[PATCH AUTOSEL 6.7 003/108] selftests/bpf: fix RELEASE=1 build for tc_opts

[PATCH AUTOSEL 6.7 003/108] selftests/bpf: fix RELEASE=1 build for tc_opts

[Sasha Levin]

From: Andrii Nakryiko <andrii@kernel.org>

[ Upstream commit 2b62aa59d02ed281fa4fc218df3ca91b773e1e62 ]

Compiler complains about malloc(). We also don't need to dynamically
allocate anything, so make the life easier by using statically sized
buffer.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231102033759.2541186-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/prog_tests/tc_opts.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/tc_opts.c b/tools/testing/selftests/bpf/prog_tests/tc_opts.c
index 51883ccb8020..196abf223465 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_opts.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_opts.c
@@ -2387,12 +2387,9 @@ static int generate_dummy_prog(void)
 	const size_t prog_insn_cnt = sizeof(prog_insns) / sizeof(struct bpf_insn);
 	LIBBPF_OPTS(bpf_prog_load_opts, opts);
 	const size_t log_buf_sz = 256;
-	char *log_buf;
+	char log_buf[log_buf_sz];
 	int fd = -1;
 
-	log_buf = malloc(log_buf_sz);
-	if (!ASSERT_OK_PTR(log_buf, "log_buf_alloc"))
-		return fd;
 	opts.log_buf = log_buf;
 	opts.log_size = log_buf_sz;
 
@@ -2402,7 +2399,6 @@ static int generate_dummy_prog(void)
 			   prog_insns, prog_insn_cnt, &opts);
 	ASSERT_STREQ(log_buf, "", "log_0");
 	ASSERT_GE(fd, 0, "prog_fd");
-	free(log_buf);
 	return fd;
 }
 
-- 
2.43.0

[PATCH AUTOSEL 6.7 004/108] selftests/bpf: satisfy compiler by having explicit return in btf test

[Sasha Levin]

From: Andrii Nakryiko <andrii@kernel.org>

[ Upstream commit f4c7e887324f5776eef6e6e47a90e0ac8058a7a8 ]

Some compilers complain about get_pprint_mapv_size() not returning value
in some code paths. Fix with explicit return.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231102033759.2541186-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 92d51f377fe5..8fb4a04fbbc0 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -5265,6 +5265,7 @@ static size_t get_pprint_mapv_size(enum pprint_mapv_kind_t mapv_kind)
 #endif
 
 	assert(0);
+	return 0;
 }
 
 static void set_pprint_mapv(enum pprint_mapv_kind_t mapv_kind,
-- 
2.43.0

[PATCH AUTOSEL 6.7 006/108] selftests/bpf: Fix pyperf180 compilation failure with clang18

[Sasha Levin]

From: Yonghong Song <yonghong.song@linux.dev>

[ Upstream commit 100888fb6d8a185866b1520031ee7e3182b173de ]

With latest clang18 (main branch of llvm-project repo), when building bpf selftests,
    [~/work/bpf-next (master)]$ make -C tools/testing/selftests/bpf LLVM=1 -j

The following compilation error happens:
    fatal error: error in backend: Branch target out of insn range
    ...
    Stack dump:
    0.      Program arguments: clang -g -Wall -Werror -D__TARGET_ARCH_x86 -mlittle-endian
      -I/home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/include
      -I/home/yhs/work/bpf-next/tools/testing/selftests/bpf -I/home/yhs/work/bpf-next/tools/include/uapi
      -I/home/yhs/work/bpf-next/tools/testing/selftests/usr/include -idirafter
      /home/yhs/work/llvm-project/llvm/build.18/install/lib/clang/18/include -idirafter /usr/local/include
      -idirafter /usr/include -Wno-compare-distinct-pointer-types -DENABLE_ATOMICS_TESTS -O2 --target=bpf
      -c progs/pyperf180.c -mcpu=v3 -o /home/yhs/work/bpf-next/tools/testing/selftests/bpf/pyperf180.bpf.o
    1.      <eof> parser at end of file
    2.      Code generation
    ...

The compilation failure only happens to cpu=v2 and cpu=v3. cpu=v4 is okay
since cpu=v4 supports 32-bit branch target offset.

The above failure is due to upstream llvm patch [1] where some inlining behavior
are changed in clang18.

To workaround the issue, previously all 180 loop iterations are fully unrolled.
The bpf macro __BPF_CPU_VERSION__ (implemented in clang18 recently) is used to avoid
unrolling changes if cpu=v4. If __BPF_CPU_VERSION__ is not available and the
compiler is clang18, the unrollng amount is unconditionally reduced.

