Commit e7b8e675 authored by Mike Frysinger's avatar Mike Frysinger Committed by Frederic Weisbecker
Browse files

tracing: Unify arch_syscall_addr() implementations 



Most implementations of arch_syscall_addr() are the same, so create a
default version in common code and move the one piece that differs (the
syscall table) to asm/syscall.h.  New arch ports don't have to waste
time copying & pasting this simple function.

The s390/sparc versions need to be different, so document why.

Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
Acked-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent ea2c68a0

Documentation/trace/ftrace-design.txt

+2 −3
Original line number Diff line number Diff line
@@ -218,11 +218,10 @@ HAVE_SYSCALL_TRACEPOINTS 


You need very few things to get the syscalls tracing in an arch.



- Support HAVE_ARCH_TRACEHOOK (see arch/Kconfig).

- Have a NR_syscalls variable in <asm/unistd.h> that provides the number

  of syscalls supported by the arch.

- Implement arch_syscall_addr() that resolves a syscall address from a

  syscall number.

- Support the TIF_SYSCALL_TRACEPOINT thread flags

- Support the TIF_SYSCALL_TRACEPOINT thread flags.

- Put the trace_sys_enter() and trace_sys_exit() tracepoints calls from ptrace

  in the ptrace syscalls tracing path.

- Tag this arch as HAVE_SYSCALL_TRACEPOINTS.

arch/s390/include/asm/syscall.h

+7 −0
Original line number Diff line number Diff line
@@ -15,6 +15,13 @@ 
#include <linux/sched.h>

#include <asm/ptrace.h>



/*

 * The syscall table always contains 32 bit pointers since we know that the

 * address of the function to be called is (way) below 4GB.  So the "int"

 * type here is what we want [need] for both 32 bit and 64 bit systems.

 */

extern const unsigned int sys_call_table[];



static inline long syscall_get_nr(struct task_struct *task,

				  struct pt_regs *regs)

{

arch/s390/kernel/ftrace.c

+0 −10
Original line number Diff line number Diff line
@@ -200,13 +200,3 @@ out: 
	return parent;

}

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 


#ifdef CONFIG_FTRACE_SYSCALLS



extern unsigned int sys_call_table[];



unsigned long __init arch_syscall_addr(int nr)

{

	return (unsigned long)sys_call_table[nr];

}

#endif

arch/sh/include/asm/syscall.h

+2 −0
Original line number Diff line number Diff line 
#ifndef __ASM_SH_SYSCALL_H

#define __ASM_SH_SYSCALL_H



extern const unsigned long sys_call_table[];



#ifdef CONFIG_SUPERH32

# include "syscall_32.h"

#else

arch/sh/kernel/ftrace.c

+0 −9
Original line number Diff line number Diff line
@@ -399,12 +399,3 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) 
	}

}

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 


#ifdef CONFIG_FTRACE_SYSCALLS

extern unsigned long *sys_call_table;



unsigned long __init arch_syscall_addr(int nr)

{

	return (unsigned long)sys_call_table[nr];

}

#endif /* CONFIG_FTRACE_SYSCALLS */

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