From 1f2436229bf64ac040f2f5018df059c21fc5526a Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Sun, 7 Jun 2020 17:36:15 -0700
Subject: selftests/bpf: Fix ringbuf selftest sample counting undeterminism

Fix test race, in which background poll can get either 5 or 6 samples,
depending on timing of notification. Prevent this by open-coding sample
triggering and forcing notification for the very last sample only.

Also switch to using atomic increments and exchanges for more obviously
reliable counting and checking. Additionally, check expected processed sample
counters for single-threaded use cases as well.

Fixes: 9a5f25ad30e5 ("selftests/bpf: Fix sample_cnt shared between two threads")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200608003615.3549991-1-andriin@fb.com
---
 tools/testing/selftests/bpf/prog_tests/ringbuf.c | 42 ++++++++++++++++++++----
 1 file changed, 35 insertions(+), 7 deletions(-)

(limited to 'tools')

diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
index 2bba908dfa63..c1650548433c 100644
--- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c
+++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
@@ -25,13 +25,23 @@ struct sample {
 	char comm[16];
 };
 
-static volatile int sample_cnt;
+static int sample_cnt;
+
+static void atomic_inc(int *cnt)
+{
+	__atomic_add_fetch(cnt, 1, __ATOMIC_SEQ_CST);
+}
+
+static int atomic_xchg(int *cnt, int val)
+{
+	return __atomic_exchange_n(cnt, val, __ATOMIC_SEQ_CST);
+}
 
 static int process_sample(void *ctx, void *data, size_t len)
 {
 	struct sample *s = data;
 
-	sample_cnt++;
+	atomic_inc(&sample_cnt);
 
 	switch (s->seq) {
 	case 0:
@@ -76,7 +86,7 @@ void test_ringbuf(void)
 	const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample);
 	pthread_t thread;
 	long bg_ret = -1;
-	int err;
+	int err, cnt;
 
 	skel = test_ringbuf__open_and_load();
 	if (CHECK(!skel, "skel_open_load", "skeleton open&load failed\n"))
@@ -116,11 +126,15 @@ void test_ringbuf(void)
 	/* -EDONE is used as an indicator that we are done */
 	if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err))
 		goto cleanup;
+	cnt = atomic_xchg(&sample_cnt, 0);
+	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
 
 	/* we expect extra polling to return nothing */
 	err = ring_buffer__poll(ringbuf, 0);
 	if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err))
 		goto cleanup;
+	cnt = atomic_xchg(&sample_cnt, 0);
+	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
 
 	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
 	      0L, skel->bss->dropped);
@@ -136,6 +150,8 @@ void test_ringbuf(void)
 	      3L * rec_sz, skel->bss->cons_pos);
 	err = ring_buffer__poll(ringbuf, -1);
 	CHECK(err <= 0, "poll_err", "err %d\n", err);
+	cnt = atomic_xchg(&sample_cnt, 0);
+	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
 
 	/* start poll in background w/ long timeout */
 	err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000);
@@ -164,6 +180,8 @@ void test_ringbuf(void)
 	      2L, skel->bss->total);
 	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
 	      1L, skel->bss->discarded);
+	cnt = atomic_xchg(&sample_cnt, 0);
+	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
 
 	/* clear flags to return to "adaptive" notification mode */
 	skel->bss->flags = 0;
@@ -178,10 +196,20 @@ void test_ringbuf(void)
 	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
 		goto cleanup;
 
+	/* still no samples, because consumer is behind */
+	cnt = atomic_xchg(&sample_cnt, 0);
+	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
+
+	skel->bss->dropped = 0;
+	skel->bss->total = 0;
+	skel->bss->discarded = 0;
+
+	skel->bss->value = 333;
+	syscall(__NR_getpgid);
 	/* now force notifications */
 	skel->bss->flags = BPF_RB_FORCE_WAKEUP;
-	sample_cnt = 0;
-	trigger_samples();
+	skel->bss->value = 777;
+	syscall(__NR_getpgid);
 
 	/* now we should get a pending notification */
 	usleep(50000);
@@ -193,8 +221,8 @@ void test_ringbuf(void)
 		goto cleanup;
 
 	/* 3 rounds, 2 samples each */
-	CHECK(sample_cnt != 6, "wrong_sample_cnt",
-	      "expected to see %d samples, got %d\n", 6, sample_cnt);
+	cnt = atomic_xchg(&sample_cnt, 0);
+	CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt);
 
 	/* BPF side did everything right */
 	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
-- 
cgit v1.2.3


From 0e6fbe39bdf71b4e665767bcbf53567a3e6d0623 Mon Sep 17 00:00:00 2001
From: Pooja Trivedi <poojatrivedi@gmail.com>
Date: Fri, 5 Jun 2020 16:01:18 +0000
Subject: net/tls(TLS_SW): Add selftest for 'chunked' sendfile test

This selftest tests for cases where sendfile's 'count'
parameter is provided with a size greater than the intended
file size.

