tracing/uprobes: Support ftrace_event_file base multibuffer
Support multi-buffer on uprobe-based dynamic events by
using ftrace_event_file.
This patch is based kprobe-based dynamic events multibuffer
support work initially, commited by Masami(commit 41a7dd420c),
but revised as below:
Oleg changed the kprobe-based multibuffer design from
array-pointers of ftrace_event_file into simple list,
so this patch also change to the list design.
rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
to synchronize with ftrace_event_file list add and delete.
Even though we allow multi-uprobes instances now,
but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
in probe_event_enable currently, this means we cannot allow
one user is using uprobe-tracer, and another user is using
perf-probe on same uprobe concurrently.
(Perhaps this will be fix in future, kprobe don't have this
limitation now)
Link: http://lkml.kernel.org/r/1389946120-19610-4-git-send-email-namhyung@kernel.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
zhangwei(Jovi)
Steven Rostedt
Родитель
dd9fa555d7
Коммит
70ed91c6ec
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@ -35,11 +35,6 @@ struct trace_kprobe {
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struct trace_probe tp;
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};
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struct event_file_link {
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struct ftrace_event_file *file;
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struct list_head list;
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};
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#define SIZEOF_TRACE_KPROBE(n) \
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(offsetof(struct trace_kprobe, tp.args) + \
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(sizeof(struct probe_arg) * (n)))
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@ -387,18 +382,6 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct ftrace_event_file *file)
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return ret;
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}
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static struct event_file_link *
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find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file)
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{
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struct event_file_link *link;
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list_for_each_entry(link, &tp->files, list)
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if (link->file == file)
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return link;
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return NULL;
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}
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/*
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* Disable trace_probe
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* if the file is NULL, disable "perf" handler, or disable "trace" handler.
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@ -288,6 +288,11 @@ struct trace_probe {
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struct probe_arg args[];
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};
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struct event_file_link {
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struct ftrace_event_file *file;
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struct list_head list;
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};
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static inline bool trace_probe_is_enabled(struct trace_probe *tp)
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{
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return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
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@ -316,6 +321,18 @@ static inline int is_good_name(const char *name)
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return 1;
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}
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static inline struct event_file_link *
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find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file)
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{
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struct event_file_link *link;
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list_for_each_entry(link, &tp->files, list)
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if (link->file == file)
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return link;
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return NULL;
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}
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extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
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struct probe_arg *parg, bool is_return, bool is_kprobe);
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@ -260,6 +260,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
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goto error;
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INIT_LIST_HEAD(&tu->list);
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INIT_LIST_HEAD(&tu->tp.files);
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tu->consumer.handler = uprobe_dispatcher;
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if (is_ret)
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tu->consumer.ret_handler = uretprobe_dispatcher;
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@ -760,7 +761,8 @@ static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
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static void __uprobe_trace_func(struct trace_uprobe *tu,
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unsigned long func, struct pt_regs *regs,
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struct uprobe_cpu_buffer *ucb, int dsize)
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struct uprobe_cpu_buffer *ucb, int dsize,
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struct ftrace_event_file *ftrace_file)
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{
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struct uprobe_trace_entry_head *entry;
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struct ring_buffer_event *event;
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@ -769,13 +771,15 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
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int size, esize;
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struct ftrace_event_call *call = &tu->tp.call;
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WARN_ON(call != ftrace_file->event_call);
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if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
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return;
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esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
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size = esize + tu->tp.size + dsize;
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event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
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size, 0, 0);
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event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
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call->event.type, size, 0, 0);
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if (!event)
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return;
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@ -799,8 +803,16 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
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static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
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struct uprobe_cpu_buffer *ucb, int dsize)
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{
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if (!is_ret_probe(tu))
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__uprobe_trace_func(tu, 0, regs, ucb, dsize);
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struct event_file_link *link;
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if (is_ret_probe(tu))
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return 0;
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rcu_read_lock();
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list_for_each_entry_rcu(link, &tu->tp.files, list)
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__uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
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rcu_read_unlock();
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return 0;
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}
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@ -808,7 +820,12 @@ static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
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struct pt_regs *regs,
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struct uprobe_cpu_buffer *ucb, int dsize)
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{
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__uprobe_trace_func(tu, func, regs, ucb, dsize);
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struct event_file_link *link;
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rcu_read_lock();
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list_for_each_entry_rcu(link, &tu->tp.files, list)
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__uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
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rcu_read_unlock();
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}
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/* Event entry printers */
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@ -855,37 +872,81 @@ typedef bool (*filter_func_t)(struct uprobe_consumer *self,
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struct mm_struct *mm);
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static int
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probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
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probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
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filter_func_t filter)
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{
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int ret = 0;
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bool enabled = trace_probe_is_enabled(&tu->tp);
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struct event_file_link *link = NULL;
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int ret;
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if (trace_probe_is_enabled(&tu->tp))
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if (file) {
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if (tu->tp.flags & TP_FLAG_PROFILE)
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return -EINTR;
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link = kmalloc(sizeof(*link), GFP_KERNEL);
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if (!link)
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return -ENOMEM;
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link->file = file;
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list_add_tail_rcu(&link->list, &tu->tp.files);
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tu->tp.flags |= TP_FLAG_TRACE;
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} else {
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if (tu->tp.flags & TP_FLAG_TRACE)
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return -EINTR;
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tu->tp.flags |= TP_FLAG_PROFILE;
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}
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ret = uprobe_buffer_enable();
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if (ret < 0)
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return ret;
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WARN_ON(!uprobe_filter_is_empty(&tu->filter));
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tu->tp.flags |= flag;
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if (enabled)
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return 0;
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tu->consumer.filter = filter;
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ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
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if (ret)
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tu->tp.flags &= ~flag;
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if (ret) {
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if (file) {
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list_del(&link->list);
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kfree(link);
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tu->tp.flags &= ~TP_FLAG_TRACE;
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} else
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tu->tp.flags &= ~TP_FLAG_PROFILE;
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}
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return ret;
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}
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static void probe_event_disable(struct trace_uprobe *tu, int flag)
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static void
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probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
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{
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if (!trace_probe_is_enabled(&tu->tp))
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return;
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if (file) {
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struct event_file_link *link;
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link = find_event_file_link(&tu->tp, file);
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if (!link)
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return;
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list_del_rcu(&link->list);
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/* synchronize with u{,ret}probe_trace_func */
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synchronize_sched();
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kfree(link);
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if (!list_empty(&tu->tp.files))
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return;
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}
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WARN_ON(!uprobe_filter_is_empty(&tu->filter));
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uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
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tu->tp.flags &= ~flag;
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tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
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uprobe_buffer_disable();
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}
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@ -1077,25 +1138,27 @@ static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
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}
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#endif /* CONFIG_PERF_EVENTS */
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static
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int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
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static int
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trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
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void *data)
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{
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struct trace_uprobe *tu = event->data;
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struct ftrace_event_file *file = data;
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switch (type) {
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case TRACE_REG_REGISTER:
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return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
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return probe_event_enable(tu, file, NULL);
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case TRACE_REG_UNREGISTER:
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probe_event_disable(tu, TP_FLAG_TRACE);
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probe_event_disable(tu, file);
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return 0;
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#ifdef CONFIG_PERF_EVENTS
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case TRACE_REG_PERF_REGISTER:
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return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
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return probe_event_enable(tu, NULL, uprobe_perf_filter);
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case TRACE_REG_PERF_UNREGISTER:
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probe_event_disable(tu, TP_FLAG_PROFILE);
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probe_event_disable(tu, NULL);
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return 0;
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case TRACE_REG_PERF_OPEN:
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