From 9254970cbbf542a0085e491810f0144a27885702 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Mon, 19 Oct 2015 13:38:09 +0100 Subject: ARM: 8447/1: catch pending imprecise abort on unmask Install a non-faulting handler just before unmasking imprecise aborts and switch back to the regular one after unmasking is done. This catches any pending imprecise abort that the firmware/bootloader may have left behind that would normally crash the kernel at that point. As there are apparently a lot of bootlaoders out there that do such a thing it makes sense to handle it in the common startup code. Signed-off-by: Lucas Stach Tested-by: Tyler Baker Signed-off-by: Russell King --- arch/arm/mm/fault.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'arch/arm/mm/fault.c') diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 0d629b8f973f..daafcf121ce0 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -593,6 +593,28 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs) arm_notify_die("", regs, &info, ifsr, 0); } +/* + * Abort handler to be used only during first unmasking of asynchronous aborts + * on the boot CPU. This makes sure that the machine will not die if the + * firmware/bootloader left an imprecise abort pending for us to trip over. + */ +static int __init early_abort_handler(unsigned long addr, unsigned int fsr, + struct pt_regs *regs) +{ + pr_warn("Hit pending asynchronous external abort (FSR=0x%08x) during " + "first unmask, this is most likely caused by a " + "firmware/bootloader bug.\n", fsr); + + return 0; +} + +void __init early_abt_enable(void) +{ + fsr_info[22].fn = early_abort_handler; + local_abt_enable(); + fsr_info[22].fn = do_bad; +} + #ifndef CONFIG_ARM_LPAE static int __init exceptions_init(void) { -- cgit v1.2.3