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Groups > linux.kernel > #1180711
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file |
| Date | 2015-07-09 14:50 +0200 |
| Message-ID | <pKjr5-dD-35@gated-at.bofh.it> (permalink) |
| References | <pKjhn-9T-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This patch creates maps based on 'map' section in object file using
bpf_create_map(), and stores the fds into an array in 'struct
bpf_object'.
Previous patches parse ELF object file and collects required data, but
doesn't play with the kernel. They belong to the 'opening' phase. This
patch is the first patch in 'loading' phase. The 'loaded' field is
introduced in 'struct bpf_object' to avoid loading an object twice,
because the loading phase clears resources collected during the opening
which becomes useless after loading. In this patch, maps_buf is cleared.
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/1435716878-189507-17-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/lib/bpf/libbpf.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++
tools/lib/bpf/libbpf.h | 4 ++
2 files changed, 106 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4f13772..c214e1c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -21,6 +21,7 @@
#include <gelf.h>
#include "libbpf.h"
+#include "bpf.h"
#define __printf(a, b) __attribute__((format(printf, a, b)))
@@ -105,6 +106,13 @@ struct bpf_object {
struct bpf_program *programs;
size_t nr_programs;
+ int *map_fds;
+ /*
+ * This field is required because maps_buf will be freed and
+ * maps_buf_sz will be set to 0 after loaded.
+ */
+ size_t nr_map_fds;
+ bool loaded;
/*
* Information when doing elf related work. Only valid if fd
@@ -232,6 +240,7 @@ static struct bpf_object *bpf_object__new(const char *path,
obj->efile.obj_buf = obj_buf;
obj->efile.obj_buf_sz = obj_buf_sz;
+ obj->loaded = false;
return obj;
}
@@ -568,6 +577,62 @@ bpf_program__collect_reloc(struct bpf_program *prog,
return 0;
}
+static int
+bpf_object__create_maps(struct bpf_object *obj)
+{
+ unsigned int i;
+ size_t nr_maps;
+ int *pfd;
+
+ nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
+ if (!obj->maps_buf || !nr_maps) {
+ pr_debug("don't need create maps for %s\n",
+ obj->path);
+ return 0;
+ }
+
+ obj->map_fds = malloc(sizeof(int) * nr_maps);
+ if (!obj->map_fds) {
+ pr_warning("realloc perf_bpf_map_fds failed\n");
+ return -ENOMEM;
+ }
+ obj->nr_map_fds = nr_maps;
+
+ /* fill all fd with -1 */
+ memset(obj->map_fds, 0xff, sizeof(int) * nr_maps);
+
+ pfd = obj->map_fds;
+ for (i = 0; i < nr_maps; i++) {
+ struct bpf_map_def def;
+
+ def = *(struct bpf_map_def *)(obj->maps_buf +
+ i * sizeof(struct bpf_map_def));
+
+ *pfd = bpf_create_map(def.type,
+ def.key_size,
+ def.value_size,
+ def.max_entries);
+ if (*pfd < 0) {
+ size_t j;
+ int err = *pfd;
+
+ pr_warning("failed to create map: %s\n",
+ strerror(errno));
+ for (j = 0; j < i; j++)
+ zclose(obj->map_fds[j]);
+ obj->nr_map_fds = 0;
+ zfree(&obj->map_fds);
+ return err;
+ }
+ pr_debug("create map: fd=%d\n", *pfd);
+ pfd++;
+ }
+
+ zfree(&obj->maps_buf);
+ obj->maps_buf_sz = 0;
+ return 0;
+}
+
static int bpf_object__collect_reloc(struct bpf_object *obj)
{
int i, err;
@@ -671,6 +736,42 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
}
+int bpf_object__unload(struct bpf_object *obj)
+{
+ size_t i;
+
+ if (!obj)
+ return -EINVAL;
+
+ for (i = 0; i < obj->nr_map_fds; i++)
+ zclose(obj->map_fds[i]);
+ zfree(&obj->map_fds);
+ obj->nr_map_fds = 0;
+
+ return 0;
+}
+
+int bpf_object__load(struct bpf_object *obj)
+{
+ if (!obj)
+ return -EINVAL;
+
+ if (obj->loaded) {
+ pr_warning("object should not be loaded twice\n");
+ return -EINVAL;
+ }
+
+ obj->loaded = true;
+ if (bpf_object__create_maps(obj))
+ goto out;
+
+ return 0;
+out:
+ bpf_object__unload(obj);
+ pr_warning("failed to load object '%s'\n", obj->path);
+ return -EINVAL;
+}
+
void bpf_object__close(struct bpf_object *obj)
{
size_t i;
@@ -679,6 +780,7 @@ void bpf_object__close(struct bpf_object *obj)
return;
bpf_object__elf_finish(obj);
+ bpf_object__unload(obj);
zfree(&obj->maps_buf);
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6e75acd..3e69600 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -30,6 +30,10 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
size_t obj_buf_sz);
void bpf_object__close(struct bpf_object *object);
+/* Load/unload object into/from kernel */
+int bpf_object__load(struct bpf_object *obj);
+int bpf_object__unload(struct bpf_object *obj);
+
/*
* We don't need __attribute__((packed)) now since it is
* unnecessary for 'bpf_map_def' because they are all aligned.
--
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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