diff options
| author | Benjamin Herrenschmidt | 2017-07-08 07:45:32 -0500 |
|---|---|---|
| committer | Michael Ellerman | 2017-07-10 21:24:34 +1000 |
| commit | c6bb0b8d426a8cf865ca9c8a532cc3a2927cfceb (patch) | |
| tree | b147167c3c0635c5fbb395f665a006b7f5bce0f1 | |
| parent | 1c0eaf0f56d6128af7f0f252855173fcee85d202 (diff) | |
powerpc/mm/radix: Properly clear process table entry
On radix, the process table entry we want to clear when destroying a
context is entry 0, not entry 1. This has no *immediate* consequence
on Power9, but it can cause other bugs to become worse.
Fixes: 7e381c0ff618 ("powerpc/mm/radix: Add mmu context handling callback for radix")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/mm/mmu_context_book3s64.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c index 71de2c6d88f3..ceff76262c7e 100644 --- a/arch/powerpc/mm/mmu_context_book3s64.c +++ b/arch/powerpc/mm/mmu_context_book3s64.c @@ -223,9 +223,15 @@ void destroy_context(struct mm_struct *mm) mm->context.cop_lockp = NULL; #endif /* CONFIG_PPC_ICSWX */ - if (radix_enabled()) - process_tb[mm->context.id].prtb1 = 0; - else + if (radix_enabled()) { + /* + * Radix doesn't have a valid bit in the process table + * entries. However we know that at least P9 implementation + * will avoid caching an entry with an invalid RTS field, + * and 0 is invalid. So this will do. + */ + process_tb[mm->context.id].prtb0 = 0; + } else subpage_prot_free(mm); destroy_pagetable_page(mm); __destroy_context(mm->context.id); |