[PATCH AUTOSEL 5.4 056/350] selftests/bpf: Correct path to include msg + path

[PATCH AUTOSEL 5.4 056/350] selftests/bpf: Correct path to include msg + path

[Sasha Levin]

From: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>

[ Upstream commit c588146378962786ddeec817f7736a53298a7b01 ]

The "path" buf is supposed to contain path + printf msg up to 24 bytes.
It will be cut anyway, but compiler generates truncation warns like:

"
samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c: In
function ‘setup_cgroup_environment’:
samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:52:34:
warning: ‘/cgroup.controllers’ directive output may be truncated
writing 19 bytes into a region of size between 1 and 4097
[-Wformat-truncation=]
snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path);
				  ^~~~~~~~~~~~~~~~~~~
samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:52:2:
note: ‘snprintf’ output between 20 and 4116 bytes into a destination
of size 4097
snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:72:34:
warning: ‘/cgroup.subtree_control’ directive output may be truncated
writing 23 bytes into a region of size between 1 and 4097
[-Wformat-truncation=]
snprintf(path, sizeof(path), "%s/cgroup.subtree_control",
				  ^~~~~~~~~~~~~~~~~~~~~~~
cgroup_path);
samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:72:2:
note: ‘snprintf’ output between 24 and 4120 bytes into a destination
of size 4097
snprintf(path, sizeof(path), "%s/cgroup.subtree_control",
cgroup_path);
"

In order to avoid warns, lets decrease buf size for cgroup workdir on
24 bytes with assumption to include also "/cgroup.subtree_control" to
the address. The cut will never happen anyway.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191002120404.26962-3-ivan.khoronzhuk@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/cgroup_helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index e95c33e333a40..b29a73fe64dbc 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -98,7 +98,7 @@ int enable_all_controllers(char *cgroup_path)
  */
 int setup_cgroup_environment(void)
 {
-	char cgroup_workdir[PATH_MAX + 1];
+	char cgroup_workdir[PATH_MAX - 24];
 
 	format_cgroup_path(cgroup_workdir, "");
 
-- 
2.20.1

[PATCH AUTOSEL 5.4 079/350] selftests/bpf: Fix btf_dump padding test case

[Sasha Levin]

From: Andrii Nakryiko <andriin@fb.com>

[ Upstream commit 76790c7c66ccc8695afc75e73f54c0ca86267ed2 ]

Existing padding test case for btf_dump has a good test that was
supposed to test padding generation at the end of a struct, but its
expected output was specified incorrectly. Fix this.

Fixes: 2d2a3ad872f8 ("selftests/bpf: add btf_dump BTF-to-C conversion tests")
Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191008231009.2991130-4-andriin@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../testing/selftests/bpf/progs/btf_dump_test_case_padding.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c
index 3a62119c74986..35c512818a56b 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c
@@ -62,6 +62,10 @@ struct padded_a_lot {
  *	long: 64;
  *	long: 64;
  *	int b;
+ *	long: 32;
+ *	long: 64;
+ *	long: 64;
+ *	long: 64;
  *};
  *
  */
@@ -95,7 +99,6 @@ struct zone_padding {
 struct zone {
 	int a;
 	short b;
-	short: 16;
 	struct zone_padding __pad__;
 };
 
-- 
2.20.1

[PATCH AUTOSEL 5.4 122/350] selftests: Fix O= and KBUILD_OUTPUT handling for relative paths

[Sasha Levin]

From: Shuah Khan <skhan@linuxfoundation.org>

[ Upstream commit 303e6218ecec475d5bc3e5922dec770ee5baf107 ]

Fix O= and KBUILD_OUTPUT handling for relative paths.

export KBUILD_OUTPUT=../kselftest_size
make TARGETS=size kselftest-all

or

make O=../kselftest_size TARGETS=size kselftest-all

In both of these cases, targets get built in ../kselftest_size which is
a one level up from the size test directory.

