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Diffstat (limited to 'kernel/trace/bpf_trace.c')
-rw-r--r--kernel/trace/bpf_trace.c59
1 files changed, 58 insertions, 1 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 40207c2a4113..fc2838ac8b78 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -13,6 +13,10 @@
#include <linux/filter.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>
+#include <linux/kprobes.h>
+#include <linux/error-injection.h>
+
+#include "trace_probe.h"
#include "trace.h"
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
@@ -76,6 +80,23 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
}
EXPORT_SYMBOL_GPL(trace_call_bpf);
+#ifdef CONFIG_BPF_KPROBE_OVERRIDE
+BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
+{
+ regs_set_return_value(regs, rc);
+ override_function_with_return(regs);
+ return 0;
+}
+
+static const struct bpf_func_proto bpf_override_return_proto = {
+ .func = bpf_override_return,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+};
+#endif
+
BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
{
int ret;
@@ -224,7 +245,7 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
*/
#define __BPF_TP_EMIT() __BPF_ARG3_TP()
#define __BPF_TP(...) \
- __trace_printk(1 /* Fake ip will not be printed. */, \
+ __trace_printk(0 /* Fake ip */, \
fmt, ##__VA_ARGS__)
#define __BPF_ARG1_TP(...) \
@@ -556,6 +577,10 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func
return &bpf_get_stackid_proto;
case BPF_FUNC_perf_event_read_value:
return &bpf_perf_event_read_value_proto;
+#ifdef CONFIG_BPF_KPROBE_OVERRIDE
+ case BPF_FUNC_override_return:
+ return &bpf_override_return_proto;
+#endif
default:
return tracing_func_proto(func_id);
}
@@ -773,6 +798,15 @@ int perf_event_attach_bpf_prog(struct perf_event *event,
struct bpf_prog_array *new_array;
int ret = -EEXIST;
+ /*
+ * Kprobe override only works if they are on the function entry,
+ * and only if they are on the opt-in list.
+ */
+ if (prog->kprobe_override &&
+ (!trace_kprobe_on_func_entry(event->tp_event) ||
+ !trace_kprobe_error_injectable(event->tp_event)))
+ return -EINVAL;
+
mutex_lock(&bpf_event_mutex);
if (event->prog)
@@ -825,3 +859,26 @@ void perf_event_detach_bpf_prog(struct perf_event *event)
unlock:
mutex_unlock(&bpf_event_mutex);
}
+
+int perf_event_query_prog_array(struct perf_event *event, void __user *info)
+{
+ struct perf_event_query_bpf __user *uquery = info;
+ struct perf_event_query_bpf query = {};
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (event->attr.type != PERF_TYPE_TRACEPOINT)
+ return -EINVAL;
+ if (copy_from_user(&query, uquery, sizeof(query)))
+ return -EFAULT;
+
+ mutex_lock(&bpf_event_mutex);
+ ret = bpf_prog_array_copy_info(event->tp_event->prog_array,
+ uquery->ids,
+ query.ids_len,
+ &uquery->prog_cnt);
+ mutex_unlock(&bpf_event_mutex);
+
+ return ret;
+}