From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Wed, 25 Feb 2015 16:43:20 +0000 Subject: [PATCH] arm64: enable PTE type bit in the mask for pte_modify In-Reply-To: <1424821221-16396-1-git-send-email-fkan@apm.com> References: <1424821221-16396-1-git-send-email-fkan@apm.com> Message-ID: <20150225164319.GF1105@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Feb 24, 2015 at 03:40:21PM -0800, Feng Kan wrote: > Caught during Trinity testing. The pte_modify does not allow > modification for PTE type bit. This cause the test to hang > the system. It is found that the PTE can't transit from an > inaccessible page (b00) to a valid page (b11) because the mask > does not allow it. This happens when a big block of mmaped > memory is set the PROT_NONE, then the a small piece is broken > off and set to PROT_WRITE | PROT_READ cause a huge page split. > > Signed-off-by: Feng Kan It looks fine to me. Thanks. I wonder whether mprotect() to change between PROT_NONE and an accessible protection ever worked (I thought we tested this). -- Catalin