make[1]: Entering directory '/mnt/data/lkml/kselftest_size'
make --no-builtin-rules INSTALL_HDR_PATH=$BUILD/usr \
        ARCH=x86 -C ../../.. headers_install
  INSTALL ../kselftest_size/usr/include
gcc -static -ffreestanding -nostartfiles -s    get_size.c  -o ../kselftest_size/size/get_size
/usr/bin/ld: cannot open output file ../kselftest_size/size/get_size: No such file or directory
collect2: error: ld returned 1 exit status
make[3]: *** [../lib.mk:138: ../kselftest_size/size/get_size] Error 1
make[2]: *** [Makefile:143: all] Error 2
make[1]: *** [/mnt/data/lkml/linux_5.4/Makefile:1221: kselftest-all] Error 2
make[1]: Leaving directory '/mnt/data/lkml/kselftest_size'
make: *** [Makefile:179: sub-make] Error 2

Use abs_objtree exported by the main Makefile.

Reported-by: Tim Bird <Tim.Bird@sony.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Tim Bird <tim.bird@sony.com>
Acked-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 4cdbae6f4e61b..3405aa26a655a 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -86,10 +86,10 @@ override LDFLAGS =
 endif
 
 ifneq ($(O),)
-	BUILD := $(O)
+	BUILD := $(abs_objtree)
 else
 	ifneq ($(KBUILD_OUTPUT),)
-		BUILD := $(KBUILD_OUTPUT)/kselftest
+		BUILD := $(abs_objtree)/kselftest
 	else
 		BUILD := $(shell pwd)
 		DEFAULT_INSTALL_HDR_PATH := 1
@@ -102,6 +102,7 @@ include $(top_srcdir)/scripts/subarch.include
 ARCH           ?= $(SUBARCH)
 export KSFT_KHDR_INSTALL_DONE := 1
 export BUILD
+#$(info abd_objtree = $(abs_objtree) BUILD = $(BUILD))
 
 # build and run gpio when output directory is the src dir.
 # gpio has dependency on tools/gpio and builds tools/gpio
-- 
2.20.1

[PATCH AUTOSEL 5.4 132/350] selftests/bpf: Make a copy of subtest name

[Sasha Levin]

From: Andrii Nakryiko <andriin@fb.com>

[ Upstream commit f90415e9600c5227131531c0ed11514a2d3bbe62 ]

test_progs never created a copy of subtest name, rather just stored
pointer to whatever string test provided. This is bad as that string
might be freed or modified by the end of subtest. Fix this by creating
a copy of given subtest name when subtest starts.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-6-andriin@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/test_progs.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index af75a1c7a4587..3bf18364c67c9 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -20,7 +20,7 @@ struct prog_test_def {
 	bool tested;
 	bool need_cgroup_cleanup;
 
-	const char *subtest_name;
+	char *subtest_name;
 	int subtest_num;
 
 	/* store counts before subtest started */
@@ -81,16 +81,17 @@ void test__end_subtest()
 	fprintf(env.stdout, "#%d/%d %s:%s\n",
 	       test->test_num, test->subtest_num,
 	       test->subtest_name, sub_error_cnt ? "FAIL" : "OK");
+
+	free(test->subtest_name);
+	test->subtest_name = NULL;
 }
 
 bool test__start_subtest(const char *name)
 {
 	struct prog_test_def *test = env.test;
 
-	if (test->subtest_name) {
+	if (test->subtest_name)
 		test__end_subtest();
-		test->subtest_name = NULL;
-	}
 
 	test->subtest_num++;
 
@@ -104,7 +105,13 @@ bool test__start_subtest(const char *name)
 	if (!should_run(&env.subtest_selector, test->subtest_num, name))
 		return false;
 
-	test->subtest_name = name;
+	test->subtest_name = strdup(name);
+	if (!test->subtest_name) {
+		fprintf(env.stderr,
+			"Subtest #%d: failed to copy subtest name!\n",
+			test->subtest_num);
+		return false;
+	}
 	env.test->old_error_cnt = env.test->error_cnt;
 
 	return true;
-- 
2.20.1

[PATCH AUTOSEL 5.4 245/350] selftests: proc: Make va_max 1MB

[Sasha Levin]

From: Masami Hiramatsu <mhiramat@kernel.org>

[ Upstream commit 2f3571ea71311bbb2cbb9c3bbefc9c1969a3e889 ]

Currently proc-self-map-files-002.c sets va_max (max test address
of user virtual address) to 4GB, but it is too big for 32bit
arch and 1UL << 32 is overflow on 32bit long.
Also since this value should be enough bigger than vm.mmap_min_addr
(64KB or 32KB by default), 1MB should be enough.

