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Diffstat (limited to 'kernel/trace/trace_uprobe.c')
-rw-r--r--kernel/trace/trace_uprobe.c107
1 files changed, 63 insertions, 44 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 9e461362450a..c98e3b3386ba 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -854,6 +854,7 @@ static const struct file_operations uprobe_profile_ops = {
struct uprobe_cpu_buffer {
struct mutex mutex;
void *buf;
+ int dsize;
};
static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
static int uprobe_buffer_refcnt;
@@ -940,12 +941,36 @@ static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
{
+ if (!ucb)
+ return;
mutex_unlock(&ucb->mutex);
}
+static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu,
+ struct pt_regs *regs,
+ struct uprobe_cpu_buffer **ucbp)
+{
+ struct uprobe_cpu_buffer *ucb;
+ int dsize, esize;
+
+ if (*ucbp)
+ return *ucbp;
+
+ esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+ dsize = __get_data_size(&tu->tp, regs, NULL);
+
+ ucb = uprobe_buffer_get();
+ ucb->dsize = tu->tp.size + dsize;
+
+ store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
+
+ *ucbp = ucb;
+ return ucb;
+}
+
static void __uprobe_trace_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
- struct uprobe_cpu_buffer *ucb, int dsize,
+ struct uprobe_cpu_buffer *ucb,
struct trace_event_file *trace_file)
{
struct uprobe_trace_entry_head *entry;
@@ -956,14 +981,14 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
WARN_ON(call != trace_file->event_call);
- if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
+ if (WARN_ON_ONCE(ucb->dsize > PAGE_SIZE))
return;
if (trace_trigger_soft_disabled(trace_file))
return;
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
- size = esize + tu->tp.size + dsize;
+ size = esize + ucb->dsize;
entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
if (!entry)
return;
@@ -977,23 +1002,26 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
data = DATAOF_TRACE_ENTRY(entry, false);
}
- memcpy(data, ucb->buf, tu->tp.size + dsize);
+ memcpy(data, ucb->buf, ucb->dsize);
trace_event_buffer_commit(&fbuffer);
}
/* uprobe handler */
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
- struct uprobe_cpu_buffer *ucb, int dsize)
+ struct uprobe_cpu_buffer **ucbp)
{
struct event_file_link *link;
+ struct uprobe_cpu_buffer *ucb;
if (is_ret_probe(tu))
return 0;
+ ucb = prepare_uprobe_buffer(tu, regs, ucbp);
+
rcu_read_lock();
trace_probe_for_each_link_rcu(link, &tu->tp)
- __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
+ __uprobe_trace_func(tu, 0, regs, ucb, link->file);
rcu_read_unlock();
return 0;
@@ -1001,13 +1029,16 @@ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs,
- struct uprobe_cpu_buffer *ucb, int dsize)
+ struct uprobe_cpu_buffer **ucbp)
{
struct event_file_link *link;
+ struct uprobe_cpu_buffer *ucb;
+
+ ucb = prepare_uprobe_buffer(tu, regs, ucbp);
rcu_read_lock();
trace_probe_for_each_link_rcu(link, &tu->tp)
- __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
+ __uprobe_trace_func(tu, func, regs, ucb, link->file);
rcu_read_unlock();
}
@@ -1199,9 +1230,6 @@ __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
{
struct perf_event *event;
- if (filter->nr_systemwide)
- return true;
-
list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
if (event->hw.target->mm == mm)
return true;
@@ -1326,6 +1354,13 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc,
tu = container_of(uc, struct trace_uprobe, consumer);
filter = tu->tp.event->filter;
+ /*
+ * speculative short-circuiting check to avoid unnecessarily taking
+ * filter->rwlock below, if the uprobe has system-wide consumer
+ */
+ if (READ_ONCE(filter->nr_systemwide))
+ return true;
+
read_lock(&filter->rwlock);
ret = __uprobe_perf_filter(filter, mm);
read_unlock(&filter->rwlock);
@@ -1335,10 +1370,11 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc,
static void __uprobe_perf_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
- struct uprobe_cpu_buffer *ucb, int dsize)
+ struct uprobe_cpu_buffer **ucbp)
{
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
struct uprobe_trace_entry_head *entry;
+ struct uprobe_cpu_buffer *ucb;
struct hlist_head *head;
void *data;
int size, esize;
@@ -1356,7 +1392,8 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
- size = esize + tu->tp.size + dsize;
+ ucb = prepare_uprobe_buffer(tu, regs, ucbp);
+ size = esize + ucb->dsize;
size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
return;
@@ -1379,13 +1416,10 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
data = DATAOF_TRACE_ENTRY(entry, false);
}
- memcpy(data, ucb->buf, tu->tp.size + dsize);
-
- if (size - esize > tu->tp.size + dsize) {
- int len = tu->tp.size + dsize;
+ memcpy(data, ucb->buf, ucb->dsize);
- memset(data + len, 0, size - esize - len);
- }
+ if (size - esize > ucb->dsize)
+ memset(data + ucb->dsize, 0, size - esize - ucb->dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
@@ -1395,21 +1429,21 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
/* uprobe profile handler */
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
- struct uprobe_cpu_buffer *ucb, int dsize)
+ struct uprobe_cpu_buffer **ucbp)
{
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
return UPROBE_HANDLER_REMOVE;
if (!is_ret_probe(tu))
- __uprobe_perf_func(tu, 0, regs, ucb, dsize);
+ __uprobe_perf_func(tu, 0, regs, ucbp);
return 0;
}
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs,
- struct uprobe_cpu_buffer *ucb, int dsize)
+ struct uprobe_cpu_buffer **ucbp)
{
- __uprobe_perf_func(tu, func, regs, ucb, dsize);
+ __uprobe_perf_func(tu, func, regs, ucbp);
}
int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
@@ -1474,11 +1508,9 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
{
struct trace_uprobe *tu;
struct uprobe_dispatch_data udd;
- struct uprobe_cpu_buffer *ucb;
- int dsize, esize;
+ struct uprobe_cpu_buffer *ucb = NULL;
int ret = 0;
-
tu = container_of(con, struct trace_uprobe, consumer);
tu->nhit++;
@@ -1490,18 +1522,12 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
- dsize = __get_data_size(&tu->tp, regs, NULL);
- esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
-
- ucb = uprobe_buffer_get();
- store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
-
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
- ret |= uprobe_trace_func(tu, regs, ucb, dsize);
+ ret |= uprobe_trace_func(tu, regs, &ucb);
#ifdef CONFIG_PERF_EVENTS
if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
- ret |= uprobe_perf_func(tu, regs, ucb, dsize);
+ ret |= uprobe_perf_func(tu, regs, &ucb);
#endif
uprobe_buffer_put(ucb);
return ret;
@@ -1512,8 +1538,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
{
struct trace_uprobe *tu;
struct uprobe_dispatch_data udd;
- struct uprobe_cpu_buffer *ucb;
- int dsize, esize;
+ struct uprobe_cpu_buffer *ucb = NULL;
tu = container_of(con, struct trace_uprobe, consumer);
@@ -1525,18 +1550,12 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
- dsize = __get_data_size(&tu->tp, regs, NULL);
- esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
-
- ucb = uprobe_buffer_get();
- store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
-
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
- uretprobe_trace_func(tu, func, regs, ucb, dsize);
+ uretprobe_trace_func(tu, func, regs, &ucb);
#ifdef CONFIG_PERF_EVENTS
if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
- uretprobe_perf_func(tu, func, regs, ucb, dsize);
+ uretprobe_perf_func(tu, func, regs, &ucb);
#endif
uprobe_buffer_put(ucb);
return 0;
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