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authorIngo Molnar <mingo@elte.hu>2010-11-18 20:07:12 +0100
committerIngo Molnar <mingo@elte.hu>2010-11-18 20:07:12 +0100
commitae51ce9061b1ddc0fde363913c932bee5b9bc5fd (patch)
tree40fd3d633714d2a53fdbd2bdd172fb61232d999a
parent072b198a4ad48bd722ec6d203d65422a4698eae7 (diff)
parent423478cde453eebdfcfebf4b8d378d8f5d49b853 (diff)
Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core
-rw-r--r--arch/x86/include/asm/kdebug.h2
-rw-r--r--arch/x86/include/asm/stacktrace.h33
-rw-r--r--arch/x86/kernel/cpu/perf_event.c2
-rw-r--r--arch/x86/kernel/dumpstack.c12
-rw-r--r--arch/x86/kernel/dumpstack_32.c25
-rw-r--r--arch/x86/kernel/dumpstack_64.c24
-rw-r--r--arch/x86/kernel/process.c3
-rw-r--r--arch/x86/kernel/stacktrace.c8
-rw-r--r--arch/x86/mm/kmemcheck/error.c2
-rw-r--r--arch/x86/oprofile/backtrace.c2
-rw-r--r--include/linux/ftrace_event.h10
-rw-r--r--include/linux/stacktrace.h4
-rw-r--r--include/linux/syscalls.h10
-rw-r--r--include/linux/tracepoint.h4
-rw-r--r--include/trace/events/syscalls.h4
-rw-r--r--include/trace/ftrace.h7
-rw-r--r--kernel/perf_event.c9
-rw-r--r--kernel/trace/trace_event_perf.c31
18 files changed, 121 insertions, 71 deletions
diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
index 5bdfca86581b..f23eb2528464 100644
--- a/arch/x86/include/asm/kdebug.h
+++ b/arch/x86/include/asm/kdebug.h
@@ -28,7 +28,7 @@ extern void die(const char *, struct pt_regs *,long);
extern int __must_check __die(const char *, struct pt_regs *, long);
extern void show_registers(struct pt_regs *regs);
extern void show_trace(struct task_struct *t, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp);
+ unsigned long *sp);
extern void __show_regs(struct pt_regs *regs, int all);
extern void show_regs(struct pt_regs *regs);
extern unsigned long oops_begin(void);
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 2b16a2ad23dc..52b5c7ed3608 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -7,6 +7,7 @@
#define _ASM_X86_STACKTRACE_H
#include <linux/uaccess.h>
+#include <linux/ptrace.h>
extern int kstack_depth_to_print;
@@ -46,7 +47,7 @@ struct stacktrace_ops {
};
void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
+ unsigned long *stack,
const struct stacktrace_ops *ops, void *data);
#ifdef CONFIG_X86_32
@@ -57,13 +58,39 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
#endif
+#ifdef CONFIG_FRAME_POINTER
+static inline unsigned long
+stack_frame(struct task_struct *task, struct pt_regs *regs)
+{
+ unsigned long bp;
+
+ if (regs)
+ return regs->bp;
+
+ if (task == current) {
+ /* Grab bp right from our regs */
+ get_bp(bp);
+ return bp;
+ }
+
+ /* bp is the last reg pushed by switch_to */
+ return *(unsigned long *)task->thread.sp;
+}
+#else
+static inline unsigned long
+stack_frame(struct task_struct *task, struct pt_regs *regs)
+{
+ return 0;
+}
+#endif
+
extern void
show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp, char *log_lvl);
+ unsigned long *stack, char *log_lvl);
extern void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl);
+ unsigned long *sp, char *log_lvl);
extern unsigned int code_bytes;
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 1f129a14e3a2..5273c7b90b8b 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1657,7 +1657,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
perf_callchain_store(entry, regs->ip);
- dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry);
+ dump_trace(NULL, regs, NULL, &backtrace_ops, entry);
}
#ifdef CONFIG_COMPAT
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 6e8752c1bd52..8474c998cbd4 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -175,21 +175,21 @@ static const struct stacktrace_ops print_trace_ops = {
void
show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp, char *log_lvl)
+ unsigned long *stack, char *log_lvl)
{
printk("%sCall Trace:\n", log_lvl);
- dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
+ dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
}
void show_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp)
+ unsigned long *stack)
{
- show_trace_log_lvl(task, regs, stack, bp, "");
