From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
linuxppc-dev@lists.ozlabs.org,
Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH AUTOSEL 5.8 006/132] powerpc: select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
Date: Mon, 26 Oct 2020 19:49:58 -0400 [thread overview]
Message-ID: <20201026235205.1023962-6-sashal@kernel.org> (raw)
In-Reply-To: <20201026235205.1023962-1-sashal@kernel.org>
From: Nicholas Piggin <npiggin@gmail.com>
[ Upstream commit 66acd46080bd9e5ad2be4b0eb1d498d5145d058e ]
powerpc uses IPIs in some situations to switch a kernel thread away
from a lazy tlb mm, which is subject to the TLB flushing race
described in the changelog introducing ARCH_WANT_IRQS_OFF_ACTIVATE_MM.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914045219.3736466-3-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/mmu_context.h | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9fa23eb320ff5..1692c9def44c9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -146,6 +146,7 @@ config PPC
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select ARCH_WANT_IPC_PARSE_VERSION
+ select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
select ARCH_WEAK_RELEASE_ACQUIRE
select BINFMT_ELF
select BUILDTIME_TABLE_SORT
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 1a474f6b1992a..6cb10c7a52025 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -246,7 +246,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
*/
static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
- switch_mm(prev, next, current);
+ switch_mm_irqs_off(prev, next, current);
}
/* We don't currently use enter_lazy_tlb() for anything */
--
2.25.1
next prev parent reply other threads:[~2020-10-27 0:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 23:49 [PATCH AUTOSEL 5.8 001/132] powerpc/powernv/smp: Fix spurious DBG() warning Sasha Levin
2020-10-26 23:49 ` [PATCH AUTOSEL 5.8 004/132] powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N Sasha Levin
2020-10-26 23:49 ` Sasha Levin [this message]
2020-10-26 23:50 ` [PATCH AUTOSEL 5.8 018/132] powerpc/64s: handle ISA v3.1 local copy-paste context switches Sasha Levin
2020-10-26 23:51 ` [PATCH AUTOSEL 5.8 112/132] KVM: PPC: Book3S HV: Do not allocate HPT for a nested guest Sasha Levin
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