libbpf: misc internal libbpf clean ups around log fixup

Normalize internal constants, field names, and comments related to log
fixup. Also add explicit `ext_idx` alias for relocation where relocation
is pointing to extern description for additional information.

No functional changes, just a clean up before subsequent additions.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230418002148.3255690-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko 2023-04-17 17:21:43 -07:00 committed by Alexei Starovoitov
parent 49859de997
commit 3055ddd654

View file

@ -333,6 +333,7 @@ struct reloc_desc {
struct {
int map_idx;
int sym_off;
int ext_idx;
};
};
};
@ -4042,7 +4043,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
else
reloc_desc->type = RELO_EXTERN_LD64;
reloc_desc->insn_idx = insn_idx;
reloc_desc->sym_off = i; /* sym_off stores extern index */
reloc_desc->ext_idx = i;
return 0;
}
@ -5811,8 +5812,8 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
}
/* base map load ldimm64 special constant, used also for log fixup logic */
#define MAP_LDIMM64_POISON_BASE 2001000000
#define MAP_LDIMM64_POISON_PFX "200100"
#define POISON_LDIMM64_MAP_BASE 2001000000
#define POISON_LDIMM64_MAP_PFX "200100"
static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx,
int insn_idx, struct bpf_insn *insn,
@ -5834,7 +5835,7 @@ static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx,
* invalid func unknown#2001000123
* where lower 123 is map index into obj->maps[] array
*/
insn->imm = MAP_LDIMM64_POISON_BASE + map_idx;
insn->imm = POISON_LDIMM64_MAP_BASE + map_idx;
insn++;
}
@ -5885,7 +5886,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
}
break;
case RELO_EXTERN_LD64:
ext = &obj->externs[relo->sym_off];
ext = &obj->externs[relo->ext_idx];
if (ext->type == EXT_KCFG) {
if (obj->gen_loader) {
insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE;
@ -5907,7 +5908,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
}
break;
case RELO_EXTERN_CALL:
ext = &obj->externs[relo->sym_off];
ext = &obj->externs[relo->ext_idx];
insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
if (ext->is_set) {
insn[0].imm = ext->ksym.kernel_btf_id;
@ -7022,13 +7023,13 @@ static void fixup_log_missing_map_load(struct bpf_program *prog,
char *buf, size_t buf_sz, size_t log_sz,
char *line1, char *line2, char *line3)
{
/* Expected log for failed and not properly guarded CO-RE relocation:
/* Expected log for failed and not properly guarded map reference:
* line1 -> 123: (85) call unknown#2001000345
* line2 -> invalid func unknown#2001000345
* line3 -> <anything else or end of buffer>
*
* "123" is the index of the instruction that was poisoned.
* "345" in "2001000345" are map index in obj->maps to fetch map name.
* "345" in "2001000345" is a map index in obj->maps to fetch map name.
*/
struct bpf_object *obj = prog->obj;
const struct bpf_map *map;
@ -7038,7 +7039,7 @@ static void fixup_log_missing_map_load(struct bpf_program *prog,
if (sscanf(line1, "%d: (%*d) call unknown#%d\n", &insn_idx, &map_idx) != 2)
return;
map_idx -= MAP_LDIMM64_POISON_BASE;
map_idx -= POISON_LDIMM64_MAP_BASE;
if (map_idx < 0 || map_idx >= obj->nr_maps)
return;
map = &obj->maps[map_idx];
@ -7070,20 +7071,21 @@ static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_s
if (!cur_line)
return;
/* failed CO-RE relocation case */
if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) {
prev_line = find_prev_line(buf, cur_line);
if (!prev_line)
continue;
/* failed CO-RE relocation case */
fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz,
prev_line, cur_line, next_line);
return;
} else if (str_has_pfx(cur_line, "invalid func unknown#"MAP_LDIMM64_POISON_PFX)) {
} else if (str_has_pfx(cur_line, "invalid func unknown#"POISON_LDIMM64_MAP_PFX)) {
prev_line = find_prev_line(buf, cur_line);
if (!prev_line)
continue;
/* reference to uncreated BPF map */
fixup_log_missing_map_load(prog, buf, buf_sz, log_sz,
prev_line, cur_line, next_line);
return;
@ -7098,7 +7100,7 @@ static int bpf_program_record_relos(struct bpf_program *prog)
for (i = 0; i < prog->nr_reloc; i++) {
struct reloc_desc *relo = &prog->reloc_desc[i];
struct extern_desc *ext = &obj->externs[relo->sym_off];
struct extern_desc *ext = &obj->externs[relo->ext_idx];
int kind;
switch (relo->type) {