io: mark mixed functions that can suspend

There should be no paths from a coroutine_fn to aio_poll, however in
practice coroutine_mixed_fn will call aio_poll in the !qemu_in_coroutine()
path.  By marking mixed functions, we can track accurately the call paths
that execute entirely in coroutine context, and find more missing
coroutine_fn markers.  This results in more accurate checks that
coroutine code does not end up blocking.

If the marking were extended transitively to all functions that call
these ones, static analysis could be done much more efficiently.
However, this is a start and makes it possible to use vrc's path-based
searches to find potential bugs where coroutine_fns call blocking functions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/io/channel.h b/include/io/channel.h
index 153fbd29049f069cb6bb048738aade887ffd416a..446a566e5e1b21ff79a623b550a9b290026cdc85 100644 (file)
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -301,10 +301,10 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
  * Returns: 1 if all bytes were read, 0 if end-of-file
  *          occurs without data, or -1 on error
  */
-int qio_channel_readv_all_eof(QIOChannel *ioc,
-                              const struct iovec *iov,
-                              size_t niov,
-                              Error **errp);
+int coroutine_mixed_fn qio_channel_readv_all_eof(QIOChannel *ioc,
+                                                 const struct iovec *iov,
+                                                 size_t niov,
+                                                 Error **errp);
 
 /**
  * qio_channel_readv_all:
@@ -328,10 +328,10 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
  *
  * Returns: 0 if all bytes were read, or -1 on error
  */
-int qio_channel_readv_all(QIOChannel *ioc,
-                          const struct iovec *iov,
-                          size_t niov,
-                          Error **errp);
+int coroutine_mixed_fn qio_channel_readv_all(QIOChannel *ioc,
+                                             const struct iovec *iov,
+                                             size_t niov,
+                                             Error **errp);
 
 
 /**
@@ -353,10 +353,10 @@ int qio_channel_readv_all(QIOChannel *ioc,
  *
  * Returns: 0 if all bytes were written, or -1 on error
  */
-int qio_channel_writev_all(QIOChannel *ioc,
-                           const struct iovec *iov,
-                           size_t niov,
-                           Error **errp);
+int coroutine_mixed_fn qio_channel_writev_all(QIOChannel *ioc,
+                                              const struct iovec *iov,
+                                              size_t niov,
+                                              Error **errp);
 
 /**
  * qio_channel_readv:
@@ -437,10 +437,10 @@ ssize_t qio_channel_write(QIOChannel *ioc,
  * Returns: 1 if all bytes were read, 0 if end-of-file occurs
  *          without data, or -1 on error
  */
-int qio_channel_read_all_eof(QIOChannel *ioc,
-                             char *buf,
-                             size_t buflen,
-                             Error **errp);
+int coroutine_mixed_fn qio_channel_read_all_eof(QIOChannel *ioc,
+                                                char *buf,
+                                                size_t buflen,
+                                                Error **errp);
 
 /**
  * qio_channel_read_all:
@@ -457,10 +457,10 @@ int qio_channel_read_all_eof(QIOChannel *ioc,
  *
  * Returns: 0 if all bytes were read, or -1 on error
  */
-int qio_channel_read_all(QIOChannel *ioc,
-                         char *buf,
-                         size_t buflen,
-                         Error **errp);
+int coroutine_mixed_fn qio_channel_read_all(QIOChannel *ioc,
+                                            char *buf,
+                                            size_t buflen,
+                                            Error **errp);
 
 /**
  * qio_channel_write_all:
@@ -476,10 +476,10 @@ int qio_channel_read_all(QIOChannel *ioc,
  *
  * Returns: 0 if all bytes were written, or -1 on error
  */
-int qio_channel_write_all(QIOChannel *ioc,
-                          const char *buf,
-                          size_t buflen,
-                          Error **errp);
+int coroutine_mixed_fn qio_channel_write_all(QIOChannel *ioc,
+                                             const char *buf,
+                                             size_t buflen,
+                                             Error **errp);
 
 /**
  * qio_channel_set_blocking:
@@ -812,11 +812,11 @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
  *          occurs without data, or -1 on error
  */
 
-int qio_channel_readv_full_all_eof(QIOChannel *ioc,
-                                   const struct iovec *iov,
-                                   size_t niov,
-                                   int **fds, size_t *nfds,
-                                   Error **errp);
+int coroutine_mixed_fn qio_channel_readv_full_all_eof(QIOChannel *ioc,
+                                                      const struct iovec *iov,
+                                                      size_t niov,
+                                                      int **fds, size_t *nfds,
+                                                      Error **errp);
 
 /**
  * qio_channel_readv_full_all:
@@ -838,11 +838,11 @@ int qio_channel_readv_full_all_eof(QIOChannel *ioc,
  * Returns: 0 if all bytes were read, or -1 on error
  */
 
-int qio_channel_readv_full_all(QIOChannel *ioc,
-                               const struct iovec *iov,
-                               size_t niov,
-                               int **fds, size_t *nfds,
-                               Error **errp);
+int coroutine_mixed_fn qio_channel_readv_full_all(QIOChannel *ioc,
+                                                  const struct iovec *iov,
+                                                  size_t niov,
+                                                  int **fds, size_t *nfds,
+                                                  Error **errp);
 
 /**
  * qio_channel_writev_full_all:
@@ -872,11 +872,11 @@ int qio_channel_readv_full_all(QIOChannel *ioc,
  * Returns: 0 if all bytes were written, or -1 on error
  */
 
