forkfd: remove FFD_VFORK_SEMANTICS

This will never work, not unless libc implements it
themselves, since the child process is not allowed to return
from the function that does the vfork(), as subsequent use
of the stack would trash the frozen parent's return address,
and in our case that's syscall(). Instead, we may add a
vforkfd() function that takes a callback function that will
be called in that context, like the glibc clone(3) wrapper
does.

Pick-to: 5.15
Change-Id: I1dba29bc0f454df09ca1fffd161800b453c00593
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 0 insertions, 1 deletions

diff --git a/src/3rdparty/forkfd/forkfd.h b/src/3rdparty/forkfd/forkfd.h
index a864b59861..6bc1f0c1b9 100644
--- a/src/3rdparty/forkfd/forkfd.h
+++ b/src/3rdparty/forkfd/forkfd.h
@@ -41,7 +41,6 @@ extern "C" {
 #define FFD_CLOEXEC             1
 #define FFD_NONBLOCK            2
 #define FFD_USE_FORK            4
-#define FFD_VFORK_SEMANTICS     8
 
 #define FFD_CHILD_PROCESS (-2)