  [1] https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a566eebb16e

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20231110193644.3130906-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/progs/pyperf180.c | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/pyperf180.c b/tools/testing/selftests/bpf/progs/pyperf180.c
index c39f559d3100..42c4a8b62e36 100644
--- a/tools/testing/selftests/bpf/progs/pyperf180.c
+++ b/tools/testing/selftests/bpf/progs/pyperf180.c
@@ -1,4 +1,26 @@
 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2019 Facebook
 #define STACK_MAX_LEN 180
+
+/* llvm upstream commit at clang18
+ *   https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a566eebb16e
+ * changed inlining behavior and caused compilation failure as some branch
+ * target distance exceeded 16bit representation which is the maximum for
+ * cpu v1/v2/v3. Macro __BPF_CPU_VERSION__ is later implemented in clang18
+ * to specify which cpu version is used for compilation. So a smaller
+ * unroll_count can be set if __BPF_CPU_VERSION__ is less than 4, which
+ * reduced some branch target distances and resolved the compilation failure.
+ *
+ * To capture the case where a developer/ci uses clang18 but the corresponding
+ * repo checkpoint does not have __BPF_CPU_VERSION__, a smaller unroll_count
+ * will be set as well to prevent potential compilation failures.
+ */
+#ifdef __BPF_CPU_VERSION__
+#if __BPF_CPU_VERSION__ < 4
+#define UNROLL_COUNT 90
+#endif
+#elif __clang_major__ == 18
+#define UNROLL_COUNT 90
+#endif
+
 #include "pyperf.h"
-- 
2.43.0

[PATCH AUTOSEL 6.7 008/108] selftests/bpf: Fix issues in setup_classid_environment()

[Sasha Levin]

From: Yafang Shao <laoar.shao@gmail.com>

[ Upstream commit 4849775587844e44d215289c425bcd70f315efe7 ]

If the net_cls subsystem is already mounted, attempting to mount it again
in setup_classid_environment() will result in a failure with the error code
EBUSY. Despite this, tmpfs will have been successfully mounted at
/sys/fs/cgroup/net_cls. Consequently, the /sys/fs/cgroup/net_cls directory
will be empty, causing subsequent setup operations to fail.

Here's an error log excerpt illustrating the issue when net_cls has already
been mounted at /sys/fs/cgroup/net_cls prior to running
setup_classid_environment():

- Before that change

  $ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2
  test_cgroup_v1v2:PASS:server_fd 0 nsec
  test_cgroup_v1v2:PASS:client_fd 0 nsec
  test_cgroup_v1v2:PASS:cgroup_fd 0 nsec
  test_cgroup_v1v2:PASS:server_fd 0 nsec
  run_test:PASS:skel_open 0 nsec
  run_test:PASS:prog_attach 0 nsec
  test_cgroup_v1v2:PASS:cgroup-v2-only 0 nsec
  (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs
  (cgroup_helpers.c:540: errno: No such file or directory) Opening cgroup classid: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/net_cls.classid
  run_test:PASS:skel_open 0 nsec
  run_test:PASS:prog_attach 0 nsec
  (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/cgroup.procs
  run_test:FAIL:join_classid unexpected error: 1 (errno 2)
  test_cgroup_v1v2:FAIL:cgroup-v1v2 unexpected error: -1 (errno 2)
  (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs
  #44      cgroup_v1v2:FAIL
  Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED

- After that change
  $ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2
  #44      cgroup_v1v2:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-3-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/cgroup_helpers.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index 5b1da2a32ea7..10b5f42e65e7 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -523,10 +523,20 @@ int setup_classid_environment(void)
 		return 1;
 	}
 
-	if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls") &&
-	    errno != EBUSY) {
-		log_err("mount cgroup net_cls");
-		return 1;
+	if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls")) {
+		if (errno != EBUSY) {
+			log_err("mount cgroup net_cls");
+			return 1;
+		}
+
+		if (rmdir(NETCLS_MOUNT_PATH)) {
+			log_err("rmdir cgroup net_cls");
+			return 1;
+		}
+		if (umount(CGROUP_MOUNT_DFLT)) {
+			log_err("umount cgroup base");
+			return 1;
+		}
 	}
 
 	cleanup_classid_environment();
-- 
2.43.0

[PATCH AUTOSEL 6.7 031/108] bpf: Fix a few selftest failures due to llvm18 change

[Sasha Levin]

From: Yonghong Song <yonghong.song@linux.dev>

[ Upstream commit b16904fd9f01b580db357ef2b1cc9e86d89576c2 ]