+ show_trace_log_lvl(task, regs, stack, "");
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
- show_stack_log_lvl(task, NULL, sp, 0, "");
+ show_stack_log_lvl(task, NULL, sp, "");
}
/*
@@ -210,7 +210,7 @@ void dump_stack(void)
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
- show_trace(NULL, NULL, &stack, bp);
+ show_trace(NULL, NULL, &stack);
}
EXPORT_SYMBOL(dump_stack);
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 1bc7f75a5bda..74cc1eda384b 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -17,11 +17,12 @@
#include <asm/stacktrace.h>
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
+void dump_trace(struct task_struct *task,
+ struct pt_regs *regs, unsigned long *stack,
const struct stacktrace_ops *ops, void *data)
{
int graph = 0;
+ unsigned long bp;
if (!task)
task = current;
@@ -34,18 +35,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
stack = (unsigned long *)task->thread.sp;
}
-#ifdef CONFIG_FRAME_POINTER
- if (!bp) {
- if (task == current) {
- /* Grab bp right from our regs */
- get_bp(bp);
- } else {
- /* bp is the last reg pushed by switch_to */
- bp = *(unsigned long *) task->thread.sp;
- }
- }
-#endif
-
+ bp = stack_frame(task, regs);
for (;;) {
struct thread_info *context;
@@ -65,7 +55,7 @@ EXPORT_SYMBOL(dump_trace);
void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+ unsigned long *sp, char *log_lvl)
{
unsigned long *stack;
int i;
@@ -87,7 +77,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
touch_nmi_watchdog();
}
printk(KERN_CONT "\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
}
@@ -112,8 +102,7 @@ void show_registers(struct pt_regs *regs)
u8 *ip;
printk(KERN_EMERG "Stack:\n");
- show_stack_log_lvl(NULL, regs, &regs->sp,
- 0, KERN_EMERG);
+ show_stack_log_lvl(NULL, regs, &regs->sp, KERN_EMERG);
printk(KERN_EMERG "Code: ");
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 6a340485249a..64101335de19 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -139,8 +139,8 @@ fixup_bp_irq_link(unsigned long bp, unsigned long *stack,
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
+void dump_trace(struct task_struct *task,
+ struct pt_regs *regs, unsigned long *stack,
const struct stacktrace_ops *ops, void *data)
{
const unsigned cpu = get_cpu();
@@ -149,6 +149,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
unsigned used = 0;
struct thread_info *tinfo;
int graph = 0;
+ unsigned long bp;
if (!task)
task = current;
@@ -160,18 +161,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
stack = (unsigned long *)task->thread.sp;
}
-#ifdef CONFIG_FRAME_POINTER
- if (!bp) {
- if (task == current) {
- /* Grab bp right from our regs */
- get_bp(bp);
- } else {
- /* bp is the last reg pushed by switch_to */
- bp = *(unsigned long *) task->thread.sp;
- }
- }
-#endif
-
+ bp = stack_frame(task, regs);
/*
* Print function call entries in all stacks, starting at the
* current stack address. If the stacks consist of nested
@@ -235,7 +225,7 @@ EXPORT_SYMBOL(dump_trace);
void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+ unsigned long *sp, char *log_lvl)
{
unsigned long *irq_stack_end;
unsigned long *irq_stack;
@@ -279,7 +269,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
preempt_enable();
printk(KERN_CONT "\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
}
void show_registers(struct pt_regs *regs)
@@ -308,7 +298,7 @@ void show_registers(struct pt_regs *regs)
printk(KERN_EMERG "Stack:\n");
show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
- regs->bp, KERN_EMERG);
+ KERN_EMERG);
printk(KERN_EMERG "Code: ");
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 57d1868a86aa..96ed1aac543a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -91,8 +91,7 @@ void exit_thread(void)
void show_regs(struct pt_regs *regs)
{
show_registers(regs);
- show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs),
- regs->bp);
+ show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs));
}
void show_regs_common(void)
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index b53c525368a7..938c8e10a19a 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -73,22 +73,22 @@ static const struct stacktrace_ops save_stack_ops_nosched = {
