diff mbox series

[bpf-next,5/5] bpf: Implement bpf_get_attach_cookie() for tracing programs.

Message ID 20220126214809.3868787-6-kuifeng@fb.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series Attach a cookie to a tracing program. | expand

Checks

Context Check Description
bpf/vmtest-bpf-next fail VM_Test
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 9 this patch: 10
netdev/cc_maintainers warning 10 maintainers not CCed: rostedt@goodmis.org linux-kselftest@vger.kernel.org kpsingh@kernel.org john.fastabend@gmail.com kafai@fb.com songliubraving@fb.com shuah@kernel.org yhs@fb.com mingo@redhat.com netdev@vger.kernel.org
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 14 this patch: 14
netdev/checkpatch warning WARNING: line length of 99 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Kui-Feng Lee Jan. 26, 2022, 9:48 p.m. UTC 
Implement bpf_get_attach_cookie() for fentry, fexit, and fmod_ret
tracing programs.  The cookie is from the bpf_prog from the program ID
of the current BPF program.

Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
---
 kernel/trace/bpf_trace.c                      | 22 +++++++
 .../selftests/bpf/prog_tests/bpf_cookie.c     | 57 +++++++++++++++++++
 .../selftests/bpf/progs/test_bpf_cookie.c     | 24 ++++++++
 3 files changed, 103 insertions(+)

Comments

kernel test robot Jan. 26, 2022, 11:38 p.m. UTC | #1 
Hi Kui-Feng,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on bpf-next/master]

url:    https://github.com/0day-ci/linux/commits/Kui-Feng-Lee/Attach-a-cookie-to-a-tracing-program/20220127-054929
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: mips-allmodconfig (https://download.01.org/0day-ci/archive/20220127/202201270704.kcMiWFUK-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/6dffffc1fe68f386715b4ee396fb6a5c738fb065
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Kui-Feng-Lee/Attach-a-cookie-to-a-tracing-program/20220127-054929
        git checkout 6dffffc1fe68f386715b4ee396fb6a5c738fb065
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/trace/bpf_trace.c: In function '____bpf_get_attach_cookie_tracing':
>> kernel/trace/bpf_trace.c:1095:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    1095 |         prog = (const struct bpf_prog *)((u64 *)ctx)[-off];
         |                ^


vim +1095 kernel/trace/bpf_trace.c

  1086	
  1087	BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
  1088	{
  1089		const struct bpf_prog *prog;
  1090		int off = get_trampo_var_off(ctx, BPF_TRAMP_F_PROG_ID);
  1091	
  1092		if (off < 0)
  1093			return 0;
  1094	
> 1095		prog = (const struct bpf_prog *)((u64 *)ctx)[-off];
  1096	
  1097		return prog->aux->cookie;
  1098	}
  1099	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index bf2c9d11ad05..7b1f4c8a10de 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1084,6 +1084,26 @@  static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
 	.arg1_type	= ARG_PTR_TO_CTX,
 };
 
+BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
+{
+	const struct bpf_prog *prog;
+	int off = get_trampo_var_off(ctx, BPF_TRAMP_F_PROG_ID);
+
+	if (off < 0)
+		return 0;
+
+	prog = (const struct bpf_prog *)((u64 *)ctx)[-off];
+
+	return prog->aux->cookie;
+}
+
+static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
+	.func		= bpf_get_attach_cookie_tracing,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+};
+
 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
 {
 #ifndef CONFIG_X86
@@ -1706,6 +1726,8 @@  tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
 	case BPF_FUNC_get_func_arg_cnt:
 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
+	case BPF_FUNC_get_attach_cookie:
+		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
 	default:
 		fn = raw_tp_prog_func_proto(func_id, prog);
 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
index 5eea3c3a40fe..41a73c0a3a8e 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
@@ -231,6 +231,61 @@  static void pe_subtest(struct test_bpf_cookie *skel)
 	bpf_link__destroy(link);
 }
 