Motivation: When sendfile is provided with 'count' parameter
value that is greater than the size of the file, kTLS example
fails to send the file correctly. Last chunk of the file is
not sent, and the data integrity is compromised.
The reason is that the last chunk has MSG_MORE flag set
because of which it gets added to pending records, but is
not pushed.
Note that if user space were to send SSL_shutdown control
message, pending records would get flushed and the issue
would not happen. So a shutdown control message following
sendfile can mask the issue.

Signed-off-by: Pooja Trivedi <pooja.trivedi@stackpath.com>
Signed-off-by: Mallesham Jatharkonda <mallesham.jatharkonda@oneconvergence.com>
Signed-off-by: Josh Tway <josh.tway@stackpath.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 tools/testing/selftests/net/tls.c | 58 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

(limited to 'tools')

diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index c5282e62df75..b599f1fa99b5 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -213,6 +213,64 @@ TEST_F(tls, send_then_sendfile)
 	EXPECT_EQ(recv(self->cfd, buf, st.st_size, MSG_WAITALL), st.st_size);
 }
 
+static void chunked_sendfile(struct __test_metadata *_metadata,
+			     struct _test_data_tls *self,
+			     uint16_t chunk_size,
+			     uint16_t extra_payload_size)
+{
+	char buf[TLS_PAYLOAD_MAX_LEN];
+	uint16_t test_payload_size;
+	int size = 0;
+	int ret;
+	char filename[] = "/tmp/mytemp.XXXXXX";
+	int fd = mkstemp(filename);
+	off_t offset = 0;
+
+	unlink(filename);
+	ASSERT_GE(fd, 0);
+	EXPECT_GE(chunk_size, 1);
+	test_payload_size = chunk_size + extra_payload_size;
+	ASSERT_GE(TLS_PAYLOAD_MAX_LEN, test_payload_size);
+	memset(buf, 1, test_payload_size);
+	size = write(fd, buf, test_payload_size);
+	EXPECT_EQ(size, test_payload_size);
+	fsync(fd);
+
+	while (size > 0) {
+		ret = sendfile(self->fd, fd, &offset, chunk_size);
+		EXPECT_GE(ret, 0);
+		size -= ret;
+	}
+
+	EXPECT_EQ(recv(self->cfd, buf, test_payload_size, MSG_WAITALL),
+		  test_payload_size);
+
+	close(fd);
+}
+
+TEST_F(tls, multi_chunk_sendfile)
+{
+	chunked_sendfile(_metadata, self, 4096, 4096);
+	chunked_sendfile(_metadata, self, 4096, 0);
+	chunked_sendfile(_metadata, self, 4096, 1);
+	chunked_sendfile(_metadata, self, 4096, 2048);
+	chunked_sendfile(_metadata, self, 8192, 2048);
+	chunked_sendfile(_metadata, self, 4096, 8192);
+	chunked_sendfile(_metadata, self, 8192, 4096);
+	chunked_sendfile(_metadata, self, 12288, 1024);
+	chunked_sendfile(_metadata, self, 12288, 2000);
+	chunked_sendfile(_metadata, self, 15360, 100);
+	chunked_sendfile(_metadata, self, 15360, 300);
+	chunked_sendfile(_metadata, self, 1, 4096);
+	chunked_sendfile(_metadata, self, 2048, 4096);
+	chunked_sendfile(_metadata, self, 2048, 8192);
+	chunked_sendfile(_metadata, self, 4096, 8192);
+	chunked_sendfile(_metadata, self, 1024, 12288);
+	chunked_sendfile(_metadata, self, 2000, 12288);
+	chunked_sendfile(_metadata, self, 100, 15360);
+	chunked_sendfile(_metadata, self, 300, 15360);
+}
+
 TEST_F(tls, recv_max)
 {
 	unsigned int send_len = TLS_PAYLOAD_MAX_LEN;
-- 
cgit v1.2.3


From 8027bc0307ce59759b90679fa5d8b22949586d20 Mon Sep 17 00:00:00 2001
From: tannerlove <tannerlove@google.com>
Date: Mon, 8 Jun 2020 15:37:15 -0400
Subject: selftests/net: in timestamping, strncpy needs to preserve null byte
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

If user passed an interface option longer than 15 characters, then
device.ifr_name and hwtstamp.ifr_name became non-null-terminated
strings. The compiler warned about this:

timestamping.c:353:2: warning: ‘strncpy’ specified bound 16 equals \
destination size [-Wstringop-truncation]
  353 |  strncpy(device.ifr_name, interface, sizeof(device.ifr_name));

Fixes: cb9eff097831 ("net: new user space API for time stamping of incoming and outgoing packets")
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 tools/testing/selftests/net/timestamping.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