*/
void save_stack_trace(struct stack_trace *trace)
{
- dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
+ dump_trace(current, NULL, NULL, &save_stack_ops, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
EXPORT_SYMBOL_GPL(save_stack_trace);
-void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp)
+void save_stack_trace_regs(struct stack_trace *trace, struct pt_regs *regs)
{
- dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace);
+ dump_trace(current, regs, NULL, &save_stack_ops, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
- dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
+ dump_trace(tsk, NULL, NULL, &save_stack_ops_nosched, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
diff --git a/arch/x86/mm/kmemcheck/error.c b/arch/x86/mm/kmemcheck/error.c
index af3b6c8a436f..704a37cedddb 100644
--- a/arch/x86/mm/kmemcheck/error.c
+++ b/arch/x86/mm/kmemcheck/error.c
@@ -185,7 +185,7 @@ void kmemcheck_error_save(enum kmemcheck_shadow state,
e->trace.entries = e->trace_entries;
e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
e->trace.skip = 0;
- save_stack_trace_bp(&e->trace, regs->bp);
+ save_stack_trace_regs(&e->trace, regs);
/* Round address down to nearest 16 bytes */
shadow_copy = kmemcheck_shadow_lookup(address
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index 2d49d4e19a36..72cbec14d783 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -126,7 +126,7 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
if (!user_mode_vm(regs)) {
unsigned long stack = kernel_stack_pointer(regs);
if (depth)
- dump_trace(NULL, regs, (unsigned long *)stack, 0,
+ dump_trace(NULL, regs, (unsigned long *)stack,
&backtrace_ops, &depth);
return;
}
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 8beabb958f61..725bf6bd39f7 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -154,12 +154,14 @@ enum {
TRACE_EVENT_FL_ENABLED_BIT,
TRACE_EVENT_FL_FILTERED_BIT,
TRACE_EVENT_FL_RECORDED_CMD_BIT,
+ TRACE_EVENT_FL_CAP_ANY_BIT,
};
enum {
TRACE_EVENT_FL_ENABLED = (1 << TRACE_EVENT_FL_ENABLED_BIT),
TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
TRACE_EVENT_FL_RECORDED_CMD = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
+ TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
};
struct ftrace_event_call {
@@ -196,6 +198,14 @@ struct ftrace_event_call {
#endif
};
+#define __TRACE_EVENT_FLAGS(name, value) \
+ static int __init trace_init_flags_##name(void) \
+ { \
+ event_##name.flags = value; \
+ return 0; \
+ } \
+ early_initcall(trace_init_flags_##name);
+
#define PERF_MAX_TRACE_SIZE 2048
#define MAX_FILTER_PRED 32
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index 51efbef38fb0..25310f1d7f37 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -2,6 +2,7 @@
#define __LINUX_STACKTRACE_H
struct task_struct;
+struct pt_regs;
#ifdef CONFIG_STACKTRACE
struct task_struct;
@@ -13,7 +14,8 @@ struct stack_trace {
};
extern void save_stack_trace(struct stack_trace *trace);
-extern void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp);
+extern void save_stack_trace_regs(struct stack_trace *trace,
+ struct pt_regs *regs);
extern void save_stack_trace_tsk(struct task_struct *tsk,
struct stack_trace *trace);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index cacc27a0e285..18cd0684fc4e 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -127,8 +127,6 @@ extern struct trace_event_functions exit_syscall_print_funcs;
#define SYSCALL_TRACE_ENTER_EVENT(sname) \
static struct syscall_metadata \
__attribute__((__aligned__(4))) __syscall_meta_##sname; \
- static struct ftrace_event_call \
- __attribute__((__aligned__(4))) event_enter_##sname; \
static struct ftrace_event_call __used \
__attribute__((__aligned__(4))) \
__attribute__((section("_ftrace_events"))) \
@@ -137,13 +135,12 @@ extern struct trace_event_functions exit_syscall_print_funcs;
.class = &event_class_syscall_enter, \
.event.funcs = &enter_syscall_print_funcs, \
.data = (void *)&__syscall_meta_##sname,\
- }
+ }; \
+ __TRACE_EVENT_FLAGS(enter_##sname, TRACE_EVENT_FL_CAP_ANY)
#define SYSCALL_TRACE_EXIT_EVENT(sname) \
static struct syscall_metadata \
