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 <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
index dc52bd4..6fca17b 100644
--- a/Documentation/trace/ftrace-design.txt
+++ b/Documentation/trace/ftrace-design.txt
@@ -247,6 +247,9 @@
- 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 4230942..af83154 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -446,7 +446,7 @@
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];
}
