From 601c942176d8ad8334118bddb747e3720bed24f8 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Fri, 9 May 2014 17:37:44 +0100 Subject: [PATCH 1/2] arm64: use cpu_online_mask when using forced irq_set_affinity Commit 01f8fa4f01d8("genirq: Allow forcing cpu affinity of interrupts") enabled the forced irq_set_affinity which previously refused to route an interrupt to an offline cpu. Commit ffde1de64012("irqchip: Gic: Support forced affinity setting") implements this force logic and disables the cpu online check for GIC interrupt controller. When __cpu_disable calls migrate_irqs, it disables the current cpu in cpu_online_mask and uses forced irq_set_affinity to migrate the IRQs away from the cpu but passes affinity mask with the cpu being offlined also included in it. When calling irq_set_affinity with force == true in a cpu hotplug path, the caller must ensure that the cpu being offlined is not present in the affinity mask or it may be selected as the target CPU, leading to the interrupt not being migrated. This patch uses cpu_online_mask when using forced irq_set_affinity so that the IRQs are properly migrated away. Signed-off-by: Sudeep Holla Acked-by: Mark Rutland Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/irq.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index 473e5dbf8f39..0f08dfd69ebc 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -97,11 +97,15 @@ static bool migrate_one_irq(struct irq_desc *desc) if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) return false; - if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { - affinity = cpu_online_mask; + if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) ret = true; - } + /* + * when using forced irq_set_affinity we must ensure that the cpu + * being offlined is not present in the affinity mask, it may be + * selected as the target CPU otherwise + */ + affinity = cpu_online_mask; c = irq_data_get_irq_chip(d); if (!c->irq_set_affinity) pr_debug("IRQ%u: unable to set affinity\n", d->irq); From 4797ec2dc83a43be35bad56037d1b53db9e2b5d5 Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Thu, 15 May 2014 15:19:22 +0100 Subject: [PATCH 2/2] arm64: fix pud_huge() for 2-level pagetables The following happens when trying to run a kvm guest on a kernel configured for 64k pages. This doesn't happen with 4k pages: BUG: failure at include/linux/mm.h:297/put_page_testzero()! Kernel panic - not syncing: BUG! CPU: 2 PID: 4228 Comm: qemu-system-aar Tainted: GF 3.13.0-0.rc7.31.sa2.k32v1.aarch64.debug #1 Call trace: [] dump_backtrace+0x0/0x16c [] show_stack+0x14/0x1c [] dump_stack+0x84/0xb0 [] panic+0xf4/0x220 [] free_reserved_area+0x0/0x110 [] free_pages+0x50/0x88 [] kvm_free_stage2_pgd+0x30/0x40 [] kvm_arch_destroy_vm+0x18/0x44 [] kvm_put_kvm+0xf0/0x184 [] kvm_vm_release+0x10/0x1c [] __fput+0xb0/0x288 [] ____fput+0xc/0x14 [] task_work_run+0xa8/0x11c [] do_notify_resume+0x54/0x58 In arch/arm/kvm/mmu.c:unmap_range(), we end up doing an extra put_page() on the stage2 pgd which leads to the BUG in put_page_testzero(). This happens because a pud_huge() test in unmap_range() returns true when it should always be false with 2-level pages tables used by 64k pages. This patch removes support for huge puds if 2-level pagetables are being used. Signed-off-by: Mark Salter [catalin.marinas@arm.com: removed #ifndef around PUD_SIZE check] Signed-off-by: Catalin Marinas Cc: # v3.11+ --- arch/arm64/mm/hugetlbpage.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 5e9aec358306..31eb959e9aa8 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -51,7 +51,11 @@ int pmd_huge(pmd_t pmd) int pud_huge(pud_t pud) { +#ifndef __PAGETABLE_PMD_FOLDED return !(pud_val(pud) & PUD_TABLE_BIT); +#else + return 0; +#endif } int pmd_huge_support(void)