(limited to 'tools')

diff --git a/tools/testing/selftests/net/timestamping.c b/tools/testing/selftests/net/timestamping.c
index aca3491174a1..f4bb4fef0f39 100644
--- a/tools/testing/selftests/net/timestamping.c
+++ b/tools/testing/selftests/net/timestamping.c
@@ -313,10 +313,16 @@ int main(int argc, char **argv)
 	int val;
 	socklen_t len;
 	struct timeval next;
+	size_t if_len;
 
 	if (argc < 2)
 		usage(0);
 	interface = argv[1];
+	if_len = strlen(interface);
+	if (if_len >= IFNAMSIZ) {
+		printf("interface name exceeds IFNAMSIZ\n");
+		exit(1);
+	}
 
 	for (i = 2; i < argc; i++) {
 		if (!strcasecmp(argv[i], "SO_TIMESTAMP"))
@@ -350,12 +356,12 @@ int main(int argc, char **argv)
 		bail("socket");
 
 	memset(&device, 0, sizeof(device));
-	strncpy(device.ifr_name, interface, sizeof(device.ifr_name));
+	memcpy(device.ifr_name, interface, if_len + 1);
 	if (ioctl(sock, SIOCGIFADDR, &device) < 0)
 		bail("getting interface IP address");
 
 	memset(&hwtstamp, 0, sizeof(hwtstamp));
-	strncpy(hwtstamp.ifr_name, interface, sizeof(hwtstamp.ifr_name));
+	memcpy(hwtstamp.ifr_name, interface, if_len + 1);
 	hwtstamp.ifr_data = (void *)&hwconfig;
 	memset(&hwconfig, 0, sizeof(hwconfig));
 	hwconfig.tx_type =
-- 
cgit v1.2.3


From 248e00ac47d64e153b9c50f45aad73cd61894a73 Mon Sep 17 00:00:00 2001
From: Lorenz Bauer <lmb@cloudflare.com>
Date: Mon, 8 Jun 2020 17:22:01 +0100
Subject: bpf: cgroup: Allow multi-attach program to replace itself

When using BPF_PROG_ATTACH to attach a program to a cgroup in
BPF_F_ALLOW_MULTI mode, it is not possible to replace a program
with itself. This is because the check for duplicate programs
doesn't take the replacement program into account.

Replacing a program with itself might seem weird, but it has
some uses: first, it allows resetting the associated cgroup storage.
Second, it makes the API consistent with the non-ALLOW_MULTI usage,
where it is possible to replace a program with itself. Third, it
aligns BPF_PROG_ATTACH with bpf_link, where replacing itself is
also supported.

Sice this code has been refactored a few times this change will
only apply to v5.7 and later. Adjustments could be made to
commit 1020c1f24a94 ("bpf: Simplify __cgroup_bpf_attach") and
commit d7bf2c10af05 ("bpf: allocate cgroup storage entries on attaching bpf programs")
as well as commit 324bda9e6c5a ("bpf: multi program support for cgroup+bpf")

Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program attachment")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200608162202.94002-1-lmb@cloudflare.com
---
 kernel/bpf/cgroup.c                                          | 2 +-
 tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

(limited to 'tools')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index fdf7836750a3..4d76f16524cc 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -378,7 +378,7 @@ static struct bpf_prog_list *find_attach_entry(struct list_head *progs,
 	}
 
 	list_for_each_entry(pl, progs, node) {
-		if (prog && pl->prog == prog)
+		if (prog && pl->prog == prog && prog != replace_prog)
 			/* disallow attaching the same prog twice */
 			return ERR_PTR(-EINVAL);
 		if (link && pl->link == link)
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c
index 139f8e82c7c6..b549fcfacc0b 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c
@@ -230,6 +230,13 @@ void test_cgroup_attach_multi(void)
 		  "prog_replace", "errno=%d\n", errno))
 		goto err;
 
+	/* replace program with itself */
+	attach_opts.replace_prog_fd = allow_prog[6];
+	if (CHECK(bpf_prog_attach_xattr(allow_prog[6], cg1,
+					BPF_CGROUP_INET_EGRESS, &attach_opts),
+		  "prog_replace", "errno=%d\n", errno))
+		goto err;
+
 	value = 0;
 	CHECK_FAIL(bpf_map_update_elem(map_fd, &key, &value, 0));
 	CHECK_FAIL(system(PING_CMD));
-- 
cgit v1.2.3


From 042b1545fe47788e734b0f074a8ae65856015cdf Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Tue, 9 Jun 2020 15:31:52 +0200
Subject: bpf: Selftests and tools use struct bpf_devmap_val from uapi

Sync tools uapi bpf.h header file and update selftests that use
struct bpf_devmap_val.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/159170951195.2102545.1833108712124273987.stgit@firesoul
---
 tools/include/uapi/linux/bpf.h                              | 13 +++++++++++++
 tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c  |  8 --------
 tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c |  2 +-
 .../selftests/bpf/progs/test_xdp_with_devmap_helpers.c      |  3 +--
 4 files changed, 15 insertions(+), 11 deletions(-)

(limited to 'tools')

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index c65b374a5090..19684813faae 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3761,6 +3761,19 @@ struct xdp_md {
 	__u32 egress_ifindex;  /* txq->dev->ifindex */
 };
 
