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

Overlapping changes in selftests Makefile.

Signed-off-by: David S. Miller <davem@davemloft.net>

tools/bpf/bpf_dbg.c

@@ -1063,7 +1063,7 @@ static int cmd_load_pcap(char *file)
 
 static int cmd_load(char *arg)
 {
-	char *subcmd, *cont, *tmp = strdup(arg);
+	char *subcmd, *cont = NULL, *tmp = strdup(arg);
 	int ret = CMD_OK;
 
 	subcmd = strtok_r(tmp, " ", &cont);
@@ -1073,7 +1073,10 @@ static int cmd_load(char *arg)
 		bpf_reset();
 		bpf_reset_breakpoints();
 
-		ret = cmd_load_bpf(cont);
+		if (!cont)
+			ret = CMD_ERR;
+		else
+			ret = cmd_load_bpf(cont);
 	} else if (matches(subcmd, "pcap") == 0) {
 		ret = cmd_load_pcap(cont);
 	} else {

tools/perf/Documentation/perf-mem.txt

@@ -28,29 +28,46 @@ OPTIONS
 <command>...::
 	Any command you can specify in a shell.
 
+-i::
+--input=<file>::
+	Input file name.
+
 -f::
 --force::
 	Don't do ownership validation
 
 -t::
---type=::
+--type=<type>::
 	Select the memory operation type: load or store (default: load,store)
 
 -D::
---dump-raw-samples=::
+--dump-raw-samples::
 	Dump the raw decoded samples on the screen in a format that is easy to parse with
 	one sample per line.
 
 -x::
---field-separator::
+--field-separator=<separator>::
 	Specify the field separator used when dump raw samples (-D option). By default,
 	The separator is the space character.
 
 -C::
---cpu-list::
-	Restrict dump of raw samples to those provided via this option. Note that the same
-	option can be passed in record mode. It will be interpreted the same way as perf
-	record.
+--cpu=<cpu>::
+	Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a
+        comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2. Default
+        is to monitor all CPUS.
+-U::
+--hide-unresolved::
+	Only display entries resolved to a symbol.
+
+-p::
+--phys-data::
+	Record/Report sample physical addresses
+
+RECORD OPTIONS
+--------------
+-e::
+--event <event>::
+	Event selector. Use 'perf mem record -e list' to list available events.
 
 -K::
 --all-kernel::
@@ -60,12 +77,12 @@ OPTIONS
 --all-user::
 	Configure all used events to run in user space.
 
---ldload::
-	Specify desired latency for loads event.
+-v::
+--verbose::
+	Be more verbose (show counter open errors, etc)
 
--p::
---phys-data::
-	Record/Report sample physical addresses
+--ldlat <n>::
+	Specify desired latency for loads event.
 
 In addition, for report all perf report options are valid, and for record
 all perf record options.

tools/perf/arch/s390/util/auxtrace.c

@@ -87,6 +87,7 @@ struct auxtrace_record *auxtrace_record__init(struct perf_evlist *evlist,
 	struct perf_evsel *pos;
 	int diagnose = 0;
 
+	*err = 0;
 	if (evlist->nr_entries == 0)
 		return NULL;
 

tools/perf/arch/s390/util/header.c

@@ -146,21 +146,3 @@ char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
 		zfree(&buf);
 	return buf;
 }
-
-/*
- * Compare the cpuid string returned by get_cpuid() function
- * with the name generated by the jevents file read from
- * pmu-events/arch/s390/mapfile.csv.
- *
- * Parameter mapcpuid is the cpuid as stored in the
- * pmu-events/arch/s390/mapfile.csv. This is just the type number.
- * Parameter cpuid is the cpuid returned by function get_cpuid().
- */
-int strcmp_cpuid_str(const char *mapcpuid, const char *cpuid)
-{
-	char *cp = strchr(cpuid, ',');
-
-	if (cp == NULL)
-		return -1;
-	return strncmp(cp + 1, mapcpuid, strlen(mapcpuid));
-}

tools/perf/builtin-stat.c

@@ -172,6 +172,7 @@ static bool			interval_count;
 static const char		*output_name;
 static int			output_fd;
 static int			print_free_counters_hint;
+static int			print_mixed_hw_group_error;
 
 struct perf_stat {
 	bool			 record;
@@ -1126,6 +1127,30 @@ static void abs_printout(int id, int nr, struct perf_evsel *evsel, double avg)
 		fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);
 }
 
+static bool is_mixed_hw_group(struct perf_evsel *counter)
+{
+	struct perf_evlist *evlist = counter->evlist;
+	u32 pmu_type = counter->attr.type;
+	struct perf_evsel *pos;
+
+	if (counter->nr_members < 2)
+		return false;
+
+	evlist__for_each_entry(evlist, pos) {
+		/* software events can be part of any hardware group */
+		if (pos->attr.type == PERF_TYPE_SOFTWARE)
+			continue;
+		if (pmu_type == PERF_TYPE_SOFTWARE) {
+			pmu_type = pos->attr.type;
+			continue;
+		}
+		if (pmu_type != pos->attr.type)
+			return true;
+	}
+
+	return false;
+}
+
 static void printout(int id, int nr, struct perf_evsel *counter, double uval,
 		     char *prefix, u64 run, u64 ena, double noise,
 		     struct runtime_stat *st)
@@ -1178,8 +1203,11 @@ static void printout(int id, int nr, struct perf_evsel *counter, double uval,
 			counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
 			csv_sep);
 