Make va_max 1MB unconditionally.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/proc/proc-self-map-files-002.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/proc/proc-self-map-files-002.c b/tools/testing/selftests/proc/proc-self-map-files-002.c
index 47b7473dedef7..e6aa00a183bcd 100644
--- a/tools/testing/selftests/proc/proc-self-map-files-002.c
+++ b/tools/testing/selftests/proc/proc-self-map-files-002.c
@@ -47,7 +47,11 @@ static void fail(const char *fmt, unsigned long a, unsigned long b)
 int main(void)
 {
 	const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
-	const unsigned long va_max = 1UL << 32;
+	/*
+	 * va_max must be enough bigger than vm.mmap_min_addr, which is
+	 * 64KB/32KB by default. (depends on CONFIG_LSM_MMAP_MIN_ADDR)
+	 */
+	const unsigned long va_max = 1UL << 20;
 	unsigned long va;
 	void *p;
 	int fd;
-- 
2.20.1

[PATCH AUTOSEL 5.4 250/350] selftests: net: Fix printf format warnings on arm

[Sasha Levin]

From: Masami Hiramatsu <mhiramat@kernel.org>

[ Upstream commit 670cd6849ea36ea4df2f2941cf4717dff8755abe ]

Fix printf format warnings on arm (and other 32bit arch).

 - udpgso.c and udpgso_bench_tx use %lu for size_t but it
   should be unsigned long long on 32bit arch.

 - so_txtime.c uses %ld for int64_t, but it should be
   unsigned long long on 32bit arch.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/net/so_txtime.c       | 4 ++--
 tools/testing/selftests/net/udpgso.c          | 3 ++-
 tools/testing/selftests/net/udpgso_bench_tx.c | 3 ++-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/net/so_txtime.c b/tools/testing/selftests/net/so_txtime.c
index 53f598f066470..34df4c8882afb 100644
--- a/tools/testing/selftests/net/so_txtime.c
+++ b/tools/testing/selftests/net/so_txtime.c
@@ -105,8 +105,8 @@ static void do_recv_one(int fdr, struct timed_send *ts)
 	tstop = (gettime_ns() - glob_tstart) / 1000;
 	texpect = ts->delay_us >= 0 ? ts->delay_us : 0;
 
-	fprintf(stderr, "payload:%c delay:%ld expected:%ld (us)\n",
-			rbuf[0], tstop, texpect);
+	fprintf(stderr, "payload:%c delay:%lld expected:%lld (us)\n",
+			rbuf[0], (long long)tstop, (long long)texpect);
 
 	if (rbuf[0] != ts->data)
 		error(1, 0, "payload mismatch. expected %c", ts->data);
diff --git a/tools/testing/selftests/net/udpgso.c b/tools/testing/selftests/net/udpgso.c
index 614b31aad168b..c66da6ffd6d8d 100644
--- a/tools/testing/selftests/net/udpgso.c
+++ b/tools/testing/selftests/net/udpgso.c
@@ -440,7 +440,8 @@ static bool __send_one(int fd, struct msghdr *msg, int flags)
 	if (ret == -1)
 		error(1, errno, "sendmsg");
 	if (ret != msg->msg_iov->iov_len)
-		error(1, 0, "sendto: %d != %lu", ret, msg->msg_iov->iov_len);
+		error(1, 0, "sendto: %d != %llu", ret,
+			(unsigned long long)msg->msg_iov->iov_len);
 	if (msg->msg_flags)
 		error(1, 0, "sendmsg: return flags 0x%x\n", msg->msg_flags);
 
diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c
index ada99496634aa..17512a43885e7 100644
--- a/tools/testing/selftests/net/udpgso_bench_tx.c
+++ b/tools/testing/selftests/net/udpgso_bench_tx.c
@@ -405,7 +405,8 @@ static int send_udp_segment(int fd, char *data)
 	if (ret == -1)
 		error(1, errno, "sendmsg");
 	if (ret != iov.iov_len)
-		error(1, 0, "sendmsg: %u != %lu\n", ret, iov.iov_len);
+		error(1, 0, "sendmsg: %u != %llu\n", ret,
+			(unsigned long long)iov.iov_len);
 
 	return 1;
 }
-- 
2.20.1

[PATCH AUTOSEL 5.4 267/350] bpf, testing: Workaround a verifier failure for test_progs

