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authorWang Nan <wangnan0@huawei.com>2015-07-01 02:13:57 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-08-07 10:16:57 -0300
commitcb1e5e961991ee9b2cbfd3bf06ef490ea578cd2f (patch)
treeca588da8a349ded2f2cf7d1b310124b84df2ae44 /tools/lib/bpf
parent296036653ae8b1367ec9d06d65377c2e2371b153 (diff)
bpf tools: Collect version and license from ELF sections
Expand bpf_obj_elf_collect() to collect license and kernel version information in eBPF object file. eBPF object file should have a section named 'license', which contains a string. It should also have a section named 'version', contains a u32 LINUX_VERSION_CODE. bpf_obj_validate() is introduced to validate object file after loaded. Currently it only check existence of 'version' section. 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: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-10-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/bpf')
-rw-r--r--tools/lib/bpf/libbpf.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index d8d6eb580188..95c8d8e5c350 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -14,6 +14,7 @@
#include <fcntl.h>
#include <errno.h>
#include <asm/unistd.h>
+#include <linux/kernel.h>
#include <linux/bpf.h>
#include <libelf.h>
#include <gelf.h>
@@ -78,6 +79,8 @@ void libbpf_set_print(libbpf_print_fn_t warn,
#endif
struct bpf_object {
+ char license[64];
+ u32 kern_version;
/*
* Information when doing elf related work. Only valid if fd
* is valid.
@@ -220,6 +223,33 @@ mismatch:
return -EINVAL;
}
+static int
+bpf_object__init_license(struct bpf_object *obj,
+ void *data, size_t size)
+{
+ memcpy(obj->license, data,
+ min(size, sizeof(obj->license) - 1));
+ pr_debug("license of %s is %s\n", obj->path, obj->license);
+ return 0;
+}
+
+static int
+bpf_object__init_kversion(struct bpf_object *obj,
+ void *data, size_t size)
+{
+ u32 kver;
+
+ if (size != sizeof(kver)) {
+ pr_warning("invalid kver section in %s\n", obj->path);
+ return -EINVAL;
+ }
+ memcpy(&kver, data, sizeof(kver));
+ obj->kern_version = kver;
+ pr_debug("kernel version of %s is %x\n", obj->path,
+ obj->kern_version);
+ return 0;
+}
+
static int bpf_object__elf_collect(struct bpf_object *obj)
{
Elf *elf = obj->efile.elf;
@@ -266,11 +296,32 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
name, (unsigned long)data->d_size,
(int)sh.sh_link, (unsigned long)sh.sh_flags,
(int)sh.sh_type);
+
+ if (strcmp(name, "license") == 0)
+ err = bpf_object__init_license(obj,
+ data->d_buf,
+ data->d_size);
+ else if (strcmp(name, "version") == 0)
+ err = bpf_object__init_kversion(obj,
+ data->d_buf,
+ data->d_size);
+ if (err)
+ goto out;
}
out:
return err;
}
+static int bpf_object__validate(struct bpf_object *obj)
+{
+ if (obj->kern_version == 0) {
+ pr_warning("%s doesn't provide kernel version\n",
+ obj->path);
+ return -EINVAL;
+ }
+ return 0;
+}
+
static struct bpf_object *
__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
{
@@ -291,6 +342,8 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
goto out;
if (bpf_object__elf_collect(obj))
goto out;
+ if (bpf_object__validate(obj))
+ goto out;
bpf_object__elf_finish(obj);
return obj;