From c94fbe1d9e1e9b1a1f82eb0b53b1cf53bcf9712b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 14 Jan 2011 11:25:58 -0500 Subject: tracing: Only process module tracepoints once The commit: 9f987b3141f086de27832514aad9f50a53f754 tracing: Include module.h in define_trace.h only solved half the problem. If the trace/events/module.h header is included at the time of define_trace.h (or in ftrace.h within it), the module.h TRACE_SYSTEM will override the current TRACE_SYSTEM macro. Since define_trace.h is included when CREATE_TRACE_POINTS is set, and the first thing it does is to #undef CREATE_TRACE_POINTS, by placing the module.h TRACE_SYSTEM inside a #ifdef CREATE_TRACE_POINTS we can prevent it from overriding the TRACE_SYSTEM that is being processed, and still process the module.h tracepoints when the module code defines CREATE_TRACE_POINTS and includes the trace/events/module.h header. As with commit 9f987b3141, this is only an issue if module.h is not included before the trace/events/.h file is included, which (luckily) has not happened yet. Reported-by: Peter Zijlstra Signed-off-by: Steven Rostedt diff --git a/include/trace/events/module.h b/include/trace/events/module.h index c7bb2f0..c6bae36 100644 --- a/include/trace/events/module.h +++ b/include/trace/events/module.h @@ -1,5 +1,15 @@ +/* + * Because linux/module.h has tracepoints in the header, and ftrace.h + * eventually includes this file, define_trace.h includes linux/module.h + * But we do not want the module.h to override the TRACE_SYSTEM macro + * variable that define_trace.h is processing, so we only set it + * when module events are being processed, which would happen when + * CREATE_TRACE_POINTS is defined. + */ +#ifdef CREATE_TRACE_POINTS #undef TRACE_SYSTEM #define TRACE_SYSTEM module +#endif #if !defined(_TRACE_MODULE_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_MODULE_H -- cgit v0.10.2 From 7f85803a26f304e698c673838aab06cc6d4d6e59 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 14 Jan 2011 17:49:02 +0800 Subject: tracing: Remove syscall_exit_fields There is no need for syscall_exit_fields as the syscall exit event class can already host the fields in its structure, like most other trace events do by default. Use that default behavior instead. Following this scheme, we don't need anymore to override the get_fields() callback of the syscall exit event class either. Hence both syscall_exit_fields and syscall_get_exit_fields() can be removed. Also changed some indentation to keep the following under 80 characters: ".fields = LIST_HEAD_INIT(event_class_syscall_exit.fields)," Acked-by: Frederic Weisbecker Signed-off-by: Lai Jiangshan LKML-Reference: <4D301C0E.8090408@cn.fujitsu.com> Signed-off-by: Steven Rostedt diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index bac752f..b706529 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -23,9 +23,6 @@ static int syscall_exit_register(struct ftrace_event_call *event, static int syscall_enter_define_fields(struct ftrace_event_call *call); static int syscall_exit_define_fields(struct ftrace_event_call *call); -/* All syscall exit events have the same fields */ -static LIST_HEAD(syscall_exit_fields); - static struct list_head * syscall_get_enter_fields(struct ftrace_event_call *call) { @@ -34,34 +31,28 @@ syscall_get_enter_fields(struct ftrace_event_call *call) return &entry->enter_fields; } -static struct list_head * -syscall_get_exit_fields(struct ftrace_event_call *call) -{ - return &syscall_exit_fields; -} - struct trace_event_functions enter_syscall_print_funcs = { - .trace = print_syscall_enter, + .trace = print_syscall_enter, }; struct trace_event_functions exit_syscall_print_funcs = { - .trace = print_syscall_exit, + .trace = print_syscall_exit, }; struct ftrace_event_class event_class_syscall_enter = { - .system = "syscalls", - .reg = syscall_enter_register, - .define_fields = syscall_enter_define_fields, - .get_fields = syscall_get_enter_fields, - .raw_init = init_syscall_trace, + .system = "syscalls", + .reg = syscall_enter_register, + .define_fields = syscall_enter_define_fields, + .get_fields = syscall_get_enter_fields, + .raw_init = init_syscall_trace, }; struct ftrace_event_class event_class_syscall_exit = { - .system = "syscalls", - .reg = syscall_exit_register, - .define_fields = syscall_exit_define_fields, - .get_fields = syscall_get_exit_fields, - .raw_init = init_syscall_trace, + .system = "syscalls", + .reg = syscall_exit_register, + .define_fields = syscall_exit_define_fields, + .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), + .raw_init = init_syscall_trace, }; extern unsigned long __start_syscalls_metadata[]; -- cgit v0.10.2