[Sasha Levin]

From: Yonghong Song <yhs@fb.com>

[ Upstream commit b7a0d65d80a0c5034b366392624397a0915b7556 ]

With latest llvm compiler, running test_progs will have the following
verifier failure for test_sysctl_loop1.o:

  libbpf: load bpf program failed: Permission denied
  libbpf: -- BEGIN DUMP LOG ---
  libbpf:
  invalid indirect read from stack var_off (0x0; 0xff)+196 size 7
  ...
  libbpf: -- END LOG --
  libbpf: failed to load program 'cgroup/sysctl'
  libbpf: failed to load object 'test_sysctl_loop1.o'

The related bytecode looks as below:

  0000000000000308 LBB0_8:
      97:       r4 = r10
      98:       r4 += -288
      99:       r4 += r7
     100:       w8 &= 255
     101:       r1 = r10
     102:       r1 += -488
     103:       r1 += r8
     104:       r2 = 7
     105:       r3 = 0
     106:       call 106
     107:       w1 = w0
     108:       w1 += -1
     109:       if w1 > 6 goto -24 <LBB0_5>
     110:       w0 += w8
     111:       r7 += 8
     112:       w8 = w0
     113:       if r7 != 224 goto -17 <LBB0_8>

And source code:

     for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) {
             ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0,
                               tcp_mem + i);
             if (ret <= 0 || ret > MAX_ULONG_STR_LEN)
                     return 0;
             off += ret & MAX_ULONG_STR_LEN;
     }

Current verifier is not able to conclude that register w0 before '+'
at insn 110 has a range of 1 to 7 and thinks it is from 0 - 255. This
leads to more conservative range for w8 at insn 112, and later verifier
complaint.

Let us workaround this issue until we found a compiler and/or verifier
solution. The workaround in this patch is to make variable 'ret' volatile,
which will force a reload and then '&' operation to ensure better value
range. With this patch, I got the below byte code for the loop:

  0000000000000328 LBB0_9:
     101:       r4 = r10
     102:       r4 += -288
     103:       r4 += r7
     104:       w8 &= 255
     105:       r1 = r10
     106:       r1 += -488
     107:       r1 += r8
     108:       r2 = 7
     109:       r3 = 0
     110:       call 106
     111:       *(u32 *)(r10 - 64) = r0
     112:       r1 = *(u32 *)(r10 - 64)
     113:       if w1 s< 1 goto -28 <LBB0_5>
     114:       r1 = *(u32 *)(r10 - 64)
     115:       if w1 s> 7 goto -30 <LBB0_5>
     116:       r1 = *(u32 *)(r10 - 64)
     117:       w1 &= 7
     118:       w1 += w8
     119:       r7 += 8
     120:       w8 = w1
     121:       if r7 != 224 goto -21 <LBB0_9>

Insn 117 did the '&' operation and we got more precise value range
for 'w8' at insn 120. The test is happy then:

  #3/17 test_sysctl_loop1.o:OK

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191107170045.2503480-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/progs/test_sysctl_loop1.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c b/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c
index 608a06871572d..d22e438198cf7 100644
--- a/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c
+++ b/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c
@@ -44,7 +44,10 @@ int sysctl_tcp_mem(struct bpf_sysctl *ctx)
 	unsigned long tcp_mem[TCP_MEM_LOOPS] = {};
 	char value[MAX_VALUE_STR_LEN];
 	unsigned char i, off = 0;
-	int ret;
+	/* a workaround to prevent compiler from generating
+	 * codes verifier cannot handle yet.
+	 */
+	volatile int ret;
 
 	if (ctx->write)
 		return 0;
-- 
2.20.1

[PATCH AUTOSEL 5.4 306/350] selftests, bpf: Fix test_tc_tunnel hanging

[Sasha Levin]

From: Jiri Benc <jbenc@redhat.com>

[ Upstream commit 3b054b7133b4ad93671c82e8d6185258e3f1a7a5 ]

When run_kselftests.sh is run, it hangs after test_tc_tunnel.sh. The reason
is test_tc_tunnel.sh ensures the server ('nc -l') is run all the time,
starting it again every time it is expected to terminate. The exception is
the final client_connect: the server is not started anymore, which ensures
no process is kept running after the test is finished.

For a sit test, though, the script is terminated prematurely without the
final client_connect and the 'nc' process keeps running. This in turn causes
the run_one function in kselftest/runner.sh to hang forever, waiting for the
runaway process to finish.

Ensure a remaining server is terminated on cleanup.

Fixes: f6ad6accaa99 ("selftests/bpf: expand test_tc_tunnel with SIT encap")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/bpf/60919291657a9ee89c708d8aababc28ebe1420be.1573821780.git.jbenc@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/test_tc_tunnel.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh
index ff0d31d38061f..7c76b841b17bb 100755
--- a/tools/testing/selftests/bpf/test_tc_tunnel.sh
+++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh
@@ -62,6 +62,10 @@ cleanup() {
 	if [[ -f "${infile}" ]]; then
 		rm "${infile}"
 	fi
+
+	if [[ -n $server_pid ]]; then
+		kill $server_pid 2> /dev/null
+	fi
 }
 
 server_listen() {
@@ -77,6 +81,7 @@ client_connect() {
 
 verify_data() {
 	wait "${server_pid}"
+	server_pid=
 	# sha1sum returns two fields [sha1] [filepath]
 	# convert to bash array and access first elem
 	insum=($(sha1sum ${infile}))
-- 
2.20.1

[PATCH AUTOSEL 5.4 307/350] selftests, bpf: Workaround an alu32 sub-register spilling issue

[Sasha Levin]

From: Yonghong Song <yhs@fb.com>

[ Upstream commit 2ea2612b987ad703235c92be21d4e98ee9c2c67c ]

Currently, with latest llvm trunk, selftest test_progs failed obj
file test_seg6_loop.o with the following error in verifier:

  infinite loop detected at insn 76

The byte code sequence looks like below, and noted that alu32 has been
turned off by default for better generated codes in general:

      48:       w3 = 100
      49:       *(u32 *)(r10 - 68) = r3
      ...
  ;             if (tlv.type == SR6_TLV_PADDING) {
      76:       if w3 == 5 goto -18 <LBB0_19>
      ...
      85:       r1 = *(u32 *)(r10 - 68)
  ;     for (int i = 0; i < 100; i++) {
      86:       w1 += -1
      87:       if w1 == 0 goto +5 <LBB0_20>
      88:       *(u32 *)(r10 - 68) = r1

The main reason for verification failure is due to partial spills at
r10 - 68 for induction variable "i".

Current verifier only handles spills with 8-byte values. The above 4-byte
value spill to stack is treated to STACK_MISC and its content is not
saved. For the above example:

    w3 = 100
      R3_w=inv100 fp-64_w=inv1086626730498
    *(u32 *)(r10 - 68) = r3
      R3_w=inv100 fp-64_w=inv1086626730498
    ...
    r1 = *(u32 *)(r10 - 68)
      R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
      fp-64=inv1086626730498

To resolve this issue, verifier needs to be extended to track sub-registers
in spilling, or llvm needs to enhanced to prevent sub-register spilling
in register allocation phase. The former will increase verifier complexity
and the latter will need some llvm "hacking".

