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libbpf: misc internal libbpf clean ups around log fixup

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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 Andrii Nakryiko
parent 44f59ec077
commit 0db753a9f8
1 changed files with 14 additions and 12 deletions
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26
src/libbpf.c
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@@ -333,6 +333,7 @@ struct reloc_desc {
struct { struct {
int map_idx; int map_idx;
int sym_off; int sym_off;
int ext_idx;
}; };
}; };
}; };
@@ -4042,7 +4043,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
else else
reloc_desc->type = RELO_EXTERN_LD64; reloc_desc->type = RELO_EXTERN_LD64;
reloc_desc->insn_idx = insn_idx; reloc_desc->insn_idx = insn_idx;
reloc_desc->sym_off = i; /* sym_off stores extern index */ reloc_desc->ext_idx = i;
return 0; return 0;
} }
@@ -5811,8 +5812,8 @@ out:
} }
/* base map load ldimm64 special constant, used also for log fixup logic */ /* base map load ldimm64 special constant, used also for log fixup logic */
#define MAP_LDIMM64_POISON_BASE 2001000000 #define POISON_LDIMM64_MAP_BASE 2001000000
#define MAP_LDIMM64_POISON_PFX "200100" #define POISON_LDIMM64_MAP_PFX "200100"
static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx, static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx,
int insn_idx, struct bpf_insn *insn, 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 * invalid func unknown#2001000123
* where lower 123 is map index into obj->maps[] array * 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++; insn++;
} }
@@ -5885,7 +5886,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
} }
break; break;
case RELO_EXTERN_LD64: case RELO_EXTERN_LD64:
ext = &obj->externs[relo->sym_off]; ext = &obj->externs[relo->ext_idx];
if (ext->type == EXT_KCFG) { if (ext->type == EXT_KCFG) {
if (obj->gen_loader) { if (obj->gen_loader) {
insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE; 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; break;
case RELO_EXTERN_CALL: case RELO_EXTERN_CALL:
ext = &obj->externs[relo->sym_off]; ext = &obj->externs[relo->ext_idx];
insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL; insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
if (ext->is_set) { if (ext->is_set) {
insn[0].imm = ext->ksym.kernel_btf_id; 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 *buf, size_t buf_sz, size_t log_sz,
char *line1, char *line2, char *line3) 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 * line1 -> 123: (85) call unknown#2001000345
* line2 -> invalid func unknown#2001000345 * line2 -> invalid func unknown#2001000345
* line3 -> <anything else or end of buffer> * line3 -> <anything else or end of buffer>
* *
* "123" is the index of the instruction that was poisoned. * "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; struct bpf_object *obj = prog->obj;
const struct bpf_map *map; 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) if (sscanf(line1, "%d: (%*d) call unknown#%d\n", &insn_idx, &map_idx) != 2)
return; return;
map_idx -= MAP_LDIMM64_POISON_BASE; map_idx -= POISON_LDIMM64_MAP_BASE;
if (map_idx < 0 || map_idx >= obj->nr_maps) if (map_idx < 0 || map_idx >= obj->nr_maps)
return; return;
map = &obj->maps[map_idx]; 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) if (!cur_line)
return; return;
/* failed CO-RE relocation case */
if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) { if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) {
prev_line = find_prev_line(buf, cur_line); prev_line = find_prev_line(buf, cur_line);
if (!prev_line) if (!prev_line)
continue; continue;
/* failed CO-RE relocation case */
fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz, fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz,
prev_line, cur_line, next_line); prev_line, cur_line, next_line);
return; 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); prev_line = find_prev_line(buf, cur_line);
if (!prev_line) if (!prev_line)
continue; continue;
/* reference to uncreated BPF map */
fixup_log_missing_map_load(prog, buf, buf_sz, log_sz, fixup_log_missing_map_load(prog, buf, buf_sz, log_sz,
prev_line, cur_line, next_line); prev_line, cur_line, next_line);
return; return;
@@ -7098,7 +7100,7 @@ static int bpf_program_record_relos(struct bpf_program *prog)
for (i = 0; i < prog->nr_reloc; i++) { for (i = 0; i < prog->nr_reloc; i++) {
struct reloc_desc *relo = &prog->reloc_desc[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; int kind;
switch (relo->type) { switch (relo->type) {