Re: [BUG] next-20081216 - WARNING: at kernel/smp.c:333 smp_call_function_mask

Ingo Molnar
2008-12-27T08:40:18Z

* Ingo Molnar <mingo@elte.hu> wrote:

> * Yinghai Lu <yinghai@kernel.org> wrote:
>
> > +extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
>
> when you change a function declaration's return type, you _must_ double
> check whether you properly updated all instances of that function. In
> this case you forgot about the io_apic.c instance.

the corrected patch is below.

Ingo

--------------->
>From d353c528bbb29be434f7688cba9b59781e9151e3 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yinghai@kernel.org>
Date: Fri, 26 Dec 2008 02:05:47 -0800
Subject: [PATCH] sparseirq: work around compiler optimizing away __weak functions

Impact: fix panic on null pointer with sparseirq

Some GCC versions seem to inline the weak global function,
when that function is empty.

Work it around, by making the functions return a (dummy) integer.

Signed-off-by: Yinghai <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/io_apic.c | 6 ++++--
include/linux/irq.h | 6 +++---
init/main.c | 7 ++++---
kernel/irq/handle.c | 7 ++++---
4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 2fe543f..e4d4d19 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -170,7 +170,7 @@ static struct irq_cfg irq_cfgx[NR_IRQS] = {
[15] = { .domain = CPU_MASK_ALL, .vector = IRQ15_VECTOR, },
};

-void __init arch_early_irq_init(void)
+int __init arch_early_irq_init(void)
{
struct irq_cfg *cfg;
struct irq_desc *desc;
@@ -184,6 +184,8 @@ void __init arch_early_irq_init(void)
desc = irq_to_desc(i);
desc->chip_data = &cfg[i];
}
+
+ return 0;
}

#ifdef CONFIG_SPARSE_IRQ
@@ -212,7 +214,7 @@ static struct irq_cfg *get_one_free_irq_cfg(int cpu)
return cfg;
}

-void arch_init_chip_data(struct irq_desc *desc, int cpu)
+int arch_init_chip_data(struct irq_desc *desc, int cpu)
{
struct irq_cfg *cfg;

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 69da275..0e40af4 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -193,9 +193,9 @@ struct irq_desc {
const char *name;
} ____cacheline_internodealigned_in_smp;

-extern void early_irq_init(void);
-extern void arch_early_irq_init(void);
-extern void arch_init_chip_data(struct irq_desc *desc, int cpu);
+extern int early_irq_init(void);
+extern int arch_early_irq_init(void);
+extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
struct irq_desc *desc, int cpu);
extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);
diff --git a/init/main.c b/init/main.c
index c1f999a..b541c9a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -539,13 +539,14 @@ void __init __weak thread_info_cache_init(void)
{
}

-void __init __weak arch_early_irq_init(void)
+int __init __weak arch_early_irq_init(void)
{
+ return 0;
}

-void __init __weak early_irq_init(void)
+int __init __weak early_irq_init(void)
{
- arch_early_irq_init();
+ return 0;
}

asmlinkage void __init start_kernel(void)
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 893da67..0bef3ec 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -86,8 +86,9 @@ void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
desc->kstat_irqs = (unsigned int *)ptr;
}

-void __attribute__((weak)) arch_init_chip_data(struct irq_desc *desc, int cpu)
+int __weak arch_init_chip_data(struct irq_desc *desc, int cpu)
{
+ return 0;
}

static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
@@ -132,7 +133,7 @@ static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_sm
/* FIXME: use bootmem alloc ...*/
static unsigned int kstat_irqs_legacy[NR_IRQS_LEGACY][NR_CPUS];

-void __init early_irq_init(void)
+int __init early_irq_init(void)
{
struct irq_desc *desc;
int legacy_count;
@@ -151,7 +152,7 @@ void __init early_irq_init(void)
for (i = legacy_count; i < NR_IRQS; i++)
irq_desc_ptrs[i] = NULL;

- arch_early_irq_init();
+ return arch_early_irq_init();
}

struct irq_desc *irq_to_desc(unsigned int irq)