The perf_event_read_event_output helper is currently only available to
tracing protrams, but is useful for other BPF programs like sched_ext
schedulers. When the helper is available, provide its bpf_func_proto
directly from the bpf core.
Signed-off-by: Emil Tsalapatis (Meta) <emil@xxxxxxxxxxxxxxx>
---
include/linux/bpf.h | 2 ++
kernel/bpf/core.c | 5 +++++
kernel/bpf/helpers.c | 2 ++
kernel/trace/bpf_trace.c | 5 +++++
4 files changed, 14 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 0d7b70124d81..973a88d9b52b 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2059,6 +2059,8 @@ int bpf_prog_calc_tag(struct bpf_prog *fp);
const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void);
+const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void);
+
typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
unsigned long off, unsigned long len);
typedef u32 (*bpf_convert_ctx_access_t)(enum bpf_access_type type,
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 62cb9557ad3b..ba6b6118cf50 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2972,6 +2972,11 @@ const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
return NULL;
}
+const struct bpf_func_proto * __weak bpf_get_perf_event_read_value_proto(void)
+{
+ return NULL;
+}
+
u64 __weak
bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 5449756ba102..ddaa41a70676 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -2056,6 +2056,8 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_task_pt_regs_proto;
case BPF_FUNC_trace_vprintk:
return bpf_get_trace_vprintk_proto();
+ case BPF_FUNC_perf_event_read_value:
+ return bpf_get_perf_event_read_value_proto();
default:
return NULL;
}
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 13bef2462e94..6b07fa7081d9 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -607,6 +607,11 @@ static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
.arg4_type = ARG_CONST_SIZE,
};
+const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void)
+{
+ return &bpf_perf_event_read_value_proto;
+}
+
static __always_inline u64
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
u64 flags, struct perf_raw_record *raw,
--
2.47.1
