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sparc64: Run NMIs on the hardirq stack.

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

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2010-04-14 02:04:29 -07:00
parent 035df35d96
commit ec687886de
3 changed files with 27 additions and 18 deletions
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19
arch/sparc/kernel/irq_64.c
View File

@ -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;

19
arch/sparc/kernel/kstack.h
View File

@ -61,4 +61,23 @@ check_magic:
}
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 */

7
arch/sparc/kernel/nmi.c
View File

@ -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();
}