powerpc/64s: Fix __pte_needs_flush() false positive warning

Browse source

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: b11931e9ad ("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

...

This commit is contained in:

Benjamin Gray 2023-03-03 09:59:47 +11:00 • committed by Michael Ellerman

parent f2c7e3562b

commit 1abce0580b

1 changed files with 7 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

9

arch/powerpc/include/asm/book3s/64/tlbflush.h

View file