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* [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment
@ 2019-05-25 16:37 Roman Gushchin
  2019-05-25 16:37 ` [PATCH v5 bpf-next 2/4] selftests/bpf: convert test_cgrp2_attach2 example into kselftest Roman Gushchin
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Roman Gushchin @ 2019-05-25 16:37 UTC (permalink / raw)
  To: Alexei Starovoitov, bpf
  Cc: Daniel Borkmann, netdev, Tejun Heo, kernel-team, cgroups,
	Stanislav Fomichev, Yonghong Song, linux-kernel, Roman Gushchin

This patchset implements a cgroup bpf auto-detachment functionality:
bpf programs are detached as soon as possible after removal of the
cgroup, without waiting for the release of all associated resources.

Patches 2 and 3 are required to implement a corresponding kselftest
in patch 4.

v5:
  1) rebase

v4:
  1) release cgroup bpf data using a workqueue
  2) add test_cgroup_attach to .gitignore

v3:
  1) some minor changes and typo fixes

v2:
  1) removed a bogus check in patch 4
  2) moved buf[len] = 0 in patch 2


Roman Gushchin (4):
  bpf: decouple the lifetime of cgroup_bpf from cgroup itself
  selftests/bpf: convert test_cgrp2_attach2 example into kselftest
  selftests/bpf: enable all available cgroup v2 controllers
  selftests/bpf: add auto-detach test

 include/linux/bpf-cgroup.h                    |  11 +-
 include/linux/cgroup.h                        |  18 +++
 kernel/bpf/cgroup.c                           |  41 ++++-
 kernel/cgroup/cgroup.c                        |  11 +-
 samples/bpf/Makefile                          |   2 -
 tools/testing/selftests/bpf/.gitignore        |   1 +
 tools/testing/selftests/bpf/Makefile          |   3 +-
 tools/testing/selftests/bpf/cgroup_helpers.c  |  57 +++++++
 .../selftests/bpf/test_cgroup_attach.c        | 146 ++++++++++++++++--
 9 files changed, 261 insertions(+), 29 deletions(-)
 rename samples/bpf/test_cgrp2_attach2.c => tools/testing/selftests/bpf/test_cgroup_attach.c (79%)

-- 
2.21.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v5 bpf-next 2/4] selftests/bpf: convert test_cgrp2_attach2 example into kselftest
  2019-05-25 16:37 [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Roman Gushchin
@ 2019-05-25 16:37 ` Roman Gushchin
  2019-05-25 16:37 ` [PATCH v5 bpf-next 3/4] selftests/bpf: enable all available cgroup v2 controllers Roman Gushchin
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: Roman Gushchin @ 2019-05-25 16:37 UTC (permalink / raw)
  To: Alexei Starovoitov, bpf
  Cc: Daniel Borkmann, netdev, Tejun Heo, kernel-team, cgroups,
	Stanislav Fomichev, Yonghong Song, linux-kernel, Roman Gushchin

Convert test_cgrp2_attach2 example into a proper test_cgroup_attach
kselftest. It's better because we do run kselftest on a constant
basis, so there are better chances to spot a potential regression.

Also make it slightly less verbose to conform kselftests output style.

Output example:
  $ ./test_cgroup_attach
  #override:PASS
  #multi:PASS
  test_cgroup_attach:PASS

