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author | Catalin Marinas <catalin.marinas@arm.com> | 2017-01-27 10:54:12 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-14 12:00:15 (GMT) |
commit | f46fdb8a2611b4ffe9dda5b712ac02add90e930f (patch) | |
tree | 16c94a7326cce07bfbc8cf825773d33d283913ee /Documentation | |
parent | aadb7e073e813a447ba6c5f5636702f07e8805dd (diff) | |
download | linux-f46fdb8a2611b4ffe9dda5b712ac02add90e930f.tar.xz |
arm64: Improve detection of user/non-user mappings in set_pte(_at)
commit ec663d967b2276448a416406ca59ff247c0c80c5 upstream.
Commit cab15ce604e5 ("arm64: Introduce execute-only page access
permissions") allowed a valid user PTE to have the PTE_USER bit clear.
As a consequence, the pte_valid_not_user() macro in set_pte() was
replaced with pte_valid_global() under the assumption that only user
pages have the nG bit set. EFI mappings, however, also have the nG bit
set and set_pte() wrongly ignores issuing the DSB+ISB.
This patch reinstates the pte_valid_not_user() macro and adds the
PTE_UXN bit check since all kernel mappings have this bit set. For
clarity, pte_exec() is renamed to pte_user_exec() as it only checks for
the absence of PTE_UXN. Consequently, the user executable check in
set_pte_at() drops the pte_ng() test since pte_user_exec() is
sufficient.
Fixes: cab15ce604e5 ("arm64: Introduce execute-only page access permissions")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions