Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/sfc/tc.c
  622ab656344a ("sfc: fix error unwinds in TC offload")
  b6583d5e9e94 ("sfc: support TC decap rules matching on enc_src_port")

net/mptcp/protocol.c
  5b825727d087 ("mptcp: add annotations around msk->subflow accesses")
  e76c8ef5cc5b ("mptcp: refactor mptcp_stream_accept()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

29 files changed, 181 insertions, 33 deletions

diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c
index c61d061247e1..52a0be45410c 100644
--- a/tools/gpio/lsgpio.c
+++ b/tools/gpio/lsgpio.c
@@ -94,7 +94,7 @@ static void print_attributes(struct gpio_v2_line_info *info)
 	for (i = 0; i < info->num_attrs; i++) {
 		if (info->attrs[i].id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE)
 			fprintf(stdout, ", debounce_period=%dusec",
-				info->attrs[0].debounce_period_us);
+				info->attrs[i].debounce_period_us);
 	}
 }
 
diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h
index cef3b1c25335..51ac441a37c3 100644
--- a/tools/include/linux/coresight-pmu.h
+++ b/tools/include/linux/coresight-pmu.h
@@ -21,19 +21,6 @@
  */
 #define CORESIGHT_LEGACY_CPU_TRACE_ID(cpu)  (0x10 + (cpu * 2))
 
-/* CoreSight trace ID is currently the bottom 7 bits of the value */
-#define CORESIGHT_TRACE_ID_VAL_MASK	GENMASK(6, 0)
-
-/*
- * perf record will set the legacy meta data values as unused initially.
- * This allows perf report to manage the decoders created when dynamic
- * allocation in operation.
- */
-#define CORESIGHT_TRACE_ID_UNUSED_FLAG	BIT(31)
-
-/* Value to set for unused trace ID values */
-#define CORESIGHT_TRACE_ID_UNUSED_VAL	0x7F
-
 /*
  * Below are the definition of bit offsets for perf option, and works as
  * arbitrary values for all ETM versions.
diff --git a/tools/include/uapi/linux/in.h b/tools/include/uapi/linux/in.h
index 4b7f2df66b99..e682ab628dfa 100644
--- a/tools/include/uapi/linux/in.h
+++ b/tools/include/uapi/linux/in.h
@@ -163,6 +163,7 @@ struct in_addr {
 #define IP_MULTICAST_ALL		49
 #define IP_UNICAST_IF			50
 #define IP_LOCAL_PORT_RANGE		51
+#define IP_PROTOCOL			52
 
 #define MCAST_EXCLUDE	0
 #define MCAST_INCLUDE	1
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 0692293447ad..3b343d6cbbc0 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -582,8 +582,9 @@ class YnlFamily(SpecFamily):
                         print('Unexpected message: ' + repr(gm))
                         continue
 
-                rsp.append(self._decode(gm.raw_attrs, op.attr_set.name)
-                           | gm.fixed_header_attrs)
+                rsp_msg = self._decode(gm.raw_attrs, op.attr_set.name)
+                rsp_msg.update(gm.fixed_header_attrs)
+                rsp.append(rsp_msg)
 
         if not rsp:
             return None
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 70268442f7ee..a794d9eca93d 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -927,6 +927,7 @@ ifndef NO_DEMANGLE
     EXTLIBS += -lstdc++
     CFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
     CXXFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
+    $(call detected,CONFIG_CXX_DEMANGLE)
   endif
   ifdef BUILD_NONDISTRO
     ifeq ($(filter -liberty,$(EXTLIBS)),)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 1593c5dcaa9e..f48794816d82 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -181,7 +181,6 @@ HOSTCC  ?= gcc
 HOSTLD  ?= ld
 HOSTAR  ?= ar
 CLANG   ?= clang
-LLVM_STRIP ?= llvm-strip
 
 PKG_CONFIG = $(CROSS_COMPILE)pkg-config
 
@@ -1083,7 +1082,7 @@ $(BPFTOOL): | $(SKEL_TMP_OUT)
 
 $(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) | $(SKEL_TMP_OUT)
 	$(QUIET_CLANG)$(CLANG) -g -O2 -target bpf -Wall -Werror $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
-	  -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@ && $(LLVM_STRIP) -g $@
+	  -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@
 