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
 samples/bpf/Makefile                          |  2 -
 tools/testing/selftests/bpf/.gitignore        |  1 +
 tools/testing/selftests/bpf/Makefile          |  3 +-
 .../selftests/bpf/test_cgroup_attach.c        | 50 ++++++++++++-------
 4 files changed, 36 insertions(+), 20 deletions(-)
 rename samples/bpf/test_cgrp2_attach2.c => tools/testing/selftests/bpf/test_cgroup_attach.c (91%)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 4f0a1cdbfe7c..253e5a2856be 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -26,7 +26,6 @@ hostprogs-y += map_perf_test
 hostprogs-y += test_overhead
 hostprogs-y += test_cgrp2_array_pin
 hostprogs-y += test_cgrp2_attach
-hostprogs-y += test_cgrp2_attach2
 hostprogs-y += test_cgrp2_sock
 hostprogs-y += test_cgrp2_sock2
 hostprogs-y += xdp1
@@ -81,7 +80,6 @@ map_perf_test-objs := bpf_load.o map_perf_test_user.o
 test_overhead-objs := bpf_load.o test_overhead_user.o
 test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
 test_cgrp2_attach-objs := test_cgrp2_attach.o
-test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(CGROUP_HELPERS)
 test_cgrp2_sock-objs := test_cgrp2_sock.o
 test_cgrp2_sock2-objs := bpf_load.o test_cgrp2_sock2.o
 xdp1-objs := xdp1_user.o
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index b3da2ffdc158..b2a9902f11c5 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -22,6 +22,7 @@ test_lirc_mode2_user
 get_cgroup_id_user
 test_skb_cgroup_id_user
 test_socket_cookie
+test_cgroup_attach
 test_cgroup_storage
 test_select_reuseport
 test_flow_dissector
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index fa002da36d0d..9b21391c4966 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -26,7 +26,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
 	test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \
 	test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \
 	test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \
-	test_btf_dump
+	test_btf_dump test_cgroup_attach
 
 BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c)))
 TEST_GEN_FILES = $(BPF_OBJ_FILES)
@@ -99,6 +99,7 @@ $(OUTPUT)/test_cgroup_storage: cgroup_helpers.c
 $(OUTPUT)/test_netcnt: cgroup_helpers.c
 $(OUTPUT)/test_sock_fields: cgroup_helpers.c
 $(OUTPUT)/test_sysctl: cgroup_helpers.c
+$(OUTPUT)/test_cgroup_attach: cgroup_helpers.c
 
 .PHONY: force
 
diff --git a/samples/bpf/test_cgrp2_attach2.c b/tools/testing/selftests/bpf/test_cgroup_attach.c
similarity index 91%
rename from samples/bpf/test_cgrp2_attach2.c
rename to tools/testing/selftests/bpf/test_cgroup_attach.c
index 0bb6507256b7..2d6d57f50e10 100644
--- a/samples/bpf/test_cgrp2_attach2.c
+++ b/tools/testing/selftests/bpf/test_cgroup_attach.c
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+
 /* eBPF example program:
  *
  * - Creates arraymap in kernel with 4 bytes keys and 8 byte values
@@ -25,20 +27,27 @@
 #include <sys/resource.h>
 #include <sys/time.h>
 #include <unistd.h>
+#include <linux/filter.h>
 
 #include <linux/bpf.h>
 #include <bpf/bpf.h>
 
-#include "bpf_insn.h"
+#include "bpf_util.h"
 #include "bpf_rlimit.h"
 #include "cgroup_helpers.h"
 
 #define FOO		"/foo"
 #define BAR		"/foo/bar/"
-#define PING_CMD	"ping -c1 -w1 127.0.0.1 > /dev/null"
+#define PING_CMD	"ping -q -c1 -w1 127.0.0.1 > /dev/null"
 
 char bpf_log_buf[BPF_LOG_BUF_SIZE];
 
+#ifdef DEBUG
+#define debug(args...) printf(args)
+#else
+#define debug(args...)
+#endif
+
 static int prog_load(int verdict)
 {
 	int ret;
@@ -89,7 +98,7 @@ static int test_foo_bar(void)
 		goto err;
 	}
 
-	printf("Attached DROP prog. This ping in cgroup /foo should fail...\n");
+	debug("Attached DROP prog. This ping in cgroup /foo should fail...\n");
 	assert(system(PING_CMD) != 0);
 
 	/* Create cgroup /foo/bar, get fd, and join it */
@@ -100,7 +109,7 @@ static int test_foo_bar(void)
 	if (join_cgroup(BAR))
 		goto err;
 
-	printf("Attached DROP prog. This ping in cgroup /foo/bar should fail...\n");
+	debug("Attached DROP prog. This ping in cgroup /foo/bar should fail...\n");
 	assert(system(PING_CMD) != 0);
 
 	if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
@@ -109,7 +118,7 @@ static int test_foo_bar(void)
 		goto err;
 	}
 
-	printf("Attached PASS prog. This ping in cgroup /foo/bar should pass...\n");
+	debug("Attached PASS prog. This ping in cgroup /foo/bar should pass...\n");
 	assert(system(PING_CMD) == 0);
 
 	if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
@@ -117,7 +126,7 @@ static int test_foo_bar(void)
 		goto err;
 	}
 
