Re: [PATCH 0/4] arm64: wire up VM_FLUSH_RESET_PERMS

[Will Deacon]

On Thu, May 23, 2019 at 11:22:52AM +0100, Ard Biesheuvel wrote:
> Wire up the code introduced in v5.2 to manage the permissions
> of executable vmalloc regions (and their linear aliases) more
> strictly.
> 
> One of the things that came up in the internal discussion is
> whether non-x86 architectures have any benefit at all from the
> lazy vunmap feature, and whether it would perhaps be better to
> implement eager vunmap instead.
> 
> Cc: Nadav Amit <namit@xxxxxxxxxx>
> Cc: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Cc: James Morse <james.morse@xxxxxxx>
> 
> Ard Biesheuvel (4):
>   arm64: module: create module allocations without exec permissions
>   arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP
>   arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages
>   arm64: bpf: do not allocate executable memory
> 
>  arch/arm64/Kconfig                  |  1 +
>  arch/arm64/include/asm/cacheflush.h |  3 ++
>  arch/arm64/kernel/module.c          |  4 +-
>  arch/arm64/kernel/probes/kprobes.c  |  4 +-
>  arch/arm64/mm/pageattr.c            | 48 ++++++++++++++++----
>  arch/arm64/net/bpf_jit_comp.c       |  2 +-
>  mm/vmalloc.c                        | 11 -----
>  7 files changed, 50 insertions(+), 23 deletions(-)

Thanks, this all looks good to me. I can get pick this up for 5.2 if
Rick's fixes [1] land soon enough.

Cheers,

Will

[1] https://lore.kernel.org/lkml/20190527211058.2729-1-rick.p.edgecombe@xxxxxxxxx/T/#u