From: Larysa Zaremba <larysa.zaremba@xxxxxxxxx> Return both BTF type id and BTF object id from bpf_core_type_id_kernel(). Earlier only type id was returned despite the fact that llvm has enabled the 64-bit return type for this instruction [1]. This was done as a preparation to the patch [2], which also strongly served as a inspiration for this implementation. [1] https://reviews.llvm.org/D91489 [2] https://lore.kernel.org/all/20201205025140.443115-1-andrii@xxxxxxxxxx Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx> Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> --- tools/lib/bpf/bpf_core_read.h | 3 ++- tools/lib/bpf/relo_core.c | 8 +++++++- tools/lib/bpf/relo_core.h | 1 + 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index 496e6a8ee0dc..f033ec65fc01 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -168,7 +168,8 @@ enum bpf_enum_value_kind { * Convenience macro to get BTF type ID of a target kernel's type that matches * specified local type. * Returns: - * - valid 32-bit unsigned type ID in kernel BTF; + * - valid 64-bit unsigned integer: the upper 32 bits is the BTF object ID + * and the lower 32 bits is the BTF type ID within the BTF object. * - 0, if no matching type was found in a target kernel BTF. */ #define bpf_core_type_id_kernel(type) \ diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index c4b0e81ae293..ca94f8e2c698 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -892,6 +892,7 @@ static int bpf_core_calc_relo(const char *prog_name, res->fail_memsz_adjust = false; res->orig_sz = res->new_sz = 0; res->orig_type_id = res->new_type_id = 0; + res->btf_obj_id = 0; if (core_relo_is_field_based(relo->kind)) { err = bpf_core_calc_field_relo(prog_name, relo, local_spec, @@ -942,6 +943,8 @@ static int bpf_core_calc_relo(const char *prog_name, } else if (core_relo_is_type_based(relo->kind)) { err = bpf_core_calc_type_relo(relo, local_spec, &res->orig_val, &res->validate); err = err ?: bpf_core_calc_type_relo(relo, targ_spec, &res->new_val, NULL); + if (!err && relo->kind == BPF_CORE_TYPE_ID_TARGET) + res->btf_obj_id = btf_obj_id(targ_spec->btf); } else if (core_relo_is_enumval_based(relo->kind)) { err = bpf_core_calc_enumval_relo(relo, local_spec, &res->orig_val); err = err ?: bpf_core_calc_enumval_relo(relo, targ_spec, &res->new_val); @@ -1133,7 +1136,10 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, } insn[0].imm = new_val; - insn[1].imm = new_val >> 32; + /* For type IDs, upper 32 bits are used for BTF object ID */ + insn[1].imm = relo->kind == BPF_CORE_TYPE_ID_TARGET ? + res->btf_obj_id : + (new_val >> 32); pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %llu\n", prog_name, relo_idx, insn_idx, (unsigned long long)imm, (unsigned long long)new_val); diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h index 1c0566daf8e8..52de7c018fb8 100644 --- a/tools/lib/bpf/relo_core.h +++ b/tools/lib/bpf/relo_core.h @@ -66,6 +66,7 @@ struct bpf_core_relo_res { __u32 orig_type_id; __u32 new_sz; __u32 new_type_id; + __u32 btf_obj_id; }; int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
