| From fc5ceba2495d205149e515a65044092e996c3cf8 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 13 Jan 2021 07:12:44 +0000 |
| Subject: powerpc: Fix incorrect stw{, ux, u, x} instructions in __set_pte_at |
| |
| From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| |
| [ Upstream commit d85be8a49e733dcd23674aa6202870d54bf5600d ] |
| |
| The placeholder for instruction selection should use the second |
| argument's operand, which is %1, not %0. This could generate incorrect |
| assembly code if the memory addressing of operand %0 is a different |
| form from that of operand %1. |
| |
| Also remove the %Un placeholder because having %Un placeholders |
| for two operands which are based on the same local var (ptep) doesn't |
| make much sense. By the way, it doesn't change the current behaviour |
| because "<>" constraint is missing for the associated "=m". |
| |
| [chleroy: revised commit log iaw segher's comments and removed %U0] |
| |
| Fixes: 9bf2b5cdc5fe ("powerpc: Fixes for CONFIG_PTE_64BIT for SMP support") |
| Cc: <stable@vger.kernel.org> # v2.6.28+ |
| Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> |
| Acked-by: Segher Boessenkool <segher@kernel.crashing.org> |
| Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
| Link: https://lore.kernel.org/r/96354bd77977a6a933fe9020da57629007fdb920.1603358942.git.christophe.leroy@csgroup.eu |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/powerpc/include/asm/book3s/32/pgtable.h | 4 ++-- |
| arch/powerpc/include/asm/nohash/pgtable.h | 4 ++-- |
| 2 files changed, 4 insertions(+), 4 deletions(-) |
| |
| --- a/arch/powerpc/include/asm/book3s/32/pgtable.h |
| +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h |
| @@ -411,9 +411,9 @@ static inline void __set_pte_at(struct m |
| if (pte_val(*ptep) & _PAGE_HASHPTE) |
| flush_hash_entry(mm, ptep, addr); |
| __asm__ __volatile__("\ |
| - stw%U0%X0 %2,%0\n\ |
| + stw%X0 %2,%0\n\ |
| eieio\n\ |
| - stw%U0%X0 %L2,%1" |
| + stw%X1 %L2,%1" |
| : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4)) |
| : "r" (pte) : "memory"); |
| |
| --- a/arch/powerpc/include/asm/nohash/pgtable.h |
| +++ b/arch/powerpc/include/asm/nohash/pgtable.h |
| @@ -155,9 +155,9 @@ static inline void __set_pte_at(struct m |
| flush_hash_entry(mm, ptep, addr); |
| #endif |
| __asm__ __volatile__("\ |
| - stw%U0%X0 %2,%0\n\ |
| + stw%X0 %2,%0\n\ |
| eieio\n\ |
| - stw%U0%X0 %L2,%1" |
| + stw%X1 %L2,%1" |
| : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4)) |
| : "r" (pte) : "memory"); |
| |