+/* DEVMAP map-value layout
+ *
+ * The struct data-layout of map-value is a configuration interface.
+ * New members can only be added to the end of this structure.
+ */
+struct bpf_devmap_val {
+	__u32 ifindex;   /* device index */
+	union {
+		int   fd;  /* prog fd on map write */
+		__u32 id;  /* prog id on map read */
+	} bpf_prog;
+};
+
 enum sk_action {
 	SK_DROP = 0,
 	SK_PASS,
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
index d19dbd668f6a..88ef3ec8ac4c 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
@@ -8,14 +8,6 @@
 
 #define IFINDEX_LO 1
 
-struct bpf_devmap_val {
-	u32 ifindex;   /* device index */
-	union {
-		int fd;  /* prog fd on map write */
-		u32 id;  /* prog id on map read */
-	} bpf_prog;
-};
-
 void test_xdp_with_devmap_helpers(void)
 {
 	struct test_xdp_with_devmap_helpers *skel;
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c
index e5c0f131c8a7..b360ba2bd441 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c
@@ -2,7 +2,7 @@
 /* fails to load without expected_attach_type = BPF_XDP_DEVMAP
  * because of access to egress_ifindex
  */
-#include "vmlinux.h"
+#include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 
 SEC("xdp_dm_log")
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c
index deef0e050863..330811260123 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-
-#include "vmlinux.h"
+#include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 
 struct {
-- 
cgit v1.2.3


From 865a6cbb2288f8af7f9dc3b153c61b7014fdcf1e Mon Sep 17 00:00:00 2001
From: tannerlove <tannerlove@google.com>
Date: Tue, 9 Jun 2020 17:21:32 -0400
Subject: selftests/net: in rxtimestamp getopt_long needs terminating null
 entry

getopt_long requires the last element to be filled with zeros.
Otherwise, passing an unrecognized option can cause a segfault.

Fixes: 16e781224198 ("selftests/net: Add a test to validate behavior of rx timestamps")
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 tools/testing/selftests/net/rxtimestamp.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools')

diff --git a/tools/testing/selftests/net/rxtimestamp.c b/tools/testing/selftests/net/rxtimestamp.c
index 6dee9e636a95..422e7761254d 100644
--- a/tools/testing/selftests/net/rxtimestamp.c
+++ b/tools/testing/selftests/net/rxtimestamp.c
@@ -115,6 +115,7 @@ static struct option long_options[] = {
 	{ "tcp", no_argument, 0, 't' },
 	{ "udp", no_argument, 0, 'u' },
 	{ "ip", no_argument, 0, 'i' },
+	{ NULL, 0, NULL, 0 },
 };
 
 static int next_port = 19999;
-- 
cgit v1.2.3


From 8ca8d4a841730c02e77bf3c87bf658cc44f364b9 Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: Tue, 9 Jun 2020 18:16:53 -0300
Subject: libbpf: Define __WORDSIZE if not available

Some systems, such as Android, don't have a define for __WORDSIZE, do it
in terms of __SIZEOF_LONG__, as done in perf since 2012:

   http://git.kernel.org/torvalds/c/3f34f6c0233ae055b5

For reference: https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html

I build tested it here and Andrii did some Travis CI build tests too.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200608161150.GA3073@kernel.org
---
 tools/lib/bpf/hashmap.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

(limited to 'tools')

diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
index e823b35e7371..df59fd4fc95b 100644
--- a/tools/lib/bpf/hashmap.h
+++ b/tools/lib/bpf/hashmap.h
@@ -10,10 +10,9 @@
 
 #include <stdbool.h>
 #include <stddef.h>
-#ifdef __GLIBC__
-#include <bits/wordsize.h>
-#else
-#include <bits/reg.h>
+#include <limits.h>
+#ifndef __WORDSIZE
+#define __WORDSIZE (__SIZEOF_LONG__ * 8)
 #endif
 
 static inline size_t hash_bits(size_t h, int bits)
-- 
cgit v1.2.3


From 32022fd97ed34f6812802bf1288db27c313576f4 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Tue, 9 Jun 2020 22:23:35 -0700
Subject: libbpf: Handle GCC noreturn-turned-volatile quirk

Handle a GCC quirk of emitting extra volatile modifier in DWARF (and
subsequently preserved in BTF by pahole) for function pointers marked as
__attribute__((noreturn)). This was the way to mark such functions before GCC
2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how
it's done for array (also to handle GCC quirk/bug).

