libffi: backport incorrect detection of selinux
This patch unbreaks ghci on GRSEC kernels hardened with
TPE (Trusted Path Execution) protection.
TPE forbids mmap('rwx') files opened for writes:
fd = open (a_file_in_tmp, O_RDWR); mmap (..., PROT_READ | PROT_WRITE | PROT_EXEC, fd);
while allows anonymous RWX mappings:
mmap (...MAP_ANONYMOUS , PROT_READ | PROT_WRITE | PROT_EXEC, -1);
Thanks to klondike for finding it out.
The result of a horrible typo.
(unreleased yet) upstream also has the patch: