On Jul 15 18:19, Xavier Joubert wrote: > Hello dear Cygwin developpers ! > > > This is my first post here, so I would like to begin by sending you a big thank > for Cygwin ! This is a great tool to port programs to Windows.
Thanks :-) > I think I found a bug in mprotect() implementation. This call is unable to set > some protections (PROT_READ|PROT_WRITE for example) on a given memory area, > while it can set some others (PROT_NONE or PROT_READ for example) on the same > memory area. From my tests, it seems to happen only on WNT5+ (ie. Windows 2000 > and Windows XP - detailed results below). Thanks for the helpful testcase. The cause is a limitation in newer Windows NT versions, which make sense. Well, sort of. The protection modes PAGE_READWRITE and PAGE_WRITECOPY are mutually exlusive, which is enforced in calls to VirtualProtect since W2K. Since your example uses MAP_PRIVATE, which Cygwin maps to PAGE_WRITECOPY, trying to protect with MAP_WRITE, which internally maps to PAGE_READWRTE, fails on W2K and later. I've checked in a fix, so that mprotect tests for the original protection mode of the first page in the area, and uses READWRITE or WRITECOPY, whichever matches the original protection. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Co-Project Leader mailto:[EMAIL PROTECTED] Red Hat, Inc. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