-	printf("Detached PASS from /foo/bar while DROP is attached to /foo.\n"
+	debug("Detached PASS from /foo/bar while DROP is attached to /foo.\n"
 	       "This ping in cgroup /foo/bar should fail...\n");
 	assert(system(PING_CMD) != 0);
 
@@ -132,7 +141,7 @@ static int test_foo_bar(void)
 		goto err;
 	}
 
-	printf("Attached PASS from /foo/bar and detached DROP from /foo.\n"
+	debug("Attached PASS from /foo/bar and detached DROP from /foo.\n"
 	       "This ping in cgroup /foo/bar should pass...\n");
 	assert(system(PING_CMD) == 0);
 
@@ -199,9 +208,9 @@ static int test_foo_bar(void)
 	close(bar);
 	cleanup_cgroup_environment();
 	if (!rc)
-		printf("### override:PASS\n");
+		printf("#override:PASS\n");
 	else
-		printf("### override:FAIL\n");
+		printf("#override:FAIL\n");
 	return rc;
 }
 
@@ -441,19 +450,26 @@ static int test_multiprog(void)
 	close(cg5);
 	cleanup_cgroup_environment();
 	if (!rc)
-		printf("### multi:PASS\n");
+		printf("#multi:PASS\n");
 	else
-		printf("### multi:FAIL\n");
+		printf("#multi:FAIL\n");
 	return rc;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
-	int rc = 0;
+	int (*tests[])(void) = {test_foo_bar, test_multiprog};
+	int errors = 0;
+	int i;
 
-	rc = test_foo_bar();
-	if (rc)
-		return rc;
+	for (i = 0; i < ARRAY_SIZE(tests); i++)
+		if (tests[i]())
+			errors++;
+
+	if (errors)
+		printf("test_cgroup_attach:FAIL\n");
+	else
+		printf("test_cgroup_attach:PASS\n");
 
-	return test_multiprog();
+	return errors ? EXIT_FAILURE : EXIT_SUCCESS;
 }
-- 
2.21.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v5 bpf-next 3/4] selftests/bpf: enable all available cgroup v2 controllers
  2019-05-25 16:37 [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Roman Gushchin
  2019-05-25 16:37 ` [PATCH v5 bpf-next 2/4] selftests/bpf: convert test_cgrp2_attach2 example into kselftest Roman Gushchin
@ 2019-05-25 16:37 ` Roman Gushchin
  2019-05-25 16:37 ` [PATCH v5 bpf-next 4/4] selftests/bpf: add auto-detach test Roman Gushchin
  2019-05-28 16:34 ` [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Alexei Starovoitov
  3 siblings, 0 replies; 5+ messages in thread
From: Roman Gushchin @ 2019-05-25 16:37 UTC (permalink / raw)
  To: Alexei Starovoitov, bpf
  Cc: Daniel Borkmann, netdev, Tejun Heo, kernel-team, cgroups,
	Stanislav Fomichev, Yonghong Song, linux-kernel, Roman Gushchin

Enable all available cgroup v2 controllers when setting up
the environment for the bpf kselftests. It's required to properly test
the bpf prog auto-detach feature. Also it will generally increase
the code coverage.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/cgroup_helpers.c | 57 ++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index 6692a40a6979..0d89f0396be4 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -33,6 +33,60 @@
 	snprintf(buf, sizeof(buf), "%s%s%s", CGROUP_MOUNT_PATH, \
 		 CGROUP_WORK_DIR, path)
 
