Follow up to fix 376956 syswrap of SNDDRV and DRM_IOCTL_VERSION causing some

        addresses to be wrongly marked as addressable

As noted by Ivo, if the syscall fails, then we have a leak.

So, enable the flag SfPostOnFail if we allocate memory.
In the POST ioctl, check that FAILURE only happens for this drm ioctl,
and free the memory for both SUCCESS and FAILURE.
Do the POST_MEM_WRITE only if SUCCESS

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16277

diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index a739a5d9dd25f65803120f303e7a202c2ba0780c..8d2f7d880b914b6ab674ea8659e176d8942082ef 100644 (file)
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -7706,6 +7706,8 @@ PRE(sys_ioctl)
          PRE_MEM_READ("ioctl(DRM_VERSION).desc", (Addr)&data->desc, sizeof(data->desc));
          PRE_MEM_WRITE("ioctl(DRM_VERSION).desc", (Addr)data->desc, data->desc_len);
          info = VG_(malloc)("syswrap.ioctl.1", sizeof(*info));
+         // To ensure we VG_(free) info even when syscall fails:
+         *flags |= SfPostOnFail;
          info->data = *data;
          info->orig = data;
          ARG3 = (Addr)&info->data;
@@ -9011,7 +9013,7 @@ PRE(sys_ioctl)
 
 POST(sys_ioctl)
 {
-   vg_assert(SUCCESS);
+   vg_assert(SUCCESS || (FAILURE && VKI_DRM_IOCTL_VERSION == ARG2));
 
    ARG2 = (UInt)ARG2;
 
@@ -10193,15 +10195,17 @@ POST(sys_ioctl)
          ARG3 = (Addr)info->orig;
          data = info->orig;
          VG_(free)(info);
-        POST_MEM_WRITE((Addr)&data->version_major, sizeof(data->version_major));
-         POST_MEM_WRITE((Addr)&data->version_minor, sizeof(data->version_minor));
-         POST_MEM_WRITE((Addr)&data->version_patchlevel, sizeof(data->version_patchlevel));
-         POST_MEM_WRITE((Addr)&data->name_len, sizeof(data->name_len));
-         POST_MEM_WRITE((Addr)data->name, VG_MIN(data->name_len, orig_name_len));
-         POST_MEM_WRITE((Addr)&data->date_len, sizeof(data->date_len));
-         POST_MEM_WRITE((Addr)data->date, VG_MIN(data->date_len, orig_date_len));
-         POST_MEM_WRITE((Addr)&data->desc_len, sizeof(data->desc_len));
-         POST_MEM_WRITE((Addr)data->desc, VG_MIN(data->desc_len, orig_desc_len));
+         if (SUCCESS) {
+            POST_MEM_WRITE((Addr)&data->version_major, sizeof(data->version_major));
+            POST_MEM_WRITE((Addr)&data->version_minor, sizeof(data->version_minor));
+            POST_MEM_WRITE((Addr)&data->version_patchlevel, sizeof(data->version_patchlevel));
+            POST_MEM_WRITE((Addr)&data->name_len, sizeof(data->name_len));
+            POST_MEM_WRITE((Addr)data->name, VG_MIN(data->name_len, orig_name_len));
+            POST_MEM_WRITE((Addr)&data->date_len, sizeof(data->date_len));
+            POST_MEM_WRITE((Addr)data->date, VG_MIN(data->date_len, orig_date_len));
+            POST_MEM_WRITE((Addr)&data->desc_len, sizeof(data->desc_len));
+            POST_MEM_WRITE((Addr)data->desc, VG_MIN(data->desc_len, orig_desc_len));
+         }
       }
       break;
    case VKI_DRM_IOCTL_GET_UNIQUE: