Commit 3b7babc6 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Greg Kroah-Hartman

powerpc/mm/radix: Properly clear process table entry

commit c6bb0b8d upstream.

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: 7e381c0f ("powerpc/mm/radix: Add mmu context handling callback for radix")
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 88481a2c
......@@ -167,9 +167,15 @@ 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);
......
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