This patch records the extern sym relocs first before recording
subprog relocs. The later patch will have relocs for extern
kernel function call which is also using BPF_JMP | BPF_CALL.
It will be easier to handle the extern symbols first in
the later patch.
is_call_insn() helper is added. The existing is_ldimm64() helper
is renamed to is_ldimm64_insn() for consistency.
Acked-by: Andrii Nakryiko <and...@kernel.org>
Signed-off-by: Martin KaFai Lau <ka...@fb.com>
---
tools/lib/bpf/libbpf.c | 63 +++++++++++++++++++++++-------------------
1 file changed, 34 insertions(+), 29 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 1a2dbde19b7e..23148566ab3a 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -573,14 +573,19 @@ static bool insn_is_subprog_call(const struct bpf_insn
*insn)
insn->off == 0;
}
-static bool is_ldimm64(struct bpf_insn *insn)
+static bool is_ldimm64_insn(struct bpf_insn *insn)
{
return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
}
+static bool is_call_insn(const struct bpf_insn *insn)
+{
+ return insn->code == (BPF_JMP | BPF_CALL);
+}
+
static bool insn_is_pseudo_func(struct bpf_insn *insn)
{
- return is_ldimm64(insn) && insn->src_reg == BPF_PSEUDO_FUNC;
+ return is_ldimm64_insn(insn) && insn->src_reg == BPF_PSEUDO_FUNC;
}
static int
@@ -3407,31 +3412,7 @@ static int bpf_program__record_reloc(struct bpf_program
*prog,
reloc_desc->processed = false;
- /* sub-program call relocation */
- if (insn->code == (BPF_JMP | BPF_CALL)) {
- if (insn->src_reg != BPF_PSEUDO_CALL) {
- pr_warn("prog '%s': incorrect bpf_call opcode\n",
prog->name);
- return -LIBBPF_ERRNO__RELOC;
- }
- /* text_shndx can be 0, if no default "main" program exists */
- if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
- sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj,
shdr_idx));
- pr_warn("prog '%s': bad call relo against '%s' in
section '%s'\n",
- prog->name, sym_name, sym_sec_name);
- return -LIBBPF_ERRNO__RELOC;
- }
- if (sym->st_value % BPF_INSN_SZ) {
- pr_warn("prog '%s': bad call relo against '%s' at
offset %zu\n",
- prog->name, sym_name, (size_t)sym->st_value);
- return -LIBBPF_ERRNO__RELOC;
- }
- reloc_desc->type = RELO_CALL;
- reloc_desc->insn_idx = insn_idx;
- reloc_desc->sym_off = sym->st_value;
- return 0;
- }
-
- if (!is_ldimm64(insn)) {
+ if (!is_call_insn(insn) && !is_ldimm64_insn(insn)) {
pr_warn("prog '%s': invalid relo against '%s' for
insns[%d].code 0x%x\n",
prog->name, sym_name, insn_idx, insn->code);
return -LIBBPF_ERRNO__RELOC;
@@ -3460,6 +3441,30 @@ static int bpf_program__record_reloc(struct bpf_program
*prog,
return 0;
}
+ /* sub-program call relocation */
+ if (is_call_insn(insn)) {
+ if (insn->src_reg != BPF_PSEUDO_CALL) {
+ pr_warn("prog '%s': incorrect bpf_call opcode\n",
prog->name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ /* text_shndx can be 0, if no default "main" program exists */
+ if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
+ sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj,
shdr_idx));
+ pr_warn("prog '%s': bad call relo against '%s' in
section '%s'\n",
+ prog->name, sym_name, sym_sec_name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ if (sym->st_value % BPF_INSN_SZ) {
+ pr_warn("prog '%s': bad call relo against '%s' at
offset %zu\n",
+ prog->name, sym_name, (size_t)sym->st_value);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ reloc_desc->type = RELO_CALL;
+ reloc_desc->insn_idx = insn_idx;
+ reloc_desc->sym_off = sym->st_value;
+ return 0;
+ }
+
if (!shdr_idx || shdr_idx >= SHN_LORESERVE) {
pr_warn("prog '%s': invalid relo against '%s' in special
section 0x%x; forgot to initialize global var?..\n",
prog->name, sym_name, shdr_idx);
@@ -5699,7 +5704,7 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
/* poison second part of ldimm64 to avoid confusing error from
* verifier about "unknown opcode 00"
*/
- if (is_ldimm64(insn))
+ if (is_ldimm64_insn(insn))
bpf_core_poison_insn(prog, relo_idx, insn_idx + 1, insn
+ 1);
bpf_core_poison_insn(prog, relo_idx, insn_idx, insn);
return 0;
@@ -5775,7 +5780,7 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
case BPF_LD: {
__u64 imm;
- if (!is_ldimm64(insn) ||
+ if (!is_ldimm64_insn(insn) ||
insn[0].src_reg != 0 || insn[0].off != 0 ||
insn_idx + 1 >= prog->insns_cnt ||
insn[1].code != 0 || insn[1].dst_reg != 0 ||
--
2.30.2
