From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Sinan Kaya <okaya@codeaurora.org>,
Arnd Bergmann <arnd@arndb.de>, Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paul.burton@mips.com>,
linux-mips@linux-mips.org, James Hogan <jhogan@kernel.org>,
Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.16 006/279] MIPS: io: Prevent compiler reordering writeX()
Date: Mon, 18 Jun 2018 10:09:51 +0200 [thread overview]
Message-ID: <20180618080609.101669238@linuxfoundation.org> (raw)
In-Reply-To: <20180618080608.851973560@linuxfoundation.org>
4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sinan Kaya <okaya@codeaurora.org>
[ Upstream commit f6b7aeee8f167409195fbf1364d02988fecad1d0 ]
writeX() has strong ordering semantics with respect to memory updates.
In the absence of a write barrier or a compiler barrier, the compiler
can reorder register and memory update instructions. This breaks the
writeX() API.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18997/
[jhogan@kernel.org: Tidy commit message]
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/include/asm/io.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -307,7 +307,7 @@ static inline void iounmap(const volatil
#if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT)
#define war_io_reorder_wmb() wmb()
#else
-#define war_io_reorder_wmb() do { } while (0)
+#define war_io_reorder_wmb() barrier()
#endif
#define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq) \
next parent reply other threads:[~2018-06-18 8:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20180618080608.851973560@linuxfoundation.org>
2018-06-18 8:09 ` Greg Kroah-Hartman [this message]
2018-06-18 8:09 ` [PATCH 4.16 013/279] MIPS: io: Add barrier after register read in readX() Greg Kroah-Hartman
2018-06-18 8:10 ` [PATCH 4.16 016/279] MIPS: dts: Boston: Fix PCI bus dtc warnings: Greg Kroah-Hartman
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