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authorOleg Nesterov <oleg@redhat.com>2013-02-04 17:48:34 +0100
committerOleg Nesterov <oleg@redhat.com>2013-02-08 18:28:07 +0100
commitf42d24a1d20d2e72d1e5d48930f18b138dfad117 (patch)
tree10696fc2f0a21d60a7fb1581efecd172435f0408 /kernel/trace/trace_uprobe.c
parent31ba334836c0ac0039084859f14a5b96858493dc (diff)
downloadop-kernel-dev-f42d24a1d20d2e72d1e5d48930f18b138dfad117.zip
op-kernel-dev-f42d24a1d20d2e72d1e5d48930f18b138dfad117.tar.gz
uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE
Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change uprobe_dispatcher() to return "trace_ret | perf_ret" although this is not needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive. The only functional change is that uprobe_perf_func() checks the filtering too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current. Testing: # perf probe -x /lib/libc.so.6 syscall # perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 20 A child process doesn't have a counter, but still it hits this breakoint "copied" by dup_mmap(). After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 11 The child process hits this int3 only once and does unapply_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'kernel/trace/trace_uprobe.c')
-rw-r--r--kernel/trace/trace_uprobe.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b7850f5..2399f14 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -486,7 +486,7 @@ static const struct file_operations uprobe_profile_ops = {
};
/* uprobe handler */
-static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
+static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
{
struct uprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
@@ -504,7 +504,7 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
size, irq_flags, pc);
if (!event)
- return;
+ return 0;
entry = ring_buffer_event_data(event);
entry->ip = instruction_pointer(task_pt_regs(current));
@@ -514,6 +514,8 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
if (!filter_current_check_discard(buffer, call, entry, event))
trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+
+ return 0;
}
/* Event entry printers */
@@ -721,7 +723,7 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc,
}
/* uprobe profile handler */
-static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
+static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
{
struct ftrace_event_call *call = &tu->call;
struct uprobe_trace_entry_head *entry;
@@ -730,11 +732,14 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
int size, __size, i;
int rctx;
+ if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
+ return UPROBE_HANDLER_REMOVE;
+
__size = sizeof(*entry) + tu->size;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
- return;
+ return 0;
preempt_disable();
@@ -752,6 +757,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
out:
preempt_enable();
+ return 0;
}
#endif /* CONFIG_PERF_EVENTS */
@@ -792,18 +798,19 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
{
struct trace_uprobe *tu;
+ int ret = 0;
tu = container_of(con, struct trace_uprobe, consumer);
tu->nhit++;
if (tu->flags & TP_FLAG_TRACE)
- uprobe_trace_func(tu, regs);
+ ret |= uprobe_trace_func(tu, regs);
#ifdef CONFIG_PERF_EVENTS
if (tu->flags & TP_FLAG_PROFILE)
- uprobe_perf_func(tu, regs);
+ ret |= uprobe_perf_func(tu, regs);
#endif
- return 0;
+ return ret;
}
static struct trace_event_functions uprobe_funcs = {
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