Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753042AbbEQLD6 (ORCPT ); Sun, 17 May 2015 07:03:58 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:61128 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753237AbbEQK5u (ORCPT ); Sun, 17 May 2015 06:57:50 -0400 From: Wang Nan To: , , , , , , , , , , CC: , , Subject: [RFC PATCH v3 12/37] bpf tools: Collect version and license from ELF sections Date: Sun, 17 May 2015 10:56:37 +0000 Message-ID: <1431860222-61636-13-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1431860222-61636-1-git-send-email-wangnan0@huawei.com> References: <1431860222-61636-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.200] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3438 Lines: 130 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 existance of 'version' section. Signed-off-by: Wang Nan --- tools/lib/bpf/libbpf.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 1af80c3..b26f1ee 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -15,12 +15,22 @@ #include #include #include +#include #include #include #include #include "libbpf.h" +#ifdef min +# undef min +#endif +#define min(x, y) ({ \ + typeof(x) _min1 = (x); \ + typeof(y) _min2 = (y); \ + (void) (&_min1 == &_min2); \ + _min1 < _min2 ? _min1 : _min2; }) + #define __printf(a, b) __attribute__((format(printf, a, b))) __printf(1, 2) @@ -70,6 +80,8 @@ void libbpf_set_print(int (*warn)(const char *format, ...), struct bpf_object { char *path; bool needs_swap; + char license[64]; + u32 kern_version; /* * Information when doing elf related work. Only valid if fd @@ -206,6 +218,32 @@ bpf_obj_swap_init(struct bpf_object *obj) } } +static int bpf_obj_license_init(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_obj_kver_init(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)); + if (obj->needs_swap) + kver = bswap_32(kver); + obj->kern_version = kver; + pr_debug("kernel version of %s is %x\n", obj->path, + obj->kern_version); + return 0; +} + static int bpf_obj_elf_collect(struct bpf_object *obj) { Elf *elf = obj->elf.elf; @@ -253,11 +291,30 @@ static int bpf_obj_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_obj_license_init(obj, data->d_buf, + data->d_size); + else if (strcmp(name, "version") == 0) + err = bpf_obj_kver_init(obj, data->d_buf, + data->d_size); + if (err) + goto out; } out: return err; } +static int bpf_obj_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; +} + struct bpf_object *bpf_open_object(const char *path) { struct bpf_object *obj; @@ -283,6 +340,8 @@ struct bpf_object *bpf_open_object(const char *path) goto out; if (bpf_obj_elf_collect(obj)) goto out; + if (bpf_obj_validate(obj)) + goto out; return obj; -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/