This is a note to let you know that I've just added the patch titled selftests/bpf: Fix field existence CO-RE reloc tests to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-bpf-fix-field-existence-co-re-reloc-tests.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6ddc9e3146a67838d5925e89cd75f34b215bd2fb Author: Andrii Nakryiko <andrii@xxxxxxxxxx> Date: Mon Apr 26 12:29:48 2021 -0700 selftests/bpf: Fix field existence CO-RE reloc tests [ Upstream commit 5a30eb23922b52f33222c6729b6b3ff1c37a6c66 ] Negative field existence cases for have a broken assumption that FIELD_EXISTS CO-RE relo will fail for fields that match the name but have incompatible type signature. That's not how CO-RE relocations generally behave. Types and fields that match by name but not by expected type are treated as non-matching candidates and are skipped. Error later is reported if no matching candidate was found. That's what happens for most relocations, but existence relocations (FIELD_EXISTS and TYPE_EXISTS) are more permissive and they are designed to return 0 or 1, depending if a match is found. This allows to handle name-conflicting but incompatible types in BPF code easily. Combined with ___flavor suffixes, it's possible to handle pretty much any structural type changes in kernel within the compiled once BPF source code. So, long story short, negative field existence test cases are invalid in their assumptions, so this patch reworks them into a single consolidated positive case that doesn't match any of the fields. Fixes: c7566a69695c ("selftests/bpf: Add field existence CO-RE relocs tests") Reported-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> Acked-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/bpf/20210426192949.416837-5-andrii@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index 30e40ff4b0d8..e15c0903fa4d 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -185,11 +185,6 @@ static int duration = 0; .bpf_obj_file = "test_core_reloc_existence.o", \ .btf_src_file = "btf__core_reloc_" #name ".o" \ -#define FIELD_EXISTS_ERR_CASE(name) { \ - FIELD_EXISTS_CASE_COMMON(name), \ - .fails = true, \ -} - #define BITFIELDS_CASE_COMMON(objfile, test_name_prefix, name) \ .case_name = test_name_prefix#name, \ .bpf_obj_file = objfile, \ @@ -592,13 +587,25 @@ static struct core_reloc_test_case test_cases[] = { }, .output_len = sizeof(struct core_reloc_existence_output), }, - - FIELD_EXISTS_ERR_CASE(existence__err_int_sz), - FIELD_EXISTS_ERR_CASE(existence__err_int_type), - FIELD_EXISTS_ERR_CASE(existence__err_int_kind), - FIELD_EXISTS_ERR_CASE(existence__err_arr_kind), - FIELD_EXISTS_ERR_CASE(existence__err_arr_value_type), - FIELD_EXISTS_ERR_CASE(existence__err_struct_type), + { + FIELD_EXISTS_CASE_COMMON(existence___wrong_field_defs), + .input = STRUCT_TO_CHAR_PTR(core_reloc_existence___wrong_field_defs) { + }, + .input_len = sizeof(struct core_reloc_existence___wrong_field_defs), + .output = STRUCT_TO_CHAR_PTR(core_reloc_existence_output) { + .a_exists = 0, + .b_exists = 0, + .c_exists = 0, + .arr_exists = 0, + .s_exists = 0, + .a_value = 0xff000001u, + .b_value = 0xff000002u, + .c_value = 0xff000003u, + .arr_value = 0xff000004u, + .s_value = 0xff000005u, + }, + .output_len = sizeof(struct core_reloc_existence_output), + }, /* bitfield relocation checks */ BITFIELDS_CASE(bitfields, { diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c deleted file mode 100644 index dd0ffa518f36..000000000000 --- a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_kind.c +++ /dev/null @@ -1,3 +0,0 @@ -#include "core_reloc_types.h" - -void f(struct core_reloc_existence___err_wrong_arr_kind x) {} diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c deleted file mode 100644 index bc83372088ad..000000000000 --- a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_arr_value_type.c +++ /dev/null @@ -1,3 +0,0 @@ -#include "core_reloc_types.h" - -void f(struct core_reloc_existence___err_wrong_arr_value_type x) {} diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c deleted file mode 100644 index 917bec41be08..000000000000 --- a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_kind.c +++ /dev/null @@ -1,3 +0,0 @@ -#include "core_reloc_types.h" - -void f(struct core_reloc_existence___err_wrong_int_kind x) {} diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c deleted file mode 100644 index 6ec7e6ec1c91..000000000000 --- a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_sz.c +++ /dev/null @@ -1,3 +0,0 @@ -#include "core_reloc_types.h" - -void f(struct core_reloc_existence___err_wrong_int_sz x) {} diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c deleted file mode 100644 index 7bbcacf2b0d1..000000000000 --- a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_int_type.c +++ /dev/null @@ -1,3 +0,0 @@ -#include "core_reloc_types.h" - -void f(struct core_reloc_existence___err_wrong_int_type x) {} diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c deleted file mode 100644 index f384dd38ec70..000000000000 --- a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___err_wrong_struct_type.c +++ /dev/null @@ -1,3 +0,0 @@ -#include "core_reloc_types.h" - -void f(struct core_reloc_existence___err_wrong_struct_type x) {} diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___wrong_field_defs.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___wrong_field_defs.c new file mode 100644 index 000000000000..d14b496190c3 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_existence___wrong_field_defs.c @@ -0,0 +1,3 @@ +#include "core_reloc_types.h" + +void f(struct core_reloc_existence___wrong_field_defs x) {} diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h index e6e616cb7bc9..af58ef9a28ca 100644 --- a/tools/testing/selftests/bpf/progs/core_reloc_types.h +++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h @@ -683,27 +683,11 @@ struct core_reloc_existence___minimal { int a; }; -struct core_reloc_existence___err_wrong_int_sz { - short a; -}; - -struct core_reloc_existence___err_wrong_int_type { +struct core_reloc_existence___wrong_field_defs { + void *a; int b[1]; -}; - -struct core_reloc_existence___err_wrong_int_kind { struct{ int x; } c; -}; - -struct core_reloc_existence___err_wrong_arr_kind { int arr; -}; - -struct core_reloc_existence___err_wrong_arr_value_type { - short arr[1]; -}; - -struct core_reloc_existence___err_wrong_struct_type { int s; };