On Thu, 26 Nov 2015 19:02:28 +0100 Petr Tesarik <ptesarik at suse.cz> wrote: > On Thu, 26 Nov 2015 18:32:31 +0100 > Michael Holzheu <holzheu at linux.vnet.ibm.com> wrote: > > > Hi Simon again, > > > > After a bit more thinking: In theory mmap() could also return NULL. > > Therefore the following fix is probably the better one ... > > No, if you let the kernel choose the address (i.e. call mmap with NULL > addr), it will return at least PAGE_SIZE (and a higher limit is usually > enforced by sys.vm.mmap_min_addr sysctl). Admittedly the limit is set > in arch-specific code, so theoretically there can be an architecture > which sets the limit to 0, but I doubt it, because it would break too > many assumptions in user space (for example gcc assumes that > dereferencing a NULL pointer terminates a process). > > In short, this other fix is just as good as the previous one. Hi Petr, Thanks for clarification! I still would vote for the second one ;-) Michael
