Commit a45d575f authored by Robin Getz's avatar Robin Getz Committed by Bryan Wu
Browse files

Blackfin arch: Add basic irq stack checking for Blackfin 



Signed-off-by: default avatarRobin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
parent f768a0eb

arch/blackfin/Kconfig.debug

+16 −0
Original line number Diff line number Diff line
@@ -2,6 +2,22 @@ menu "Kernel hacking" 


source "lib/Kconfig.debug"



config DEBUG_STACKOVERFLOW

	bool "Check for stack overflows"

	depends on DEBUG_KERNEL

	help

	  This option will cause messages to be printed if free stack space

	  drops below a certain limit.



config DEBUG_STACK_USAGE

	bool "Enable stack utilization instrumentation"

	depends on DEBUG_KERNEL

	help

	  Enables the display of the minimum amount of free stack which each

	  task has ever had available in the sysrq-T output.



	  This option will slow down process creation somewhat.



config HAVE_ARCH_KGDB

       def_bool y

arch/blackfin/include/asm/processor.h

+8 −0
Original line number Diff line number Diff line
@@ -24,6 +24,14 @@ static inline void wrusp(unsigned long usp) 
	__asm__ __volatile__("usp = %0;\n\t"::"da"(usp));

}



static inline unsigned long __get_SP(void)

{

	unsigned long sp;



	__asm__ __volatile__("%0 = sp;\n\t" : "=da"(sp));

	return sp;

}



/*

 * User space process size: 1st byte beyond user address space.

 * Fairly meaningless on nommu.  Parts of user programs can be scattered

arch/blackfin/include/asm/thread_info.h

+1 −0
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 
 */

#define THREAD_SIZE_ORDER	1

#define THREAD_SIZE		8192	/* 2 pages */

#define STACK_WARN		(THREAD_SIZE/8)



#ifndef __ASSEMBLY__

arch/blackfin/kernel/irqchip.c

+15 −1
Original line number Diff line number Diff line
@@ -120,7 +120,21 @@ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs) 
		desc = &bad_irq_desc;



	irq_enter();

#ifdef CONFIG_DEBUG_STACKOVERFLOW

	/* Debugging check for stack overflow: is there less than STACK_WARN free? */

	{

		long sp;



		sp = __get_SP() & (THREAD_SIZE-1);



		if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {

			dump_stack();

			printk(KERN_EMERG "%s: possible stack overflow while handling irq %i "

					" only %ld bytes free\n",

				__func__, irq, sp - sizeof(struct thread_info));

		}

	}

#endif

	generic_handle_irq(irq);



	/* If we're the only interrupt running (ignoring IRQ15 which is for