[PATCH AUTOSEL 5.7 25/54] selftests/bpf: Correct various core_reloc 64-bit assumptions

From: Sasha Levin
Date: Mon Aug 24 2020 - 13:11:39 EST


From: Andrii Nakryiko <andriin@xxxxxx>

[ Upstream commit 5705d705832f74395c5465ce93192688f543006a ]

Ensure that types are memory layout- and field alignment-compatible regardless
of 32/64-bitness mix of libbpf and BPF architecture.

Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-8-andriin@xxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/core_reloc.c | 20 +++---
.../selftests/bpf/progs/core_reloc_types.h | 69 ++++++++++---------
2 files changed, 47 insertions(+), 42 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 084ed26a7d78c..a54eafc5e4b31 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -237,8 +237,8 @@
.union_sz = sizeof(((type *)0)->union_field), \
.arr_sz = sizeof(((type *)0)->arr_field), \
.arr_elem_sz = sizeof(((type *)0)->arr_field[0]), \
- .ptr_sz = sizeof(((type *)0)->ptr_field), \
- .enum_sz = sizeof(((type *)0)->enum_field), \
+ .ptr_sz = 8, /* always 8-byte pointer for BPF */ \
+ .enum_sz = sizeof(((type *)0)->enum_field), \
}

#define SIZE_CASE(name) { \
@@ -432,20 +432,20 @@ static struct core_reloc_test_case test_cases[] = {
.sb4 = -1,
.sb20 = -0x17654321,
.u32 = 0xBEEF,
- .s32 = -0x3FEDCBA987654321,
+ .s32 = -0x3FEDCBA987654321LL,
}),
BITFIELDS_CASE(bitfields___bitfield_vs_int, {
- .ub1 = 0xFEDCBA9876543210,
+ .ub1 = 0xFEDCBA9876543210LL,
.ub2 = 0xA6,
- .ub7 = -0x7EDCBA987654321,
- .sb4 = -0x6123456789ABCDE,
- .sb20 = 0xD00D,
+ .ub7 = -0x7EDCBA987654321LL,
+ .sb4 = -0x6123456789ABCDELL,
+ .sb20 = 0xD00DLL,
.u32 = -0x76543,
- .s32 = 0x0ADEADBEEFBADB0B,
+ .s32 = 0x0ADEADBEEFBADB0BLL,
}),
BITFIELDS_CASE(bitfields___just_big_enough, {
- .ub1 = 0xF,
- .ub2 = 0x0812345678FEDCBA,
+ .ub1 = 0xFLL,
+ .ub2 = 0x0812345678FEDCBALL,
}),
BITFIELDS_ERR_CASE(bitfields___err_too_big_bitfield),

diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 6d598cfbdb3e2..f9da9f62c4b34 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -1,5 +1,10 @@
#include <stdint.h>
#include <stdbool.h>
+
+void preserce_ptr_sz_fn(long x) {}
+
+#define __bpf_aligned __attribute__((aligned(8)))
+
/*
* KERNEL
*/
@@ -444,51 +449,51 @@ struct core_reloc_primitives {
char a;
int b;
enum core_reloc_primitives_enum c;
- void *d;
- int (*f)(const char *);
+ void *d __bpf_aligned;
+ int (*f)(const char *) __bpf_aligned;
};

struct core_reloc_primitives___diff_enum_def {
char a;
int b;
- void *d;
- int (*f)(const char *);
+ void *d __bpf_aligned;
+ int (*f)(const char *) __bpf_aligned;
enum {
X = 100,
Y = 200,
- } c; /* inline enum def with differing set of values */
+ } c __bpf_aligned; /* inline enum def with differing set of values */
};

struct core_reloc_primitives___diff_func_proto {
- void (*f)(int); /* incompatible function prototype */
- void *d;
- enum core_reloc_primitives_enum c;
+ void (*f)(int) __bpf_aligned; /* incompatible function prototype */
+ void *d __bpf_aligned;
+ enum core_reloc_primitives_enum c __bpf_aligned;
int b;
char a;
};

struct core_reloc_primitives___diff_ptr_type {
- const char * const d; /* different pointee type + modifiers */
- char a;
+ const char * const d __bpf_aligned; /* different pointee type + modifiers */
+ char a __bpf_aligned;
int b;
enum core_reloc_primitives_enum c;
- int (*f)(const char *);
+ int (*f)(const char *) __bpf_aligned;
};

