From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758008Ab0EMHor (ORCPT ); Thu, 13 May 2010 03:44:47 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:58687 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751181Ab0EMHoG (ORCPT ); Thu, 13 May 2010 03:44:06 -0400 From: "Ian Munsie" To: linux-kernel@vger.kernel.org Cc: Steven Rostedt , Frederic Weisbecker , Ingo Molnar , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, Jason Baron , Ian Munsie Subject: [PATCH 2/4] ftrace syscalls: Make arch_syscall_addr weak Date: Thu, 13 May 2010 17:43:12 +1000 Message-Id: <1273736594-19320-3-git-send-email-imunsie@au1.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1273736594-19320-1-git-send-email-imunsie@au1.ibm.com> References: <1273736594-19320-1-git-send-email-imunsie@au1.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Munsie Some architectures use non-trivial system call tables and will not work with the generic arch_syscall_addr code. For example, PowerPC64 uses a table of twin long longs. This patch makes the generic arch_syscall_addr weak to allow architectures with non-trivial system call tables to override it. Signed-off-by: Ian Munsie --- Documentation/trace/ftrace-design.txt | 3 +++ kernel/trace/trace_syscalls.c | 2 +- 2 files changed, 4 insertions(+), 1 deletions(-) diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index f1f81af..8369a1c 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -244,6 +244,9 @@ You need very few things to get the syscalls tracing in an arch. - 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. +- If the system call table on this arch is more complicated than a simple array + of addresses of the system calls, implement an arch_syscall_addr to return + the address of a given system call. - Tag this arch as HAVE_SYSCALL_TRACEPOINTS. diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 732f021..1c231d0 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -403,7 +403,7 @@ int init_syscall_trace(struct ftrace_event_call *call) return id; } -unsigned long __init arch_syscall_addr(int nr) +unsigned long __init __weak arch_syscall_addr(int nr) { return (unsigned long)sys_call_table[nr]; } -- 1.7.1