From 547db12fd8a0ce753c6bafd130827f1755c93fe6 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Sat, 21 Dec 2019 08:32:30 +0000 Subject: [PATCH] powerpc/32: Use vmapped stacks for interrupts In order to also catch overflows on IRQ stacks, use vmapped stacks. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d33ad1b36ddff4dcc19f96c592c12a61cf85d406.1576916812.git.christophe.leroy@c-s.fr --- arch/powerpc/kernel/irq.c | 22 ++++++++++++++++++++++ arch/powerpc/kernel/setup_32.c | 3 +++ 2 files changed, 25 insertions(+) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index add67498c126..5c9b11878555 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include @@ -664,8 +665,29 @@ void do_IRQ(struct pt_regs *regs) set_irq_regs(old_regs); } +static void *__init alloc_vm_stack(void) +{ + return __vmalloc_node_range(THREAD_SIZE, THREAD_ALIGN, VMALLOC_START, + VMALLOC_END, THREADINFO_GFP, PAGE_KERNEL, + 0, NUMA_NO_NODE, (void*)_RET_IP_); +} + +static void __init vmap_irqstack_init(void) +{ + int i; + + for_each_possible_cpu(i) { + softirq_ctx[i] = alloc_vm_stack(); + hardirq_ctx[i] = alloc_vm_stack(); + } +} + + void __init init_IRQ(void) { + if (IS_ENABLED(CONFIG_VMAP_STACK)) + vmap_irqstack_init(); + if (ppc_md.init_IRQ) ppc_md.init_IRQ(); } diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index a55b4d9ab824..5b49b26eb154 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -153,6 +153,9 @@ void __init irqstack_early_init(void) { unsigned int i; + if (IS_ENABLED(CONFIG_VMAP_STACK)) + return; + /* interrupt stacks must be in lowmem, we get that for free on ppc32 * as the memblock is limited to lowmem by default */ for_each_possible_cpu(i) { -- 2.45.2