diff options
Diffstat (limited to 'winsup/cygwin/sigproc.cc')
| -rw-r--r-- | winsup/cygwin/sigproc.cc | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc index 3a764fe..a8d4a33 100644 --- a/winsup/cygwin/sigproc.cc +++ b/winsup/cygwin/sigproc.cc @@ -788,6 +788,29 @@ child_info::child_info (unsigned in_cb, child_info_types chtype, bool need_subpr memset (this, 0, in_cb); cb = in_cb; + /* It appears that when running under WOW64 on Vista 64, the first DWORD + value in the datastructure lpReserved2 is pointing to (msv_count in + Cygwin), has to reflect the size of that datastructure as used in the + Microsoft C runtime (a count value, counting the number of elements in + two subsequent arrays, BYTE[count and HANDLE[count]), even though the C + runtime isn't used. Otherwise, if msv_count is 0 or too small, the + datastructure gets overwritten. + + This seems to be a bug in Vista's WOW64, which apparently copies the + lpReserved2 datastructure not using the cbReserved2 size information, + but using the information given in the first DWORD within lpReserved2 + instead. 32 bit Windows and former WOW64 don't care if msv_count is 0 + or a sensible non-0 count value. However, it's not clear if a non-0 + count doesn't result in trying to evaluate the content, so we do this + really only for Vista 64 for now. + + However, since this doesn't seem to harm normal windows operation we'll + just set it unconditionally until we hear complaints. + + The value is sizeof (child_info_*) / 5 which results in a count which + covers the full datastructure, plus not more than 4 extra bytes. This + is ok as long as the child_info structure is cosily stored within a bigger + datastructure. */ msv_count = in_cb / 5; intro = PROC_MAGIC_GENERIC; |