Such volatile attribute is emitted by GCC only, so existing selftests can't
express such test. Simple repro is like this (compiled with GCC + BTF
generated by pahole):

  struct my_struct {
      void __attribute__((noreturn)) (*fn)(int);
  };
  struct my_struct a;

Without this fix, output will be:

struct my_struct {
    voidvolatile  (*fn)(int);
};

With the fix:

struct my_struct {
    void (*fn)(int);
};

Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com
---
 tools/lib/bpf/btf_dump.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

(limited to 'tools')

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index de07e559a11d..bbb430317260 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1137,6 +1137,20 @@ static void btf_dump_emit_mods(struct btf_dump *d, struct id_stack *decl_stack)
 	}
 }
 
+static void btf_dump_drop_mods(struct btf_dump *d, struct id_stack *decl_stack)
+{
+	const struct btf_type *t;
+	__u32 id;
+
+	while (decl_stack->cnt) {
+		id = decl_stack->ids[decl_stack->cnt - 1];
+		t = btf__type_by_id(d->btf, id);
+		if (!btf_is_mod(t))
+			return;
+		decl_stack->cnt--;
+	}
+}
+
 static void btf_dump_emit_name(const struct btf_dump *d,
 			       const char *name, bool last_was_ptr)
 {
@@ -1235,14 +1249,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			 * a const/volatile modifier for array, so we are
 			 * going to silently skip them here.
 			 */
-			while (decls->cnt) {
-				next_id = decls->ids[decls->cnt - 1];
-				next_t = btf__type_by_id(d->btf, next_id);
-				if (btf_is_mod(next_t))
-					decls->cnt--;
-				else
-					break;
-			}
+			btf_dump_drop_mods(d, decls);
 
 			if (decls->cnt == 0) {
 				btf_dump_emit_name(d, fname, last_was_ptr);
@@ -1270,7 +1277,15 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			__u16 vlen = btf_vlen(t);
 			int i;
 
-			btf_dump_emit_mods(d, decls);
+			/*
+			 * GCC emits extra volatile qualifier for
+			 * __attribute__((noreturn)) function pointers. Clang
+			 * doesn't do it. It's a GCC quirk for backwards
+			 * compatibility with code written for GCC <2.5. So,
+			 * similarly to extra qualifiers for array, just drop
+			 * them, instead of handling them.
+			 */
+			btf_dump_drop_mods(d, decls);
 			if (decls->cnt) {
 				btf_dump_printf(d, " (");
 				btf_dump_emit_type_chain(d, decls, fname, lvl);
-- 
cgit v1.2.3


From 47f6bc4ce1ff70d7ba0924c2f1c218c96cd585fb Mon Sep 17 00:00:00 2001
From: Brett Mastbergen <brett.mastbergen@gmail.com>
Date: Tue, 9 Jun 2020 17:35:06 -0400
Subject: tools, bpf: Do not force gcc as CC

This allows transparent cross-compilation with CROSS_COMPILE by
relying on 7ed1c1901fe5 ("tools: fix cross-compile var clobbering").

Same change was applied to tools/bpf/bpftool/Makefile in
9e88b9312acb ("tools: bpftool: do not force gcc as CC").

Signed-off-by: Brett Mastbergen <brett.mastbergen@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200609213506.3299-1-brett.mastbergen@gmail.com
---
 tools/bpf/Makefile | 1 -
 1 file changed, 1 deletion(-)

(limited to 'tools')

diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile
index 77472e28c8fd..6df1850f8353 100644
--- a/tools/bpf/Makefile
+++ b/tools/bpf/Makefile
@@ -3,7 +3,6 @@ include ../scripts/Makefile.include
 
 prefix ?= /usr/local
 
-CC = gcc
 LEX = flex
 YACC = bison
 MAKE = make
-- 
cgit v1.2.3


From bd6fecb9a99cceb949271c1821cfbad2b2db97c6 Mon Sep 17 00:00:00 2001
From: YiFei Zhu <zhuyifei1999@gmail.com>
Date: Wed, 10 Jun 2020 13:41:40 -0500
Subject: selftests/bpf: Add cgroup_skb/egress test for load_bytes_relative

When cgroup_skb/egress triggers the MAC header is not set. Added a
test that asserts reading MAC header is a -EFAULT but NET header
succeeds. The test result from within the eBPF program is stored in
an 1-element array map that the userspace then reads and asserts on.

Another assertion is added that reading from a large offset, past
the end of packet, returns -EFAULT.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/9028ccbea4385a620e69c0a104f469ffd655c01e.1591812755.git.zhuyifei@google.com
---
 .../selftests/bpf/prog_tests/load_bytes_relative.c | 71 ++++++++++++++++++++++
 .../selftests/bpf/progs/load_bytes_relative.c      | 48 +++++++++++++++
 2 files changed, 119 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c
 create mode 100644 tools/testing/selftests/bpf/progs/load_bytes_relative.c

