ARM: pxa: add memory resource to SA1100 RTC device

[deliverable/linux.git] / kernel / trace / bpf_trace.c

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 88a041adee901f5109c50e560cb5e13fc96f0357..0fe96c7c8803c759b963411198fa18153a539f46 100644 (file)
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -81,13 +81,16 @@ static const struct bpf_func_proto bpf_probe_read_proto = {
 
 /*
  * limited trace_printk()
- * only %d %u %x %ld %lu %lx %lld %llu %llx %p conversion specifiers allowed
+ * only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed
  */
 static u64 bpf_trace_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5)
 {
        char *fmt = (char *) (long) r1;
+       bool str_seen = false;
        int mod[3] = {};
        int fmt_cnt = 0;
+       u64 unsafe_addr;
+       char buf[64];
        int i;
 
        /*
@@ -114,12 +117,37 @@ static u64 bpf_trace_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5)
                if (fmt[i] == 'l') {
                        mod[fmt_cnt]++;
                        i++;
-               } else if (fmt[i] == 'p') {
+               } else if (fmt[i] == 'p' || fmt[i] == 's') {
                        mod[fmt_cnt]++;
                        i++;
                        if (!isspace(fmt[i]) && !ispunct(fmt[i]) && fmt[i] != 0)
                                return -EINVAL;
                        fmt_cnt++;
+                       if (fmt[i - 1] == 's') {
+                               if (str_seen)
+                                       /* allow only one '%s' per fmt string */
+                                       return -EINVAL;
+                               str_seen = true;
+
+                               switch (fmt_cnt) {
+                               case 1:
+                                       unsafe_addr = r3;
+                                       r3 = (long) buf;
+                                       break;
+                               case 2:
+                                       unsafe_addr = r4;
+                                       r4 = (long) buf;
+                                       break;
+                               case 3:
+                                       unsafe_addr = r5;
+                                       r5 = (long) buf;
+                                       break;
+                               }
+                               buf[0] = 0;
+                               strncpy_from_unsafe(buf,
+                                                   (void *) (long) unsafe_addr,
+                                                   sizeof(buf));
+                       }
                        continue;
                }
 
@@ -158,6 +186,35 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
        return &bpf_trace_printk_proto;
 }
 
+static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5)
+{
+       struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
+       struct bpf_array *array = container_of(map, struct bpf_array, map);
+       struct perf_event *event;
+
+       if (unlikely(index >= array->map.max_entries))
+               return -E2BIG;
+
+       event = (struct perf_event *)array->ptrs[index];
+       if (!event)
+               return -ENOENT;
+
+       /*
+        * we don't know if the function is run successfully by the
+        * return value. It can be judged in other places, such as
+        * eBPF programs.
+        */
+       return perf_event_read_local(event);
+}
+
+const struct bpf_func_proto bpf_perf_event_read_proto = {
+       .func           = bpf_perf_event_read,
+       .gpl_only       = false,
+       .ret_type       = RET_INTEGER,
+       .arg1_type      = ARG_CONST_MAP_PTR,
+       .arg2_type      = ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id)
 {
        switch (func_id) {
@@ -183,6 +240,8 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func
                return bpf_get_trace_printk_proto();
        case BPF_FUNC_get_smp_processor_id:
                return &bpf_get_smp_processor_id_proto;
+       case BPF_FUNC_perf_event_read:
+               return &bpf_perf_event_read_proto;
        default:
                return NULL;
        }