+/**
+ * enable_all_controllers() - Enable all available cgroup v2 controllers
+ *
+ * Enable all available cgroup v2 controllers in order to increase
+ * the code coverage.
+ *
+ * If successful, 0 is returned.
+ */
+int enable_all_controllers(char *cgroup_path)
+{
+	char path[PATH_MAX + 1];
+	char buf[PATH_MAX];
+	char *c, *c2;
+	int fd, cfd;
+	size_t len;
+
+	snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path);
+	fd = open(path, O_RDONLY);
+	if (fd < 0) {
+		log_err("Opening cgroup.controllers: %s", path);
+		return 1;
+	}
+
+	len = read(fd, buf, sizeof(buf) - 1);
+	if (len < 0) {
+		close(fd);
+		log_err("Reading cgroup.controllers: %s", path);
+		return 1;
+	}
+	buf[len] = 0;
+	close(fd);
+
+	/* No controllers available? We're probably on cgroup v1. */
+	if (len == 0)
+		return 0;
+
+	snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);
+	cfd = open(path, O_RDWR);
+	if (cfd < 0) {
+		log_err("Opening cgroup.subtree_control: %s", path);
+		return 1;
+	}
+
+	for (c = strtok_r(buf, " ", &c2); c; c = strtok_r(NULL, " ", &c2)) {
+		if (dprintf(cfd, "+%s\n", c) <= 0) {
+			log_err("Enabling controller %s: %s", c, path);
+			close(cfd);
+			return 1;
+		}
+	}
+	close(cfd);
+	return 0;
+}
+
 /**
  * setup_cgroup_environment() - Setup the cgroup environment
  *
@@ -71,6 +125,9 @@ int setup_cgroup_environment(void)
 		return 1;
 	}
 
+	if (enable_all_controllers(cgroup_workdir))
+		return 1;
+
 	return 0;
 }
 
-- 
2.21.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v5 bpf-next 4/4] selftests/bpf: add auto-detach test
  2019-05-25 16:37 [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Roman Gushchin
  2019-05-25 16:37 ` [PATCH v5 bpf-next 2/4] selftests/bpf: convert test_cgrp2_attach2 example into kselftest Roman Gushchin
  2019-05-25 16:37 ` [PATCH v5 bpf-next 3/4] selftests/bpf: enable all available cgroup v2 controllers Roman Gushchin
@ 2019-05-25 16:37 ` Roman Gushchin
  2019-05-28 16:34 ` [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Alexei Starovoitov
  3 siblings, 0 replies; 5+ messages in thread
From: Roman Gushchin @ 2019-05-25 16:37 UTC (permalink / raw)
  To: Alexei Starovoitov, bpf
  Cc: Daniel Borkmann, netdev, Tejun Heo, kernel-team, cgroups,
	Stanislav Fomichev, Yonghong Song, linux-kernel, Roman Gushchin

Add a kselftest to cover bpf auto-detachment functionality.
The test creates a cgroup, associates some resources with it,
attaches a couple of bpf programs and deletes the cgroup.

Then it checks that bpf programs are going away in 5 seconds.

Expected output:
  $ ./test_cgroup_attach
  #override:PASS
  #multi:PASS
  #autodetach:PASS
  test_cgroup_attach:PASS

On a kernel without auto-detaching:
  $ ./test_cgroup_attach
  #override:PASS
  #multi:PASS
  #autodetach:FAIL
  test_cgroup_attach:FAIL

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
 .../selftests/bpf/test_cgroup_attach.c        | 98 ++++++++++++++++++-
 1 file changed, 97 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_cgroup_attach.c b/tools/testing/selftests/bpf/test_cgroup_attach.c
index 2d6d57f50e10..7671909ee1cb 100644
--- a/tools/testing/selftests/bpf/test_cgroup_attach.c
+++ b/tools/testing/selftests/bpf/test_cgroup_attach.c
@@ -456,9 +456,105 @@ static int test_multiprog(void)
 	return rc;
 }
 
