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authorRobin Getz <rgetz@blackfin.uclinux.org>2009-01-07 10:14:38 -0500
committerBryan Wu <cooloney@kernel.org>2009-01-07 10:14:38 -0500
commita45d575f53c9ed2926840377e59aa19e2024ee87 (patch)
tree0789f43eaee963ea5c4f4f011080b4e36a77c7eb /arch/blackfin
parentf768a0eb90831ced2129df6ccba6f1177fa5a0fa (diff)
Blackfin arch: Add basic irq stack checking for Blackfin
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/Kconfig.debug16
-rw-r--r--arch/blackfin/include/asm/processor.h8
-rw-r--r--arch/blackfin/include/asm/thread_info.h1
-rw-r--r--arch/blackfin/kernel/irqchip.c16
4 files changed, 40 insertions, 1 deletions
diff --git a/arch/blackfin/Kconfig.debug b/arch/blackfin/Kconfig.debug
index 3ad25983ec97..bfd712ab125c 100644
--- a/arch/blackfin/Kconfig.debug
+++ b/arch/blackfin/Kconfig.debug
@@ -2,6 +2,22 @@ menu "Kernel hacking"
2 2
3source "lib/Kconfig.debug" 3source "lib/Kconfig.debug"
4 4
5config DEBUG_STACKOVERFLOW
6 bool "Check for stack overflows"
7 depends on DEBUG_KERNEL
8 help
9 This option will cause messages to be printed if free stack space
10 drops below a certain limit.
11
12config DEBUG_STACK_USAGE
13 bool "Enable stack utilization instrumentation"
14 depends on DEBUG_KERNEL
15 help
16 Enables the display of the minimum amount of free stack which each
17 task has ever had available in the sysrq-T output.
18
19 This option will slow down process creation somewhat.
20
5config HAVE_ARCH_KGDB 21config HAVE_ARCH_KGDB
6 def_bool y 22 def_bool y
7 23
diff --git a/arch/blackfin/include/asm/processor.h b/arch/blackfin/include/asm/processor.h
index 2cb0b8711fa4..83d57a85b14f 100644
--- a/arch/blackfin/include/asm/processor.h
+++ b/arch/blackfin/include/asm/processor.h
@@ -24,6 +24,14 @@ static inline void wrusp(unsigned long usp)
24 __asm__ __volatile__("usp = %0;\n\t"::"da"(usp)); 24 __asm__ __volatile__("usp = %0;\n\t"::"da"(usp));
25} 25}
26 26
27static inline unsigned long __get_SP(void)
28{
29 unsigned long sp;
30
31 __asm__ __volatile__("%0 = sp;\n\t" : "=da"(sp));
32 return sp;
33}
34
27/* 35/*
28 * User space process size: 1st byte beyond user address space. 36 * User space process size: 1st byte beyond user address space.
29 * Fairly meaningless on nommu. Parts of user programs can be scattered 37 * Fairly meaningless on nommu. Parts of user programs can be scattered
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index 642769329d12..1d380def2410 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -44,6 +44,7 @@
44 */ 44 */
45#define THREAD_SIZE_ORDER 1 45#define THREAD_SIZE_ORDER 1
46#define THREAD_SIZE 8192 /* 2 pages */ 46#define THREAD_SIZE 8192 /* 2 pages */
47#define STACK_WARN (THREAD_SIZE/8)
47 48
48#ifndef __ASSEMBLY__ 49#ifndef __ASSEMBLY__
49 50
diff --git a/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c
index 5ad07525ea3f..1624e1129681 100644
--- a/arch/blackfin/kernel/irqchip.c
+++ b/arch/blackfin/kernel/irqchip.c
@@ -120,7 +120,21 @@ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
120 desc = &bad_irq_desc; 120 desc = &bad_irq_desc;
121 121
122 irq_enter(); 122 irq_enter();
123 123#ifdef CONFIG_DEBUG_STACKOVERFLOW
124 /* Debugging check for stack overflow: is there less than STACK_WARN free? */
125 {
126 long sp;
127
128 sp = __get_SP() & (THREAD_SIZE-1);
129
130 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
131 dump_stack();
132 printk(KERN_EMERG "%s: possible stack overflow while handling irq %i "
133 " only %ld bytes free\n",
134 __func__, irq, sp - sizeof(struct thread_info));
135 }
136 }
137#endif
124 generic_handle_irq(irq); 138 generic_handle_irq(irq);
125 139
126 /* If we're the only interrupt running (ignoring IRQ15 which is for 140 /* If we're the only interrupt running (ignoring IRQ15 which is for