lkml.org 
[lkml]   [2019]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v16 05/16] arm64: untag user pointers passed to memory syscalls
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@google.com>

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:

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

--
Catalin

\
 
 \ /
  Last update: 2019-06-10 16:29    [W:0.409 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site