This series adds explicit tests that verify a page fault will occur for attempts to write to an r/o page while CR0.WP is 1 as well as access is granted when CR0.WP is 0. There are existing tests already, e.g. in pks.c, pku.c, smap.c or even access.c that implicitly test this. However, they all either explicitly (via INVLPG) or implicitly (via CR3 reload) flush the TLB before doing the access which might lead to false positives if the access succeeded before, e.g. because CR0.WP was 0 before. Better to have an explicit test, especially to back up the changes of [1] which were missing the emulator case, initially. Please apply! Thanks, Mathias [1] https://lore.kernel.org/kvm/20230322013731.102955-1-minipli@xxxxxxxxxxxxxx/ Mathias Krause (4): x86: Use existing CR0.WP / CR4.SMEP bit definitions x86/access: CR0.WP toggling write to r/o data test x86/access: Forced emulation support x86/access: Try emulation for CR0.WP test as well x86/access.c | 120 +++++++++++++++++++++++++++++++++++++++++++++------ x86/pks.c | 5 +-- x86/pku.c | 5 +-- 3 files changed, 110 insertions(+), 20 deletions(-) -- 2.39.2
