Commit 738c345b authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

selftests/bpf: Fix get_func_ip offset test for CONFIG_X86_KERNEL_IBT 



With CONFIG_X86_KERNEL_IBT enabled the test for kprobe with offset
won't work because of the extra endbr instruction.

As suggested by Andrii adding CONFIG_X86_KERNEL_IBT detection
and using appropriate offset value based on that.

Also removing test7 program, because it does the same as test6.

Suggested-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220926153340.1621984-7-jolsa@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 0e253f7e

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

+48 −11
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
#include <test_progs.h>

#include "get_func_ip_test.skel.h"



void test_get_func_ip_test(void)

static void test_function_entry(void)

{

	struct get_func_ip_test *skel = NULL;

	int err, prog_fd;
@@ -12,14 +12,6 @@ void test_get_func_ip_test(void) 
	if (!ASSERT_OK_PTR(skel, "get_func_ip_test__open"))

		return;



	/* test6 is x86_64 specifc because of the instruction

	 * offset, disabling it for all other archs

	 */

#ifndef __x86_64__

	bpf_program__set_autoload(skel->progs.test6, false);

	bpf_program__set_autoload(skel->progs.test7, false);

#endif



	err = get_func_ip_test__load(skel);

	if (!ASSERT_OK(err, "get_func_ip_test__load"))

		goto cleanup;
@@ -43,11 +35,56 @@ void test_get_func_ip_test(void) 
	ASSERT_EQ(skel->bss->test3_result, 1, "test3_result");

	ASSERT_EQ(skel->bss->test4_result, 1, "test4_result");

	ASSERT_EQ(skel->bss->test5_result, 1, "test5_result");



cleanup:

	get_func_ip_test__destroy(skel);

}



/* test6 is x86_64 specific because of the instruction

 * offset, disabling it for all other archs

 */

#ifdef __x86_64__

static void test_function_body(void)

{

	struct get_func_ip_test *skel = NULL;

	LIBBPF_OPTS(bpf_test_run_opts, topts);

	LIBBPF_OPTS(bpf_kprobe_opts, kopts);

	struct bpf_link *link6 = NULL;

	int err, prog_fd;



	skel = get_func_ip_test__open();

	if (!ASSERT_OK_PTR(skel, "get_func_ip_test__open"))

		return;



	bpf_program__set_autoload(skel->progs.test6, true);



	err = get_func_ip_test__load(skel);

	if (!ASSERT_OK(err, "get_func_ip_test__load"))

		goto cleanup;



	kopts.offset = skel->kconfig->CONFIG_X86_KERNEL_IBT ? 9 : 5;



	link6 = bpf_program__attach_kprobe_opts(skel->progs.test6, "bpf_fentry_test6", &kopts);

	if (!ASSERT_OK_PTR(link6, "link6"))

		goto cleanup;



	prog_fd = bpf_program__fd(skel->progs.test1);

	err = bpf_prog_test_run_opts(prog_fd, &topts);

	ASSERT_OK(err, "test_run");

	ASSERT_EQ(topts.retval, 0, "test_run");



	ASSERT_EQ(skel->bss->test6_result, 1, "test6_result");

	ASSERT_EQ(skel->bss->test7_result, 1, "test7_result");

#endif



cleanup:

	bpf_link__destroy(link6);

	get_func_ip_test__destroy(skel);

}

#else

#define test_function_body()

#endif



void test_get_func_ip_test(void)

{

	test_function_entry();

	test_function_body();

}

tools/testing/selftests/bpf/progs/get_func_ip_test.c

+12 −11
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <stdbool.h>



char _license[] SEC("license") = "GPL";
@@ -13,6 +14,16 @@ extern const void bpf_modify_return_test __ksym; 
extern const void bpf_fentry_test6 __ksym;

extern const void bpf_fentry_test7 __ksym;



extern bool CONFIG_X86_KERNEL_IBT __kconfig __weak;



/* This function is here to have CONFIG_X86_KERNEL_IBT

 * used and added to object BTF.

 */

int unused(void)

{

	return CONFIG_X86_KERNEL_IBT ? 0 : 1;

}



__u64 test1_result = 0;

SEC("fentry/bpf_fentry_test1")

int BPF_PROG(test1, int a)
@@ -64,7 +75,7 @@ int BPF_PROG(test5, int a, int *b, int ret) 
}



__u64 test6_result = 0;

SEC("kprobe/bpf_fentry_test6+0x5")

SEC("?kprobe")

int test6(struct pt_regs *ctx)

{

	__u64 addr = bpf_get_func_ip(ctx);
@@ -72,13 +83,3 @@ int test6(struct pt_regs *ctx) 
	test6_result = (const void *) addr == 0;

	return 0;

}
 


__u64 test7_result = 0;

SEC("kprobe/bpf_fentry_test7+5")

int test7(struct pt_regs *ctx)

{

	__u64 addr = bpf_get_func_ip(ctx);



	test7_result = (const void *) addr == 0;

	return 0;

}