From: Daniel Borkmann <daniel@iogearbox.net>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, ast@kernel.org, joe@wand.net.nz,
yhs@fb.com, andrii.nakryiko@gmail.com, kafai@fb.com,
Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next v4 10/16] bpf, libbpf: refactor relocation handling
Date: Fri, 5 Apr 2019 22:59:36 +0200 [thread overview]
Message-ID: <2475c1d25de8b26f56673cd653bb36a273d41f5a.1554497408.git.daniel@iogearbox.net> (raw)
In-Reply-To: <cover.1554497408.git.daniel@iogearbox.net>
In-Reply-To: <cover.1554497408.git.daniel@iogearbox.net>
From: Joe Stringer <joe@wand.net.nz>
Adjust the code for relocations slightly with no functional changes,
so that upcoming patches that will introduce support for relocations
into the .data, .rodata and .bss sections can be added independent
of these changes.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
---
tools/lib/bpf/libbpf.c | 62 ++++++++++++++++++++++++++------------------------
1 file changed, 32 insertions(+), 30 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e1e4d35..476da3d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -866,20 +866,20 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
obj->efile.symbols = data;
obj->efile.strtabidx = sh.sh_link;
}
- } else if ((sh.sh_type == SHT_PROGBITS) &&
- (sh.sh_flags & SHF_EXECINSTR) &&
- (data->d_size > 0)) {
- if (strcmp(name, ".text") == 0)
- obj->efile.text_shndx = idx;
- err = bpf_object__add_program(obj, data->d_buf,
- data->d_size, name, idx);
- if (err) {
- char errmsg[STRERR_BUFSIZE];
- char *cp = libbpf_strerror_r(-err, errmsg,
- sizeof(errmsg));
-
- pr_warning("failed to alloc program %s (%s): %s",
- name, obj->path, cp);
+ } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
+ if (sh.sh_flags & SHF_EXECINSTR) {
+ if (strcmp(name, ".text") == 0)
+ obj->efile.text_shndx = idx;
+ err = bpf_object__add_program(obj, data->d_buf,
+ data->d_size, name, idx);
+ if (err) {
+ char errmsg[STRERR_BUFSIZE];
+ char *cp = libbpf_strerror_r(-err, errmsg,
+ sizeof(errmsg));
+
+ pr_warning("failed to alloc program %s (%s): %s",
+ name, obj->path, cp);
+ }
}
} else if (sh.sh_type == SHT_REL) {
void *reloc = obj->efile.reloc;
@@ -1041,24 +1041,26 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
return -LIBBPF_ERRNO__RELOC;
}
- /* TODO: 'maps' is sorted. We can use bsearch to make it faster. */
- for (map_idx = 0; map_idx < nr_maps; map_idx++) {
- if (maps[map_idx].offset == sym.st_value) {
- pr_debug("relocation: find map %zd (%s) for insn %u\n",
- map_idx, maps[map_idx].name, insn_idx);
- break;
+ if (sym.st_shndx == maps_shndx) {
+ /* TODO: 'maps' is sorted. We can use bsearch to make it faster. */
+ for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+ if (maps[map_idx].offset == sym.st_value) {
+ pr_debug("relocation: find map %zd (%s) for insn %u\n",
+ map_idx, maps[map_idx].name, insn_idx);
+ break;
+ }
}
- }
- if (map_idx >= nr_maps) {
- pr_warning("bpf relocation: map_idx %d large than %d\n",
- (int)map_idx, (int)nr_maps - 1);
- return -LIBBPF_ERRNO__RELOC;
- }
+ if (map_idx >= nr_maps) {
+ pr_warning("bpf relocation: map_idx %d large than %d\n",
+ (int)map_idx, (int)nr_maps - 1);
+ return -LIBBPF_ERRNO__RELOC;
+ }
- prog->reloc_desc[i].type = RELO_LD64;
- prog->reloc_desc[i].insn_idx = insn_idx;
- prog->reloc_desc[i].map_idx = map_idx;
+ prog->reloc_desc[i].type = RELO_LD64;
+ prog->reloc_desc[i].insn_idx = insn_idx;
+ prog->reloc_desc[i].map_idx = map_idx;
+ }
}
return 0;
}
@@ -1420,7 +1422,7 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
}
insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
insns[insn_idx].imm = obj->maps[map_idx].fd;
- } else {
+ } else if (prog->reloc_desc[i].type == RELO_CALL) {
err = bpf_program__reloc_text(prog, obj,
&prog->reloc_desc[i]);
if (err)
--
2.9.5
next prev parent reply other threads:[~2019-04-05 21:00 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-05 20:59 [PATCH bpf-next v4 00/16] BPF support for global data Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 01/16] bpf: implement lookup-free direct value access for maps Daniel Borkmann
2019-04-06 1:56 ` Alexei Starovoitov
2019-04-06 10:58 ` Daniel Borkmann
2019-04-06 16:54 ` Alexei Starovoitov
2019-04-06 23:55 ` Daniel Borkmann
2019-04-07 2:57 ` Alexei Starovoitov
2019-04-07 18:35 ` Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 02/16] bpf: do not retain flags that are not tied to map lifetime Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 03/16] bpf: add program side {rd,wr}only support for maps Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 04/16] bpf: add syscall side map freeze support Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 05/16] bpf: allow . char as part of the object name Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 06/16] bpf: add specification for BTF Var and DataSec kinds Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 07/16] bpf: kernel side support for BTF Var and DataSec Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 08/16] bpf: allow for key-less BTF in array map Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 09/16] bpf: sync {btf,bpf}.h uapi header from tools infrastructure Daniel Borkmann
2019-04-05 20:59 ` Daniel Borkmann [this message]
2019-04-05 20:59 ` [PATCH bpf-next v4 11/16] bpf, libbpf: support global data/bss/rodata sections Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 12/16] bpf, libbpf: add support for BTF Var and DataSec Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 13/16] bpf: bpftool support for dumping data/bss/rodata sections Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 14/16] bpf, selftest: test {rd,wr}only flags and direct value access Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 15/16] bpf, selftest: test global data/bss/rodata sections Daniel Borkmann
2019-04-05 20:59 ` [PATCH bpf-next v4 16/16] bpf, selftest: add test cases for BTF Var and DataSec Daniel Borkmann
2019-04-06 5:57 ` [PATCH bpf-next v4 00/16] BPF support for global data Martin Lau
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