x86/irq/32: Handle irq stack allocation failure proper

irq_ctx_init() crashes hard on page allocation failures. While that's ok
during early boot, it's just wrong in the CPU hotplug bringup code.

Check the page allocation failure and return -ENOMEM and handle it at the
call sites. On early boot the only way out is to BUG(), but on CPU hotplug
there is no reason to crash, so just abort the operation.

Rename the function to something more sensible while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Link: https://lkml.kernel.org/r/20190414160146.089060584@linutronix.de

1 files changed, 16 insertions, 16 deletions

diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index f37489c806fa..fc34816c6f04 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -107,28 +107,28 @@ static inline int execute_on_irq_stack(int overflow, struct irq_desc *desc)
 }
 
 /*
- * allocate per-cpu stacks for hardirq and for softirq processing
+ * Allocate per-cpu stacks for hardirq and softirq processing
  */
-void irq_ctx_init(int cpu)
+int irq_init_percpu_irqstack(unsigned int cpu)
 {
-	struct irq_stack *irqstk;
+	int node = cpu_to_node(cpu);
+	struct page *ph, *ps;
 
 	if (per_cpu(hardirq_stack_ptr, cpu))
-		return;
-
-	irqstk = page_address(alloc_pages_node(cpu_to_node(cpu),
-					       THREADINFO_GFP,
-					       THREAD_SIZE_ORDER));
-	per_cpu(hardirq_stack_ptr, cpu) = irqstk;
+		return 0;
 
-	irqstk = page_address(alloc_pages_node(cpu_to_node(cpu),
-					       THREADINFO_GFP,
-					       THREAD_SIZE_ORDER));
-	per_cpu(softirq_stack_ptr, cpu) = irqstk;
+	ph = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER);
+	if (!ph)
+		return -ENOMEM;
+	ps = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER);
+	if (!ps) {
+		__free_pages(ph, THREAD_SIZE_ORDER);
+		return -ENOMEM;
+	}
 
-	pr_debug("CPU %u irqstacks, hard=%p soft=%p\n",
-		 cpu, per_cpu(hardirq_stack_ptr, cpu),
-		 per_cpu(softirq_stack_ptr, cpu));
+	per_cpu(hardirq_stack_ptr, cpu) = page_address(ph);
+	per_cpu(softirq_stack_ptr, cpu) = page_address(ps);
+	return 0;
 }
 
 void do_softirq_own_stack(void)