 $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o | $(BPFTOOL)
 	$(QUIET_GENSKEL)$(BPFTOOL) gen skeleton $< > $@
diff --git a/tools/perf/arch/arm/util/pmu.c b/tools/perf/arch/arm/util/pmu.c
index 860a8b42b4b5..a9623b128ece 100644
--- a/tools/perf/arch/arm/util/pmu.c
+++ b/tools/perf/arch/arm/util/pmu.c
@@ -12,7 +12,7 @@
 #include "arm-spe.h"
 #include "hisi-ptt.h"
 #include "../../../util/pmu.h"
-#include "../cs-etm.h"
+#include "../../../util/cs-etm.h"
 
 struct perf_event_attr
 *perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 810e3376c7d6..f9906f52e4fa 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -1175,7 +1175,7 @@ int cmd_ftrace(int argc, const char **argv)
 	OPT_BOOLEAN('b', "use-bpf", &ftrace.target.use_bpf,
 		    "Use BPF to measure function latency"),
 #endif
-	OPT_BOOLEAN('n', "--use-nsec", &ftrace.use_nsec,
+	OPT_BOOLEAN('n', "use-nsec", &ftrace.use_nsec,
 		    "Use nano-second histogram"),
 	OPT_PARENT(common_options),
 	};
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index bd18fe5f2719..f9df1df1eec0 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -214,7 +214,7 @@ perf-$(CONFIG_ZSTD) += zstd.o
 
 perf-$(CONFIG_LIBCAP) += cap.o
 
-perf-y += demangle-cxx.o
+perf-$(CONFIG_CXX_DEMANGLE) += demangle-cxx.o
 perf-y += demangle-ocaml.o
 perf-y += demangle-java.o
 perf-y += demangle-rust.o
diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
index cffe493af1ed..fb94f5280626 100644
--- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
+++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
@@ -25,7 +25,7 @@ struct perf_sample_data___new {
 } __attribute__((preserve_access_index));
 
 /* new kernel perf_mem_data_src definition */
-union perf_mem_data_src__new {
+union perf_mem_data_src___new {
 	__u64 val;
 	struct {
 		__u64   mem_op:5,	/* type of opcode */
@@ -108,7 +108,7 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
 		if (entry->part == 7)
 			return kctx->data->data_src.mem_blk;
 		if (entry->part == 8) {
-			union perf_mem_data_src__new *data = (void *)&kctx->data->data_src;
+			union perf_mem_data_src___new *data = (void *)&kctx->data->data_src;
 
 			if (bpf_core_field_exists(data->mem_hops))
 				return data->mem_hops;
diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
index 70cac0375b34..ecca40787ac9 100644
--- a/tools/perf/util/cs-etm.h
+++ b/tools/perf/util/cs-etm.h
@@ -227,6 +227,19 @@ struct cs_etm_packet_queue {
 #define INFO_HEADER_SIZE (sizeof(((struct perf_record_auxtrace_info *)0)->type) + \
 			  sizeof(((struct perf_record_auxtrace_info *)0)->reserved__))
 
+/* CoreSight trace ID is currently the bottom 7 bits of the value */
+#define CORESIGHT_TRACE_ID_VAL_MASK	GENMASK(6, 0)
+
+/*
+ * perf record will set the legacy meta data values as unused initially.
+ * This allows perf report to manage the decoders created when dynamic
+ * allocation in operation.
+ */
+#define CORESIGHT_TRACE_ID_UNUSED_FLAG	BIT(31)
+
+/* Value to set for unused trace ID values */
+#define CORESIGHT_TRACE_ID_UNUSED_VAL	0x7F
+
 int cs_etm__process_auxtrace_info(union perf_event *event,
 				  struct perf_session *session);
 struct perf_event_attr *cs_etm_get_default_config(struct perf_pmu *pmu);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 2f5910b31fa9..c2dbb5647e75 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -282,6 +282,7 @@ void evsel__init(struct evsel *evsel,
 	evsel->bpf_fd	   = -1;
 	INIT_LIST_HEAD(&evsel->config_terms);
 	INIT_LIST_HEAD(&evsel->bpf_counter_list);
+	INIT_LIST_HEAD(&evsel->bpf_filters);
 	perf_evsel__object.init(evsel);
 	evsel->sample_size = __evsel__sample_size(attr->sample_type);
 	evsel__calc_id_pos(evsel);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index df8928745fc6..0f54f28a69c2 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -151,10 +151,8 @@ struct evsel {
 	 */
 	struct bpf_counter_ops	*bpf_counter_ops;
 
