[Sanitizers] Implement interceptors for msgsnd, msgrcv

[eugenis]

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

3099

We don't use braces for single line blocks.

3100

I think this needs to be msgsz + sizeof(uptr)

3111

same here, "len" does not include the message type field at the start of *msgp.
Why does the test pass?

[guiand]

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

3111

Ah, the test passes because it makes the same assumption. Thanks for catching that!

[guiand]

Addressed comments

[eugenis]

LGTM

compiler-rt/test/sanitizer_common/TestCases/Linux/sysmsg.c

24

strictly speaking, there should be an EINTR-catching loop around both calls. It's pretty unlikely to happen in a test though...

[morehouse]

This is causing lint errors: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-android/builds/32793

/var/lib/buildbot/sanitizer-buildbot6/sanitizer-x86_64-linux-android/build/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc:3096:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
/var/lib/buildbot/sanitizer-buildbot6/sanitizer-x86_64-linux-android/build/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc:3105:  Lines should be <= 80 characters long  [whitespace/line_length] [2]

@guiand Could you please fix?

[guiand]

Yes, sorry about that!

[guiand]

Should be taken care of now.

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

INTERCEPTOR(int, sendmmsg, int fd, struct __sanitizer_mmsghdr *msgvec,
   }
   return res;
 }
 #define INIT_SENDMMSG COMMON_INTERCEPT_FUNCTION(sendmmsg);
 #else
 #define INIT_SENDMMSG
 #endif
 
+#if SANITIZER_INTERCEPT_SYSMSG
+INTERCEPTOR(int, msgsnd, int msqid, const void *msgp, SIZE_T msgsz, int msgflg) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, msgsnd, msqid, msgp, msgsz, msgflg);
+  if (msgp)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, msgp, sizeof(long) + msgsz);
+  int res = REAL(msgsnd)(msqid, msgp, msgsz, msgflg);
+  return res;
+}
+
+INTERCEPTOR(SSIZE_T, msgrcv, int msqid, void *msgp, SIZE_T msgsz, long msgtyp, int msgflg) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, msgrcv, msqid, msgp, msgsz, msgtyp, msgflg);
+  SSIZE_T len = REAL(msgrcv)(msqid, msgp, msgsz, msgtyp, msgflg);
+  if (len != -1)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, msgp, sizeof(long) + len);
+  return len;
+}
+
+#define INIT_SYSMSG                  \
+  COMMON_INTERCEPT_FUNCTION(msgsnd); \
+  COMMON_INTERCEPT_FUNCTION(msgrcv);
+#else
+#define INIT_SYSMSG
+#endif
+
 #if SANITIZER_INTERCEPT_GETPEERNAME
 INTERCEPTOR(int, getpeername, int sockfd, void *addr, unsigned *addrlen) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, getpeername, sockfd, addr, addrlen);
   unsigned addr_sz;
   if (addrlen) addr_sz = *addrlen;
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
#endif
   INIT_ACCEPT;
   INIT_ACCEPT4;
   INIT_PACCEPT;
   INIT_MODF;
   INIT_RECVMSG;
   INIT_SENDMSG;
   INIT_RECVMMSG;
   INIT_SENDMMSG;
+  INIT_SYSMSG;
   INIT_GETPEERNAME;
   INIT_IOCTL;
   INIT_INET_ATON;
   INIT_SYSINFO;
   INIT_READDIR;
   INIT_READDIR64;
   INIT_PTRACE;
   INIT_SETLOCALE;

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

 #define SANITIZER_INTERCEPT_ACCEPT4 \
   (SI_LINUX_NOT_ANDROID || SI_NETBSD || SI_OPENBSD)
 #define SANITIZER_INTERCEPT_PACCEPT SI_NETBSD
 #define SANITIZER_INTERCEPT_MODF SI_POSIX
 #define SANITIZER_INTERCEPT_RECVMSG SI_POSIX
 #define SANITIZER_INTERCEPT_SENDMSG SI_POSIX
 #define SANITIZER_INTERCEPT_RECVMMSG SI_LINUX
 #define SANITIZER_INTERCEPT_SENDMMSG SI_LINUX
+#define SANITIZER_INTERCEPT_SYSMSG SI_LINUX
 #define SANITIZER_INTERCEPT_GETPEERNAME SI_POSIX
 #define SANITIZER_INTERCEPT_IOCTL SI_POSIX
 #define SANITIZER_INTERCEPT_INET_ATON SI_POSIX
 #define SANITIZER_INTERCEPT_SYSINFO SI_LINUX
 #define SANITIZER_INTERCEPT_READDIR SI_POSIX
 #define SANITIZER_INTERCEPT_READDIR64 SI_LINUX_NOT_ANDROID || SI_SOLARIS32
 #if SI_LINUX_NOT_ANDROID && \
   (defined(__i386) || defined(__x86_64) || defined(__mips64) || \

compiler-rt/test/sanitizer_common/TestCases/Linux/sysmsg.c

+// RUN: %clang -O1 %s -o %t && %run %t
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/msg.h>
+
+#define CHECK_STRING "hello, world!"
+#define MSG_BUFLEN 0x100
+
+int main() {
+  int msgq = msgget(IPC_PRIVATE, 0666);
+  assert(msgq != -1);
+
+  struct msg_s {
+    long mtype;
+    char string[MSG_BUFLEN];
+  };
+
+  struct msg_s msg = {
+      .mtype = 1};
+  strcpy(msg.string, CHECK_STRING);
+  int res = msgsnd(msgq, &msg, MSG_BUFLEN, IPC_NOWAIT);
+  if (res) {
+    fprintf(stderr, "Error sending message! %s\n", strerror(errno));
+    return -1;
+  }
+
+  struct msg_s rcv_msg;
+  ssize_t len = msgrcv(msgq, &rcv_msg, MSG_BUFLEN, msg.mtype, IPC_NOWAIT);
+  assert(len == MSG_BUFLEN);
+  assert(msg.mtype == rcv_msg.mtype);
+  assert(!memcmp(msg.string, rcv_msg.string, MSG_BUFLEN));
+  return 0;
+}