Re: [PATCH v9 23/42] Documentation/x86: Add CET shadow stack description
From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Date: 2023-06-21 23:15:42
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On Wed, 2023-06-21 at 16:05 -0700, H.J. Lu wrote:
quoted
Which makes me think if we did want to make a more compatible longjmp() a better the way to do it might be an arch_prctl that emits a token at the current SSP. This would be loosening up the security somewhat (have to be an opt-in), but less so then enabling WRSS. But it would also be way simpler, work for all cases (I think), and be faster (maybe?) than INCSSPing through a bunch of stacks.Since longjmp isn't required to be called after setjmp, leaving a restore token doesn't work when longjmp isn't called.
Oh good point. Hmm.