Commit ec687886 authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Run NMIs on the hardirq stack. 



Otherwise we can overflow the main stack with the function tracer
enabled.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 035df35d

arch/sparc/kernel/irq_64.c

+1 −18
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ 


#include "entry.h"

#include "cpumap.h"

#include "kstack.h"



#define NUM_IVECS	(IMAP_INR + 1)
@@ -713,24 +714,6 @@ void ack_bad_irq(unsigned int virt_irq) 
void *hardirq_stack[NR_CPUS];

void *softirq_stack[NR_CPUS];



static __attribute__((always_inline)) void *set_hardirq_stack(void)

{

	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];



	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));

	if (orig_sp < sp ||

	    orig_sp > (sp + THREAD_SIZE)) {

		sp += THREAD_SIZE - 192 - STACK_BIAS;

		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));

	}



	return orig_sp;

}

static __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)

{

	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));

}



void __irq_entry handler_irq(int irq, struct pt_regs *regs)

{

	unsigned long pstate, bucket_pa;

arch/sparc/kernel/kstack.h

+19 −0
Original line number Diff line number Diff line
@@ -61,4 +61,23 @@ static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs * 


}



static inline __attribute__((always_inline)) void *set_hardirq_stack(void)

{

	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];



	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));

	if (orig_sp < sp ||

	    orig_sp > (sp + THREAD_SIZE)) {

		sp += THREAD_SIZE - 192 - STACK_BIAS;

		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));

	}



	return orig_sp;

}



static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)

{

	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));

}



#endif /* _KSTACK_H */

arch/sparc/kernel/nmi.c

+7 −0
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ 
#include <asm/ptrace.h>

#include <asm/pcr.h>



#include "kstack.h"



/* We don't have a real NMI on sparc64, but we can fake one

 * up using profiling counter overflow interrupts and interrupt

 * levels.
@@ -92,6 +94,7 @@ static void die_nmi(const char *str, struct pt_regs *regs, int do_panic) 
notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs)

{

	unsigned int sum, touched = 0;

	void *orig_sp;



	clear_softint(1 << irq);
@@ -99,6 +102,8 @@ notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs) 


	nmi_enter();



	orig_sp = set_hardirq_stack();



	if (notify_die(DIE_NMI, "nmi", regs, 0,

		       pt_regs_trap_type(regs), SIGINT) == NOTIFY_STOP)

		touched = 1;
@@ -124,6 +129,8 @@ notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs) 
		pcr_ops->write(pcr_enable);

	}



	restore_hardirq_stack(orig_sp);



	nmi_exit();

}