(limited to 'tools')

diff --git a/tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c b/tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c
new file mode 100644
index 000000000000..c1168e4a9036
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright 2020 Google LLC.
+ */
+
+#include <test_progs.h>
+#include <network_helpers.h>
+
+void test_load_bytes_relative(void)
+{
+	int server_fd, cgroup_fd, prog_fd, map_fd, client_fd;
+	int err;
+	struct bpf_object *obj;
+	struct bpf_program *prog;
+	struct bpf_map *test_result;
+	__u32 duration = 0;
+
+	__u32 map_key = 0;
+	__u32 map_value = 0;
+
+	cgroup_fd = test__join_cgroup("/load_bytes_relative");
+	if (CHECK_FAIL(cgroup_fd < 0))
+		return;
+
+	server_fd = start_server(AF_INET, SOCK_STREAM);
+	if (CHECK_FAIL(server_fd < 0))
+		goto close_cgroup_fd;
+
+	err = bpf_prog_load("./load_bytes_relative.o", BPF_PROG_TYPE_CGROUP_SKB,
+			    &obj, &prog_fd);
+	if (CHECK_FAIL(err))
+		goto close_server_fd;
+
+	test_result = bpf_object__find_map_by_name(obj, "test_result");
+	if (CHECK_FAIL(!test_result))
+		goto close_bpf_object;
+
+	map_fd = bpf_map__fd(test_result);
+	if (map_fd < 0)
+		goto close_bpf_object;
+
+	prog = bpf_object__find_program_by_name(obj, "load_bytes_relative");
+	if (CHECK_FAIL(!prog))
+		goto close_bpf_object;
+
+	err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS,
+			      BPF_F_ALLOW_MULTI);
+	if (CHECK_FAIL(err))
+		goto close_bpf_object;
+
+	client_fd = connect_to_fd(AF_INET, SOCK_STREAM, server_fd);
+	if (CHECK_FAIL(client_fd < 0))
+		goto close_bpf_object;
+	close(client_fd);
+
+	err = bpf_map_lookup_elem(map_fd, &map_key, &map_value);
+	if (CHECK_FAIL(err))
+		goto close_bpf_object;
+
+	CHECK(map_value != 1, "bpf", "bpf program returned failure");
+
+close_bpf_object:
+	bpf_object__close(obj);
+
+close_server_fd:
+	close(server_fd);
+
+close_cgroup_fd:
+	close(cgroup_fd);
+}
diff --git a/tools/testing/selftests/bpf/progs/load_bytes_relative.c b/tools/testing/selftests/bpf/progs/load_bytes_relative.c
new file mode 100644
index 000000000000..dc1d04a7a3d6
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/load_bytes_relative.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright 2020 Google LLC.
+ */
+
+#include <errno.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u32);
+} test_result SEC(".maps");
+
+SEC("cgroup_skb/egress")
+int load_bytes_relative(struct __sk_buff *skb)
+{
+	struct ethhdr eth;
+	struct iphdr iph;
+
+	__u32 map_key = 0;
+	__u32 test_passed = 0;
+
+	/* MAC header is not set by the time cgroup_skb/egress triggers */
+	if (bpf_skb_load_bytes_relative(skb, 0, &eth, sizeof(eth),
+					BPF_HDR_START_MAC) != -EFAULT)
+		goto fail;
+
+	if (bpf_skb_load_bytes_relative(skb, 0, &iph, sizeof(iph),
+					BPF_HDR_START_NET))
+		goto fail;
+
+	if (bpf_skb_load_bytes_relative(skb, 0xffff, &iph, sizeof(iph),
+					BPF_HDR_START_NET) != -EFAULT)
+		goto fail;
+
+	test_passed = 1;
+
+fail:
+	bpf_map_update_elem(&test_result, &map_key, &test_passed, BPF_ANY);
+
+	return 1;
+}
-- 
cgit v1.2.3


From d4060ac969563113101c79433f2ae005feca1c29 Mon Sep 17 00:00:00 2001
From: Tobias Klauser <tklauser@distanz.ch>
Date: Wed, 10 Jun 2020 15:08:04 +0200
Subject: tools, bpftool: Fix memory leak in codegen error cases

Free the memory allocated for the template on error paths in function
codegen.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200610130804.21423-1-tklauser@distanz.ch
---
 tools/bpf/bpftool/gen.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools')

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index a3c4bb86c05a..ecbae47e66b8 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -224,6 +224,7 @@ static int codegen(const char *template, ...)
 		} else {
 			p_err("unrecognized character at pos %td in template '%s'",
 			      src - template - 1, template);
+			free(s);
 			return -EINVAL;
 		}
 	}
@@ -234,6 +235,7 @@ static int codegen(const char *template, ...)
 			if (*src != '\t') {
 				p_err("not enough tabs at pos %td in template '%s'",
 				      src - template - 1, template);
+				free(s);
 				return -EINVAL;
 			}
 		}
-- 
cgit v1.2.3


From 2c4779eff837f1035f6f9650d246905daadd9528 Mon Sep 17 00:00:00 2001
From: Tobias Klauser <tklauser@distanz.ch>
Date: Thu, 11 Jun 2020 12:33:41 +0200
Subject: tools, bpftool: Exit on error in function codegen

Currently, the codegen function might fail and return an error. But its
callers continue without checking its return value. Since codegen can
fail only in the unlikely case of the system running out of memory or
the static template being malformed, just exit(-1) directly from codegen
and make it void-returning.

