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Date:   Mon, 20 Jul 2020 17:54:41 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Nick Hu <nickhu@andestech.com>, Greentime Hu <green.hu@gmail.com>,
        Vincent Chen <deanbo422@gmail.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     linux-arch@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 0/6] arm: don't call addr_limit_user_check for nommu
Message-ID: <20200720155441.GA13067@lst.de>
References: <20200714105505.935079-1-hch@lst.de>
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User-Agent: Mutt/1.5.17 (2007-11-01)
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On arm nommu kernel use the same constant for USER_DS and KERNEL_DS,
and seqment_eq always returns false.  With the current check in
addr_limit_user_check that works by accident, but when replacing
seqment_eq with uaccess_kerne it will fail.  Just remove the not
needed check entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Guenter Roeck <linux@roeck-us.net>
---

Andrew: this should preferably go before the other patches in this
series.

 arch/arm/kernel/signal.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index ab2568996ddb0c..c9dc912b83f012 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -713,7 +713,9 @@ struct page *get_signal_page(void)
 /* Defer to generic check */
 asmlinkage void addr_limit_check_failed(void)
 {
+#ifdef CONFIG_MMU
 	addr_limit_user_check();
+#endif
 }
 
 #ifdef CONFIG_DEBUG_RSEQ
-- 
2.27.0