From: Wang Nan <wangnan0@huawei.com>
To: <namhyung@kernel.org>, <alexei.starovoitov@gmail.com>,
<masami.hiramatsu.pt@hitachi.com>, <acme@kernel.org>,
<paulus@samba.org>, <a.p.zijlstra@chello.nl>, <mingo@redhat.com>,
<jolsa@kernel.org>, <dsahern@gmail.com>, <daniel@iogearbox.net>,
<brendan.d.gregg@gmail.com>
Cc: <lizefan@huawei.com>, <hekuang@huawei.com>, <xiakaixu@huawei.com>,
<linux-kernel@vger.kernel.org>, <pi3orama@163.com>
Subject: [RFC PATCH v5 12/30] bpf tools: Collect eBPF programs from their own sections
Date: Mon, 1 Jun 2015 07:37:58 +0000 [thread overview]
Message-ID: <1433144296-74992-13-git-send-email-wangnan0@huawei.com> (raw)
In-Reply-To: <1433144296-74992-1-git-send-email-wangnan0@huawei.com>
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.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/lib/bpf/libbpf.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 9d40f27..5ef0ffb 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.
@@ -98,6 +113,74 @@ struct bpf_object {
};
#define obj_elf_valid(o) ((o)->efile.fd >= 0)
+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 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;
+
+ if (size < sizeof(struct bpf_insn)) {
+ pr_warning("corrupted section '%s'\n", name);
+ return NULL;
+ }
+
+ progs = obj->programs;
+ nr_progs = obj->nr_programs;
+
+ progs = realloc(progs, sizeof(*prog) * (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);
+ return NULL;
+ }
+
+ obj->programs = progs;
+
+ prog = &progs[nr_progs];
+ bzero(prog, sizeof(*prog));
+
+ obj->nr_programs = nr_progs + 1;
+
+ prog->section_name = strdup(name);
+ if (!prog->section_name) {
+ pr_warning("failed to alloc name for prog %s\n",
+ name);
+ goto out;
+ }
+
+ prog->insns = malloc(size);
+ if (!prog->insns) {
+ pr_warning("failed to alloc insns for %s\n", name);
+ goto out;
+ }
+ prog->insns_cnt = size / sizeof(struct bpf_insn);
+ memcpy(prog->insns, data,
+ prog->insns_cnt * sizeof(struct bpf_insn));
+ prog->idx = idx;
+
+ return prog;
+out:
+ bpf_program__clear(prog);
+ return NULL;
+}
+
static struct bpf_object *bpf_object__new(const char *path)
{
struct bpf_object *obj;
@@ -315,6 +398,21 @@ 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;
@@ -370,11 +468,20 @@ out:
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
next prev parent reply other threads:[~2015-06-01 9:55 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-01 7:37 [RFC PATCH v5 00/30] perf tools: filtering events using eBPF programs Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 01/30] perf tools: Move linux/kernel.h to tools/include Wang Nan
2015-06-04 14:11 ` [tip:perf/core] " tip-bot for Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 02/30] perf tools: Move linux/{list.h,poison.h} " Wang Nan
2015-06-04 14:11 ` [tip:perf/core] tools: Move tools/perf/util/include/linux/{list.h ,poison.h} " tip-bot for Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 03/30] tools build: Add feature check for eBPF API Wang Nan
2015-06-02 22:11 ` Arnaldo Carvalho de Melo
2015-06-03 1:15 ` Wangnan (F)
2015-06-03 13:47 ` Arnaldo Carvalho de Melo
2015-06-01 7:37 ` [RFC PATCH v5 04/30] bpf tools: Introduce 'bpf' library to tools Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 05/30] bpf tools: Allow caller to set printing function Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 06/30] bpf tools: Open eBPF object file and do basic validation Wang Nan
2015-06-03 21:33 ` Arnaldo Carvalho de Melo
2015-06-03 21:35 ` Arnaldo Carvalho de Melo
2015-06-04 2:18 ` Wangnan (F)
2015-06-01 7:37 ` [RFC PATCH v5 07/30] bpf tools: Check endianess and make libbpf fail early Wang Nan
2015-06-03 21:52 ` Arnaldo Carvalho de Melo
2015-06-01 7:37 ` [RFC PATCH v5 08/30] bpf tools: Iterate over ELF sections to collect information Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 09/30] bpf tools: Collect version and license from ELF sections Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 10/30] bpf tools: Collect map definitions from 'maps' section Wang Nan
2015-06-01 7:37 ` [RFC PATCH v5 11/30] bpf tools: Collect symbol table from SHT_SYMTAB section Wang Nan
2015-06-01 7:37 ` Wang Nan [this message]
2015-06-01 7:37 ` [RFC PATCH v5 13/30] bpf tools: Collect relocation sections from SHT_REL sections Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 14/30] bpf tools: Record map accessing instructions for each program Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 15/30] bpf tools: Add bpf.c/h for common bpf operations Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 16/30] bpf tools: Create eBPF maps defined in an object file Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 17/30] bpf tools: Relocate eBPF programs Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 18/30] bpf tools: Introduce bpf_load_program() to bpf.c Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 19/30] bpf tools: Load eBPF programs in object files into kernel Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 20/30] bpf tools: Introduce accessors for struct bpf_program Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 21/30] bpf tools: Introduce accessors for struct bpf_object Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 22/30] bpf tools: Link all bpf objects onto a list Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 23/30] perf tools: Make perf depend on libbpf Wang Nan
2015-06-03 2:45 ` [RFC PATCH v6 " Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 24/30] perf record: Enable passing bpf object file to --event Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 25/30] perf tools: Parse probe points of eBPF programs during preparation Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 26/30] perf probe: Attach trace_probe_event with perf_probe_event Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 27/30] perf record: Probe at kprobe points Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 28/30] perf record: Load all eBPF object into kernel Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 29/30] perf tools: Add bpf_fd field to evsel and config it Wang Nan
2015-06-01 7:38 ` [RFC PATCH v5 30/30] perf tools: Attach eBPF program to perf event Wang Nan
2015-06-02 0:48 ` [RFC PATCH v5 00/30] perf tools: filtering events using eBPF programs Alexei Starovoitov
2015-06-02 1:15 ` Arnaldo Carvalho de Melo
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