', 'libxml2.spec')
+        #if os.path.isfile(version_file):
+        #    pattern = r'Version:\s+(\d+\.\d+\.\d+)'
+        #    with open(version_file, 'r') as file:
+        #        lines = file.readlines()
+        #        VERSION = ''
+        #        for line in lines:
+        #            if 'Version: ' in line:
+        #                VERSION = re.search(pattern, line).group(1)
+        #            if VERSION != '':
+        #                return VERSION
+        #        return None
+        return '2.14.0'
 
     def merge_libxml2_install_dir(self, platform_triple, *args):
         return self.merge_out_path('third_party', 'libxml2', 'install', platform_triple, *args)