From c763ba06bd9b5db2c46c36276c89103d92d2c604 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Thu, 3 Feb 2011 14:27:22 +1100 Subject: [PATCH] tracing/syscalls: Make arch_syscall_addr weak 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 LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt --- Documentation/trace/ftrace-design.txt | 3 +++ kernel/trace/trace_syscalls.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index dc52bd442c92..6fca17beee2f 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -247,6 +247,9 @@ 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 423094288fb5..af831545f656 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -446,7 +446,7 @@ 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]; }