From: Viktor Malik Date: Thu, 26 Jun 2025 06:08:30 +0000 (+0200) Subject: selftests/bpf: Allow macros in __retval X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a55b7d39328bc6de1131cb5496816129cab2728b;p=thirdparty%2Flinux.git selftests/bpf: Allow macros in __retval Allow macro expansion for values passed to the `__retval` and `__retval_unpriv` attributes. This is especially useful for testing programs which return various error codes. With this change, the code for parsing special literals can be made simpler, as the literals are defined via macros. The only exception is INT_MIN which expands to (-INT_MAX -1), which is not single number and cannot be parsed by strtol. So, we instead use a prefixed literal _INT_MIN in __retval and handle it separately (assign the expected return to INT_MIN). Also, strtol cannot handle the "ll" suffix so change the value of POINTER_VALUE from 0xcafe4all to 0xbadcafe. Signed-off-by: Viktor Malik Link: https://lore.kernel.org/r/a6c6b551ae0575351faa7b7a1df52f9341a5cbe8.1750917800.git.vmalik@redhat.com Signed-off-by: Alexei Starovoitov --- diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h index a678463e972c3..20dce508d8e0e 100644 --- a/tools/testing/selftests/bpf/progs/bpf_misc.h +++ b/tools/testing/selftests/bpf/progs/bpf_misc.h @@ -83,9 +83,11 @@ * expect return value to match passed parameter: * - a decimal number * - a hexadecimal number, when starts from 0x - * - literal INT_MIN - * - literal POINTER_VALUE (see definition below) - * - literal TEST_DATA_LEN (see definition below) + * - a macro which expands to one of the above + * - literal _INT_MIN (expands to INT_MIN) + * In addition, two special macros are defined below: + * - POINTER_VALUE + * - TEST_DATA_LEN * __retval_unpriv Same, but load program in unprivileged mode. * * __description Text to be used instead of a program name for display @@ -125,8 +127,8 @@ #define __success_unpriv __attribute__((btf_decl_tag("comment:test_expect_success_unpriv"))) #define __log_level(lvl) __attribute__((btf_decl_tag("comment:test_log_level="#lvl))) #define __flag(flag) __attribute__((btf_decl_tag("comment:test_prog_flags="#flag))) -#define __retval(val) __attribute__((btf_decl_tag("comment:test_retval="#val))) -#define __retval_unpriv(val) __attribute__((btf_decl_tag("comment:test_retval_unpriv="#val))) +#define __retval(val) __attribute__((btf_decl_tag("comment:test_retval="XSTR(val)))) +#define __retval_unpriv(val) __attribute__((btf_decl_tag("comment:test_retval_unpriv="XSTR(val)))) #define __auxiliary __attribute__((btf_decl_tag("comment:test_auxiliary"))) #define __auxiliary_unpriv __attribute__((btf_decl_tag("comment:test_auxiliary_unpriv"))) #define __btf_path(path) __attribute__((btf_decl_tag("comment:test_btf_path=" path))) @@ -155,7 +157,7 @@ #define __imm_insn(name, expr) [name]"i"(*(long *)&(expr)) /* Magic constants used with __retval() */ -#define POINTER_VALUE 0xcafe4all +#define POINTER_VALUE 0xbadcafe #define TEST_DATA_LEN 64 #ifndef __used diff --git a/tools/testing/selftests/bpf/progs/verifier_div_overflow.c b/tools/testing/selftests/bpf/progs/verifier_div_overflow.c index 458984da804c9..34e0c012ee769 100644 --- a/tools/testing/selftests/bpf/progs/verifier_div_overflow.c +++ b/tools/testing/selftests/bpf/progs/verifier_div_overflow.c @@ -77,7 +77,7 @@ l0_%=: exit; \ SEC("tc") __description("MOD32 overflow, check 1") -__success __retval(INT_MIN) +__success __retval(_INT_MIN) __naked void mod32_overflow_check_1(void) { asm volatile (" \ @@ -92,7 +92,7 @@ __naked void mod32_overflow_check_1(void) SEC("tc") __description("MOD32 overflow, check 2") -__success __retval(INT_MIN) +__success __retval(_INT_MIN) __naked void mod32_overflow_check_2(void) { asm volatile (" \ diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c index 2c7e9729d5feb..78423cf89e01b 100644 --- a/tools/testing/selftests/bpf/test_loader.c +++ b/tools/testing/selftests/bpf/test_loader.c @@ -40,7 +40,7 @@ #define TEST_TAG_LOAD_MODE_PFX "comment:load_mode=" /* Warning: duplicated in bpf_misc.h */ -#define POINTER_VALUE 0xcafe4all +#define POINTER_VALUE 0xbadcafe #define TEST_DATA_LEN 64 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS @@ -318,20 +318,14 @@ static int parse_caps(const char *str, __u64 *val, const char *name) static int parse_retval(const char *str, int *val, const char *name) { - struct { - char *name; - int val; - } named_values[] = { - { "INT_MIN" , INT_MIN }, - { "POINTER_VALUE", POINTER_VALUE }, - { "TEST_DATA_LEN", TEST_DATA_LEN }, - }; - int i; - - for (i = 0; i < ARRAY_SIZE(named_values); ++i) { - if (strcmp(str, named_values[i].name) != 0) - continue; - *val = named_values[i].val; + /* + * INT_MIN is defined as (-INT_MAX -1), i.e. it doesn't expand to a + * single int and cannot be parsed with strtol, so we handle it + * separately here. In addition, it expands to different expressions in + * different compilers so we use a prefixed _INT_MIN instead. + */ + if (strcmp(str, "_INT_MIN") == 0) { + *val = INT_MIN; return 0; }