On Sat, May 08, 2004 at 05:02:14PM +0200, Vincent Lefevre wrote: > On 2004-05-08 15:13:40 +0200, Wolfram Gloger wrote: > > But now concerning the bug report in question: I see no bug. The > > MAP_NORESERVE does not matter here at all. Note that before malloc > > hands out memory in a region allocated with MAP_NORESERVE, it _must_ > > call mprotect(..., PROT_READ|PROT_WRITE) on a smaller subregion, and > > _that_ call definitely should be checked by the kernel against > > overcommitment accounting, as _then_ (and only then) physical memory > > really is potentially allocated. I believe this to be the case in > > Linux. > > But mprotect seems to be never called (strace just shows old_mmap > calls).
Does strace show mapping with PROT_NONE? If so and there's no mprotect, then I'm quite confused - access should fail. Does strace even show MAP_NORESERVE? I don't think the mmap call that you're looking at is even the one which uses MAP_NORESERVE, since in the copy of glibc source I'm looking at, that's only used for allocating secondary arenas. -- Daniel Jacobowitz
