diff options
Diffstat (limited to 'internal/generate/codegen_test.go')
| -rw-r--r-- | internal/generate/codegen_test.go | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/internal/generate/codegen_test.go b/internal/generate/codegen_test.go index 3178b1c..da86b86 100644 --- a/internal/generate/codegen_test.go +++ b/internal/generate/codegen_test.go @@ -132,6 +132,52 @@ func TestGeneratePidfdGetfdHandlerUsesPidfdArgument(t *testing.T) { requireContains(t, output, "ev->fd = (__s32)ctx->args[0];") } +// TestGenerateKexecFileLoadHandler locks in the generated BPF C for +// kexec_file_load(2): +// +// long kexec_file_load(int kernel_fd, int initrd_fd, +// unsigned long cmdline_len, const char *cmdline, +// unsigned long flags) +// +// kexec_file_load loads a new kernel (and optional initrd) from open file +// descriptors so it can later be booted by reboot(2); it returns 0 on success +// or -1 on error. The leading kernel_fd (args[0]) makes the enter a KindFd +// fd_event capturing ev->fd = args[0]. There are TWO fds (kernel_fd at args[0], +// initrd_fd at args[1]); by the single-fd KindFd convention only the first +// (kernel_fd) is captured, so the handler must NOT wire args[1]. Critically, +// cmdline_ptr (args[3]) is a command-line STRING for the new kernel, NOT a +// filesystem path, so it must NOT be read with bpf_probe_read_user_str. On exit +// kexec_file_load returns 0/-1 — UNCLASSIFIED (a plain ret_event, no +// read/write/transfer byte count). It shares FamilySecurity with its sibling +// kexec_load(2) (asserted in family_test.go). +func TestGenerateKexecFileLoadHandler(t *testing.T) { + output := generateFromPair(t, FormatKexecFileLoad, FormatExitKexecFileLoad) + + // Enter: KindFd fd_event capturing kernel_fd from args[0]. + requireContains(t, output, `SEC("tracepoint/syscalls/sys_enter_kexec_file_load")`) + requireContains(t, output, "struct fd_event *ev = bpf_ringbuf_reserve(&event_map, sizeof(struct fd_event), 0);") + requireContains(t, output, "ev->event_type = ENTER_FD_EVENT;") + requireContains(t, output, "ev->trace_id = SYS_ENTER_KEXEC_FILE_LOAD;") + requireContains(t, output, "ev->fd = (__s32)ctx->args[0];") + + // Negative guards: only kernel_fd (args[0]) is captured — initrd_fd (args[1]) + // must not be wired as a second fd, and cmdline_ptr (args[3]) is a kernel + // command-line string, never a filesystem path, so it must not be slurped via + // bpf_probe_read_user_str. + requireNotContains(t, output, "ev->fd = (__s32)ctx->args[1];") + requireNotContains(t, output, "bpf_probe_read_user_str") + + // Exit: plain ret_event, UNCLASSIFIED (kexec_file_load returns 0/-1, no byte + // count). + requireContains(t, output, `SEC("tracepoint/syscalls/sys_exit_kexec_file_load")`) + requireContains(t, output, "struct ret_event *ev = bpf_ringbuf_reserve(&event_map, sizeof(struct ret_event), 0);") + requireContains(t, output, "ev->ret = ctx->ret;") + requireContains(t, output, "ev->ret_type = UNCLASSIFIED;") + requireNotContains(t, output, "ev->ret_type = READ_CLASSIFIED;") + requireNotContains(t, output, "ev->ret_type = WRITE_CLASSIFIED;") + requireNotContains(t, output, "ev->ret_type = TRANSFER_CLASSIFIED;") +} + // TestGenerateProcessMadviseHandlerUsesFirstArgumentAsFd locks in the BPF // handler wiring for process_madvise(2): // |