Benjamin Gray 3f5ded2469 powerpc/64s: Fix __pte_needs_flush() false positive warning
commit 1abce0580b89464546ae06abd5891ebec43c9470 upstream.

Userspace PROT_NONE ptes set _PAGE_PRIVILEGED, triggering a false
positive debug assertion that __pte_flags_need_flush() is not called
on a kernel mapping.

Detect when it is a userspace PROT_NONE page by checking the required
bits of PAGE_NONE are set, and none of the RWX bits are set.
pte_protnone() is insufficient here because it always returns 0 when
CONFIG_NUMA_BALANCING=n.

Fixes: b11931e9adc1 ("powerpc/64s: add pte_needs_flush and huge_pmd_needs_flush")
Cc: stable@vger.kernel.org # v6.1+
Reported-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230302225947.81083-1-bgray@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-06 12:10:54 +02:00
..
2022-11-27 08:28:41 +09:00
2022-10-15 16:47:33 -07:00
2023-03-30 12:49:19 +02:00
2023-03-17 08:50:32 +01:00
2023-01-07 11:11:46 +01:00