f201ae2356
Impact: use deeper function tracing depth safely Some tests showed that function return tracing needed a more deeper depth of function calls. But it could be unsafe to store these return addresses to the stack. So these arrays will now be allocated dynamically into task_struct of current only when the tracer is activated. Typical scheme when tracer is activated: - allocate a return stack for each task in global list. - fork: allocate the return stack for the newly created task - exit: free return stack of current - idle init: same as fork I chose a default depth of 50. I don't have overruns anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
56 lines
1.2 KiB
C
56 lines
1.2 KiB
C
#ifndef _ASM_X86_FTRACE_H
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#define _ASM_X86_FTRACE_H
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#ifdef CONFIG_FUNCTION_TRACER
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#define MCOUNT_ADDR ((long)(mcount))
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#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
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#ifndef __ASSEMBLY__
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extern void mcount(void);
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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/*
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* call mcount is "e8 <4 byte offset>"
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* The addr points to the 4 byte offset and the caller of this
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* function wants the pointer to e8. Simply subtract one.
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*/
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return addr - 1;
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}
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#ifdef CONFIG_DYNAMIC_FTRACE
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struct dyn_arch_ftrace {
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/* No extra data needed for x86 */
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};
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_FUNCTION_TRACER */
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#ifdef CONFIG_FUNCTION_RET_TRACER
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#ifndef __ASSEMBLY__
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/*
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* Stack of return addresses for functions
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* of a thread.
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* Used in struct thread_info
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*/
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struct ftrace_ret_stack {
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unsigned long ret;
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unsigned long func;
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unsigned long long calltime;
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};
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/*
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* Primary handler of a function return.
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* It relays on ftrace_return_to_handler.
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* Defined in entry32.S
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*/
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extern void return_to_handler(void);
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_FUNCTION_RET_TRACER */
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#endif /* _ASM_X86_FTRACE_H */
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