 055b1212d1
			
		
	
	
	055b1212d1
	
	
	
		
			
			This patch allows system call entry or exit to be traced as ftrace events,
ie. sys_enter_*/sys_exit_*, if CONFIG_FTRACE_SYSCALLS is enabled.
Those events appear and can be controlled under
    ${sysfs}/tracing/events/syscalls/
Please note that we can't trace compat system calls here because
AArch32 mode does not share the same syscall table with AArch64.
Just define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS in order to avoid unexpected
results (bogus syscalls reported or even hang-up).
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
		
	
			
		
			
				
	
	
		
			59 lines
		
	
	
	
		
			1.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			59 lines
		
	
	
	
		
			1.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * arch/arm64/include/asm/ftrace.h
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|  *
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|  * Copyright (C) 2013 Linaro Limited
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|  * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  */
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| #ifndef __ASM_FTRACE_H
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| #define __ASM_FTRACE_H
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| 
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| #include <asm/insn.h>
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| 
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| #define MCOUNT_ADDR		((unsigned long)_mcount)
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| #define MCOUNT_INSN_SIZE	AARCH64_INSN_SIZE
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| 
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| #ifndef __ASSEMBLY__
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| #include <linux/compat.h>
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| 
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| extern void _mcount(unsigned long);
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| extern void *return_address(unsigned int);
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| 
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| struct dyn_arch_ftrace {
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| 	/* No extra data needed for arm64 */
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| };
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| 
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| extern unsigned long ftrace_graph_call;
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| 
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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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| 	 * addr is the address of the mcount call instruction.
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| 	 * recordmcount does the necessary offset calculation.
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| 	 */
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| 	return addr;
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| }
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| 
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| #define ftrace_return_address(n) return_address(n)
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| 
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| /*
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|  * Because AArch32 mode does not share the same syscall table with AArch64,
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|  * tracing compat syscalls may result in reporting bogus syscalls or even
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|  * hang-up, so just do not trace them.
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|  * See kernel/trace/trace_syscalls.c
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|  *
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|  * x86 code says:
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|  * If the user realy wants these, then they should use the
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|  * raw syscall tracepoints with filtering.
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|  */
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| #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
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| static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
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| {
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| 	return is_compat_task();
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| }
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| #endif /* ifndef __ASSEMBLY__ */
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| 
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| #endif /* __ASM_FTRACE_H */
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