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Groups > linux.kernel > #1180726
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections |
| Date | 2015-07-09 14:50 +0200 |
| Message-ID | <pKjr6-dD-69@gated-at.bofh.it> (permalink) |
| References | <pKjhn-9T-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This patch collects all programs in an object file into an array of
'struct bpf_program' for further processing. That structure is for
representing each eBPF program. 'bpf_prog' should be a better name, but
it has been used by linux/filter.h. Although it is a kernel space name,
I still prefer to call it 'bpf_program' to prevent possible confusion.
bpf_program__new() creates a new 'struct bpf_program' object. It first
init a variable in stack using __bpf_program__new(), then if success,
enlarges obj->programs array and copy the new object in.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-13-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/lib/bpf/libbpf.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 117 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 9b016c0..3b717de 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -78,12 +78,27 @@ void libbpf_set_print(libbpf_print_fn_t warn,
# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
#endif
+/*
+ * bpf_prog should be a better name but it has been used in
+ * linux/filter.h.
+ */
+struct bpf_program {
+ /* Index in elf obj file, for relocation use. */
+ int idx;
+ char *section_name;
+ struct bpf_insn *insns;
+ size_t insns_cnt;
+};
+
struct bpf_object {
char license[64];
u32 kern_version;
void *maps_buf;
size_t maps_buf_sz;
+ struct bpf_program *programs;
+ size_t nr_programs;
+
/*
* Information when doing elf related work. Only valid if fd
* is valid.
@@ -100,6 +115,84 @@ struct bpf_object {
};
#define obj_elf_valid(o) ((o)->efile.elf)
+static void bpf_program__clear(struct bpf_program *prog)
+{
+ if (!prog)
+ return;
+
+ zfree(&prog->section_name);
+ zfree(&prog->insns);
+ prog->insns_cnt = 0;
+ prog->idx = -1;
+}
+
+static int
+__bpf_program__new(void *data, size_t size, char *name, int idx,
+ struct bpf_program *prog)
+{
+ if (size < sizeof(struct bpf_insn)) {
+ pr_warning("corrupted section '%s'\n", name);
+ return -EINVAL;
+ }
+
+ bzero(prog, sizeof(*prog));
+
+ prog->section_name = strdup(name);
+ if (!prog->section_name) {
+ pr_warning("failed to alloc name for prog %s\n",
+ name);
+ goto errout;
+ }
+
+ prog->insns = malloc(size);
+ if (!prog->insns) {
+ pr_warning("failed to alloc insns for %s\n", name);
+ goto errout;
+ }
+ prog->insns_cnt = size / sizeof(struct bpf_insn);
+ memcpy(prog->insns, data,
+ prog->insns_cnt * sizeof(struct bpf_insn));
+ prog->idx = idx;
+
+ return 0;
+errout:
+ bpf_program__clear(prog);
+ return -ENOMEM;
+}
+
+static struct bpf_program *
+bpf_program__new(struct bpf_object *obj, void *data, size_t size,
+ char *name, int idx)
+{
+ struct bpf_program prog, *progs;
+ int nr_progs, err;
+
+ err = __bpf_program__new(data, size, name, idx, &prog);
+ if (err)
+ return NULL;
+
+ progs = obj->programs;
+ nr_progs = obj->nr_programs;
+
+ progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
+ if (!progs) {
+ /*
+ * In this case the original obj->programs
+ * is still valid, so don't need special treat for
+ * bpf_close_object().
+ */
+ pr_warning("failed to alloc a new program '%s'\n",
+ name);
+ bpf_program__clear(&prog);
+ return NULL;
+ }
+
+ obj->programs = progs;
+ obj->nr_programs = nr_progs + 1;
+ progs[nr_progs] = prog;
+ return &progs[nr_progs];
+}
+
static struct bpf_object *bpf_object__new(const char *path,
void *obj_buf,
size_t obj_buf_sz)
@@ -342,6 +435,21 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
err = -EEXIST;
} else
obj->efile.symbols = data;
+ } else if ((sh.sh_type == SHT_PROGBITS) &&
+ (sh.sh_flags & SHF_EXECINSTR) &&
+ (data->d_size > 0)) {
+ struct bpf_program *prog;
+
+ prog = bpf_program__new(obj, data->d_buf,
+ data->d_size, name,
+ idx);
+ if (!prog) {
+ pr_warning("failed to alloc program %s (%s)",
+ name, obj->path);
+ err = -ENOMEM;
+ } else
+ pr_debug("found program %s\n",
+ prog->section_name);
}
if (err)
goto out;
@@ -415,11 +523,20 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
void bpf_object__close(struct bpf_object *obj)
{
+ size_t i;
+
if (!obj)
return;
bpf_object__elf_finish(obj);
zfree(&obj->maps_buf);
+
+ if (obj->programs && obj->nr_programs) {
+ for (i = 0; i < obj->nr_programs; i++)
+ bpf_program__clear(&obj->programs[i]);
+ }
+ zfree(&obj->programs);
+
free(obj);
}
--
1.8.3.4
--
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[GIT PULL 00/39] perf tools: filtering events using eBPF programs Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:40 +0200
[PATCH 36/39] perf tools: Use same BPF program if arguments are identical Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 25/39] perf tools: Attach eBPF program to perf event Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 27/39] perf record: Add clang options for compiling BPF scripts Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 34/39] perf tools: Add prologue for BPF programs for fetching arguments Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 31/39] perf tools: Move linux/filter.h to tools/include Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 26/39] perf tools: Suppress probing messages when probing by BPF loading Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 28/39] bpf tools: Load a program with different instances using preprocessor Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
Re: [PATCH 28/39] bpf tools: Load a program with different instances using preprocessor "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-13 08:00 +0200
[PATCH 13/39] perf tools: Call clang to compile C source to object code Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 32/39] perf tools: Add BPF_PROLOGUE config options for further patches Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 06/39] bpf tools: Create eBPF maps defined in an object file Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
Re: [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-14 06:10 +0200
[PATCH 35/39] perf tools: Generate prologue for BPF programs Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 30/39] perf probe: Reset args and nargs for probe_trace_event when failure Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 18/39] perf record: Enable passing bpf object file to --event Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 14/39] perf tools: Auto detecting kernel build directory Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 23/39] perf record: Load all eBPF object into kernel Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 24/39] perf tools: Add bpf_fd field to evsel and config it Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 22/39] perf record: Probe at kprobe points Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 15/39] perf tools: Auto detecting kernel include options Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 29/39] perf tools: Fix probe-event.h include Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 02/39] bpf tools: Collect eBPF programs from their own sections Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
Re: [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-10 05:20 +0200
Re: [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-14 06:10 +0200
[PATCH 21/39] perf probe: Attach trace_probe_event with perf_probe_event Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 09/39] bpf tools: Load eBPF programs in object files into kernel Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 37/39] perf record: Support custom vmlinux path Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-07-14 17:40 +0200
Re: perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-15 13:10 +0200
Re: perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-07-15 13:30 +0200
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