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authorIan Munsie <imunsie@au1.ibm.com>2011-02-03 14:27:22 +1100
committerSteven Rostedt <rostedt@goodmis.org>2011-02-07 21:26:22 -0500
commitc763ba06bd9b5db2c46c36276c89103d92d2c604 (patch)
tree776ce215fc5900e747fb79dc91a160da35f4325c
parent3773b389b6927595512558594d040c1edba46f36 (diff)
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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>
-rw-r--r--Documentation/trace/ftrace-design.txt3
-rw-r--r--kernel/trace/trace_syscalls.c2
2 files changed, 4 insertions, 1 deletions
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];
}