Messages in this thread | | | Date | Mon, 15 Sep 2014 21:17:02 -0700 | From | Dave Hansen <> | Subject | Re: [PATCH v8 08/10] x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER |
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On 09/15/2014 08:20 PM, Ren, Qiaowei wrote: >> What are the semantics across execve() ? >> > This will not impact on the semantics of execve(). One runtime > library > for MPX will be provided (or merged into Glibc), and when the > application starts, this runtime will be called to initialize MPX > runtime environment, including calling prctl() to notify the kernel to > start managing the bounds directories. You can see the discussion > about exec(): https://lkml.org/lkml/2014/1/26/199
I think he's asking what happens to the kernel value at execve() time.
The short answer is that it is zero'd along with the rest of a new mm. It probably _shouldn't_ be, though. It's actually valid to have a bound directory at 0x0. We probably need to initialize it to -1 instead, and that means initializing to -1 at execve() time.
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