__attribute__((__aligned__(4))) __syscall_meta_##sname; \
- static struct ftrace_event_call \
- __attribute__((__aligned__(4))) event_exit_##sname; \
static struct ftrace_event_call __used \
__attribute__((__aligned__(4))) \
__attribute__((section("_ftrace_events"))) \
@@ -152,7 +149,8 @@ extern struct trace_event_functions exit_syscall_print_funcs;
.class = &event_class_syscall_exit, \
.event.funcs = &exit_syscall_print_funcs, \
.data = (void *)&__syscall_meta_##sname,\
- }
+ }; \
+ __TRACE_EVENT_FLAGS(exit_##sname, TRACE_EVENT_FL_CAP_ANY)
#define SYSCALL_METADATA(sname, nb) \
SYSCALL_TRACE_ENTER_EVENT(sname); \
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index a4a90b6726ce..5a6074fcd81d 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -234,6 +234,8 @@ do_trace: \
PARAMS(void *__data, proto), \
PARAMS(__data, args))
+#define TRACE_EVENT_FLAGS(event, flag)
+
#endif /* DECLARE_TRACE */
#ifndef TRACE_EVENT
@@ -354,4 +356,6 @@ do_trace: \
assign, print, reg, unreg) \
DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FLAGS(event, flag)
+
#endif /* ifdef TRACE_EVENT (see note above) */
diff --git a/include/trace/events/syscalls.h b/include/trace/events/syscalls.h
index fb726ac7caee..5a4c04a75b3d 100644
--- a/include/trace/events/syscalls.h
+++ b/include/trace/events/syscalls.h
@@ -40,6 +40,8 @@ TRACE_EVENT_FN(sys_enter,
syscall_regfunc, syscall_unregfunc
);
+TRACE_EVENT_FLAGS(sys_enter, TRACE_EVENT_FL_CAP_ANY)
+
TRACE_EVENT_FN(sys_exit,
TP_PROTO(struct pt_regs *regs, long ret),
@@ -62,6 +64,8 @@ TRACE_EVENT_FN(sys_exit,
syscall_regfunc, syscall_unregfunc
);
+TRACE_EVENT_FLAGS(sys_exit, TRACE_EVENT_FL_CAP_ANY)
+
#endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
#endif /* _TRACE_EVENTS_SYSCALLS_H */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index a9377c0083ad..e718a917d897 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -82,6 +82,10 @@
TRACE_EVENT(name, PARAMS(proto), PARAMS(args), \
PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \
+#undef TRACE_EVENT_FLAGS
+#define TRACE_EVENT_FLAGS(name, value) \
+ __TRACE_EVENT_FLAGS(name, value)
+
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
@@ -129,6 +133,9 @@
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+#undef TRACE_EVENT_FLAGS
+#define TRACE_EVENT_FLAGS(event, flag)
+
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index cb6c0d2af68f..40c3aab648a1 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4773,15 +4773,6 @@ static int perf_tp_event_init(struct perf_event *event)
if (event->attr.type != PERF_TYPE_TRACEPOINT)
return -ENOENT;
- /*
- * Raw tracepoint data is a severe data leak, only allow root to
- * have these.
- */
- if ((event->attr.sample_type & PERF_SAMPLE_RAW) &&
- perf_paranoid_tracepoint_raw() &&
- !capable(CAP_SYS_ADMIN))
- return -EPERM;
-
err = perf_trace_init(event);
if (err)
return err;
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 39c059ca670e..19a359d5e6d5 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -21,17 +21,46 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
/* Count the events in use (per event id, not per instance) */
static int total_ref_count;
+static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
+ struct perf_event *p_event)
+{
+ /* No tracing, just counting, so no obvious leak */
+ if (!(p_event->attr.sample_type & PERF_SAMPLE_RAW))
+ return 0;
+
+ /* Some events are ok to be traced by non-root users... */
+ if (p_event->attach_state == PERF_ATTACH_TASK) {
+ if (tp_event->flags & TRACE_EVENT_FL_CAP_ANY)
+ return 0;
+ }
+
+ /*
+ * ...otherwise raw tracepoint data can be a severe data leak,
+ * only allow root to have these.
+ */
+ if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ return 0;
+}
+
static int perf_trace_event_init(struct ftrace_event_call *tp_event,
struct perf_event *p_event)
{
struct hlist_head __percpu *list;
- int ret = -ENOMEM;
+ int ret;
int cpu;
+ ret = perf_trace_event_perm(tp_event, p_event);
+ if (ret)
+ return ret;
+
p_event->tp_event = tp_event;
if (tp_event->perf_refcount++ > 0)
return 0;
+ ret = -ENOMEM;
+
list = alloc_percpu(struct hlist_head);
if (!list)
goto fail;