From: Tom Zanussi <tom.zanussi@linux.intel.com>
To: rostedt@goodmis.org
Cc: masami.hiramatsu.pt@hitachi.com, jovi.zhangwei@huawei.com,
linux-kernel@vger.kernel.org,
Tom Zanussi <tom.zanussi@linux.intel.com>
Subject: [PATCH v3 1/9] tracing: Add support for SOFT_DISABLE to syscall events
Date: Fri, 19 Jul 2013 10:09:28 -0500 [thread overview]
Message-ID: <93b9f0a39401fb1d5a24ee57efeaf5ea9fcf49d9.1374245042.git.tom.zanussi@linux.intel.com> (raw)
In-Reply-To: <cover.1374245042.git.tom.zanussi@linux.intel.com>
In-Reply-To: <cover.1374245042.git.tom.zanussi@linux.intel.com>
The original SOFT_DISABLE patches didn't add support for soft disable
of syscall events; this adds it and paves the way for future patches
allowing triggers to be added to syscall events, since triggers are
built on top of SOFT_DISABLE.
Add an array of ftrace_event_file pointers indexed by syscall number
to the trace array alongside the existing enabled bitmaps. The
ftrace_event_file structs in turn contain the soft disable flags we
need for per-syscall soft disable accounting; later patches add
additional 'trigger' flags and per-syscall triggers and filters.
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/trace/trace.h | 2 ++
kernel/trace/trace_syscalls.c | 14 ++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 4a4f6e1..af6eb2c 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -202,6 +202,8 @@ struct trace_array {
int sys_refcount_exit;
DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
+ struct ftrace_event_file *enter_syscall_files[NR_syscalls];
+ struct ftrace_event_file *exit_syscall_files[NR_syscalls];
#endif
int stop_count;
int clock_id;
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 322e164..4915b69 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -302,6 +302,7 @@ static int __init syscall_exit_define_fields(struct ftrace_event_call *call)
static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
{
struct trace_array *tr = data;
+ struct ftrace_event_file *ftrace_file;
struct syscall_trace_enter *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
@@ -317,6 +318,10 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
if (!test_bit(syscall_nr, tr->enabled_enter_syscalls))
return;
+ ftrace_file = rcu_dereference_raw(tr->enter_syscall_files[syscall_nr]);
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+ return;
+
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
@@ -345,6 +350,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
{
struct trace_array *tr = data;
+ struct ftrace_event_file *ftrace_file;
struct syscall_trace_exit *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
@@ -359,6 +365,10 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
if (!test_bit(syscall_nr, tr->enabled_exit_syscalls))
return;
+ ftrace_file = rcu_dereference_raw(tr->exit_syscall_files[syscall_nr]);
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+ return;
+
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
@@ -397,6 +407,7 @@ static int reg_event_syscall_enter(struct ftrace_event_file *file,
if (!tr->sys_refcount_enter)
ret = register_trace_sys_enter(ftrace_syscall_enter, tr);
if (!ret) {
+ rcu_assign_pointer(tr->enter_syscall_files[num], file);
set_bit(num, tr->enabled_enter_syscalls);
tr->sys_refcount_enter++;
}
@@ -416,6 +427,7 @@ static void unreg_event_syscall_enter(struct ftrace_event_file *file,
mutex_lock(&syscall_trace_lock);
tr->sys_refcount_enter--;
clear_bit(num, tr->enabled_enter_syscalls);
+ rcu_assign_pointer(tr->enter_syscall_files[num], NULL);
if (!tr->sys_refcount_enter)
unregister_trace_sys_enter(ftrace_syscall_enter, tr);
mutex_unlock(&syscall_trace_lock);
@@ -435,6 +447,7 @@ static int reg_event_syscall_exit(struct ftrace_event_file *file,
if (!tr->sys_refcount_exit)
ret = register_trace_sys_exit(ftrace_syscall_exit, tr);
if (!ret) {
+ rcu_assign_pointer(tr->exit_syscall_files[num], file);
set_bit(num, tr->enabled_exit_syscalls);
tr->sys_refcount_exit++;
}
@@ -454,6 +467,7 @@ static void unreg_event_syscall_exit(struct ftrace_event_file *file,
mutex_lock(&syscall_trace_lock);
tr->sys_refcount_exit--;
clear_bit(num, tr->enabled_exit_syscalls);
+ rcu_assign_pointer(tr->exit_syscall_files[num], NULL);
if (!tr->sys_refcount_exit)
unregister_trace_sys_exit(ftrace_syscall_exit, tr);
mutex_unlock(&syscall_trace_lock);
--
1.7.11.4
next prev parent reply other threads:[~2013-07-19 15:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-19 15:09 [PATCH v3 0/9] tracing: trace event triggers Tom Zanussi
2013-07-19 15:09 ` Tom Zanussi [this message]
2013-07-22 7:53 ` [PATCH v3 1/9] tracing: Add support for SOFT_DISABLE to syscall events Masami Hiramatsu
2013-07-19 15:09 ` [PATCH v3 2/9] tracing: add basic event trigger framework Tom Zanussi
2013-07-22 11:19 ` Masami Hiramatsu
2013-07-19 15:09 ` [PATCH v3 3/9] tracing: add 'traceon' and 'traceoff' event trigger commands Tom Zanussi
2013-07-22 11:09 ` Masami Hiramatsu
2013-07-19 15:09 ` [PATCH v3 4/9] tracing: add 'snapshot' event trigger command Tom Zanussi
2013-07-19 15:09 ` [PATCH v3 5/9] tracing: add 'stacktrace' " Tom Zanussi
2013-07-19 15:09 ` [PATCH v3 6/9] tracing: add 'enable_event' and 'disable_event' event trigger commands Tom Zanussi
2013-07-19 15:09 ` [PATCH v3 7/9] tracing: add and use generic set_trigger_filter() implementation Tom Zanussi
2013-07-19 15:09 ` [PATCH v3 8/9] tracing: update event filters for multibuffer Tom Zanussi
2013-07-19 15:09 ` [PATCH v3 9/9] tracing: add documentation for trace event triggers Tom Zanussi
2013-07-22 7:35 ` [PATCH v3 0/9] tracing: " Masami Hiramatsu
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