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>
		
	
			
		
			
				
	
	
		
			108 lines
		
	
	
	
		
			2.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
	
		
			2.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2012 ARM Ltd.
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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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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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#ifndef __ASM_SYSCALL_H
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#define __ASM_SYSCALL_H
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#include <linux/err.h>
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extern const void *sys_call_table[];
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static inline int syscall_get_nr(struct task_struct *task,
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				 struct pt_regs *regs)
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{
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	return regs->syscallno;
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}
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static inline void syscall_rollback(struct task_struct *task,
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				    struct pt_regs *regs)
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{
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	regs->regs[0] = regs->orig_x0;
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}
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static inline long syscall_get_error(struct task_struct *task,
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				     struct pt_regs *regs)
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{
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	unsigned long error = regs->regs[0];
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	return IS_ERR_VALUE(error) ? error : 0;
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}
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static inline long syscall_get_return_value(struct task_struct *task,
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					    struct pt_regs *regs)
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{
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	return regs->regs[0];
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}
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static inline void syscall_set_return_value(struct task_struct *task,
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					    struct pt_regs *regs,
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					    int error, long val)
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{
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	regs->regs[0] = (long) error ? error : val;
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}
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#define SYSCALL_MAX_ARGS 6
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static inline void syscall_get_arguments(struct task_struct *task,
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					 struct pt_regs *regs,
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					 unsigned int i, unsigned int n,
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					 unsigned long *args)
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{
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	if (n == 0)
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		return;
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	if (i + n > SYSCALL_MAX_ARGS) {
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		unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
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		unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
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		pr_warning("%s called with max args %d, handling only %d\n",
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			   __func__, i + n, SYSCALL_MAX_ARGS);
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		memset(args_bad, 0, n_bad * sizeof(args[0]));
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	}
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	if (i == 0) {
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		args[0] = regs->orig_x0;
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		args++;
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		i++;
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		n--;
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	}
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	memcpy(args, ®s->regs[i], n * sizeof(args[0]));
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}
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static inline void syscall_set_arguments(struct task_struct *task,
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					 struct pt_regs *regs,
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					 unsigned int i, unsigned int n,
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					 const unsigned long *args)
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{
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	if (n == 0)
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		return;
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	if (i + n > SYSCALL_MAX_ARGS) {
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		pr_warning("%s called with max args %d, handling only %d\n",
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			   __func__, i + n, SYSCALL_MAX_ARGS);
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		n = SYSCALL_MAX_ARGS - i;
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	}
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	if (i == 0) {
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		regs->orig_x0 = args[0];
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		args++;
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		i++;
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		n--;
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	}
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	memcpy(®s->regs[i], args, n * sizeof(args[0]));
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}
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#endif	/* __ASM_SYSCALL_H */
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