tsan: support synchronization by means of linux aio

http://llvm-reviews.chandlerc.com/D2269

llvm-svn: 195830

compiler-rt/lib/msan/lit_tests/Linux/syscalls.cc

@@ -93,8 +93,8 @@ int main(int argc, char *argv[]) {
   iocb[1].aio_lio_opcode = IOCB_CMD_PREAD;
   iocb[1].aio_buf = (__u64)(&buf[kFortyTwo]);
   iocb[1].aio_nbytes = kFortyTwo;
-  __sanitizer_syscall_post_io_submit(1, 0, 2, &iocbp);
+  __sanitizer_syscall_pre_io_submit(0, 2, &iocbp);
-  assert(__msan_test_shadow(buf, sizeof(buf)) == kFortyTwo);
+  assert(__msan_test_shadow(buf, sizeof(buf)) == 2 * kFortyTwo);
 
   __msan_poison(buf, sizeof(buf));
   char *p = buf;

compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc

@@ -25,8 +25,16 @@
 //   COMMON_SYSCALL_POST_WRITE_RANGE
 //          Called in posthook for regions that were written to by the kernel
 //          and are now initialized.
+//   COMMON_SYSCALL_ACQUIRE(addr)
+//          Acquire memory visibility from addr.
+//   COMMON_SYSCALL_RELEASE(addr)
+//          Release memory visibility to addr.
 //   COMMON_SYSCALL_FD_CLOSE(fd)
 //          Called before closing file descriptor fd.
+//   COMMON_SYSCALL_FD_ACQUIRE(fd)
+//          Acquire memory visibility from fd.
+//   COMMON_SYSCALL_FD_RELEASE(fd)
+//          Release memory visibility to fd.
 //   COMMON_SYSCALL_PRE_FORK()
 //          Called before fork syscall.
 //   COMMON_SYSCALL_POST_FORK(long res)
@@ -48,16 +56,32 @@
 #define POST_READ(p, s) COMMON_SYSCALL_POST_READ_RANGE(p, s)
 #define POST_WRITE(p, s) COMMON_SYSCALL_POST_WRITE_RANGE(p, s)
 
+#ifndef COMMON_SYSCALL_ACQUIRE
+# define COMMON_SYSCALL_ACQUIRE(addr) ((void)(addr))
+#endif
+
+#ifndef COMMON_SYSCALL_RELEASE
+# define COMMON_SYSCALL_RELEASE(addr) ((void)(addr))
+#endif
+
 #ifndef COMMON_SYSCALL_FD_CLOSE
-# define COMMON_SYSCALL_FD_CLOSE(fd)
+# define COMMON_SYSCALL_FD_CLOSE(fd) ((void)(fd))
+#endif
+
+#ifndef COMMON_SYSCALL_FD_ACQUIRE
+# define COMMON_SYSCALL_FD_ACQUIRE(fd) ((void)(fd))
+#endif
+
+#ifndef COMMON_SYSCALL_FD_RELEASE
+# define COMMON_SYSCALL_FD_RELEASE(fd) ((void)(fd))
 #endif
 
 #ifndef COMMON_SYSCALL_PRE_FORK
-# define COMMON_SYSCALL_PRE_FORK()
+# define COMMON_SYSCALL_PRE_FORK() {}
 #endif
 
 #ifndef COMMON_SYSCALL_POST_FORK
-# define COMMON_SYSCALL_POST_FORK(res)
+# define COMMON_SYSCALL_POST_FORK(res) {}
 #endif
 
 // FIXME: do some kind of PRE_READ for all syscall arguments (int(s) and such).
@@ -1263,44 +1287,70 @@ PRE_SYSCALL(io_destroy)(long ctx) {}
 
 POST_SYSCALL(io_destroy)(long res, long ctx) {}
 
-PRE_SYSCALL(io_getevents)(long ctx_id, long min_nr, long nr, void *events,
+PRE_SYSCALL(io_getevents)(long ctx_id, long min_nr, long nr,
-                          void *timeout) {
+                          __sanitizer_io_event *ioevpp, void *timeout) {
   if (timeout) PRE_READ(timeout, struct_timespec_sz);
 }
 