-	union {
-		struct list_head	bpf_counter_list; /* for perf-stat -b */
-		struct list_head	bpf_filters; /* for perf-record --filter */
-	};
+	struct list_head	bpf_counter_list; /* for perf-stat -b */
+	struct list_head	bpf_filters; /* for perf-record --filter */
 
 	/* for perf-stat --use-bpf */
 	int			bperf_leader_prog_fd;
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index b2ed9cc52265..63882a4db5c7 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -31,6 +31,13 @@
 #include <bfd.h>
 #endif
 
+#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
+#ifndef DMGL_PARAMS
+#define DMGL_PARAMS     (1 << 0)  /* Include function args */
+#define DMGL_ANSI       (1 << 1)  /* Include const, volatile, etc */
+#endif
+#endif
+
 #ifndef EM_AARCH64
 #define EM_AARCH64	183  /* ARM 64 bit */
 #endif
@@ -271,6 +278,26 @@ static bool want_demangle(bool is_kernel_sym)
 	return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
 }
 
+/*
+ * Demangle C++ function signature, typically replaced by demangle-cxx.cpp
+ * version.
+ */
+__weak char *cxx_demangle_sym(const char *str __maybe_unused, bool params __maybe_unused,
+			      bool modifiers __maybe_unused)
+{
+#ifdef HAVE_LIBBFD_SUPPORT
+	int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
+
+	return bfd_demangle(NULL, str, flags);
+#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
+	int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
+
+	return cplus_demangle(str, flags);
+#else
+	return NULL;
+#endif
+}
+
 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 {
 	char *demangled = NULL;
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index fba7bec96acd..6f9347ade82c 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -6,6 +6,7 @@ ldflags-y += --wrap=acpi_pci_find_root
 ldflags-y += --wrap=nvdimm_bus_register
 ldflags-y += --wrap=devm_cxl_port_enumerate_dports
 ldflags-y += --wrap=devm_cxl_setup_hdm
+ldflags-y += --wrap=devm_cxl_enable_hdm
 ldflags-y += --wrap=devm_cxl_add_passthrough_decoder
 ldflags-y += --wrap=devm_cxl_enumerate_decoders
 ldflags-y += --wrap=cxl_await_media_ready
diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index ba572d03c687..34b48027b3de 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -1256,6 +1256,7 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
+	cxlds->media_ready = true;
 	rc = cxl_dev_state_identify(cxlds);
 	if (rc)
 		return rc;
diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index de3933a776fd..284416527644 100644
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -149,6 +149,21 @@ struct cxl_hdm *__wrap_devm_cxl_setup_hdm(struct cxl_port *port,
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_setup_hdm, CXL);
 
+int __wrap_devm_cxl_enable_hdm(struct cxl_port *port, struct cxl_hdm *cxlhdm)
+{
+	int index, rc;
+	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
+
+	if (ops && ops->is_mock_port(port->uport))
+		rc = 0;
+	else
+		rc = devm_cxl_enable_hdm(port, cxlhdm);
+	put_cxl_mock_ops(index);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_enable_hdm, CXL);
+
 int __wrap_devm_cxl_add_passthrough_decoder(struct cxl_port *port)
 {
 	int rc, index;
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack-legacy.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack-legacy.tc
new file mode 100644
index 000000000000..d0cd91a93069
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack-legacy.tc
@@ -0,0 +1,24 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: event trigger - test inter-event histogram trigger trace action with dynamic string param (legacy stack)
+# requires: set_event synthetic_events events/sched/sched_process_exec/hist "long[] stack' >> synthetic_events":README
+
+fail() { #msg
+    echo $1
+    exit_fail
+}
+
+echo "Test create synthetic event with stack"
+
+# Test the old stacktrace keyword (for backward compatibility)
+echo 's:wake_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
+echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace  if prev_state == 1||prev_state == 2' >> events/sched/sched_switch/trigger
+echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(wake_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger
+echo 1 > events/synthetic/wake_lat/enable
+sleep 1
+
+if ! grep -q "=>.*sched" trace; then
+    fail "Failed to create synthetic event with stack"
+fi
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack.tc
index 755dbe94ccf4..8f1cc9a86a06 100644
--- a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack.tc
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-stack.tc
@@ -1,7 +1,7 @@
 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 # description: event trigger - test inter-event histogram trigger trace action with dynamic string param
-# requires: set_event synthetic_events events/sched/sched_process_exec/hist "long[]' >> synthetic_events":README
+# requires: set_event synthetic_events events/sched/sched_process_exec/hist "can be any field, or the special string 'common_stacktrace'":README
 
