On Tue, Jun 11, 2019 at 05:35:31PM +0200, Andrey Konovalov wrote: > On Mon, Jun 10, 2019 at 4:28 PM Catalin Marinas <catalin.marinas@xxxxxxx> wrote: > > On Mon, Jun 03, 2019 at 06:55:07PM +0200, Andrey Konovalov wrote: > > > This patch is a part of a series that extends arm64 kernel ABI to allow to > > > pass tagged user pointers (with the top byte set to something else other > > > than 0x00) as syscall arguments. > > > > > > This patch allows tagged pointers to be passed to the following memory > > > syscalls: get_mempolicy, madvise, mbind, mincore, mlock, mlock2, mprotect, > > > mremap, msync, munlock. > > > > > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > > > I would add in the commit log (and possibly in the code with a comment) > > that mremap() and mmap() do not currently accept tagged hint addresses. > > Architectures may interpret the hint tag as a background colour for the > > corresponding vma. With this: > > I'll change the commit log. Where do you you think I should put this > comment? Before mmap and mremap definitions in mm/? On arm64 we use our own sys_mmap(). I'd say just add a comment on the generic mremap() just before the untagged_addr() along the lines that new_address is not untagged for preserving similar behaviour to mmap(). -- Catalin