Let us workaround this issue by declaring the induction variable as "long"
type so spilling will happen at non sub-register level. We can revisit this
later if sub-register spilling causes similar or other verification issues.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191117214036.1309510-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/progs/test_seg6_loop.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_seg6_loop.c b/tools/testing/selftests/bpf/progs/test_seg6_loop.c
index c4d104428643e..69880c1e7700c 100644
--- a/tools/testing/selftests/bpf/progs/test_seg6_loop.c
+++ b/tools/testing/selftests/bpf/progs/test_seg6_loop.c
@@ -132,8 +132,10 @@ static __always_inline int is_valid_tlv_boundary(struct __sk_buff *skb,
 	*pad_off = 0;
 
 	// we can only go as far as ~10 TLVs due to the BPF max stack size
+	// workaround: define induction variable "i" as "long" instead
+	// of "int" to prevent alu32 sub-register spilling.
 	#pragma clang loop unroll(disable)
-	for (int i = 0; i < 100; i++) {
+	for (long i = 0; i < 100; i++) {
 		struct sr6_tlv_t tlv;
 
 		if (cur_off == *tlv_off)
-- 
2.20.1

[PATCH AUTOSEL 5.4 327/350] libbpf: Fix call relocation offset calculation bug

[Sasha Levin]

From: Andrii Nakryiko <andriin@fb.com>

[ Upstream commit a0d7da26ce86a25e97ae191cb90574ada6daea98 ]

When relocating subprogram call, libbpf doesn't take into account
relo->text_off, which comes from symbol's value. This generally works fine for
subprograms implemented as static functions, but breaks for global functions.

Taking a simplified test_pkt_access.c as an example:

__attribute__ ((noinline))
static int test_pkt_access_subprog1(volatile struct __sk_buff *skb)
{
        return skb->len * 2;
}

__attribute__ ((noinline))
static int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb)
{
        return skb->len + val;
}

SEC("classifier/test_pkt_access")
int test_pkt_access(struct __sk_buff *skb)
{
        if (test_pkt_access_subprog1(skb) != skb->len * 2)
                return TC_ACT_SHOT;
        if (test_pkt_access_subprog2(2, skb) != skb->len + 2)
                return TC_ACT_SHOT;
        return TC_ACT_UNSPEC;
}

When compiled, we get two relocations, pointing to '.text' symbol. .text has
st_value set to 0 (it points to the beginning of .text section):

0000000000000008  000000050000000a R_BPF_64_32            0000000000000000 .text
0000000000000040  000000050000000a R_BPF_64_32            0000000000000000 .text

test_pkt_access_subprog1 and test_pkt_access_subprog2 offsets (targets of two
calls) are encoded within call instruction's imm32 part as -1 and 2,
respectively:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       4:       04 00 00 00 02 00 00 00 w0 += 2
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 08 00 00 00 00 00 if w1 != w2 goto +8 <LBB0_3>
       7:       bf 61 00 00 00 00 00 00 r1 = r6
===>   8:       85 10 00 00 02 00 00 00 call 2
       9:       bc 01 00 00 00 00 00 00 w1 = w0
      10:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      11:       04 02 00 00 02 00 00 00 w2 += 2
      12:       b4 00 00 00 ff ff ff ff w0 = -1
      13:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB0_3>
      14:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000078 LBB0_3:
      15:       95 00 00 00 00 00 00 00 exit

Now, if we compile example with global functions, the setup changes.
Relocations are now against specifically test_pkt_access_subprog1 and
test_pkt_access_subprog2 symbols, with test_pkt_access_subprog2 pointing 24
bytes into its respective section (.text), i.e., 3 instructions in:

0000000000000008  000000070000000a R_BPF_64_32            0000000000000000 test_pkt_access_subprog1
0000000000000048  000000080000000a R_BPF_64_32            0000000000000018 test_pkt_access_subprog2

Calls instructions now encode offsets relative to function symbols and are both
set ot -1:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 20 00 00 00 00 00 00 r0 = *(u32 *)(r2 + 0)
       4:       0c 10 00 00 00 00 00 00 w0 += w1
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 09 00 00 00 00 00 if w1 != w2 goto +9 <LBB2_3>
       7:       b4 01 00 00 02 00 00 00 w1 = 2
       8:       bf 62 00 00 00 00 00 00 r2 = r6
===>   9:       85 10 00 00 ff ff ff ff call -1
      10:       bc 01 00 00 00 00 00 00 w1 = w0
      11:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      12:       04 02 00 00 02 00 00 00 w2 += 2
      13:       b4 00 00 00 ff ff ff ff w0 = -1
      14:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB2_3>
      15:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000080 LBB2_3:
      16:       95 00 00 00 00 00 00 00 exit

Thus the right formula to calculate target call offset after relocation should
take into account relocation's target symbol value (offset within section),
call instruction's imm32 offset, and (subtracting, to get relative instruction
offset) instruction index of call instruction itself. All that is shifted by
number of instructions in main program, given all sub-programs are copied over
after main program.

