On Mon, 2023-03-27 at 12:06 +0100, Quentin Monnet wrote:
> This set contains some improvements for bpftool's "visual" program dump
> option, which produces the control flow graph in a DOT format. The main
> objective is to add support for inline annotations on such graphs, so that
> we can have the C source code for the program showing up alongside the
> instructions, when available. The last commits also make it possible to
> display the line numbers or the bare opcodes in the graph, as supported by
> regular program dumps.
>
> v2: Replace fputc(..., stdout) with putchar(...) in dotlabel_puts().
Hi Quentin,
It looks like currently there are no test cases for bpftool prog dump.
Borrowing an idea to mix bpf program with comments parsed by awk from
prog_tests/btf_dump.c it is possible to put together something like
below (although, would be much simpler as a bash script). Is it worth
the effort or dump format is too unstable?
Thanks,
Eduard
---
diff --git a/tools/testing/selftests/bpf/prog_tests/bpftool_cfg.c b/tools/testing/selftests/bpf/prog_tests/bpftool_cfg.c
new file mode 100644
index 000000000000..f582a93b5ee9
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/bpftool_cfg.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+
+#include "bpf/libbpf.h"
+#include "bpftool_cfg.skel.h"
+
+static int system_to_tmp(char *tmp_template, char *cmd)
+{
+ char buf[1024];
+ int fd, err;
+
+ fd = mkstemp(tmp_template);
+ if (!ASSERT_GE(fd, 0, "mkstemp"))
+ return fd;
+
+ snprintf(buf, sizeof(buf), "%s > %s", cmd, tmp_template);
+ err = system(buf);
+ if (err) {
+ PRINT_FAIL("Command %s failed: err %d\n", cmd, err);
+ remove(tmp_template);
+ return err;
+ }
+
+ return 0;
+}
+
+void test_bpftool_cfg(void)
+{
+ const char *prog_pin_path = "/sys/fs/bpf/bpftool_cfg_test_pin";
+ const char *bpftool = "./tools/build/bpftool/bpftool";
+ char bpftool_tmp[256] = "/tmp/bpftool_test_cfg.XXXXXX";
+ char awk_tmp[256] = "/tmp/bpftool_test_awk.XXXXXX";
+ struct bpftool_cfg *skel;
+ const char *test_file;
+ char cmd_buf[1024];
+ FILE *cmd;
+ int err;
+
+ skel = bpftool_cfg__open_and_load();
+ if (!skel) {
+ PRINT_FAIL("failed to load bpftool_cfg program: %d (%s)\n",
+ errno, strerror(errno));
+ return;
+ }
+
+ err = bpf_program__pin(skel->progs.bpftool_cfg_nanosleep, prog_pin_path);
+ if (err) {
+ PRINT_FAIL("failed to pin bpftool_cfg program: err %d, errno = %d (%s)\n",
+ err, errno, strerror(errno));
+ goto out;
+ }
+
+ /* When the test is run with O=, kselftest copies TEST_FILES
+ * without preserving the directory structure.
+ */
+ if (access("progs/bpftool_cfg.c", R_OK) == 0)
+ test_file = "progs/bpftool_cfg.c";
+ else if (access("bpftool_cfg.c", R_OK) == 0)
+ test_file = "bpftool_cfg.c";
+ else {
+ PRINT_FAIL("Can't find bpftool_cfg.c\n");
+ goto out_unpin;
+ }
+
+ cmd = fmemopen(cmd_buf, sizeof(cmd_buf), "w");
+ fprintf(cmd, "awk '");
+ fprintf(cmd, " /END-BPFTOOL-CFG/ { out=0 } ");
+ fprintf(cmd, " out { print $0 } ");
+ fprintf(cmd, " /START-BPFTOOL-CFG/ { out=1 } ");
+ fprintf(cmd, "' '%s' > '%s'", test_file, awk_tmp);
+ fclose(cmd);
+ err = system_to_tmp(awk_tmp, cmd_buf);
+ if (!ASSERT_OK(err, "awk"))
+ goto out_unpin;
+
+ cmd = fmemopen(cmd_buf, sizeof(cmd_buf), "w");
+ fprintf(cmd, "%s prog dump xlated pinned %s visual", bpftool, prog_pin_path);
+ fclose(cmd);
+ err = system_to_tmp(bpftool_tmp, cmd_buf);
+ if (!ASSERT_OK(err, "bpftool"))
+ goto out_delete;
+
+ cmd = fmemopen(cmd_buf, sizeof(cmd_buf), "w");
+ fprintf(cmd, "diff -u %s %s", awk_tmp, bpftool_tmp);
+ fclose(cmd);
+ err = system(cmd_buf);
+ if (!ASSERT_OK(err, "diff"))
+ goto out_delete;
+
+out_delete:
+ if (awk_tmp[0])
+ remove(awk_tmp);
+ if (bpftool_tmp[0])
+ remove(bpftool_tmp);
+out_unpin:
+ bpf_program__unpin(skel->progs.bpftool_cfg_nanosleep, prog_pin_path);
+out:
+ bpftool_cfg__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/bpftool_cfg.c b/tools/testing/selftests/bpf/progs/bpftool_cfg.c
new file mode 100644
index 000000000000..d10c4e2cecbd
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bpftool_cfg.c
@@ -0,0 +1,36 @@
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#include "bpf_misc.h"
+
+/*
+START-BPFTOOL-CFG
+digraph "DOT graph for eBPF program" {
+subgraph "cluster_0" {
+ style="dashed";
+ color="black";
+ label="func_0 ()";
+ fn_0_bb_0 [shape=Mdiamond,style=filled,label="ENTRY"];
+
+ fn_0_bb_2 [shape=record,style=filled,label="{\
+; int bpftool_cfg_nanosleep(void * ctx):\l\
+; return 0;\l\
+0: (b4) w0 = 0\l\
+ | 1: (95) exit\l\
+}"];
+
+ fn_0_bb_1 [shape=Mdiamond,style=filled,label="EXIT"];
+
+ fn_0_bb_0:s -> fn_0_bb_2:n [style="solid,bold", color=black, weight=10, constraint=true];
+ fn_0_bb_2:s -> fn_0_bb_1:n [style="solid,bold", color=black, weight=10, constraint=true];
+ fn_0_bb_0:s -> fn_0_bb_1:n [style="invis", constraint=true];
+}
+}
+END-BPFTOOL-CFG
+*/
+
+SEC("tp/syscalls/sys_enter_getpid")
+int bpftool_cfg_nanosleep(void *ctx)
+{
+ return 0;
+}
