https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=111f32f4ba709be038234fbc7f0254b8f6506564
commit 111f32f4ba709be038234fbc7f0254b8f6506564 Author: Corinna Vinschen <[email protected]> Date: Thu Dec 3 12:58:37 2015 +0100 Always restore full TEB stack info in forkee * dcrt0.cc (dll_crt0_1): Always restore the TEB stack info. Especially restore DeallocationStack. Fix comment. Signed-off-by: Corinna Vinschen <[email protected]> Diff: --- winsup/cygwin/ChangeLog | 5 +++++ winsup/cygwin/dcrt0.cc | 18 +++++++++--------- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index e539b89..03cc4e2 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,5 +1,10 @@ 2015-12-03 Corinna Vinschen <[email protected]> + * crt0.cc (dll_crt0_1): Always restore the TEB stack info. Especially + restore DeallocationStack. Fix comment. + +2015-12-03 Corinna Vinschen <[email protected]> + * dcrt0.cc (child_info_fork::alloc_stack): Don't set stackaddr to 0. 2015-12-03 Corinna Vinschen <[email protected]> diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc index ac3360c..9140fa0 100644 --- a/winsup/cygwin/dcrt0.cc +++ b/winsup/cygwin/dcrt0.cc @@ -910,18 +910,18 @@ dll_crt0_1 (void *) cygbench ("pre-forkee"); if (in_forkee) { - /* If we've played with the stack, stacksize != 0. That means that - fork() was invoked from other than the main thread. Make sure that - frame pointer is referencing the new stack so that the OS knows what - to do when it needs to increase the size of the stack. + /* Make sure to restore the TEB's stack info. If guardsize is -1 the + stack has been provided by the application and must not be deallocated + automagically when the thread exits. NOTE: Don't do anything that involves the stack until you've completed this step. */ - if (fork_info->stackaddr) - { - NtCurrentTeb()->Tib.StackBase = (PVOID) fork_info->stackbase; - NtCurrentTeb()->Tib.StackLimit = (PVOID) fork_info->stacklimit; - } + PTEB teb = NtCurrentTeb (); + teb->Tib.StackBase = (PVOID) fork_info->stackbase; + teb->Tib.StackLimit = (PVOID) fork_info->stacklimit; + teb->DeallocationStack = (fork_info->guardsize == (size_t) -1) + ? NULL + : (PVOID) fork_info->stackaddr; /* Not resetting _my_tls.incyg here because presumably fork will overwrite it with the value of the forker and all will be good. */