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200611103341.21532-1-tklauser@distanz.ch
---
 tools/bpf/bpftool/gen.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

(limited to 'tools')

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index ecbae47e66b8..7443879e87af 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -200,7 +200,7 @@ out:
 	return err;
 }
 
-static int codegen(const char *template, ...)
+static void codegen(const char *template, ...)
 {
 	const char *src, *end;
 	int skip_tabs = 0, n;
@@ -211,7 +211,7 @@ static int codegen(const char *template, ...)
 	n = strlen(template);
 	s = malloc(n + 1);
 	if (!s)
-		return -ENOMEM;
+		exit(-1);
 	src = template;
 	dst = s;
 
@@ -225,7 +225,7 @@ static int codegen(const char *template, ...)
 			p_err("unrecognized character at pos %td in template '%s'",
 			      src - template - 1, template);
 			free(s);
-			return -EINVAL;
+			exit(-1);
 		}
 	}
 
@@ -236,7 +236,7 @@ static int codegen(const char *template, ...)
 				p_err("not enough tabs at pos %td in template '%s'",
 				      src - template - 1, template);
 				free(s);
-				return -EINVAL;
+				exit(-1);
 			}
 		}
 		/* trim trailing whitespace */
@@ -257,7 +257,8 @@ static int codegen(const char *template, ...)
 	va_end(args);
 
 	free(s);
-	return n;
+	if (n)
+		exit(-1);
 }
 
 static int do_skeleton(int argc, char **argv)
-- 
cgit v1.2.3


From 22eb78792e07a4dfb63c85f34950d4e58eb90326 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 12 Jun 2020 13:16:03 -0700
Subject: tools/bpftool: Fix skeleton codegen

Remove unnecessary check at the end of codegen() routine which makes codegen()
to always fail and exit bpftool with error code. Positive value of variable
n is not an indicator of a failure.

Fixes: 2c4779eff837 ("tools, bpftool: Exit on error in function codegen")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/bpf/20200612201603.680852-1-andriin@fb.com
---
 tools/bpf/bpftool/gen.c | 2 --
 1 file changed, 2 deletions(-)

(limited to 'tools')

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 7443879e87af..10de76b296ba 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -257,8 +257,6 @@ static void codegen(const char *template, ...)
 	va_end(args);
 
 	free(s);
-	if (n)
-		exit(-1);
 }
 
 static int do_skeleton(int argc, char **argv)
-- 
cgit v1.2.3


From caf62492f479585296e9d636c798d5ac256b7b04 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 12 Jun 2020 12:45:04 -0700
Subject: libbpf: Support pre-initializing .bss global variables

Remove invalid assumption in libbpf that .bss map doesn't have to be updated
in kernel. With addition of skeleton and memory-mapped initialization image,
.bss doesn't have to be all zeroes when BPF map is created, because user-code
might have initialized those variables from user-space.

Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200612194504.557844-1-andriin@fb.com
---
 tools/lib/bpf/libbpf.c                            |  4 --
 tools/testing/selftests/bpf/prog_tests/skeleton.c | 45 ++++++++++++++++++++---
 tools/testing/selftests/bpf/progs/test_skeleton.c | 19 ++++++++--
 3 files changed, 55 insertions(+), 13 deletions(-)

(limited to 'tools')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7f01be2b88b8..477c679ed945 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3564,10 +3564,6 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
 	char *cp, errmsg[STRERR_BUFSIZE];
 	int err, zero = 0;
 
-	/* kernel already zero-initializes .bss map. */
-	if (map_type == LIBBPF_MAP_BSS)
-		return 0;
-
 	err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0);
 	if (err) {
 		err = -errno;
diff --git a/tools/testing/selftests/bpf/prog_tests/skeleton.c b/tools/testing/selftests/bpf/prog_tests/skeleton.c
index 9264a2736018..fa153cf67b1b 100644
--- a/tools/testing/selftests/bpf/prog_tests/skeleton.c
+++ b/tools/testing/selftests/bpf/prog_tests/skeleton.c
@@ -15,6 +15,8 @@ void test_skeleton(void)
 	int duration = 0, err;
 	struct test_skeleton* skel;
 	struct test_skeleton__bss *bss;
+	struct test_skeleton__data *data;
+	struct test_skeleton__rodata *rodata;
 	struct test_skeleton__kconfig *kcfg;
 
 	skel = test_skeleton__open();
@@ -24,13 +26,45 @@ void test_skeleton(void)
 	if (CHECK(skel->kconfig, "skel_kconfig", "kconfig is mmaped()!\n"))
 		goto cleanup;
 
