Messages in this thread | | | Date | Wed, 21 Feb 2018 17:53:44 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH v2] x86: consider effective protection attributes in W+X check |
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* Jan Beulich <JBeulich@suse.com> wrote:
> Using just the leaf page table entry flags would cause a false warning > in case _PAGE_RW is clear or _PAGE_NX is set in a higher level entry. > Hand through both the current entry's flags as well as the accumulated > effective value (the latter as pgprotval_t instead of pgprot_t, as it's > not an actual entry's value). > > This in particular eliminates the false W+X warning when running under > Xen, as commit 2cc42bac1c ("x86-64/Xen: eliminate W+X mappings") has to > make the necessary adjustment in L2 rather than L1 (the reason is > explained there). I.e. _PAGE_RW is clear there in L1, but _PAGE_NX is > set in L2. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> > Reviewed-by: Juergen Gross <jgross@suse.com> > --- > v2: Re-base onto tip tree. Add Xen related paragraph to description. > --- > arch/x86/mm/dump_pagetables.c | 92 ++++++++++++++++++++++++++---------------- > 1 file changed, 57 insertions(+), 35 deletions(-)
There's a build failure with CONFIG_KASAN=y enabled:
arch/x86/mm/dump_pagetables.c: In function ‘kasan_page_table’: arch/x86/mm/dump_pagetables.c:365:3: error: too few arguments to function ‘note_page’ arch/x86/mm/dump_pagetables.c:238:13: note: declared here
Thanks,
Ingo
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