selftests/bpf: Double the size of test_loader log

Testing long jumps requires having >32k instructions. That many
instructions require the verifier log buffer of 2 megabytes.

The regular test_progs run doesn't need an increased buffer, since
gotol test with 40k instructions doesn't request a log,
but test_progs -v will set the verifier log level.
Hence to avoid breaking gotol test with -v increase the buffer size.

Signed-off-by: Ilya Leoshkevich <[e-mail]>
Acked-by: Yonghong Song <[e-mail]>
Acked-by: John Fastabend <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexei Starovoitov <[e-mail]>

tools/testing/selftests/bpf/test_loader.c

···
 #define str_has_pfx(str, pfx) \
 	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
 
-#define TEST_LOADER_LOG_BUF_SZ 1048576
+#define TEST_LOADER_LOG_BUF_SZ 2097152
 
 #define TEST_TAG_EXPECT_FAILURE "comment:test_expect_failure"
 #define TEST_TAG_EXPECT_SUCCESS "comment:test_expect_success"