On 9/16/21 6:55 AM, Hou Tao wrote:
Add a writable bare tracepoint in bpf_testmod module, and
trigger its calling when reading /sys/kernel/bpf_testmod
with a specific buffer length.
The patch cannot be applied cleanly with bpf-next tree.
Please rebase and resubmit.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
.../bpf/bpf_testmod/bpf_testmod-events.h | 15 +++++++
.../selftests/bpf/bpf_testmod/bpf_testmod.c | 10 +++++
.../selftests/bpf/bpf_testmod/bpf_testmod.h | 5 +++
.../selftests/bpf/prog_tests/module_attach.c | 40 ++++++++++++++++++-
.../selftests/bpf/progs/test_module_attach.c | 14 +++++++
5 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
index 89c6d58e5dd6..11ee801e75e7 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
@@ -34,6 +34,21 @@ DECLARE_TRACE(bpf_testmod_test_write_bare,
TP_ARGS(task, ctx)
);
+#undef BPF_TESTMOD_DECLARE_TRACE
+#ifdef DECLARE_TRACE_WRITABLE
+#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
+ DECLARE_TRACE_WRITABLE(call, PARAMS(proto), PARAMS(args), size)
+#else
+#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
+ DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
+#endif
+
+BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare,
+ TP_PROTO(struct bpf_testmod_test_writable_ctx *ctx),
+ TP_ARGS(ctx),
+ sizeof(struct bpf_testmod_test_writable_ctx)
+);
+
#endif /* _BPF_TESTMOD_EVENTS_H */
#undef TRACE_INCLUDE_PATH
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 141d8da687d2..3d3fb16eaf8c 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -26,6 +26,16 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
trace_bpf_testmod_test_read(current, &ctx);
+ /* Magic number to enable writable tp */
+ if (len == 1024) {
+ struct bpf_testmod_test_writable_ctx writable = {
+ .val = 1024,
+ };
+ trace_bpf_testmod_test_writable_bare(&writable);
+ if (writable.ret)
+ return snprintf(buf, len, "%d\n", writable.val);
+ }
+
return -EIO; /* always fail */
}
EXPORT_SYMBOL(bpf_testmod_test_read);
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
index b3892dc40111..553d94214aa6 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
@@ -17,4 +17,9 @@ struct bpf_testmod_test_write_ctx {
size_t len;
};
+struct bpf_testmod_test_writable_ctx {
+ bool ret;
+ int val;
+};
+
#endif /* _BPF_TESTMOD_H */
diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c
index d85a69b7ce44..5565bcab1531 100644
--- a/tools/testing/selftests/bpf/prog_tests/module_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c
@@ -6,11 +6,39 @@
static int duration;
+#define BPF_TESTMOD_PATH "/sys/kernel/bpf_testmod"
+
+static int trigger_module_test_writable(int *val)
+{
+ int fd, err;
+ char buf[1025];
Not critical, but do you need such a big stack size?
Maybe smaller one?
+ ssize_t rd;
+
+ fd = open(BPF_TESTMOD_PATH, O_RDONLY);
+ err = -errno;
+ if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
+ return err;
+
+ rd = read(fd, buf, sizeof(buf) - 1);
+ err = rd < 0 ? -errno : -EIO;
+ if (CHECK(rd <= 0, "testmod_file_read", "failed: %d\n", err)) {
Please use ASSERT_* macros. You can take a look at other self tests.
+ close(fd);
+ return err;
+ }
Put one blank line here and remove the following three blank lines.
+ buf[rd] = '\0';
+
+ *val = strtol(buf, NULL, 0);
+
+ close(fd);
+
+ return 0;
+}
+
static int trigger_module_test_read(int read_sz)
{
int fd, err;
- fd = open("/sys/kernel/bpf_testmod", O_RDONLY);
+ fd = open(BPF_TESTMOD_PATH, O_RDONLY);
err = -errno;
if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
return err;
@@ -32,7 +60,7 @@ static int trigger_module_test_write(int write_sz)
memset(buf, 'a', write_sz);
buf[write_sz-1] = '\0';
- fd = open("/sys/kernel/bpf_testmod", O_WRONLY);
+ fd = open(BPF_TESTMOD_PATH, O_WRONLY);
err = -errno;
if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) {
free(buf);
@@ -58,6 +86,7 @@ void test_module_attach(void)
struct test_module_attach__bss *bss;
struct bpf_link *link;
int err;
+ int writable_val;
skel = test_module_attach__open();
if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
@@ -90,6 +119,13 @@ void test_module_attach(void)
ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet");
ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret");
+ bss->raw_tp_writable_bare_ret = 1;
+ bss->raw_tp_writable_bare_val = 511;
+ writable_val = 0;
+ ASSERT_OK(trigger_module_test_writable(&writable_val), "trigger_writable");
+ ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test");
+ ASSERT_EQ(bss->raw_tp_writable_bare_val, writable_val, "writable_test");
+
test_module_attach__detach(skel);
/* attach fentry/fexit and make sure it get's module reference */
diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c b/tools/testing/selftests/bpf/progs/test_module_attach.c
index bd37ceec5587..4f5c780fcd21 100644
--- a/tools/testing/selftests/bpf/progs/test_module_attach.c
+++ b/tools/testing/selftests/bpf/progs/test_module_attach.c
@@ -27,6 +27,20 @@ int BPF_PROG(handle_raw_tp_bare,
return 0;
}
+int raw_tp_writable_bare_in_val = 0;
+int raw_tp_writable_bare_ret = 0;
+int raw_tp_writable_bare_val = 0;
+
+SEC("raw_tp_writable/bpf_testmod_test_writable_bare")
+int BPF_PROG(handle_raw_tp_writable_bare,
+ struct bpf_testmod_test_writable_ctx *writable)
+{
+ raw_tp_writable_bare_in_val = writable->val;
+ writable->ret = raw_tp_writable_bare_ret;
+ writable->val = raw_tp_writable_bare_val;
+ return 0;
+}
+
__u32 tp_btf_read_sz = 0;
SEC("tp_btf/bpf_testmod_test_read")
