* Jan Beulich <jbeul...@suse.com> wrote: > >>> On 21.02.18 at 17:53, <mi...@kernel.org> wrote: > > > * Jan Beulich <jbeul...@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 <jbeul...@suse.com> > >> Reviewed-by: Juergen Gross <jgr...@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 > > Oh, I see. Question though is what to pass as the extra argument: > Do I need to pass in the caller's effective rights, or should I take > kasan_page_table()'s checking against kasan_zero_p?d as an > indication that the effective permission is zero here? I'm sorry for > this probably trivial question, but I know nothing about how KASAN > works.
I'm not sure either - but I've Cc:-ed the KASAN gents who might be able to help us out here? Thanks, Ingo