With latest upstream llvm18, the following test cases failed:

  $ ./test_progs -j
  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #77      fentry_fexit:FAIL
  #78/1    fentry_test/fentry:FAIL
  #78      fentry_test:FAIL
  #82/1    fexit_test/fexit:FAIL
  #82      fexit_test:FAIL
  #112/1   kprobe_multi_test/skel_api:FAIL
  #112/2   kprobe_multi_test/link_api_addrs:FAIL
  [...]
  #112     kprobe_multi_test:FAIL
  #356/17  test_global_funcs/global_func17:FAIL
  #356     test_global_funcs:FAIL

Further analysis shows llvm upstream patch [1] is responsible for the above
failures. For example, for function bpf_fentry_test7() in net/bpf/test_run.c,
without [1], the asm code is:

  0000000000000400 <bpf_fentry_test7>:
     400: f3 0f 1e fa                   endbr64
     404: e8 00 00 00 00                callq   0x409 <bpf_fentry_test7+0x9>
     409: 48 89 f8                      movq    %rdi, %rax
     40c: c3                            retq
     40d: 0f 1f 00                      nopl    (%rax)

... and with [1], the asm code is:

  0000000000005d20 <bpf_fentry_test7.specialized.1>:
    5d20: e8 00 00 00 00                callq   0x5d25 <bpf_fentry_test7.specialized.1+0x5>
    5d25: c3                            retq

... and <bpf_fentry_test7.specialized.1> is called instead of <bpf_fentry_test7>
and this caused test failures for #13/#77 etc. except #356.

For test case #356/17, with [1] (progs/test_global_func17.c)), the main prog
looks like:

  0000000000000000 <global_func17>:
       0:       b4 00 00 00 2a 00 00 00 w0 = 0x2a
       1:       95 00 00 00 00 00 00 00 exit

... which passed verification while the test itself expects a verification
failure.

Let us add 'barrier_var' style asm code in both places to prevent function
specialization which caused selftests failure.

  [1] https://github.com/llvm/llvm-project/pull/72903

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231127050342.1945270-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bpf/test_run.c                                     | 2 +-
 tools/testing/selftests/bpf/progs/test_global_func17.c | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index c9fdcc5cdce1..711cf5d59816 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -542,7 +542,7 @@ struct bpf_fentry_test_t {
 
 int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
 {
-	asm volatile ("");
+	asm volatile ("": "+r"(arg));
 	return (long)arg;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/test_global_func17.c b/tools/testing/selftests/bpf/progs/test_global_func17.c
index a32e11c7d933..5de44b09e8ec 100644
--- a/tools/testing/selftests/bpf/progs/test_global_func17.c
+++ b/tools/testing/selftests/bpf/progs/test_global_func17.c
@@ -5,6 +5,7 @@
 
 __noinline int foo(int *p)
 {
+	barrier_var(p);
 	return p ? (*p = 42) : 0;
 }
 
-- 
2.43.0

[PATCH AUTOSEL 6.7 066/108] selftests/bpf: fix compiler warnings in RELEASE=1 mode

[Sasha Levin]

From: Andrii Nakryiko <andrii@kernel.org>

[ Upstream commit 62d9a969f4a95219c757831e9ad66cd4dd9edee5 ]

When compiling BPF selftests with RELEASE=1, we get two new
warnings, which are treated as errors. Fix them.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20231212225343.1723081-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/veristat.c        | 2 +-
 tools/testing/selftests/bpf/xdp_hw_metadata.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
index 655095810d4a..0ad98b6a8e6e 100644
--- a/tools/testing/selftests/bpf/veristat.c
+++ b/tools/testing/selftests/bpf/veristat.c
@@ -1214,7 +1214,7 @@ static int cmp_join_stat(const struct verif_stats_join *s1,
 			 enum stat_id id, enum stat_variant var, bool asc)
 {
 	const char *str1 = NULL, *str2 = NULL;
-	double v1, v2;
+	double v1 = 0.0, v2 = 0.0;
 	int cmp = 0;
 
 	fetch_join_stat_value(s1, id, var, &str1, &v1);
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index c3ba40d0b9de..c5e7937d7f63 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -70,7 +70,7 @@ static int open_xsk(int ifindex, struct xsk *xsk, __u32 queue_id)
 		.frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE,
 		.flags = XDP_UMEM_UNALIGNED_CHUNK_FLAG,
 	};
-	__u32 idx;
+	__u32 idx = 0;
 	u64 addr;
 	int ret;
 	int i;
-- 
2.43.0