 fail() { #msg
     echo $1
@@ -10,9 +10,8 @@ fail() { #msg
 
 echo "Test create synthetic event with stack"
 
-
 echo 's:wake_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
-echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace  if prev_state == 1||prev_state == 2' >> events/sched/sched_switch/trigger
+echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=common_stacktrace  if prev_state == 1||prev_state == 2' >> events/sched/sched_switch/trigger
 echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(wake_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger
 echo 1 > events/synthetic/wake_lat/enable
 sleep 1
diff --git a/tools/testing/selftests/gpio/gpio-sim.sh b/tools/testing/selftests/gpio/gpio-sim.sh
index 9f539d454ee4..fa2ce2b9dd5f 100755
--- a/tools/testing/selftests/gpio/gpio-sim.sh
+++ b/tools/testing/selftests/gpio/gpio-sim.sh
@@ -389,6 +389,9 @@ create_chip chip
 create_bank chip bank
 set_num_lines chip bank 8
 enable_chip chip
+DEVNAME=`configfs_dev_name chip`
+CHIPNAME=`configfs_chip_name chip bank`
+SYSFS_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio0/value"
 $BASE_DIR/gpio-mockup-cdev -b pull-up /dev/`configfs_chip_name chip bank` 0
 test `cat $SYSFS_PATH` = "1" || fail "bias setting does not work"
 remove_chip chip
diff --git a/tools/testing/selftests/net/mptcp/Makefile b/tools/testing/selftests/net/mptcp/Makefile
index 43a723626126..7b936a926859 100644
--- a/tools/testing/selftests/net/mptcp/Makefile
+++ b/tools/testing/selftests/net/mptcp/Makefile
@@ -9,7 +9,7 @@ TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh \
 
 TEST_GEN_FILES = mptcp_connect pm_nl_ctl mptcp_sockopt mptcp_inq
 
-TEST_FILES := settings
+TEST_FILES := mptcp_lib.sh settings
 
 EXTRA_CLEAN := *.pcap
 
diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
index ef628b16fe9b..4eacdb1ab962 100755
--- a/tools/testing/selftests/net/mptcp/diag.sh
+++ b/tools/testing/selftests/net/mptcp/diag.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
 sec=$(date +%s)
 rndh=$(printf %x $sec)-$(mktemp -u XXXXXX)
 ns="ns1-$rndh"
@@ -31,6 +33,8 @@ cleanup()
 	ip netns del $ns
 }
 
+mptcp_lib_check_mptcp
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Could not run test without ip tool"
diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index a43d3e2f59bb..c1f7bac19942 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
 time_start=$(date +%s)
 
 optstring="S:R:d:e:l:r:h4cm:f:tC"
@@ -141,6 +143,8 @@ cleanup()
 	done
 }
 
+mptcp_lib_check_mptcp
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Could not run test without ip tool"
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index e74d3074ef90..38b3994b3c8d 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -10,6 +10,8 @@
 # because it's invoked by variable name, see how the "tests" array is used
 #shellcheck disable=SC2317
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
 ret=0
 sin=""
 sinfail=""
@@ -17,6 +19,7 @@ sout=""
 cin=""
 cinfail=""
 cinsent=""
+tmpfile=""
 cout=""
 capout=""
 ns1=""
@@ -138,6 +141,8 @@ cleanup_partial()
 
