128 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /**
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|  * @file backtrace.c
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|  *
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|  * @remark Copyright 2002 OProfile authors
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|  * @remark Read the file COPYING
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|  *
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|  * @author John Levon
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|  * @author David Smith
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|  */
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| 
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| #include <linux/oprofile.h>
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| #include <linux/sched.h>
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| #include <linux/mm.h>
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| #include <linux/compat.h>
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| #include <linux/uaccess.h>
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| 
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| #include <asm/ptrace.h>
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| #include <asm/stacktrace.h>
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| #include <asm/unwind.h>
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| 
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| #ifdef CONFIG_COMPAT
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| static struct stack_frame_ia32 *
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| dump_user_backtrace_32(struct stack_frame_ia32 *head)
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| {
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| 	/* Also check accessibility of one struct frame_head beyond: */
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| 	struct stack_frame_ia32 bufhead[2];
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| 	struct stack_frame_ia32 *fp;
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| 	unsigned long bytes;
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| 
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| 	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
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| 	if (bytes != 0)
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| 		return NULL;
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| 
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| 	fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
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| 
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| 	oprofile_add_trace(bufhead[0].return_address);
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| 
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| 	/* frame pointers should strictly progress back up the stack
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| 	* (towards higher addresses) */
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| 	if (head >= fp)
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| 		return NULL;
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| 
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| 	return fp;
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| }
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| 
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| static inline int
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| x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
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| {
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| 	struct stack_frame_ia32 *head;
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| 
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| 	/* User process is IA32 */
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| 	if (!current || !test_thread_flag(TIF_IA32))
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| 		return 0;
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| 
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| 	head = (struct stack_frame_ia32 *) regs->bp;
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| 	while (depth-- && head)
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| 		head = dump_user_backtrace_32(head);
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| 
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| 	return 1;
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| }
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| 
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| #else
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| static inline int
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| x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
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| {
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| 	return 0;
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| }
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| #endif /* CONFIG_COMPAT */
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| 
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| static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
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| {
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| 	/* Also check accessibility of one struct frame_head beyond: */
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| 	struct stack_frame bufhead[2];
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| 	unsigned long bytes;
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| 
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| 	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
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| 	if (bytes != 0)
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| 		return NULL;
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| 
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| 	oprofile_add_trace(bufhead[0].return_address);
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| 
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| 	/* frame pointers should strictly progress back up the stack
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| 	 * (towards higher addresses) */
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| 	if (head >= bufhead[0].next_frame)
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| 		return NULL;
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| 
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| 	return bufhead[0].next_frame;
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| }
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| 
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| void
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| x86_backtrace(struct pt_regs * const regs, unsigned int depth)
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| {
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| 	struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
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| 
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| 	if (!user_mode(regs)) {
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| 		struct unwind_state state;
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| 		unsigned long addr;
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| 
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| 		if (!depth)
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| 			return;
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| 
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| 		oprofile_add_trace(regs->ip);
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| 
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| 		if (!--depth)
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| 			return;
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| 
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| 		for (unwind_start(&state, current, regs, NULL);
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| 		     !unwind_done(&state); unwind_next_frame(&state)) {
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| 			addr = unwind_get_return_address(&state);
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| 			if (!addr)
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| 				break;
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| 
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| 			oprofile_add_trace(addr);
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| 
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| 			if (!--depth)
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| 				break;
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| 		}
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| 
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| 		return;
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| 	}
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| 
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| 	if (x86_backtrace_32(regs, depth))
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| 		return;
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| 
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| 	while (depth-- && head)
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| 		head = dump_user_backtrace(head);
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| }
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