[PATCH v5 09/17] powerpc/32: Use vmapped stacks for interrupts
From: Christophe Leroy <hidden>
Date: 2019-12-21 08:32:45
Also in:
linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
In order to also catch overflows on IRQ stacks, use vmapped stacks. Signed-off-by: Christophe Leroy <redacted> --- 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 <linux/debugfs.h> #include <linux/of.h> #include <linux/of_irq.h> +#include <linux/vmalloc.h> #include <linux/uaccess.h> #include <asm/io.h>
@@ -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) {
--
2.13.3