diff options
| -rw-r--r-- | samples/bpf/tracex6.bpf.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/samples/bpf/tracex6.bpf.c b/samples/bpf/tracex6.bpf.c index 6ad82e68f998..9b23b4737cfb 100644 --- a/samples/bpf/tracex6.bpf.c +++ b/samples/bpf/tracex6.bpf.c @@ -1,6 +1,8 @@ #include "vmlinux.h" #include <linux/version.h> #include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> struct { __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); @@ -44,13 +46,24 @@ int bpf_prog1(struct pt_regs *ctx) return 0; } -SEC("kprobe/htab_map_lookup_elem") -int bpf_prog2(struct pt_regs *ctx) +/* + * Since *_map_lookup_elem can't be expected to trigger bpf programs + * due to potential deadlocks (bpf_disable_instrumentation), this bpf + * program will be attached to bpf_map_copy_value (which is called + * from map_lookup_elem) and will only filter the hashtable type. + */ +SEC("kprobe/bpf_map_copy_value") +int BPF_KPROBE(bpf_prog2, struct bpf_map *map) { u32 key = bpf_get_smp_processor_id(); struct bpf_perf_event_value *val, buf; + enum bpf_map_type type; int error; + type = BPF_CORE_READ(map, map_type); + if (type != BPF_MAP_TYPE_HASH) + return 0; + error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf)); if (error) return 0; |