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Subject[PATCH 1/2 v2] tracing/kprobes: Add trace event trigger invocations
Date
Add code to the kprobe/kretprobe event functions that will invoke any
event triggers associated with a probe's ftrace_event_file.

The code to do this is very similar to the invocation code already
used to invoke the triggers associated with static events and
essentially replaces the existing soft-disable checks with a superset
that preserves the original behavior but adds the bits needed to
support event triggers.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/trace/trace_kprobe.c | 42 ++++++++++++++++++++++++++++++++++++------
1 file changed, 36 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index ce0ed8a..3afa716 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -929,12 +929,20 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
struct ring_buffer *buffer;
int size, dsize, pc;
unsigned long irq_flags;
+ unsigned long eflags;
+ enum event_trigger_type tt = ETT_NONE;
struct ftrace_event_call *call = &tk->tp.call;

WARN_ON(call != ftrace_file->event_call);

- if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
- return;
+ eflags = ftrace_file->flags;
+
+ if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+ event_triggers_call(ftrace_file, NULL);
+ if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ return;
+ }

local_save_flags(irq_flags);
pc = preempt_count();
@@ -952,9 +960,16 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
entry->ip = (unsigned long)tk->rp.kp.addr;
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);

- if (!filter_check_discard(ftrace_file, entry, buffer, event))
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+ tt = event_triggers_call(ftrace_file, entry);
+
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+ ring_buffer_discard_commit(buffer, event);
+ else if (!filter_check_discard(ftrace_file, entry, buffer, event))
trace_buffer_unlock_commit_regs(buffer, event,
irq_flags, pc, regs);
+ if (tt)
+ event_triggers_post_call(ftrace_file, tt);
}

static __kprobes void
@@ -977,12 +992,20 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct ring_buffer *buffer;
int size, pc, dsize;
unsigned long irq_flags;
+ unsigned long eflags;
+ enum event_trigger_type tt = ETT_NONE;
struct ftrace_event_call *call = &tk->tp.call;

WARN_ON(call != ftrace_file->event_call);

- if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
- return;
+ eflags = ftrace_file->flags;
+
+ if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+ event_triggers_call(ftrace_file, NULL);
+ if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ return;
+ }

local_save_flags(irq_flags);
pc = preempt_count();
@@ -1001,9 +1024,16 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
entry->ret_ip = (unsigned long)ri->ret_addr;
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);

- if (!filter_check_discard(ftrace_file, entry, buffer, event))
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+ tt = event_triggers_call(ftrace_file, entry);
+
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+ ring_buffer_discard_commit(buffer, event);
+ else if (!filter_check_discard(ftrace_file, entry, buffer, event))
trace_buffer_unlock_commit_regs(buffer, event,
irq_flags, pc, regs);
+ if (tt)
+ event_triggers_post_call(ftrace_file, tt);
}

static __kprobes void
--
1.8.3.1


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