[Sanitizers] prctl interception update for the PR_SET_VMA option case.

Supports on Android but also from Linux 5.17

Reviewers: vitalybuka, eugenis

Reviewed-By: vitalybuka

Differential Revision: https://reviews.llvm.org/D127326

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -1367,8 +1367,13 @@ INTERCEPTOR(int, prctl, int option, unsigned long arg2, unsigned long arg3,
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, prctl, option, arg2, arg3, arg4, arg5);
   static const int PR_SET_NAME = 15;
+  static const int PR_SET_VMA = 0x53564d41;
   static const int PR_SCHED_CORE = 62;
   static const int PR_SCHED_CORE_GET = 0;
+  if (option == PR_SET_VMA && arg2 == 0UL) {
+    char *name = (char *)arg5;
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, name, internal_strlen(name) + 1);
+  }
   int res = REAL(prctl(option, arg2, arg3, arg4, arg5));
   if (option == PR_SET_NAME) {
     char buff[16];

compiler-rt/test/sanitizer_common/TestCases/Linux/prctl.cpp

@@ -3,6 +3,7 @@
 #include <assert.h>
 #include <errno.h>
 #include <stdint.h>
+#include <sys/mman.h>
 #include <sys/prctl.h>
 
 #ifndef PR_SCHED_CORE
@@ -17,6 +18,11 @@
 #  define PR_SCHED_CORE_GET 0
 #endif
 
+#ifndef PR_SET_VMA
+#  define PR_SET_VMA 0x53564d41
+#  define PR_SET_VMA_ANON_NAME 0
+#endif
+
 int main() {
 
   int res;
@@ -34,5 +40,25 @@ int main() {
     assert(cookie != 0);
   }
 
+  char invname[81], vlname[] = "prctl";
+  for (auto i = 0; i < sizeof(invname); i++) {
+    invname[i] = 0x1e;
+  }
+  invname[80] = 0;
+  auto p =
+      mmap(nullptr, 128, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
+  assert(p != MAP_FAILED);
+  // regardless of kernel support, the name is invalid
+  res = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, (uintptr_t)p, 128,
+              (uintptr_t)invname);
+  assert(res == -1);
+  assert(errno == EINVAL);
+  res = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, (uintptr_t)p, 128,
+              (uintptr_t)vlname);
+  if (res < 0) {
+    assert(errno == EINVAL);
+  }
+  munmap(p, 128);
+
   return 0;
 }