From: Joe Stringer <joe@wand.net.nz>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org
Subject: [PATCH bpf-next 1/4] libbpf: Refactor relocations
Date: Mon, 11 Feb 2019 16:47:26 -0800 [thread overview]
Message-ID: <20190212004729.535-2-joe@wand.net.nz> (raw)
In-Reply-To: <20190212004729.535-1-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 and .bss sections can be added independent of these changes.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
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 e3c39edfb9d3..1ec28d5154dc 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -852,20 +852,20 @@ 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;
@@ -1027,24 +1027,26 @@ 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;
}
@@ -1392,7 +1394,7 @@ 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)
--
2.19.1
next prev parent reply other threads:[~2019-02-12 0:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-12 0:47 [PATCH bpf-next 0/4] libbpf: Add support for 32-bit static data Joe Stringer
2019-02-12 0:47 ` Joe Stringer [this message]
2019-02-12 0:47 ` [PATCH bpf-next 2/4] libbpf: Support 32-bit static data loads Joe Stringer
2019-02-15 5:38 ` Y Song
2019-02-15 7:16 ` Joe Stringer
2019-02-15 20:18 ` Y Song
2019-02-27 22:42 ` Y Song
2019-02-15 16:17 ` Alexei Starovoitov
2019-02-12 0:47 ` [PATCH bpf-next 3/4] libbpf: Support relocations for bss Joe Stringer
2019-02-12 0:47 ` [PATCH bpf-next 4/4] selftests/bpf: Test static data relocation Joe Stringer
2019-02-12 5:01 ` Alexei Starovoitov
2019-02-12 20:43 ` Joe Stringer
2019-02-14 0:35 ` Alexei Starovoitov
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