struct core_reloc_primitives___err_non_enum {
char a[1];
int b;
int c; /* int instead of enum */
- void *d;
- int (*f)(const char *);
+ void *d __bpf_aligned;
+ int (*f)(const char *) __bpf_aligned;
};

struct core_reloc_primitives___err_non_int {
char a[1];
- int *b; /* ptr instead of int */
- enum core_reloc_primitives_enum c;
- void *d;
- int (*f)(const char *);
+ int *b __bpf_aligned; /* ptr instead of int */
+ enum core_reloc_primitives_enum c __bpf_aligned;
+ void *d __bpf_aligned;
+ int (*f)(const char *) __bpf_aligned;
};

struct core_reloc_primitives___err_non_ptr {
@@ -496,7 +501,7 @@ struct core_reloc_primitives___err_non_ptr {
int b;
enum core_reloc_primitives_enum c;
int d; /* int instead of ptr */
- int (*f)(const char *);
+ int (*f)(const char *) __bpf_aligned;
};

/*
@@ -507,7 +512,7 @@ struct core_reloc_mods_output {
};

typedef const int int_t;
-typedef const char *char_ptr_t;
+typedef const char *char_ptr_t __bpf_aligned;
typedef const int arr_t[7];

struct core_reloc_mods_substruct {
@@ -523,9 +528,9 @@ typedef struct {
struct core_reloc_mods {
int a;
int_t b;
- char *c;
+ char *c __bpf_aligned;
char_ptr_t d;
- int e[3];
+ int e[3] __bpf_aligned;
arr_t f;
struct core_reloc_mods_substruct g;
core_reloc_mods_substruct_t h;
@@ -535,9 +540,9 @@ struct core_reloc_mods {
struct core_reloc_mods___mod_swap {
int b;
int_t a;
- char *d;
+ char *d __bpf_aligned;
char_ptr_t c;
- int f[3];
+ int f[3] __bpf_aligned;
arr_t e;
struct {
int y;
@@ -555,7 +560,7 @@ typedef arr1_t arr2_t;
typedef arr2_t arr3_t;
typedef arr3_t arr4_t;

-typedef const char * const volatile fancy_char_ptr_t;
+typedef const char * const volatile fancy_char_ptr_t __bpf_aligned;

typedef core_reloc_mods_substruct_t core_reloc_mods_substruct_tt;

@@ -567,7 +572,7 @@ struct core_reloc_mods___typedefs {
arr4_t e;
fancy_char_ptr_t d;
fancy_char_ptr_t c;
- int3_t b;
+ int3_t b __bpf_aligned;
int3_t a;
};

@@ -739,19 +744,19 @@ struct core_reloc_bitfields___bit_sz_change {
int8_t sb4: 1; /* 4 -> 1 */
int32_t sb20: 30; /* 20 -> 30 */
/* non-bitfields */
- uint16_t u32; /* 32 -> 16 */
- int64_t s32; /* 32 -> 64 */
+ uint16_t u32; /* 32 -> 16 */
+ int64_t s32 __bpf_aligned; /* 32 -> 64 */
};

/* turn bitfield into non-bitfield and vice versa */
struct core_reloc_bitfields___bitfield_vs_int {
uint64_t ub1; /* 3 -> 64 non-bitfield */
uint8_t ub2; /* 20 -> 8 non-bitfield */
- int64_t ub7; /* 7 -> 64 non-bitfield signed */
- int64_t sb4; /* 4 -> 64 non-bitfield signed */
- uint64_t sb20; /* 20 -> 16 non-bitfield unsigned */
- int32_t u32: 20; /* 32 non-bitfield -> 20 bitfield */
- uint64_t s32: 60; /* 32 non-bitfield -> 60 bitfield */
+ int64_t ub7 __bpf_aligned; /* 7 -> 64 non-bitfield signed */
+ int64_t sb4 __bpf_aligned; /* 4 -> 64 non-bitfield signed */
+ uint64_t sb20 __bpf_aligned; /* 20 -> 16 non-bitfield unsigned */
+ int32_t u32: 20; /* 32 non-bitfield -> 20 bitfield */
+ uint64_t s32: 60 __bpf_aligned; /* 32 non-bitfield -> 60 bitfield */
};

struct core_reloc_bitfields___just_big_enough {
--
2.25.1