-int qio_channel_writev_full_all(QIOChannel *ioc,
-                                const struct iovec *iov,
-                                size_t niov,
-                                int *fds, size_t nfds,
-                                int flags, Error **errp);
+int coroutine_mixed_fn qio_channel_writev_full_all(QIOChannel *ioc,
+                                                   const struct iovec *iov,
+                                                   size_t niov,
+                                                   int *fds, size_t nfds,
+                                                   int flags, Error **errp);
 
 /**
  * qio_channel_flush:

diff --git a/io/channel.c b/io/channel.c
index a8c7f11649019d1f08041b910e3d0839b1887b3e..375a130a398d34cbc453c1d0c3b2feb9d55146dd 100644 (file)
--- a/io/channel.c
+++ b/io/channel.c
@@ -109,27 +109,27 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc,
 }
 
 
-int qio_channel_readv_all_eof(QIOChannel *ioc,
-                              const struct iovec *iov,
-                              size_t niov,
-                              Error **errp)
+int coroutine_mixed_fn qio_channel_readv_all_eof(QIOChannel *ioc,
+                                                 const struct iovec *iov,
+                                                 size_t niov,
+                                                 Error **errp)
 {
     return qio_channel_readv_full_all_eof(ioc, iov, niov, NULL, NULL, errp);
 }
 
-int qio_channel_readv_all(QIOChannel *ioc,
-                          const struct iovec *iov,
-                          size_t niov,
-                          Error **errp)
+int coroutine_mixed_fn qio_channel_readv_all(QIOChannel *ioc,
+                                             const struct iovec *iov,
+                                             size_t niov,
+                                             Error **errp)
 {
     return qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp);
 }
 
-int qio_channel_readv_full_all_eof(QIOChannel *ioc,
-                                   const struct iovec *iov,
-                                   size_t niov,
-                                   int **fds, size_t *nfds,
-                                   Error **errp)
+int coroutine_mixed_fn qio_channel_readv_full_all_eof(QIOChannel *ioc,
+                                                      const struct iovec *iov,
+                                                      size_t niov,
+                                                      int **fds, size_t *nfds,
+                                                      Error **errp)
 {
     int ret = -1;
     struct iovec *local_iov = g_new(struct iovec, niov);
@@ -215,11 +215,11 @@ next_iter:
     return ret;
 }
 
-int qio_channel_readv_full_all(QIOChannel *ioc,
-                               const struct iovec *iov,
-                               size_t niov,
-                               int **fds, size_t *nfds,
-                               Error **errp)
+int coroutine_mixed_fn qio_channel_readv_full_all(QIOChannel *ioc,
+                                                  const struct iovec *iov,
+                                                  size_t niov,
+                                                  int **fds, size_t *nfds,
+                                                  Error **errp)
 {
     int ret = qio_channel_readv_full_all_eof(ioc, iov, niov, fds, nfds, errp);
 
@@ -234,19 +234,19 @@ int qio_channel_readv_full_all(QIOChannel *ioc,
     return ret;
 }
 
-int qio_channel_writev_all(QIOChannel *ioc,
-                           const struct iovec *iov,
-                           size_t niov,
-                           Error **errp)
+int coroutine_mixed_fn qio_channel_writev_all(QIOChannel *ioc,
+                                              const struct iovec *iov,
+                                              size_t niov,
+                                              Error **errp)
 {
     return qio_channel_writev_full_all(ioc, iov, niov, NULL, 0, 0, errp);
 }
 
-int qio_channel_writev_full_all(QIOChannel *ioc,
-                                const struct iovec *iov,
-                                size_t niov,
-                                int *fds, size_t nfds,
-                                int flags, Error **errp)
+int coroutine_mixed_fn qio_channel_writev_full_all(QIOChannel *ioc,
+                                                   const struct iovec *iov,
+                                                   size_t niov,
+                                                   int *fds, size_t nfds,
+                                                   int flags, Error **errp)
 {
     int ret = -1;
     struct iovec *local_iov = g_new(struct iovec, niov);
@@ -325,30 +325,30 @@ ssize_t qio_channel_write(QIOChannel *ioc,
 }
 
 
-int qio_channel_read_all_eof(QIOChannel *ioc,
-                             char *buf,
-                             size_t buflen,
-                             Error **errp)
+int coroutine_mixed_fn qio_channel_read_all_eof(QIOChannel *ioc,
+                                                char *buf,
+                                                size_t buflen,
+                                                Error **errp)
 {
     struct iovec iov = { .iov_base = buf, .iov_len = buflen };
     return qio_channel_readv_all_eof(ioc, &iov, 1, errp);
 }
 
 
-int qio_channel_read_all(QIOChannel *ioc,
-                         char *buf,
-                         size_t buflen,
-                         Error **errp)
+int coroutine_mixed_fn qio_channel_read_all(QIOChannel *ioc,
+                                            char *buf,
+                                            size_t buflen,
+                                            Error **errp)
 {
     struct iovec iov = { .iov_base = buf, .iov_len = buflen };
     return qio_channel_readv_all(ioc, &iov, 1, errp);
 }
 
 
-int qio_channel_write_all(QIOChannel *ioc,
-                          const char *buf,
-                          size_t buflen,
-                          Error **errp)
+int coroutine_mixed_fn qio_channel_write_all(QIOChannel *ioc,
+                                             const char *buf,
+                                             size_t buflen,
+                                             Error **errp)
 {
     struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
     return qio_channel_writev_all(ioc, &iov, 1, errp);