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From:   Kefeng Wang <wangkefeng.wang@huawei.com>
To:     Russell King <linux@armlinux.org.uk>,
        <linux-arm-kernel@lists.infradead.org>
CC:     Catalin Marinas <catalin.marinas@arm.com>,
        <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jungseung Lee <js07.lee@gmail.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: [PATCH 2/2] ARM: mm: Fix PXN process when ARM_LPAE enabled
Date:   Sat, 29 May 2021 11:41:38 +0800
Message-ID: <20210529034138.83384-3-wangkefeng.wang@huawei.com>
In-Reply-To: <20210529034138.83384-1-wangkefeng.wang@huawei.com>
References: <20210529034138.83384-1-wangkefeng.wang@huawei.com>
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If we support PXN feature, should panic when user code execution
with privilege mode, but it is not true when LAPE enabled, let's
fix it by adding the check in do_page_fault().

Fixes: 1d4d37159d01 ("ARM: 8235/1: Support for the PXN CPU feature on ARMv7")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 arch/arm/mm/fault.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 81cf3e6e2a3d..a6ada914cdf5 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -241,8 +241,13 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 		vm_flags = VM_WRITE;
 	}
 
-	if (fsr & FSR_LNX_PF)
+	if (fsr & FSR_LNX_PF) {
 		vm_flags = VM_EXEC;
+#ifdef CONFIG_ARM_LPAE
+		if (addr < TASK_SIZE && !user_mode(regs))
+			__do_kernel_fault(mm, addr, fsr, regs);
+#endif
+	}
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
 
-- 
2.26.2