 POST_SYSCALL(io_getevents)(long res, long ctx_id, long min_nr, long nr,
-                           void *events, void *timeout) {
+                           __sanitizer_io_event *ioevpp, void *timeout) {
   if (res >= 0) {
-    if (events) POST_WRITE(events, res * struct_io_event_sz);
+    if (ioevpp) POST_WRITE(ioevpp, res * sizeof(*ioevpp));
     if (timeout) POST_WRITE(timeout, struct_timespec_sz);
   }
+  for (long i = 0; i < res; i++) {
+    // We synchronize io_submit -> io_getevents/io_cancel using the
+    // user-provided data context. Data is not necessary a pointer, it can be
+    // an int, 0 or whatever; acquire/release will correctly handle this.
+    // This scheme can lead to false negatives, e.g. when all operations
+    // synchronize on 0. But there does not seem to be a better solution
+    // (except wrapping all operations in own context, which is unreliable).
+    // We can not reliably extract fildes in io_getevents.
+    COMMON_SYSCALL_ACQUIRE((void*)ioevpp[i].data);
+  }
 }
 
 PRE_SYSCALL(io_submit)(long ctx_id, long nr, __sanitizer_iocb **iocbpp) {
   for (long i = 0; i < nr; ++i) {
-    if (iocbpp[i]->aio_lio_opcode == iocb_cmd_pwrite && iocbpp[i]->aio_buf &&
+    uptr op = iocbpp[i]->aio_lio_opcode;
-        iocbpp[i]->aio_nbytes)
+    void *data = (void*)iocbpp[i]->aio_data;
-      PRE_READ((void *)iocbpp[i]->aio_buf, iocbpp[i]->aio_nbytes);
+    void *buf = (void*)iocbpp[i]->aio_buf;
+    uptr len = (uptr)iocbpp[i]->aio_nbytes;
+    if (op == iocb_cmd_pwrite && buf && len) {
+      PRE_READ(buf, len);
+    } else if (op == iocb_cmd_pread && buf && len) {
+      POST_WRITE(buf, len);
+    } else if (op == iocb_cmd_pwritev) {
+      __sanitizer_iovec *iovec = (__sanitizer_iovec*)iocbpp[i]->aio_buf;
+      for (uptr v = 0; v < len; v++)
+        PRE_READ(iovec[i].iov_base, iovec[i].iov_len);
+    } else if (op == iocb_cmd_preadv) {
+      __sanitizer_iovec *iovec = (__sanitizer_iovec*)iocbpp[i]->aio_buf;
+      for (uptr v = 0; v < len; v++)
+        POST_WRITE(iovec[i].iov_base, iovec[i].iov_len);
+    }
+    // See comment in io_getevents.
+    COMMON_SYSCALL_RELEASE(data);
   }
 }
 
 POST_SYSCALL(io_submit)(long res, long ctx_id, long nr,
-                        __sanitizer_iocb **iocbpp) {
+    __sanitizer_iocb **iocbpp) {}
-  if (res > 0 && iocbpp) {
+
-    for (long i = 0; i < res; ++i) {
+PRE_SYSCALL(io_cancel)(long ctx_id, __sanitizer_iocb *iocb,
-      if (iocbpp[i]->aio_lio_opcode == iocb_cmd_pread && iocbpp[i]->aio_buf &&
+    __sanitizer_io_event *result) {
-          iocbpp[i]->aio_nbytes)
-        POST_WRITE((void *)iocbpp[i]->aio_buf, iocbpp[i]->aio_nbytes);
-    }
-  }
 }
 
-PRE_SYSCALL(io_cancel)(long ctx_id, void *iocb, void *result) {}
+POST_SYSCALL(io_cancel)(long res, long ctx_id, __sanitizer_iocb *iocb,
-
+    __sanitizer_io_event *result) {
-POST_SYSCALL(io_cancel)(long res, long ctx_id, void *iocb, void *result) {
+  if (res == 0) {
-  if (res >= 0) {
+    if (result) {
-    if (iocb) POST_WRITE(iocb, sizeof(__sanitizer_iocb));
+      // See comment in io_getevents.
-    if (result) POST_WRITE(result, struct_io_event_sz);
+      COMMON_SYSCALL_ACQUIRE((void*)result->data);
+      POST_WRITE(result, sizeof(*result));
+    }
+    if (iocb)
+      POST_WRITE(iocb, sizeof(*iocb));
   }
 }
 

compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_linux.cc

@@ -70,7 +70,11 @@ COMPILER_CHECK(struct_kernel_stat_sz == sizeof(struct stat));
 COMPILER_CHECK(struct_kernel_stat64_sz == sizeof(struct stat64));
 #endif
 