+static int test_autodetach(void)
+{
+	__u32 prog_cnt = 4, attach_flags;
+	int allow_prog[2] = {0};
+	__u32 prog_ids[2] = {0};
+	int cg = 0, i, rc = -1;
+	void *ptr = NULL;
+	int attempts;
+
+	for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {
+		allow_prog[i] = prog_load_cnt(1, 1 << i);
+		if (!allow_prog[i])
+			goto err;
+	}
+
+	if (setup_cgroup_environment())
+		goto err;
+
+	/* create a cgroup, attach two programs and remember their ids */
+	cg = create_and_get_cgroup("/cg_autodetach");
+	if (cg < 0)
+		goto err;
+
+	if (join_cgroup("/cg_autodetach"))
+		goto err;
+
+	for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {
+		if (bpf_prog_attach(allow_prog[i], cg, BPF_CGROUP_INET_EGRESS,
+				    BPF_F_ALLOW_MULTI)) {
+			log_err("Attaching prog[%d] to cg:egress", i);
+			goto err;
+		}
+	}
+
+	/* make sure that programs are attached and run some traffic */
+	assert(bpf_prog_query(cg, BPF_CGROUP_INET_EGRESS, 0, &attach_flags,
+			      prog_ids, &prog_cnt) == 0);
+	assert(system(PING_CMD) == 0);
+
+	/* allocate some memory (4Mb) to pin the original cgroup */
+	ptr = malloc(4 * (1 << 20));
+	if (!ptr)
+		goto err;
+
+	/* close programs and cgroup fd */
+	for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {
+		close(allow_prog[i]);
+		allow_prog[i] = 0;
+	}
+
+	close(cg);
+	cg = 0;
+
+	/* leave the cgroup and remove it. don't detach programs */
+	cleanup_cgroup_environment();
+
+	/* wait for the asynchronous auto-detachment.
+	 * wait for no more than 5 sec and give up.
+	 */
+	for (i = 0; i < ARRAY_SIZE(prog_ids); i++) {
+		for (attempts = 5; attempts >= 0; attempts--) {
+			int fd = bpf_prog_get_fd_by_id(prog_ids[i]);
+
+			if (fd < 0)
+				break;
+
+			/* don't leave the fd open */
+			close(fd);
+
+			if (!attempts)
+				goto err;
+
+			sleep(1);
+		}
+	}
+
+	rc = 0;
+err:
+	for (i = 0; i < ARRAY_SIZE(allow_prog); i++)
+		if (allow_prog[i] > 0)
+			close(allow_prog[i]);
+	if (cg)
+		close(cg);
+	free(ptr);
+	cleanup_cgroup_environment();
+	if (!rc)
+		printf("#autodetach:PASS\n");
+	else
+		printf("#autodetach:FAIL\n");
+	return rc;
+}
+
 int main(void)
 {
-	int (*tests[])(void) = {test_foo_bar, test_multiprog};
+	int (*tests[])(void) = {
+		test_foo_bar,
+		test_multiprog,
+		test_autodetach,
+	};
 	int errors = 0;
 	int i;
 
-- 
2.21.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment
  2019-05-25 16:37 [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Roman Gushchin
                   ` (2 preceding siblings ...)
  2019-05-25 16:37 ` [PATCH v5 bpf-next 4/4] selftests/bpf: add auto-detach test Roman Gushchin
@ 2019-05-28 16:34 ` Alexei Starovoitov
  3 siblings, 0 replies; 5+ messages in thread
From: Alexei Starovoitov @ 2019-05-28 16:34 UTC (permalink / raw)
  To: Roman Gushchin
  Cc: Alexei Starovoitov, bpf, Daniel Borkmann, Network Development,
	Tejun Heo, Kernel Team, open list:CONTROL GROUP (CGROUP),
	Stanislav Fomichev, Yonghong Song, LKML

On Sat, May 25, 2019 at 9:37 AM Roman Gushchin <guro@fb.com> wrote:
>
> This patchset implements a cgroup bpf auto-detachment functionality:
> bpf programs are detached as soon as possible after removal of the
> cgroup, without waiting for the release of all associated resources.
>
> Patches 2 and 3 are required to implement a corresponding kselftest
> in patch 4.
>
> v5:
>   1) rebase
>
> v4:
>   1) release cgroup bpf data using a workqueue
>   2) add test_cgroup_attach to .gitignore
>
> v3:
>   1) some minor changes and typo fixes
>
> v2:
>   1) removed a bogus check in patch 4
>   2) moved buf[len] = 0 in patch 2

Applied. Thanks!

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2019-05-28 16:34 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-25 16:37 [PATCH v5 bpf-next 0/4] cgroup bpf auto-detachment Roman Gushchin
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2019-05-25 16:37 ` [PATCH v5 bpf-next 3/4] selftests/bpf: enable all available cgroup v2 controllers Roman Gushchin
2019-05-25 16:37 ` [PATCH v5 bpf-next 4/4] selftests/bpf: add auto-detach test Roman Gushchin
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