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-rw-r--r--arch/s390/kernel/ptrace.c4
-rw-r--r--arch/x86/kernel/ptrace.c4
-rw-r--r--include/linux/tracepoint.h46
-rw-r--r--include/trace/define_trace.h5
-rw-r--r--include/trace/ftrace.h9
-rw-r--r--include/trace/syscall.h12
-rw-r--r--kernel/tracepoint.c14
7 files changed, 49 insertions, 45 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 9d3dcfa..c05b44b 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -51,8 +51,8 @@
#include "compat_ptrace.h"
#endif
-DEFINE_TRACE(syscall_enter);
-DEFINE_TRACE(syscall_exit);
+DEFINE_TRACE_FN(syscall_enter, syscall_regfunc, syscall_unregfunc);
+DEFINE_TRACE_FN(syscall_exit, syscall_regfunc, syscall_unregfunc);
enum s390_regset {
REGSET_GENERAL,
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index a909afe..31e9b97 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -37,8 +37,8 @@
#include <trace/syscall.h>
-DEFINE_TRACE(syscall_enter);
-DEFINE_TRACE(syscall_exit);
+DEFINE_TRACE_FN(syscall_enter, syscall_regfunc, syscall_unregfunc);
+DEFINE_TRACE_FN(syscall_exit, syscall_regfunc, syscall_unregfunc);
#include "tls.h"
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 5984ed0..846a4ae 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -23,6 +23,8 @@ struct tracepoint;
struct tracepoint {
const char *name; /* Tracepoint name */
int state; /* State. */
+ void (*regfunc)(void);
+ void (*unregfunc)(void);
void **funcs;
} __attribute__((aligned(32))); /*
* Aligned on 32 bytes because it is
@@ -60,10 +62,8 @@ struct tracepoint {
* Make sure the alignment of the structure in the __tracepoints section will
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
- * An optional set of (un)registration functions can be passed to perform any
- * additional (un)registration work.
*/
-#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \
+#define DECLARE_TRACE(name, proto, args) \
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
@@ -73,36 +73,23 @@ struct tracepoint {
} \
static inline int register_trace_##name(void (*probe)(proto)) \
{ \
- int ret; \
- void (*func)(void) = reg; \
- \
- ret = tracepoint_probe_register(#name, (void *)probe); \
- if (func && !ret) \
- func(); \
- return ret; \
+ return tracepoint_probe_register(#name, (void *)probe); \
} \
static inline int unregister_trace_##name(void (*probe)(proto)) \
{ \
- int ret; \
- void (*func)(void) = unreg; \
- \
- ret = tracepoint_probe_unregister(#name, (void *)probe);\
- if (func && !ret) \
- func(); \
- return ret; \
+ return tracepoint_probe_unregister(#name, (void *)probe);\
}
-#define DECLARE_TRACE(name, proto, args) \
- DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args),\
- NULL, NULL);
-
-#define DEFINE_TRACE(name) \
+#define DEFINE_TRACE_FN(name, reg, unreg) \
static const char __tpstrtab_##name[] \
__attribute__((section("__tracepoints_strings"))) = #name; \
struct tracepoint __tracepoint_##name \
__attribute__((section("__tracepoints"), aligned(32))) = \
- { __tpstrtab_##name, 0, NULL }
+ { __tpstrtab_##name, 0, reg, unreg, NULL }
+
+#define DEFINE_TRACE(name) \
+ DEFINE_TRACE_FN(name, NULL, NULL);
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
EXPORT_SYMBOL_GPL(__tracepoint_##name)
@@ -113,7 +100,7 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end);
#else /* !CONFIG_TRACEPOINTS */
-#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \
+#define DECLARE_TRACE(name, proto, args) \
static inline void _do_trace_##name(struct tracepoint *tp, proto) \
{ } \
static inline void trace_##name(proto) \
@@ -127,10 +114,7 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
return -ENOSYS; \
}
-#define DECLARE_TRACE(name, proto, args) \
- DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args),\
- NULL, NULL);
-
+#define DEFINE_TRACE_FN(name, reg, unreg)
#define DEFINE_TRACE(name)
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)
@@ -282,10 +266,16 @@ static inline void tracepoint_synchronize_unregister(void)
* can also by used by generic instrumentation like SystemTap), and
* it is also used to expose a structured trace record in
* /sys/kernel/debug/tracing/events/.
+ *
+ * A set of (un)registration functions can be passed to the variant
+ * TRACE_EVENT_FN to perform any (un)registration work.
