Although part of all CO-RE relocation data, type based relocations do not require an access string. Initial implementation defined it as an empty string. On the other hand, libbpf when parsing the CO-RE relocations verifies that those strings would contain "0", otherwise reports an error. This patch makes GCC compliant with libbpf expectations.
gcc/Changelog: * config/bpf/btfext-out.cc (cpf_core_reloc_add): Correct for new code. Add assert to validate the string is set. * config/bpf/core-builtins.cc (cr_final): Make string struct field as const. (process_enum_value): Correct for field type change. (process_type): Set access string to "0". gcc/testsuite/ChangeLog: * gcc.target/bpf/core-builtin-type-based.c: Correct. * gcc.target/bpf/core-builtin-type-id.c: Correct. --- gcc/config/bpf/btfext-out.cc | 5 +++-- gcc/config/bpf/core-builtins.cc | 10 ++++++---- gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c | 1 + gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c | 1 + 4 files changed, 11 insertions(+), 6 deletions(-) diff --git a/gcc/config/bpf/btfext-out.cc b/gcc/config/bpf/btfext-out.cc index 57c0dc323812..ff1fd0739f1e 100644 --- a/gcc/config/bpf/btfext-out.cc +++ b/gcc/config/bpf/btfext-out.cc @@ -299,8 +299,9 @@ bpf_core_reloc_add (const tree type, const char * section_name, /* Buffer the access string in the auxiliary strtab. */ bpfcr->bpfcr_astr_off = 0; - if (accessor != NULL) - bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor); + gcc_assert (accessor != NULL); + bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor); + bpfcr->bpfcr_type = get_btf_id (ctf_lookup_tree_type (ctfc, type)); bpfcr->bpfcr_insn_label = label; bpfcr->bpfcr_kind = kind; diff --git a/gcc/config/bpf/core-builtins.cc b/gcc/config/bpf/core-builtins.cc index 4256fea15e49..70b14e48e6e5 100644 --- a/gcc/config/bpf/core-builtins.cc +++ b/gcc/config/bpf/core-builtins.cc @@ -205,7 +205,7 @@ struct cr_local /* Core Relocation Final data */ struct cr_final { - char *str; + const char *str; tree type; enum btf_core_reloc_kind kind; }; @@ -868,8 +868,10 @@ process_enum_value (struct cr_builtins *data) { if (TREE_VALUE (l) == expr) { - ret.str = (char *) ggc_alloc_atomic ((index / 10) + 1); - sprintf (ret.str, "%d", index); + char *tmp = (char *) ggc_alloc_atomic ((index / 10) + 1); + sprintf (tmp, "%d", index); + ret.str = (const char *) tmp; + break; } index++; @@ -987,7 +989,7 @@ process_type (struct cr_builtins *data) || data->kind == BPF_RELO_TYPE_MATCHES); struct cr_final ret; - ret.str = NULL; + ret.str = ggc_strdup ("0"); ret.type = data->type; ret.kind = data->kind; diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c index 74a8d5a14d9d..9d818133c084 100644 --- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c @@ -56,3 +56,4 @@ int foo(void *data) /* { dg-final { scan-assembler-times "0x8\[\t \]+\[^\n\]*bpfcr_kind" 13 } } BPF_TYPE_EXISTS */ /* { dg-final { scan-assembler-times "0x9\[\t \]+\[^\n\]*bpfcr_kind" 11 } } BPF_TYPE_SIZE */ /* { dg-final { scan-assembler-times "0xc\[\t \]+\[^\n\]*bpfcr_kind" 13 } } BPF_TYPE_MATCHES */ +/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 37 } } */ diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c index 4b23288eac08..9576b91bc940 100644 --- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c @@ -38,3 +38,4 @@ int foo(void *data) /* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_type" 0 { xfail *-*-* } } } */ /* { dg-final { scan-assembler-times "0x6\[\t \]+\[^\n\]*bpfcr_kind" 13 } } BPF_TYPE_ID_LOCAL */ /* { dg-final { scan-assembler-times "0x7\[\t \]+\[^\n\]*bpfcr_kind" 7 } } BPF_TYPE_ID_TARGET */ +/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 20 } } */ -- 2.30.2