Otherwise we can overflow the main stack with the function tracer enabled. Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			83 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _KSTACK_H
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#define _KSTACK_H
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#include <linux/thread_info.h>
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#include <linux/sched.h>
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#include <asm/ptrace.h>
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#include <asm/irq.h>
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/* SP must be STACK_BIAS adjusted already.  */
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static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
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{
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	unsigned long base = (unsigned long) tp;
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	/* Stack pointer must be 16-byte aligned.  */
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	if (sp & (16UL - 1))
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		return false;
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	if (sp >= (base + sizeof(struct thread_info)) &&
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	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
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		return true;
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	if (hardirq_stack[tp->cpu]) {
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		base = (unsigned long) hardirq_stack[tp->cpu];
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		if (sp >= base &&
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		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
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			return true;
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		base = (unsigned long) softirq_stack[tp->cpu];
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		if (sp >= base &&
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		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
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			return true;
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	}
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	return false;
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}
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/* Does "regs" point to a valid pt_regs trap frame?  */
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static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
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{
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	unsigned long base = (unsigned long) tp;
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	unsigned long addr = (unsigned long) regs;
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	if (addr >= base &&
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	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
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		goto check_magic;
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	if (hardirq_stack[tp->cpu]) {
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		base = (unsigned long) hardirq_stack[tp->cpu];
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		if (addr >= base &&
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		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
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			goto check_magic;
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		base = (unsigned long) softirq_stack[tp->cpu];
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		if (addr >= base &&
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		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
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			goto check_magic;
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	}
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	return false;
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check_magic:
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	if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
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		return true;
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	return false;
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}
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static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
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{
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	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
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	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
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	if (orig_sp < sp ||
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	    orig_sp > (sp + THREAD_SIZE)) {
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		sp += THREAD_SIZE - 192 - STACK_BIAS;
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		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
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	}
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	return orig_sp;
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}
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static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
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{
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	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
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}
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#endif /* _KSTACK_H */
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