[msan] Intercept process_vm_readv/writev.

llvm-svn: 251059

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -5236,6 +5236,39 @@ INTERCEPTOR(int, mincore, void *addr, uptr length, unsigned char *vec) {
 #define INIT_MINCORE
 #endif
 
+#if SANITIZER_INTERCEPT_PROCESS_VM_READV
+INTERCEPTOR(SSIZE_T, process_vm_readv, int pid, __sanitizer_iovec *local_iov,
+            uptr liovcnt, __sanitizer_iovec *remote_iov, uptr riovcnt,
+            uptr flags) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, process_vm_readv, pid, local_iov, liovcnt,
+                           remote_iov, riovcnt, flags);
+  SSIZE_T res = REAL(process_vm_readv)(pid, local_iov, liovcnt, remote_iov,
+                                       riovcnt, flags);
+  if (res > 0)
+    write_iovec(ctx, local_iov, liovcnt, res);
+  return res;
+}
+
+INTERCEPTOR(SSIZE_T, process_vm_writev, int pid, __sanitizer_iovec *local_iov,
+            uptr liovcnt, __sanitizer_iovec *remote_iov, uptr riovcnt,
+            uptr flags) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, process_vm_writev, pid, local_iov, liovcnt,
+                           remote_iov, riovcnt, flags);
+  SSIZE_T res = REAL(process_vm_writev)(pid, local_iov, liovcnt, remote_iov,
+                                        riovcnt, flags);
+  if (res > 0)
+    read_iovec(ctx, local_iov, liovcnt, res);
+  return res;
+}
+#define INIT_PROCESS_VM_READV                                                  \
+  COMMON_INTERCEPT_FUNCTION(process_vm_readv);                                 \
+  COMMON_INTERCEPT_FUNCTION(process_vm_writev);
+#else
+#define INIT_PROCESS_VM_READV
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();
@@ -5409,4 +5442,5 @@ static void InitializeCommonInterceptors() {
   INIT_SEM;
   INIT_PTHREAD_SETCANCEL;
   INIT_MINCORE;
+  INIT_PROCESS_VM_READV;
 }

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

@@ -259,6 +259,7 @@
 #define SANITIZER_INTERCEPT_SEM SI_LINUX || SI_FREEBSD
 #define SANITIZER_INTERCEPT_PTHREAD_SETCANCEL SI_NOT_WINDOWS
 #define SANITIZER_INTERCEPT_MINCORE SI_LINUX
+#define SANITIZER_INTERCEPT_PROCESS_VM_READV SI_LINUX
 
 #define SANITIZER_INTERCEPTOR_HOOKS SI_LINUX
 

compiler-rt/test/msan/Linux/process_vm_readv.cc

@@ -0,0 +1,43 @@
+// RUN: %clangxx_msan -std=c++11 -O0 %s -o %t && %run %t
+// RUN: %clangxx_msan -std=c++11 -O0 %s -o %t -DPOSITIVE && not %run %t |& FileCheck %s
+
+#include <assert.h>
+#include <sanitizer/msan_interface.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+int main(void) {
+  char a[100];
+  memset(a, 0xab, 100);
+
+  char b[100];
+  iovec iov_a[] = {{(void *)a, 20}, (void *)(a + 50), 10};
+  iovec iov_b[] = {{(void *)(b + 10), 10}, (void *)(b + 30), 20};
+
+  __msan_poison(&b, sizeof(b));
+  ssize_t res = process_vm_readv(getpid(), iov_b, 2, iov_a, 2, 0);
+  assert(res == 30);
+  __msan_check_mem_is_initialized(b + 10, 10);
+  __msan_check_mem_is_initialized(b + 30, 20);
+  assert(__msan_test_shadow(b + 9, 1) == 0);
+  assert(__msan_test_shadow(b + 20, 1) == 0);
+  assert(__msan_test_shadow(b + 29, 1) == 0);
+  assert(__msan_test_shadow(b + 50, 1) == 0);
+
+#ifdef POSITIVE
+  __msan_unpoison(&b, sizeof(b));
+  __msan_poison(b + 32, 1);
+  res = process_vm_writev(getpid(), iov_b, 2, iov_a, 2, 0);
+// CHECK: Uninitialized bytes {{.*}} at offset 2 inside
+// CHECK: WARNING: MemorySanitizer: use-of-uninitialized-value
+// CHECK: #0 0x{{.*}} in {{.*}}process_vm_writev
+#else
+  __msan_unpoison(&b, sizeof(b));
+  res = process_vm_writev(getpid(), iov_b, 2, iov_a, 2, 0);
+  assert(res == 30);
+#endif
+
+  return 0;
+}