[rtsan] Add ioctl interceptor (#117569)

Author: cjappl

compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp

@@ -190,6 +190,23 @@ INTERCEPTOR(int, fcntl, int filedes, int cmd, ...) {
   return REAL(fcntl)(filedes, cmd, arg);
 }
 
+INTERCEPTOR(int, ioctl, int filedes, unsigned long request, ...) {
+  __rtsan_notify_intercepted_call("ioctl");
+
+  // See fcntl for discussion on why we use intptr_t
+  // And why we read from va_args on all request types
+  using arg_type = intptr_t;
+  static_assert(sizeof(arg_type) >= sizeof(struct ifreq *));
+  static_assert(sizeof(arg_type) >= sizeof(int));
+
+  va_list args;
+  va_start(args, request);
+  arg_type arg = va_arg(args, arg_type);
+  va_end(args);
+
+  return REAL(ioctl)(filedes, request, arg);
+}
+
 #if SANITIZER_INTERCEPT_FCNTL64
 INTERCEPTOR(int, fcntl64, int filedes, int cmd, ...) {
   __rtsan_notify_intercepted_call("fcntl64");
@@ -801,6 +818,7 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_LSEEK64;
   INTERCEPT_FUNCTION(dup);
   INTERCEPT_FUNCTION(dup2);
+  INTERCEPT_FUNCTION(ioctl);
 
 #if SANITIZER_APPLE
   INTERCEPT_FUNCTION(OSSpinLockLock);

compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp

@@ -20,7 +20,6 @@
 #if SANITIZER_APPLE
 #include <libkern/OSAtomic.h>
 #include <os/lock.h>
-#include <sys/types.h>
 #include <unistd.h>
 #endif
 
@@ -38,12 +37,16 @@
 #endif
 
 #include <fcntl.h>
+#include <ifaddrs.h>
+#include <net/if.h>
 #include <netdb.h>
 #include <poll.h>
 #include <pthread.h>
 #include <stdio.h>
+#include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <sys/uio.h>
 
 #if _FILE_OFFSET_BITS == 64 && SANITIZER_GLIBC
@@ -373,6 +376,54 @@ class RtsanOpenedFileTest : public RtsanFileTest {
   int fd = -1;
 };
 
+TEST(TestRtsanInterceptors, IoctlDiesWhenRealtime) {
+  auto Func = []() { ioctl(0, FIONREAD); };
+  ExpectRealtimeDeath(Func, "ioctl");
+  ExpectNonRealtimeSurvival(Func);
+}
+
+TEST_F(RtsanOpenedFileTest, IoctlBehavesWithOutputArg) {
+  int arg{};
+  ioctl(GetOpenFd(), FIONREAD, &arg);
+
+  EXPECT_THAT(arg, Ge(0));
+}
+
+TEST(TestRtsanInterceptors, IoctlBehavesWithOutputPointer) {
+  // These initial checks just see if we CAN run these tests.
+  // If we can't (can't open a socket, or can't find an interface, just
+  // gracefully skip.
+  int sock = socket(AF_INET, SOCK_STREAM, 0);
+  if (sock == -1) {
+    perror("socket");
+    GTEST_SKIP();
+  }
+
+  struct ifaddrs *ifaddr = nullptr;
+  if (getifaddrs(&ifaddr) == -1 || ifaddr == nullptr) {
+    perror("getifaddrs");
+    close(sock);
+    GTEST_SKIP();
+  }
+
+  struct ifreq ifr {};
+  strncpy(ifr.ifr_name, ifaddr->ifa_name, IFNAMSIZ - 1);
+
+  int retval = ioctl(sock, SIOCGIFADDR, &ifr);
+  if (retval == -1) {
+    perror("ioctl");
+    close(sock);
+    freeifaddrs(ifaddr);
+    FAIL();
+  }
+
+  freeifaddrs(ifaddr);
+  close(sock);
+
+  ASSERT_THAT(ifr.ifr_addr.sa_data, NotNull());
+  ASSERT_THAT(ifr.ifr_addr.sa_family, Eq(AF_INET));
+}
+
 TEST_F(RtsanOpenedFileTest, LseekDiesWhenRealtime) {
   auto Func = [this]() { lseek(GetOpenFd(), 0, SEEK_SET); };
   ExpectRealtimeDeath(Func, MAYBE_APPEND_64("lseek"));