tests: compile test_syscall with musl-gcc

In addition do a few more cleanups to the test:

- Use `atol` to read longs

- musl makes an ioctl that is not permitted in seccomp. We didn't use
  the return code anyway, so remove it.

Signed-off-by: Pablo Barbáchano <[email protected]>

Author: pb8o

tests/host_tools/test_syscalls.c

@@ -28,14 +28,14 @@ void install_bpf_filter(char *bpf_file) {
         exit(EXIT_FAILURE);
     }
     size_t size = sb.st_size;
-    size_t insn_len = size / sizeof(struct sock_filter);
     struct sock_filter *filterbuf = (struct sock_filter*)malloc(size);
     if (read(fd, filterbuf, size) == -1) {
         perror("read");
         exit(EXIT_FAILURE);
     }
 
     /* Install seccomp filter */
+    size_t insn_len = size / sizeof(struct sock_filter);
     struct sock_fprog prog = {
         .len = (unsigned short)(insn_len),
         .filter = filterbuf,
@@ -60,18 +60,17 @@ int main(int argc, char **argv) {
     char *bpf_file = argv[1];
     long syscall_id = atoi(argv[2]);
     long arg0, arg1, arg2, arg3;
-    arg0 = arg1 = arg2 = arg3 = 0;
-    if (argc > 3) arg0 = atoi(argv[3]);
-    if (argc > 4) arg1 = atoi(argv[4]);
-    if (argc > 5) arg2 = atoi(argv[5]);
-    if (argc > 6) arg3 = atoi(argv[6]);
+    arg0 = arg1 = arg2 = arg3 = 0L;
+    if (argc > 3) arg0 = atol(argv[3]);
+    if (argc > 4) arg1 = atol(argv[4]);
+    if (argc > 5) arg2 = atol(argv[5]);
+    if (argc > 6) arg3 = atol(argv[6]);
 
     /* read seccomp filter from file */
     if (strcmp(bpf_file, "/dev/null") != 0) {
         install_bpf_filter(bpf_file);
     }
 
     long res = syscall(syscall_id, arg0, arg1, arg2, arg3);
-    printf("%ld\n", res);
     return EXIT_SUCCESS;
 }

tests/integration_tests/security/test_seccomp_validate.py

@@ -13,18 +13,18 @@
 import seccomp
 
 from framework import utils
-from host_tools import cargo_build
 
 ARCH = platform.machine()
 
 
-@pytest.fixture(scope="session")
-def bin_test_syscall(test_fc_session_root_path):
+@pytest.fixture
+def bin_test_syscall(tmp_path):
     """Build the test_syscall binary."""
-    test_syscall_bin = Path(test_fc_session_root_path) / "test_syscall"
-    cargo_build.gcc_compile("host_tools/test_syscalls.c", test_syscall_bin)
+    test_syscall_bin = tmp_path / "test_syscall"
+    compile_cmd = f"musl-gcc -static host_tools/test_syscalls.c -o {test_syscall_bin}"
+    utils.check_output(compile_cmd)
     assert test_syscall_bin.exists()
-    yield test_syscall_bin
+    yield test_syscall_bin.resolve()
 
 
 class BpfMapReader:
@@ -77,11 +77,11 @@ def split(self):
         for _ in range(map_len):
             # read key
             key_str_len = self.read_format("<Q")
-            key_str = self.read_format(f"{key_str_len}s")
+            key_str = self.read_format(f"{key_str_len}s").decode("ascii")
             # read value: vec of instructions
             insn_len = self.read_format("<Q")
             data = self.lookahead(insn_len * self.INSN_SIZEOF)
-            threads[key_str.decode("ascii")] = data
+            threads[key_str] = data
             self.offset += len(data)
 
         assert self.is_eof()