-COMPILER_CHECK(struct_io_event_sz == sizeof(struct io_event));
+COMPILER_CHECK(sizeof(__sanitizer_io_event) == sizeof(struct io_event));
+CHECK_SIZE_AND_OFFSET(io_event, data);
+CHECK_SIZE_AND_OFFSET(io_event, obj);
+CHECK_SIZE_AND_OFFSET(io_event, res);
+CHECK_SIZE_AND_OFFSET(io_event, res2);
 
 #if !SANITIZER_ANDROID
 COMPILER_CHECK(sizeof(struct __sanitizer_perf_event_attr) <=

compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h

@@ -70,7 +70,6 @@ namespace __sanitizer {
   const unsigned struct_kernel_stat_sz = 144;
   const unsigned struct_kernel_stat64_sz = 104;
 #endif
-  const unsigned struct_io_event_sz = 32;
   struct __sanitizer_perf_event_attr {
     unsigned type;
     unsigned size;
@@ -109,8 +108,17 @@ namespace __sanitizer {
     u64   aio_reserved3;
   };
 
+  struct __sanitizer_io_event {
+    u64 data;
+    u64 obj;
+    u64 res;
+    u64 res2;
+  };
+
   const unsigned iocb_cmd_pread = 0;
   const unsigned iocb_cmd_pwrite = 1;
+  const unsigned iocb_cmd_preadv = 7;
+  const unsigned iocb_cmd_pwritev = 8;
 
   struct __sanitizer___sysctl_args {
     int *name;

compiler-rt/lib/tsan/rtl/tsan_interceptors.cc

@@ -1927,10 +1927,33 @@ static void syscall_access_range(uptr pc, uptr p, uptr s, bool write) {
   MemoryAccessRange(thr, pc, p, s, write);
 }
 
+static void syscall_acquire(uptr pc, uptr addr) {
+  TSAN_SYSCALL();
+  Acquire(thr, pc, addr);
+  Printf("syscall_acquire(%p)\n", addr);
+}
+
+static void syscall_release(uptr pc, uptr addr) {
+  TSAN_SYSCALL();
+  Printf("syscall_release(%p)\n", addr);
+  Release(thr, pc, addr);
+}
+
 static void syscall_fd_close(uptr pc, int fd) {
   TSAN_SYSCALL();
-  if (fd >= 0)
+  FdClose(thr, pc, fd);
-    FdClose(thr, pc, fd);
+}
+
+static USED void syscall_fd_acquire(uptr pc, int fd) {
+  TSAN_SYSCALL();
+  FdAcquire(thr, pc, fd);
+  Printf("syscall_fd_acquire(%p)\n", fd);
+}
+
+static USED void syscall_fd_release(uptr pc, int fd) {
+  TSAN_SYSCALL();
+  Printf("syscall_fd_release(%p)\n", fd);
+  FdRelease(thr, pc, fd);
 }
 
 static void syscall_pre_fork(uptr pc) {
@@ -1949,23 +1972,40 @@ static void syscall_post_fork(uptr pc, int res) {
 
 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) \
   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), false)
+
 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), true)
+
 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
   do {                                       \
     (void)(p);                               \
     (void)(s);                               \
   } while (false)
+
 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
   do {                                        \
     (void)(p);                                \
     (void)(s);                                \
   } while (false)
+
+#define COMMON_SYSCALL_ACQUIRE(addr) \
+    syscall_acquire(GET_CALLER_PC(), (uptr)(addr))
+
+#define COMMON_SYSCALL_RELEASE(addr) \
+    syscall_release(GET_CALLER_PC(), (uptr)(addr))
+
 #define COMMON_SYSCALL_FD_CLOSE(fd) syscall_fd_close(GET_CALLER_PC(), fd)
+
+#define COMMON_SYSCALL_FD_ACQUIRE(fd) syscall_fd_acquire(GET_CALLER_PC(), fd)
+
+#define COMMON_SYSCALL_FD_RELEASE(fd) syscall_fd_release(GET_CALLER_PC(), fd)
+
 #define COMMON_SYSCALL_PRE_FORK() \
   syscall_pre_fork(GET_CALLER_PC())
+
 #define COMMON_SYSCALL_POST_FORK(res) \
   syscall_post_fork(GET_CALLER_PC(), res)
+
 #include "sanitizer_common/sanitizer_common_syscalls.inc"
 
 namespace __tsan {