+static void tracing_subtest(struct test_bpf_cookie *skel)
+{
+	__u64 cookie;
+	__u32 duration = 0, retval;
+	int prog_fd;
+	int fentry_fd = -1, fexit_fd = -1, fmod_ret_fd = -1;
+
+	skel->bss->fentry_res = 0;
+	skel->bss->fexit_res = 0;
+
+	cookie = 0x100000;
+	prog_fd = bpf_program__fd(skel->progs.fentry_test1);
+	if (!ASSERT_GE(prog_fd, 0, "fentry.prog_fd"))
+		return;
+	fentry_fd = bpf_raw_tracepoint_cookie_open(NULL, prog_fd, cookie);
+	if (!ASSERT_GE(fentry_fd, 0, "fentry.open"))
+		return;
+
+	cookie = 0x200000;
+	prog_fd = bpf_program__fd(skel->progs.fexit_test1);
+	if (!ASSERT_GE(prog_fd, 0, "fexit.prog_fd"))
+		goto cleanup;
+	fexit_fd = bpf_raw_tracepoint_cookie_open(NULL, prog_fd, cookie);
+	if (!ASSERT_GE(fexit_fd, 0, "fexit.open"))
+		goto cleanup;
+
+	cookie = 0x300000;
+	prog_fd = bpf_program__fd(skel->progs.fmod_ret_test);
+	if (!ASSERT_GE(prog_fd, 0, "fmod_ret.prog_fd"))
+		goto cleanup;
+	fmod_ret_fd = bpf_raw_tracepoint_cookie_open(NULL, prog_fd, cookie);
+	if (!ASSERT_GE(fmod_ret_fd, 0, "fmod_ret.opoen"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.fentry_test1);
+	bpf_prog_test_run(prog_fd, 1, NULL, 0,
+			  NULL, NULL, &retval, &duration);
+
+	prog_fd = bpf_program__fd(skel->progs.fmod_ret_test);
+	bpf_prog_test_run(prog_fd, 1, NULL, 0,
+			  NULL, NULL, &retval, &duration);
+
+	ASSERT_EQ(skel->bss->fentry_res, 0x100000, "fentry_res");
+	ASSERT_EQ(skel->bss->fexit_res, 0x200000, "fexit_res");
+	ASSERT_EQ(skel->bss->fmod_ret_res, 0x300000, "fmod_ret_res");
+
+cleanup:
+	if (fentry_fd >= 0)
+		close(fentry_fd);
+	if (fexit_fd >= 0)
+		close(fexit_fd);
+	if (fmod_ret_fd >= 0)
+		close(fmod_ret_fd);
+}
+
 void test_bpf_cookie(void)
 {
 	struct test_bpf_cookie *skel;
@@ -249,6 +304,8 @@  void test_bpf_cookie(void)
 		tp_subtest(skel);
 	if (test__start_subtest("perf_event"))
 		pe_subtest(skel);
+	if (test__start_subtest("tracing"))
+		tracing_subtest(skel);
 
 	test_bpf_cookie__destroy(skel);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c
index 2d3a7710e2ce..a9f83f46e7b7 100644
--- a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c
+++ b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c
@@ -14,6 +14,9 @@  int uprobe_res;
 int uretprobe_res;
 int tp_res;
 int pe_res;
+int fentry_res;
+int fexit_res;
+int fmod_ret_res;
 
 static void update(void *ctx, int *res)
 {
@@ -82,4 +85,25 @@  int handle_pe(struct pt_regs *ctx)
 	return 0;
 }
 
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(fentry_test1, int a)
+{
+	update(ctx, &fentry_res);
+	return 0;
+}
+
+SEC("fexit/bpf_fentry_test1")
+int BPF_PROG(fexit_test1, int a, int ret)
+{
+	update(ctx, &fexit_res);
+	return 0;
+}
+
+SEC("fmod_ret/bpf_modify_return_test")
+int BPF_PROG(fmod_ret_test, int _a, int *_b, int _ret)
+{
+	update(ctx, &fmod_ret_res);
+	return 1234;
+}
+
 char _license[] SEC("license") = "GPL";