From d85be8a49e733dcd23674aa6202870d54bf5600d Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 22 Oct 2020 09:29:20 +0000 Subject: powerpc: Fix incorrect stw{, ux, u, x} instructions in __set_pte_at 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: # v2.6.28+ Signed-off-by: Mathieu Desnoyers Signed-off-by: Christophe Leroy Acked-by: Segher Boessenkool Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/96354bd77977a6a933fe9020da57629007fdb920.1603358942.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/book3s/32/pgtable.h | 4 ++-- arch/powerpc/include/asm/nohash/pgtable.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h index 36443cda8dcf..41d8bc6db303 100644 --- a/arch/powerpc/include/asm/book3s/32/pgtable.h +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h @@ -522,9 +522,9 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, 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"); diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h index 6277e7596ae5..ac75f4ab0dba 100644 --- a/arch/powerpc/include/asm/nohash/pgtable.h +++ b/arch/powerpc/include/asm/nohash/pgtable.h @@ -192,9 +192,9 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, */ if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) { __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"); return; -- cgit v1.2.3