Add PR_GET_MDWE support (Fixes #4043)

CMakeLists.txt

@@ -1273,6 +1273,7 @@ set(BASIC_TESTS
   prctl_auxv
   prctl_caps
   prctl_deathsig
+  prctl_mdwe
   prctl_name
   prctl_short_name
   prctl_speculation_ctrl

src/kernel_supplement.h

@@ -570,6 +570,11 @@ enum {
 #define MEMREAD _IOWR('M', 26, typename Arch::mtd_read_req)
 #endif
 
+// New in the 6.3 kernel
+#ifndef PR_GET_MDWE
+#define PR_GET_MDWE 66
+#endif
+
 // New in the 6.4 kernel
 #ifndef PR_GET_AUXV
 #define PR_GET_AUXV 0x41555856

src/record_syscall.cc

@@ -4791,6 +4791,7 @@ static Switchable rec_prepare_syscall_arch(RecordTask* t,
         case PR_SET_SECUREBITS:
         case PR_GET_SECUREBITS:
         case PR_GET_TAGGED_ADDR_CTRL:
+        case PR_GET_MDWE:
           break;
 
         case PR_SET_TAGGED_ADDR_CTRL:

src/test/prctl_mdwe.c

@@ -0,0 +1,15 @@
+/* -*- Mode: C; tab-width: 8; c-basic-offset: 2; indent-tabs-mode: nil; -*- */
+
+#include "util.h"
+
+int main(void) {
+  int ret = prctl(PR_GET_MDWE, 0, 0, 0, 0);
+  if (ret == -1 && errno == EINVAL) {
+    atomic_puts("PR_GET_MDWE not supported, skipping test");
+    atomic_puts("EXIT-SUCCESS");
+    return 0;
+  }
+  test_assert(ret >= 0);
+  atomic_puts("EXIT-SUCCESS");
+  return 0;
+}

src/test/util.h

@@ -557,6 +557,9 @@ struct rr_open_how {
 #ifndef PR_SET_VMA_ANON_NAME
 #define PR_SET_VMA_ANON_NAME 0
 #endif
+#ifndef PR_GET_MDWE
+#define PR_GET_MDWE 66
+#endif
 #ifndef PR_GET_AUXV
 #define PR_GET_AUXV 0x41555856
 #endif