Messages in this thread | | | Date | Wed, 1 Mar 2023 07:42:58 -0800 | From | Deepak Gupta <> | Subject | Re: [PATCH v6 20/41] x86/mm: Teach pte_mkwrite() about stack memory |
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On Sat, Feb 18, 2023 at 01:14:12PM -0800, Rick Edgecombe wrote: >If a VMA has the VM_SHADOW_STACK flag, it is shadow stack memory. So >when it is made writable with pte_mkwrite(), it should create shadow >stack memory, not conventionally writable memory. Now that pte_mkwrite() >takes a VMA, and places where shadow stack memory might be created pass >one, pte_mkwrite() can know when it should do this. > >So make pte_mkwrite() create shadow stack memory when the VMA has the >VM_SHADOW_STACK flag. Do the same thing for pmd_mkwrite(). > >This requires referencing VM_SHADOW_STACK in these functions, which are >currently defined in pgtable.h, however mm.h (where VM_SHADOW_STACK is >located) can't be pulled in without causing problems for files that >reference pgtable.h. So also move pte/pmd_mkwrite() into pgtable.c, where >they can safely reference VM_SHADOW_STACK. > >Tested-by: Pengfei Xu <pengfei.xu@intel.com> >Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> >
Acked-by: Deepak Gupta <debug@rivosinc.com>
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