From: Eduard Zingerman eddyz87@gmail.com
[ Upstream commit 203e6aba7692bca18fd97251b1354da0f5e2ba30 ]
Adjust disasm_helpers.c:disasm_insn() to account for the following part of the verifier.c:jit_subprogs:
for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) { /* ... */ if (!bpf_pseudo_call(insn)) continue; insn->off = env->insn_aux_data[i].call_imm; subprog = find_subprog(env, i + insn->off + 1); insn->imm = subprog; }
Where verifier moves offset of the subprogram to the insn->off field.
Signed-off-by: Eduard Zingerman eddyz87@gmail.com Link: https://lore.kernel.org/r/20240722233844.1406874-6-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Shung-Hsi Yu shung-hsi.yu@suse.com --- tools/testing/selftests/bpf/disasm_helpers.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/tools/testing/selftests/bpf/disasm_helpers.c b/tools/testing/selftests/bpf/disasm_helpers.c index 96b1f2ffe438..f529f1c8c171 100644 --- a/tools/testing/selftests/bpf/disasm_helpers.c +++ b/tools/testing/selftests/bpf/disasm_helpers.c @@ -4,6 +4,7 @@ #include "disasm.h"
struct print_insn_context { + char scratch[16]; char *buf; size_t sz; }; @@ -18,6 +19,22 @@ static void print_insn_cb(void *private_data, const char *fmt, ...) va_end(args); }
+static const char *print_call_cb(void *private_data, const struct bpf_insn *insn) +{ + struct print_insn_context *ctx = private_data; + + /* For pseudo calls verifier.c:jit_subprogs() hides original + * imm to insn->off and changes insn->imm to be an index of + * the subprog instead. + */ + if (insn->src_reg == BPF_PSEUDO_CALL) { + snprintf(ctx->scratch, sizeof(ctx->scratch), "%+d", insn->off); + return ctx->scratch; + } + + return NULL; +} + struct bpf_insn *disasm_insn(struct bpf_insn *insn, char *buf, size_t buf_sz) { struct print_insn_context ctx = { @@ -26,6 +43,7 @@ struct bpf_insn *disasm_insn(struct bpf_insn *insn, char *buf, size_t buf_sz) }; struct bpf_insn_cbs cbs = { .cb_print = print_insn_cb, + .cb_call = print_call_cb, .private_data = &ctx, }; char *tmp, *pfx_end, *sfx_start;