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: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220926153340.1621984-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa 2022-09-26 17:33:40 +02:00 committed by Alexei Starovoitov
parent 0e253f7e55
commit 738c345b74
2 changed files with 62 additions and 24 deletions

View file

@ -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");
#ifdef __x86_64__
ASSERT_EQ(skel->bss->test6_result, 1, "test6_result");
ASSERT_EQ(skel->bss->test7_result, 1, "test7_result");
#endif
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");
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();
}

View file

@ -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;
}