diff options
| author | Benjamin Gray <bgray@linux.ibm.com> | 2023-03-03 09:59:47 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-03-28 21:37:23 +1100 |
| commit | 1abce0580b89464546ae06abd5891ebec43c9470 (patch) | |
| tree | 7b81d20c9ae56d3242db372f2bf62e8304dba2ab /arch | |
| parent | f2c7e3562b4c4f1699acc1538ebf3e75f5cced35 (diff) | |
powerpc/64s: Fix __pte_needs_flush() false positive warning
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
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/tlbflush.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush.h b/arch/powerpc/include/asm/book3s/64/tlbflush.h index 2bbc0fcce04a..5e26c7f2c25a 100644 --- a/arch/powerpc/include/asm/book3s/64/tlbflush.h +++ b/arch/powerpc/include/asm/book3s/64/tlbflush.h @@ -148,6 +148,11 @@ static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma, */ } +static inline bool __pte_protnone(unsigned long pte) +{ + return (pte & (pgprot_val(PAGE_NONE) | _PAGE_RWX)) == pgprot_val(PAGE_NONE); +} + static inline bool __pte_flags_need_flush(unsigned long oldval, unsigned long newval) { @@ -164,8 +169,8 @@ static inline bool __pte_flags_need_flush(unsigned long oldval, /* * We do not expect kernel mappings or non-PTEs or not-present PTEs. */ - VM_WARN_ON_ONCE(oldval & _PAGE_PRIVILEGED); - VM_WARN_ON_ONCE(newval & _PAGE_PRIVILEGED); + VM_WARN_ON_ONCE(!__pte_protnone(oldval) && oldval & _PAGE_PRIVILEGED); + VM_WARN_ON_ONCE(!__pte_protnone(newval) && newval & _PAGE_PRIVILEGED); VM_WARN_ON_ONCE(!(oldval & _PAGE_PTE)); VM_WARN_ON_ONCE(!(newval & _PAGE_PTE)); VM_WARN_ON_ONCE(!(oldval & _PAGE_PRESENT)); |