 check_tools()
 {
+	mptcp_lib_check_mptcp
+
 	if ! ip -Version &> /dev/null; then
 		echo "SKIP: Could not run test without ip tool"
 		exit $ksft_skip
@@ -177,6 +182,7 @@ cleanup()
 {
 	rm -f "$cin" "$cout" "$sinfail"
 	rm -f "$sin" "$sout" "$cinsent" "$cinfail"
+	rm -f "$tmpfile"
 	rm -rf $evts_ns1 $evts_ns2
 	cleanup_partial
 }
@@ -388,9 +394,16 @@ check_transfer()
 			fail_test
 			return 1
 		fi
-		bytes="--bytes=${bytes}"
+
+		# note: BusyBox's "cmp" command doesn't support --bytes
+		tmpfile=$(mktemp)
+		head --bytes="$bytes" "$in" > "$tmpfile"
+		mv "$tmpfile" "$in"
+		head --bytes="$bytes" "$out" > "$tmpfile"
+		mv "$tmpfile" "$out"
+		tmpfile=""
 	fi
-	cmp -l "$in" "$out" ${bytes} | while read -r i a b; do
+	cmp -l "$in" "$out" | while read -r i a b; do
 		local sum=$((0${a} + 0${b}))
 		if [ $check_invert -eq 0 ] || [ $sum -ne $((0xff)) ]; then
 			echo "[ FAIL ] $what does not match (in, out):"
diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
new file mode 100644
index 000000000000..3286536b79d5
--- /dev/null
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -0,0 +1,40 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+readonly KSFT_FAIL=1
+readonly KSFT_SKIP=4
+
+# SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES env var can be set when validating all
+# features using the last version of the kernel and the selftests to make sure
+# a test is not being skipped by mistake.
+mptcp_lib_expect_all_features() {
+	[ "${SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES:-}" = "1" ]
+}
+
+# $1: msg
+mptcp_lib_fail_if_expected_feature() {
+	if mptcp_lib_expect_all_features; then
+		echo "ERROR: missing feature: ${*}"
+		exit ${KSFT_FAIL}
+	fi
+
+	return 1
+}
+
+# $1: file
+mptcp_lib_has_file() {
+	local f="${1}"
+
+	if [ -f "${f}" ]; then
+		return 0
+	fi
+
+	mptcp_lib_fail_if_expected_feature "${f} file not found"
+}
+
+mptcp_lib_check_mptcp() {
+	if ! mptcp_lib_has_file "/proc/sys/net/mptcp/enabled"; then
+		echo "SKIP: MPTCP support is not available"
+		exit ${KSFT_SKIP}
+	fi
+}
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
index 1b70c0a304ce..ff5adbb9c7f2 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
 ret=0
 sin=""
 sout=""
@@ -84,6 +86,8 @@ cleanup()
 	rm -f "$sin" "$sout"
 }
 
+mptcp_lib_check_mptcp
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Could not run test without ip tool"
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index 89839d1ff9d8..32f7533e0919 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
 ksft_skip=4
 ret=0
 
@@ -34,6 +36,8 @@ cleanup()
 	ip netns del $ns1
 }
 
+mptcp_lib_check_mptcp
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Could not run test without ip tool"
diff --git a/tools/testing/selftests/net/mptcp/simult_flows.sh b/tools/testing/selftests/net/mptcp/simult_flows.sh
index 9f22f7e5027d..36a3c9d92e20 100755
--- a/tools/testing/selftests/net/mptcp/simult_flows.sh
+++ b/tools/testing/selftests/net/mptcp/simult_flows.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
 sec=$(date +%s)
 rndh=$(printf %x $sec)-$(mktemp -u XXXXXX)
 ns1="ns1-$rndh"
@@ -34,6 +36,8 @@ cleanup()
 	done
 }
 
+mptcp_lib_check_mptcp
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Could not run test without ip tool"
diff --git a/tools/testing/selftests/net/mptcp/userspace_pm.sh b/tools/testing/selftests/net/mptcp/userspace_pm.sh
index b1eb7bce599d..8092399d911f 100755
--- a/tools/testing/selftests/net/mptcp/userspace_pm.sh
+++ b/tools/testing/selftests/net/mptcp/userspace_pm.sh
@@ -1,6 +1,10 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/mptcp_lib.sh"
+
+mptcp_lib_check_mptcp
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Cannot not run test without ip tool"