selftests/bpf: Fix core_reloc test failures on 32-bit

Update memory-layout, alignment, and expected results to ensure consistent
behaviour regardless of 32/64-bit host architecture, similar to a previous
fix [0]. All tests now pass on 32-bit armhf after these changes:

root@qemu-armhf:/usr/libexec/kselftests-bpf# ./test_progs -a core_reloc
torvalds#75/1    core_reloc/kernel:OK
torvalds#75/2    core_reloc/module_probed:OK
torvalds#75/3    core_reloc/module_direct:OK
[...]
torvalds#75/78   core_reloc/enum64val___err_missing:OK
torvalds#75      core_reloc:OK
Summary: 1/78 PASSED, 0 SKIPPED, 0 FAILED

0: 5705d70 ("selftests/bpf: Correct various core_reloc 64-bit assumptions")

Signed-off-by: Tony Ambardar <[email protected]>

Author: guidosarducci

tools/testing/selftests/bpf/prog_tests/core_reloc.c

@@ -790,11 +790,11 @@ static const struct core_reloc_test_case test_cases[] = {
 		.enum_sz = sizeof(enum an_enum),
 		.typedef_named_struct_sz = sizeof(named_struct_typedef),
 		.typedef_anon_struct_sz = sizeof(anon_struct_typedef),
-		.typedef_struct_ptr_sz = sizeof(struct_ptr_typedef),
+		.typedef_struct_ptr_sz = 8, /* always 8-byte pointer for BPF */
 		.typedef_int_sz = sizeof(int_typedef),
 		.typedef_enum_sz = sizeof(enum_typedef),
-		.typedef_void_ptr_sz = sizeof(void_ptr_typedef),
-		.typedef_func_proto_sz = sizeof(func_proto_typedef),
+		.typedef_void_ptr_sz = 8,   /* always 8-byte pointer for BPF */
+		.typedef_func_proto_sz = 8, /* always 8-byte pointer for BPF */
 		.typedef_arr_sz = sizeof(arr_typedef),
 	}),
 	TYPE_BASED_CASE(type_based___all_missing, {
@@ -832,11 +832,11 @@ static const struct core_reloc_test_case test_cases[] = {
 		.enum_sz = sizeof(enum an_enum___diff),
 		.typedef_named_struct_sz = sizeof(named_struct_typedef___diff),
 		.typedef_anon_struct_sz = sizeof(anon_struct_typedef___diff),
-		.typedef_struct_ptr_sz = sizeof(struct_ptr_typedef___diff),
+		.typedef_struct_ptr_sz = 8, /* always 8-byte pointer for BPF */
 		.typedef_int_sz = sizeof(int_typedef___diff),
 		.typedef_enum_sz = sizeof(enum_typedef___diff),
-		.typedef_void_ptr_sz = sizeof(void_ptr_typedef___diff),
-		.typedef_func_proto_sz = sizeof(func_proto_typedef___diff),
+		.typedef_void_ptr_sz = 8,   /* always 8-byte pointer for BPF */
+		.typedef_func_proto_sz = 8, /* always 8-byte pointer for BPF */
 		.typedef_arr_sz = sizeof(arr_typedef___diff),
 	}),
 	TYPE_BASED_CASE(type_based___diff_sz, {
@@ -869,11 +869,11 @@ static const struct core_reloc_test_case test_cases[] = {
 		.enum_sz = sizeof(enum an_enum___diff_sz),
 		.typedef_named_struct_sz = sizeof(named_struct_typedef___diff_sz),
 		.typedef_anon_struct_sz = sizeof(anon_struct_typedef___diff_sz),
-		.typedef_struct_ptr_sz = sizeof(struct_ptr_typedef___diff_sz),
+		.typedef_struct_ptr_sz = 8, /* always 8-byte pointer for BPF */
 		.typedef_int_sz = sizeof(int_typedef___diff_sz),
 		.typedef_enum_sz = sizeof(enum_typedef___diff_sz),
-		.typedef_void_ptr_sz = sizeof(void_ptr_typedef___diff_sz),
-		.typedef_func_proto_sz = sizeof(func_proto_typedef___diff_sz),
+		.typedef_void_ptr_sz = 8,   /* always 8-byte pointer for BPF */
+		.typedef_func_proto_sz = 8, /* always 8-byte pointer for BPF */
 		.typedef_arr_sz = sizeof(arr_typedef___diff_sz),
 	}),
 	TYPE_BASED_CASE(type_based___incompat, {

tools/testing/selftests/bpf/progs/core_reloc_types.h

@@ -818,8 +818,8 @@ struct core_reloc_size {
 	struct { int x; } struct_field;
 	union { int x; } union_field;
 	int arr_field[4];
-	void *ptr_field;
-	enum { VALUE = 123 } enum_field;
+	void *ptr_field __bpf_aligned;
+	enum { VALUE = 123 } enum_field __bpf_aligned;
 	float float_field;
 };
 
@@ -828,16 +828,16 @@ struct core_reloc_size___diff_sz {
 	struct { int x; int y; int z; } struct_field;
 	union { int x; char bla[123]; } union_field;
 	char arr_field[10];
-	void *ptr_field;
-	enum { OTHER_VALUE = 0xFFFFFFFFFFFFFFFF } enum_field;
+	void *ptr_field __bpf_aligned;
+	enum { OTHER_VALUE = 0xFFFFFFFFFFFFFFFF } enum_field __bpf_aligned;
 	double float_field;
 };
 
 struct core_reloc_size___diff_offs {
 	float float_field;
 	enum { YET_OTHER_VALUE = 123 } enum_field;
-	void *ptr_field;
-	int arr_field[4];
+	void * ptr_field __bpf_aligned;
+	int arr_field[4] __bpf_aligned;
 	union { int x; } union_field;
 	struct { int x; } struct_field;
 	int int_field;
@@ -1041,8 +1041,8 @@ struct core_reloc_type_based___diff {
 
 /* different type sizes, extra modifiers, anon vs named enums, etc */
 struct a_struct___diff_sz {
-	long x;
-	int y;
+	long x __bpf_aligned;
+	int y __bpf_aligned;
 	char z;
 };
 
@@ -1053,7 +1053,11 @@ union a_union___diff_sz {
 
 typedef struct a_struct___diff_sz named_struct_typedef___diff_sz;
 
-typedef struct { long xx, yy, zzz; } anon_struct_typedef___diff_sz;
+typedef struct {
+	long xx __bpf_aligned;
+	long yy __bpf_aligned;
+	long zz __bpf_aligned;
+} anon_struct_typedef___diff_sz;
 
 typedef struct {
 	char aa[1], bb[2], cc[3];
@@ -1064,7 +1068,7 @@ enum an_enum___diff_sz {
 	AN_ENUM_VAL2___diff_sz = 2,
 };
 
-typedef unsigned long int_typedef___diff_sz;
+typedef unsigned int int_typedef___diff_sz;
 
 typedef enum an_enum___diff_sz enum_typedef___diff_sz;