From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Thu, 13 Mar 2014 18:15:47 +0000 Subject: [PATCH 0/5] arm: Early IRQ enabling in the Undef user handler Message-ID: <1394734552-4704-1-git-send-email-catalin.marinas@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Russell, I've had this series in my repo for a long time with some follow-ups on the list but without any conclusive ACK or NAK. If there are no objections, I plan to send it to the patch system. The only change is rebasing to 3.14-rc6 and adding some Cc for the crunch bits. The __und_usr handler accesses the user space to read the opcode of the faulting instruction. This is currently done with interrupts disabled but it could potentially cause a data abort of the page table was modified from another CPU. The data abort with interrupts disabled triggers a might_sleep() warning in do_page_fault() or, worse, deadlock on the pte lock when TLB ops broadcasting is enabled (ARM11MPCore or A15 together with workaround for erratum 798181). Catalin Marinas (5): arm: Move asm macro get_thread_info to asm/assembler.h arm: Add {inc,dec}_preempt_count asm macros arm: Disable preemption in iwmmxt_task_enable() arm: Disable preemption in crunch_task_enable() arm: Enable IRQs before attempting to read user space in __und_usr arch/arm/include/asm/assembler.h | 42 ++++++++++++++++++++++++++++++++++++++ arch/arm/kernel/entry-armv.S | 11 ++++++---- arch/arm/kernel/entry-header.S | 11 ---------- arch/arm/kernel/iwmmxt.S | 15 ++++++++++---- arch/arm/mach-ep93xx/crunch-bits.S | 13 +++++++++--- arch/arm/vfp/entry.S | 28 ++++++++----------------- arch/arm/vfp/vfphw.S | 19 ++++++----------- 7 files changed, 84 insertions(+), 55 deletions(-)