On Wed, Jan 26, 2005 at 01:20:53PM -0500, linux-os wrote: > On Wed, 26 Jan 2005, Olivier Galibert wrote: > >Given that the man page itself says that unless you're using MAP_FIXED > >start is only a hint and you should use 0 if you don't care things can > >get real annoying real fast. Imagine if you want to mmap a <4K file > >and mmap then returns 0, i.e. NULL, as the mapping address as you > >asked. It's illegal from the point of view of susv3[1] and it's real > >annoying in a C/C++ program. > > mmap() can (will) return 0 if you use 0 as the hint and use MAP_FIXED > at 0. That's the reason why one does NOT check for NULL with mmap() but > for MAP_FAILED (which on this system is (void *)-1.
All the paragraph was under an obvious "when you do not use MAP_FIXED" precondition. The patch is not supposed to change anything to the MAP_FIXED case. Malloc does not use MAP_FIXED. Usual file mmaping as an alternative to read() does not use MAP_FIXED. OG. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/