Messages in this thread | | | Date | Fri, 26 Jun 2015 12:23:43 +0800 | From | "Wangnan (F)" <> | Subject | Re: [RFC PATCH v8 46/49] perf tools: Add prologue for BPF programs for fetching arguments |
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On 2015/6/24 20:31, Wang Nan wrote:
[SNIP]
> diff --git a/tools/perf/util/bpf-prologue.h b/tools/perf/util/bpf-prologue.h > new file mode 100644 > index 0000000..3f77606 > --- /dev/null > +++ b/tools/perf/util/bpf-prologue.h > @@ -0,0 +1,19 @@ > +/* > + * Copyright (C) 2015, He Kuang <hekuang@huawei.com> > + * Copyright (C) 2015, Huawei Inc. > + */ > +#ifndef __BPF_PROLOGUE_H > +#define __BPF_PROLOGUE_H > + > +#include <linux/filter.h> > +#include "probe-event.h" > + > +#define BPF_PROLOGUE_MAX_ARGS 3 > +#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3 > +#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2 > + > +int bpf__gen_prologue(struct probe_trace_arg *args, int nargs, > + struct bpf_insn *new_prog, size_t *new_cnt, > + size_t cnt_space); > +
Here is a problem: if CONFIG_BPF_PROLOGUE is not set, a missing symbol problem will be triggered.
I have updated this part in my patchset:
+/* + * Copyright (C) 2015, He Kuang <hekuang@huawei.com> + * Copyright (C) 2015, Huawei Inc. + */ +#ifndef __BPF_PROLOGUE_H +#define __BPF_PROLOGUE_H + +#include <linux/compiler.h> +#include <linux/filter.h> +#include "probe-event.h" + +#define BPF_PROLOGUE_MAX_ARGS 3 +#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3 +#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2 + +#ifdef HAVE_BPF_PROLOGUE +int bpf__gen_prologue(struct probe_trace_arg *args, int nargs, + struct bpf_insn *new_prog, size_t *new_cnt, + size_t cnt_space); +#else +static inline int +bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused, + int nargs __maybe_unused, + struct bpf_insn *new_prog __maybe_unused, + size_t *new_cnt, + size_t cnt_space __maybe_unused) +{ + if (!new_cnt) + return -EINVAL; + *new_cnt = 0; + return 0; +} +#endif +#endif /* __BPF_PROLOGUE_H */
> +#endif /* __BPF_PROLOGUE_H */
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