Commit 8798902f authored by Leon Hwang's avatar Leon Hwang Committed by Alexei Starovoitov
Browse files

bpf: Add bpf_jit_supports_fsession() 



The added fsession does not prevent running on those architectures, that
haven't added fsession support.

For example, try to run fsession tests on arm64:

test_fsession_basic:PASS:fsession_test__open_and_load 0 nsec
test_fsession_basic:PASS:fsession_attach 0 nsec
check_result:FAIL:test_run_opts err unexpected error: -14 (errno 14)

In order to prevent such errors, add bpf_jit_supports_fsession() to guard
those architectures.

Fixes: 2d419c44 ("bpf: add fsession support")
Acked-by: default avatarPuranjay Mohan <puranjay@kernel.org>
Tested-by: default avatarPuranjay Mohan <puranjay@kernel.org>
Signed-off-by: default avatarLeon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260131144950.16294-2-leon.hwang@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f0b5b3d6

arch/x86/net/bpf_jit_comp.c

+5 −0
Original line number Diff line number Diff line
@@ -4112,3 +4112,8 @@ bool bpf_jit_supports_timed_may_goto(void) 
{

	return true;

}



bool bpf_jit_supports_fsession(void)

{

	return true;

}

include/linux/filter.h

+1 −0
Original line number Diff line number Diff line
@@ -1167,6 +1167,7 @@ bool bpf_jit_supports_arena(void); 
bool bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena);

bool bpf_jit_supports_private_stack(void);

bool bpf_jit_supports_timed_may_goto(void);

bool bpf_jit_supports_fsession(void);

u64 bpf_arch_uaddress_limit(void);

void arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie);

u64 arch_bpf_timed_may_goto(void);

kernel/bpf/core.c

+5 −0
Original line number Diff line number Diff line
@@ -3144,6 +3144,11 @@ bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena) 
	return false;

}



bool __weak bpf_jit_supports_fsession(void)

{

	return false;

}



u64 __weak bpf_arch_uaddress_limit(void)

{

#if defined(CONFIG_64BIT) && defined(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE)

kernel/bpf/verifier.c

+5 −0
Original line number Diff line number Diff line
@@ -24828,6 +24828,11 @@ int bpf_check_attach_target(struct bpf_verifier_log *log, 
	case BPF_TRACE_FENTRY:

	case BPF_TRACE_FEXIT:

	case BPF_TRACE_FSESSION:

		if (prog->expected_attach_type == BPF_TRACE_FSESSION &&

		    !bpf_jit_supports_fsession()) {

			bpf_log(log, "JIT does not support fsession\n");

			return -EOPNOTSUPP;

		}

		if (!btf_type_is_func(t)) {

			bpf_log(log, "attach_btf_id %u is not a function\n",

				btf_id);

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

+24 −8
Original line number Diff line number Diff line
@@ -29,8 +29,16 @@ static void test_fsession_basic(void) 
	struct fsession_test *skel = NULL;

	int err;



	skel = fsession_test__open_and_load();

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

	skel = fsession_test__open();

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

		return;



	err = fsession_test__load(skel);

	if (err == -EOPNOTSUPP) {

		test__skip();

		goto cleanup;

	}

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

		goto cleanup;



	err = fsession_test__attach(skel);
@@ -47,8 +55,16 @@ static void test_fsession_reattach(void) 
	struct fsession_test *skel = NULL;

	int err;



	skel = fsession_test__open_and_load();

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

	skel = fsession_test__open();

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

		return;



	err = fsession_test__load(skel);

	if (err == -EOPNOTSUPP) {

		test__skip();

		goto cleanup;

	}

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

		goto cleanup;



	/* first attach */
@@ -94,6 +110,10 @@ static void test_fsession_cookie(void) 
	bpf_program__set_autoload(skel->progs.test6, false);



	err = fsession_test__load(skel);

	if (err == -EOPNOTSUPP) {

		test__skip();

		goto cleanup;

	}

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

		goto cleanup;
@@ -111,10 +131,6 @@ static void test_fsession_cookie(void) 


void test_fsession_test(void)

{

#if !defined(__x86_64__)

	test__skip();

	return;

#endif

	if (test__start_subtest("fsession_test"))

		test_fsession_basic();

	if (test__start_subtest("fsession_reattach"))