*/
#define TRACE_EVENT(name, proto, args, struct, assign, print) \
DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN(name, proto, args, struct, \
+ assign, print, reg, unreg) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#endif
#endif
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index f7a7ae1..2a96985 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -26,6 +26,11 @@
#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
DEFINE_TRACE(name)
+#undef TRACE_EVENT_FN
+#define TRACE_EVENT_FN(name, proto, args, tstruct, \
+ assign, print, reg, unreg) \
+ DEFINE_TRACE_FN(name, reg, unreg)
+
#undef DECLARE_TRACE
#define DECLARE_TRACE(name, proto, args) \
DEFINE_TRACE(name)
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 1274002..3a0b44b 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -42,6 +42,15 @@
}; \
static struct ftrace_event_call event_##name
+/* Callbacks are meaningless to ftrace. */
+#undef TRACE_EVENT_FN
+#define TRACE_EVENT_FN(name, proto, args, tstruct, \
+ assign, print, reg, unreg) \
+ TRACE_EVENT(name, TP_PROTO(proto), TP_ARGS(args), \
+ TP_STRUCT__entry(tstruct), \
+ TP_fast_assign(assign), \
+ TP_printk(print))
+
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
diff --git a/include/trace/syscall.h b/include/trace/syscall.h
index 5dcb7e3..4e19430 100644
--- a/include/trace/syscall.h
+++ b/include/trace/syscall.h
@@ -13,18 +13,14 @@
extern void syscall_regfunc(void);
extern void syscall_unregfunc(void);
-DECLARE_TRACE_WITH_CALLBACK(syscall_enter,
+DECLARE_TRACE(syscall_enter,
TP_PROTO(struct pt_regs *regs, long id),
- TP_ARGS(regs, id),
- syscall_regfunc,
- syscall_unregfunc
+ TP_ARGS(regs, id)
);
-DECLARE_TRACE_WITH_CALLBACK(syscall_exit,
+DECLARE_TRACE(syscall_exit,
TP_PROTO(struct pt_regs *regs, long ret),
- TP_ARGS(regs, ret),
- syscall_regfunc,
- syscall_unregfunc
+ TP_ARGS(regs, ret)
);
#endif
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 9e0a36f..1a6a453 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -243,6 +243,11 @@ static void set_tracepoint(struct tracepoint_entry **entry,
{
WARN_ON(strcmp((*entry)->name, elem->name) != 0);
+ if (elem->regfunc && !elem->state && active)
+ elem->regfunc();
+ else if (elem->unregfunc && elem->state && !active)
+ elem->unregfunc();
+
/*
* rcu_assign_pointer has a smp_wmb() which makes sure that the new
* probe callbacks array is consistent before setting a pointer to it.
@@ -262,6 +267,9 @@ static void set_tracepoint(struct tracepoint_entry **entry,
*/
static void disable_tracepoint(struct tracepoint *elem)
{
+ if (elem->unregfunc && elem->state)
+ elem->unregfunc();
+
elem->state = 0;
rcu_assign_pointer(elem->funcs, NULL);
}
@@ -578,7 +586,7 @@ __initcall(init_tracepoints);
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
-static DEFINE_MUTEX(regfunc_mutex);
+/* NB: reg/unreg are called while guarded with the tracepoints_mutex */
static int sys_tracepoint_refcount;
void syscall_regfunc(void)
@@ -586,7 +594,6 @@ void syscall_regfunc(void)
unsigned long flags;
struct task_struct *g, *t;
- mutex_lock(&regfunc_mutex);
if (!sys_tracepoint_refcount) {
read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, t) {
@@ -595,7 +602,6 @@ void syscall_regfunc(void)
read_unlock_irqrestore(&tasklist_lock, flags);
}
sys_tracepoint_refcount++;
- mutex_unlock(&regfunc_mutex);
}
void syscall_unregfunc(void)
@@ -603,7 +609,6 @@ void syscall_unregfunc(void)
unsigned long flags;
struct task_struct *g, *t;
- mutex_lock(&regfunc_mutex);
sys_tracepoint_refcount--;
if (!sys_tracepoint_refcount) {
read_lock_irqsave(&tasklist_lock, flags);
@@ -612,6 +617,5 @@ void syscall_unregfunc(void)
} while_each_thread(g, t);
read_unlock_irqrestore(&tasklist_lock, flags);
}
- mutex_unlock(&regfunc_mutex);
}
#endif
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