Hi,
WRT to Terry's email, I initialized the file by writing N nul ('\0')
bytes to it.Alfred Perlstein wrote: > Have you tried the mapping with PROT_READ as well? I don't think > most arches allow for access without PROT_READ along with PROT_WRITE. Oops.. and I even read the thread a little while ago about PROT_WRITE alone not working on x86, but working on alpha because write-only pages are supported on that architecture.. silly me anyhow, I changed it to use O_RDWR instead of O_WRONLY to open(2) and then I used both PROT_READ and PROT_WRITE as the protection argument, and then the file transfer worked like a charm. Which brings us to the question, on x86 arch why do we even allow a PROT_WRITE only map to be created? It is useless and a program which gets a write-only map will think it actually has such a mmap'ed region, but it will get a SIGBUS if it tries to write to it. It would be better to return -1 and set errno to EFAULT than to have this brain damage imho. -- Farooq To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
