Re: [PATCH v3 3/4] x86, mpx: add prctl commands PR_MPX_INIT, PR_MPX_RELEASE

[Ingo Molnar <mingo@kernel.org>]

* Qiaowei Ren <qiaowei.ren@intel.com> wrote:

> This patch adds the PR_MPX_INIT and PR_MPX_RELEASE prctl()
> commands on the x86 platform. These commands can be used to
> init and release MPX related resource.
> 
> A MMU notifier will be registered during PR_MPX_INIT
> command execution. So the bound tables can be automatically
> deallocated when one memory area is unmapped.
> 
> Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
> ---
>  arch/x86/Kconfig                 |    4 ++
>  arch/x86/include/asm/mpx.h       |    9 ++++
>  arch/x86/include/asm/processor.h |   16 +++++++
>  arch/x86/kernel/mpx.c            |   84 ++++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/prctl.h       |    6 +++
>  kernel/sys.c                     |   12 +++++
>  6 files changed, 131 insertions(+), 0 deletions(-)

Hm. What is the expected typical frequency of these syscalls for a 
larger application like a web browser? Only once per startup 
typically, or will they be called more frequently?

Thanks,

	Ingo