On Mon 05-10-20 11:13:48, David Hildenbrand wrote: > On 05.10.20 08:12, Michal Hocko wrote: > > On Sat 03-10-20 00:44:09, Topi Miettinen wrote: > >> On 2.10.2020 20.52, David Hildenbrand wrote: > >>> On 02.10.20 19:19, Topi Miettinen wrote: > >>>> The brk() system call allows to change data segment size (heap). This > >>>> is mainly used by glibc for memory allocation, but it can use mmap() > >>>> and that results in more randomized memory mappings since the heap is > >>>> always located at fixed offset to program while mmap()ed memory is > >>>> randomized. > >>> > >>> Want to take more Unix out of Linux? > >>> > >>> Honestly, why care about disabling? User space can happily use mmap() if > >>> it prefers. > >> > >> brk() interface doesn't seem to be used much and glibc is happy to switch to > >> mmap() if brk() fails, so why not allow disabling it optionally? If you > >> don't care to disable, don't do it and this is even the default. > > > > I do not think we want to have config per syscall, do we? > > I do wonder if grouping would be a better option then (finding a proper > level of abstraction ...). I have a vague recollection that project for the kernel tinification was aiming that direction. No idea what is the current state or whether somebody is pursuing it. -- Michal Hocko SUSE Labs