Convert few selftests relying on bpf-to-bpf calls to use global functions
instead of static ones.

Fixes: 48cca7e44f9f ("libbpf: add support for bpf_call")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191119224447.3781271-1-andriin@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/lib/bpf/libbpf.c                             | 8 ++++++--
 tools/testing/selftests/bpf/progs/test_btf_haskv.c | 4 ++--
 tools/testing/selftests/bpf/progs/test_btf_newkv.c | 4 ++--
 tools/testing/selftests/bpf/progs/test_btf_nokv.c  | 4 ++--
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a267cd0c0ce28..6a87ff9936d7b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1791,9 +1791,13 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 				pr_warning("incorrect bpf_call opcode\n");
 				return -LIBBPF_ERRNO__RELOC;
 			}
+			if (sym.st_value % 8) {
+				pr_warn("bad call relo offset: %lu\n", sym.st_value);
+				return -LIBBPF_ERRNO__RELOC;
+			}
 			prog->reloc_desc[i].type = RELO_CALL;
 			prog->reloc_desc[i].insn_idx = insn_idx;
-			prog->reloc_desc[i].text_off = sym.st_value;
+			prog->reloc_desc[i].text_off = sym.st_value / 8;
 			obj->has_pseudo_calls = true;
 			continue;
 		}
@@ -3239,7 +3243,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
 			 prog->section_name);
 	}
 	insn = &prog->insns[relo->insn_idx];
-	insn->imm += prog->main_prog_cnt - relo->insn_idx;
+	insn->imm += relo->text_off + prog->main_prog_cnt - relo->insn_idx;
 	return 0;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/test_btf_haskv.c b/tools/testing/selftests/bpf/progs/test_btf_haskv.c
index e5c79fe0ffdb2..d65c61e64df2f 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_haskv.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_haskv.c
@@ -25,7 +25,7 @@ struct dummy_tracepoint_args {
 };
 
 __attribute__((noinline))
-static int test_long_fname_2(struct dummy_tracepoint_args *arg)
+int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
 	struct ipv_counts *counts;
 	int key = 0;
@@ -43,7 +43,7 @@ static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 }
 
 __attribute__((noinline))
-static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+int test_long_fname_1(struct dummy_tracepoint_args *arg)
 {
 	return test_long_fname_2(arg);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_btf_newkv.c b/tools/testing/selftests/bpf/progs/test_btf_newkv.c
index 5ee3622ddebb6..8e83317db841f 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_newkv.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_newkv.c
@@ -33,7 +33,7 @@ struct dummy_tracepoint_args {
 };
 
 __attribute__((noinline))
-static int test_long_fname_2(struct dummy_tracepoint_args *arg)
+int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
 	struct ipv_counts *counts;
 	int key = 0;
@@ -56,7 +56,7 @@ static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 }
 
 __attribute__((noinline))
-static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+int test_long_fname_1(struct dummy_tracepoint_args *arg)
 {
 	return test_long_fname_2(arg);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_btf_nokv.c b/tools/testing/selftests/bpf/progs/test_btf_nokv.c
index 434188c377743..3f44220447594 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_nokv.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_nokv.c
@@ -23,7 +23,7 @@ struct dummy_tracepoint_args {
 };
 
 __attribute__((noinline))
-static int test_long_fname_2(struct dummy_tracepoint_args *arg)
+int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
 	struct ipv_counts *counts;
 	int key = 0;
@@ -41,7 +41,7 @@ static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 }
 
 __attribute__((noinline))
-static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+int test_long_fname_1(struct dummy_tracepoint_args *arg)
 {
 	return test_long_fname_2(arg);
 }
-- 
2.20.1