From mboxrd@z Thu Jan 1 00:00:00 1970 From: narmstrong@baylibre.com (Neil Armstrong) Date: Fri, 9 Sep 2016 09:57:38 +0200 Subject: [PATCH] RFC: ARM: fix the uaccess crash on PB11MPCore In-Reply-To: <1468256893-12811-1-git-send-email-linus.walleij@linaro.org> References: <1468256893-12811-1-git-send-email-linus.walleij@linaro.org> Message-ID: <78f8cd15-6cde-0493-e429-43d047dd58f7@baylibre.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/11/2016 07:08 PM, Linus Walleij wrote: > The following patch was sketched by Russell in response to my > crashes on the PB11MPCore after the patch for software-based > priviledged no access support for ARMv8.1. See this thread: > http://marc.info/?l=linux-arm-kernel&m=144051749807214&w=2 > > I am unsure what is going on, I suspect everyone involved in > the discussion is. I just want to repost this to get the > discussion restarted, as I still have to apply this patch > with every kernel iteration to get my PB11MPCore Realview > running. > > I also know that Oxnas has actual, mass-deployed NAS (PogoPlug > Pro variants) using PB11MPCore, and that they may or may not > be seeing the same issue so I want their feedback on this: do > you or do you not see this with mainline, or have you not even > tested? > > Cc: Russell King > Cc: Will Deacon > Cc: Neil Armstrong > Fixes: a5e090acbf54 ("ARM: software-based priviledged-no-access support") > Signed-off-by: Linus Walleij > --- > arch/arm/kernel/smp_tlb.c | 7 +++++++ > 1 file changed, 7 insertions(+) Hi Linus, Russell, Arnd, I made a quick port ox OX820 over v4.8-rc4 and when enabling CONFIG_CPU_SW_DOMAIN_PAN I get the following trace at boot time : [ 1.690000] Unable to handle kernel paging request at virtual address b6f23684 [ 1.690000] Unable to handle kernel paging request at virtual address b6f95ef4 [ 1.690000] pgd = c281c000 [ 1.690000] [b6f95ef4] *pgd=62821831, *pte=00000000, *ppte=00000000 [ 1.690000] Internal error: Oops: 81f [#1] SMP ARM [ 1.690000] Modules linked in: [ 1.690000] CPU: 1 PID: 65 Comm: mount Not tainted 4.8.0-rc4-00001-g0e9c45d-dirty #22 [ 1.690000] Hardware name: Generic DT based system [ 1.690000] task: c2aad860 task.stack: c2814000 [ 1.690000] PC is at ipi_flush_tlb_page+0x34/0x44 [ 1.690000] LR is at on_each_cpu_mask+0x58/0x60 [ 1.690000] pc : [] lr : [] psr: 20000193 [ 1.690000] sp : c2815da0 ip : 00000002 fp : 00067c40 [ 1.690000] r10: c0702744 r9 : 67c4079f r8 : 67c9e75f [ 1.690000] r7 : c2815dbc r6 : c010d3a8 r5 : c2816164 r4 : 20000113 [ 1.690000] r3 : 00000000 r2 : b6f95003 r1 : 00000003 r0 : 00000003 [ 1.690000] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none [ 1.690000] Control: 00c5787d Table: 6281c00a DAC: 00000051 [ 1.690000] Process mount (pid: 65, stack limit = 0xc2814190) [ 1.690000] Stack: (0xc2815da0 to 0xc2816000) [...] [ 1.690000] ---[ end trace 8f1207a6d611da09 ]--- When applying this patch, it solved the issue. Tested-by: Neil Armstrong Neil