Commit be983f44 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
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selftests/bpf: Add testing of log_buf==NULL condition for BPF_PROG_LOAD 



Add few extra test conditions to validate that it's ok to pass
log_buf==NULL and log_size==0 to BPF_PROG_LOAD command with the intent
to get log_true_size without providing a buffer.

Test that log_buf==NULL condition *does not* return -ENOSPC.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarLorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-19-andrii@kernel.org
parent 57875408

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

+23 −0
Original line number Diff line number Diff line
@@ -178,26 +178,47 @@ static void verif_log_subtest(const char *name, bool expect_load_error, int log_ 
	opts.log_buf = logs.buf;

	opts.log_level = log_level | 8; /* BPF_LOG_FIXED */

	opts.log_size = sizeof(logs.buf);

	opts.log_true_size = 0;

	res = load_prog(&opts, expect_load_error);

	ASSERT_NEQ(res, -ENOSPC, "prog_load_res_fixed");



	log_true_sz_fixed = opts.log_true_size;

	ASSERT_GT(log_true_sz_fixed, 0, "log_true_sz_fixed");



	/* (FIXED, NULL) get actual log size */

	opts.log_buf = NULL;

	opts.log_level = log_level | 8; /* BPF_LOG_FIXED */

	opts.log_size = 0;

	opts.log_true_size = 0;

	res = load_prog(&opts, expect_load_error);

	ASSERT_NEQ(res, -ENOSPC, "prog_load_res_fixed_null");

	ASSERT_EQ(opts.log_true_size, log_true_sz_fixed, "log_sz_fixed_null_eq");



	/* (ROLLING) get actual log size */

	opts.log_buf = logs.buf;

	opts.log_level = log_level;

	opts.log_size = sizeof(logs.buf);

	opts.log_true_size = 0;

	res = load_prog(&opts, expect_load_error);

	ASSERT_NEQ(res, -ENOSPC, "prog_load_res_rolling");



	log_true_sz_rolling = opts.log_true_size;

	ASSERT_EQ(log_true_sz_rolling, log_true_sz_fixed, "log_true_sz_eq");



	/* (ROLLING, NULL) get actual log size */

	opts.log_buf = NULL;

	opts.log_level = log_level;

	opts.log_size = 0;

	opts.log_true_size = 0;

	res = load_prog(&opts, expect_load_error);

	ASSERT_NEQ(res, -ENOSPC, "prog_load_res_rolling_null");

	ASSERT_EQ(opts.log_true_size, log_true_sz_rolling, "log_true_sz_null_eq");



	/* (FIXED) expect -ENOSPC for one byte short log */

	opts.log_buf = logs.buf;

	opts.log_level = log_level | 8; /* BPF_LOG_FIXED */

	opts.log_size = log_true_sz_fixed - 1;

	opts.log_true_size = 0;

	res = load_prog(&opts, true /* should fail */);

	ASSERT_EQ(res, -ENOSPC, "prog_load_res_too_short_fixed");
@@ -205,6 +226,7 @@ static void verif_log_subtest(const char *name, bool expect_load_error, int log_ 
	opts.log_buf = logs.buf;

	opts.log_level = log_level | 8; /* BPF_LOG_FIXED */

	opts.log_size = log_true_sz_fixed;

	opts.log_true_size = 0;

	res = load_prog(&opts, expect_load_error);

	ASSERT_NEQ(res, -ENOSPC, "prog_load_res_just_right_fixed");
@@ -219,6 +241,7 @@ static void verif_log_subtest(const char *name, bool expect_load_error, int log_ 
	opts.log_buf = logs.buf;

	opts.log_level = log_level;

	opts.log_size = log_true_sz_rolling;

	opts.log_true_size = 0;

	res = load_prog(&opts, expect_load_error);

	ASSERT_NEQ(res, -ENOSPC, "prog_load_res_just_right_rolling");