+	bss = skel->bss;
+	data = skel->data;
+	rodata = skel->rodata;
+
+	/* validate values are pre-initialized correctly */
+	CHECK(data->in1 != -1, "in1", "got %d != exp %d\n", data->in1, -1);
+	CHECK(data->out1 != -1, "out1", "got %d != exp %d\n", data->out1, -1);
+	CHECK(data->in2 != -1, "in2", "got %lld != exp %lld\n", data->in2, -1LL);
+	CHECK(data->out2 != -1, "out2", "got %lld != exp %lld\n", data->out2, -1LL);
+
+	CHECK(bss->in3 != 0, "in3", "got %d != exp %d\n", bss->in3, 0);
+	CHECK(bss->out3 != 0, "out3", "got %d != exp %d\n", bss->out3, 0);
+	CHECK(bss->in4 != 0, "in4", "got %lld != exp %lld\n", bss->in4, 0LL);
+	CHECK(bss->out4 != 0, "out4", "got %lld != exp %lld\n", bss->out4, 0LL);
+
+	CHECK(rodata->in6 != 0, "in6", "got %d != exp %d\n", rodata->in6, 0);
+	CHECK(bss->out6 != 0, "out6", "got %d != exp %d\n", bss->out6, 0);
+
+	/* validate we can pre-setup global variables, even in .bss */
+	data->in1 = 10;
+	data->in2 = 11;
+	bss->in3 = 12;
+	bss->in4 = 13;
+	rodata->in6 = 14;
+
 	err = test_skeleton__load(skel);
 	if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
 		goto cleanup;
 
-	bss = skel->bss;
-	bss->in1 = 1;
-	bss->in2 = 2;
+	/* validate pre-setup values are still there */
+	CHECK(data->in1 != 10, "in1", "got %d != exp %d\n", data->in1, 10);
+	CHECK(data->in2 != 11, "in2", "got %lld != exp %lld\n", data->in2, 11LL);
+	CHECK(bss->in3 != 12, "in3", "got %d != exp %d\n", bss->in3, 12);
+	CHECK(bss->in4 != 13, "in4", "got %lld != exp %lld\n", bss->in4, 13LL);
+	CHECK(rodata->in6 != 14, "in6", "got %d != exp %d\n", rodata->in6, 14);
+
+	/* now set new values and attach to get them into outX variables */
+	data->in1 = 1;
+	data->in2 = 2;
 	bss->in3 = 3;
 	bss->in4 = 4;
 	bss->in5.a = 5;
@@ -44,14 +78,15 @@ void test_skeleton(void)
 	/* trigger tracepoint */
 	usleep(1);
 
-	CHECK(bss->out1 != 1, "res1", "got %d != exp %d\n", bss->out1, 1);
-	CHECK(bss->out2 != 2, "res2", "got %lld != exp %d\n", bss->out2, 2);
+	CHECK(data->out1 != 1, "res1", "got %d != exp %d\n", data->out1, 1);
+	CHECK(data->out2 != 2, "res2", "got %lld != exp %d\n", data->out2, 2);
 	CHECK(bss->out3 != 3, "res3", "got %d != exp %d\n", (int)bss->out3, 3);
 	CHECK(bss->out4 != 4, "res4", "got %lld != exp %d\n", bss->out4, 4);
 	CHECK(bss->handler_out5.a != 5, "res5", "got %d != exp %d\n",
 	      bss->handler_out5.a, 5);
 	CHECK(bss->handler_out5.b != 6, "res6", "got %lld != exp %d\n",
 	      bss->handler_out5.b, 6);
+	CHECK(bss->out6 != 14, "res7", "got %d != exp %d\n", bss->out6, 14);
 
 	CHECK(bss->bpf_syscall != kcfg->CONFIG_BPF_SYSCALL, "ext1",
 	      "got %d != exp %d\n", bss->bpf_syscall, kcfg->CONFIG_BPF_SYSCALL);
diff --git a/tools/testing/selftests/bpf/progs/test_skeleton.c b/tools/testing/selftests/bpf/progs/test_skeleton.c
index de03a90f78ca..77ae86f44db5 100644
--- a/tools/testing/selftests/bpf/progs/test_skeleton.c
+++ b/tools/testing/selftests/bpf/progs/test_skeleton.c
@@ -10,16 +10,26 @@ struct s {
 	long long b;
 } __attribute__((packed));
 
-int in1 = 0;
-long long in2 = 0;
+/* .data section */
+int in1 = -1;
+long long in2 = -1;
+
+/* .bss section */
 char in3 = '\0';
 long long in4 __attribute__((aligned(64))) = 0;
 struct s in5 = {};
 
-long long out2 = 0;
+/* .rodata section */
+const volatile int in6 = 0;
+
+/* .data section */
+int out1 = -1;
+long long out2 = -1;
+
+/* .bss section */
 char out3 = 0;
 long long out4 = 0;
-int out1 = 0;
+int out6 = 0;
 
 extern bool CONFIG_BPF_SYSCALL __kconfig;
 extern int LINUX_KERNEL_VERSION __kconfig;
@@ -36,6 +46,7 @@ int handler(const void *ctx)
 	out3 = in3;
 	out4 = in4;
 	out5 = in5;
+	out6 = in6;
 
 	bpf_syscall = CONFIG_BPF_SYSCALL;
 	kern_ver = LINUX_KERNEL_VERSION;
-- 
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