-		if (counter->supported)
+		if (counter->supported) {
 			print_free_counters_hint = 1;
+			if (is_mixed_hw_group(counter))
+				print_mixed_hw_group_error = 1;
+		}
 
 		fprintf(stat_config.output, "%-*s%s",
 			csv_output ? 0 : unit_width,
@@ -1256,7 +1284,8 @@ static void uniquify_event_name(struct perf_evsel *counter)
 	char *new_name;
 	char *config;
 
-	if (!counter->pmu_name || !strncmp(counter->name, counter->pmu_name,
+	if (counter->uniquified_name ||
+	    !counter->pmu_name || !strncmp(counter->name, counter->pmu_name,
 					   strlen(counter->pmu_name)))
 		return;
 
@@ -1274,6 +1303,8 @@ static void uniquify_event_name(struct perf_evsel *counter)
 			counter->name = new_name;
 		}
 	}
+
+	counter->uniquified_name = true;
 }
 
 static void collect_all_aliases(struct perf_evsel *counter,
@@ -1757,6 +1788,11 @@ static void print_footer(void)
 "	echo 0 > /proc/sys/kernel/nmi_watchdog\n"
 "	perf stat ...\n"
 "	echo 1 > /proc/sys/kernel/nmi_watchdog\n");
+
+	if (print_mixed_hw_group_error)
+		fprintf(output,
+			"The events in group usually have to be from "
+			"the same PMU. Try reorganizing the group.\n");
 }
 
 static void print_counters(struct timespec *ts, int argc, const char **argv)

tools/perf/pmu-events/arch/s390/mapfile.csv

@@ -1,6 +1,6 @@
 Family-model,Version,Filename,EventType
-209[78],1,cf_z10,core
-281[78],1,cf_z196,core
-282[78],1,cf_zec12,core
-296[45],1,cf_z13,core
-3906,3,cf_z14,core
+^IBM.209[78].*[13]\.[1-5].[[:xdigit:]]+$,1,cf_z10,core
+^IBM.281[78].*[13]\.[1-5].[[:xdigit:]]+$,1,cf_z196,core
+^IBM.282[78].*[13]\.[1-5].[[:xdigit:]]+$,1,cf_zec12,core
+^IBM.296[45].*[13]\.[1-5].[[:xdigit:]]+$,1,cf_z13,core
+^IBM.390[67].*[13]\.[1-5].[[:xdigit:]]+$,3,cf_z14,core

tools/perf/tests/attr/test-record-group-sampling

@@ -35,3 +35,6 @@ inherit=0
 # sampling disabled
 sample_freq=0
 sample_period=0
+freq=0
+write_backward=0
+sample_id_all=0

tools/perf/tests/shell/record+probe_libc_inet_pton.sh

@@ -19,12 +19,10 @@ trace_libc_inet_pton_backtrace() {
 	expected[1]=".*inet_pton[[:space:]]\($libc\)$"
 	case "$(uname -m)" in
 	s390x)
-		eventattr='call-graph=dwarf'
+		eventattr='call-graph=dwarf,max-stack=4'
 		expected[2]="gaih_inet.*[[:space:]]\($libc|inlined\)$"
-		expected[3]="__GI_getaddrinfo[[:space:]]\($libc|inlined\)$"
+		expected[3]="(__GI_)?getaddrinfo[[:space:]]\($libc|inlined\)$"
 		expected[4]="main[[:space:]]\(.*/bin/ping.*\)$"
-		expected[5]="__libc_start_main[[:space:]]\($libc\)$"
-		expected[6]="_start[[:space:]]\(.*/bin/ping.*\)$"
 		;;
 	*)
 		eventattr='max-stack=3'

tools/perf/util/evsel.c

@@ -930,8 +930,11 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 	 * than leader in case leader 'leads' the sampling.
 	 */
 	if ((leader != evsel) && leader->sample_read) {
-		attr->sample_freq   = 0;
-		attr->sample_period = 0;
+		attr->freq           = 0;
+		attr->sample_freq    = 0;
+		attr->sample_period  = 0;
+		attr->write_backward = 0;
+		attr->sample_id_all  = 0;
 	}
 
 	if (opts->no_samples)
@@ -1922,7 +1925,8 @@ try_fallback:
 		goto fallback_missing_features;
 	} else if (!perf_missing_features.group_read &&
 		    evsel->attr.inherit &&
-		   (evsel->attr.read_format & PERF_FORMAT_GROUP)) {
+		   (evsel->attr.read_format & PERF_FORMAT_GROUP) &&
+		   perf_evsel__is_group_leader(evsel)) {
 		perf_missing_features.group_read = true;
 		pr_debug2("switching off group read\n");
 		goto fallback_missing_features;
@@ -2754,8 +2758,14 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 		   (paranoid = perf_event_paranoid()) > 1) {
 		const char *name = perf_evsel__name(evsel);
 		char *new_name;
+		const char *sep = ":";
 
-		if (asprintf(&new_name, "%s%su", name, strchr(name, ':') ? "" : ":") < 0)
+		/* Is there already the separator in the name. */
+		if (strchr(name, '/') ||
+		    strchr(name, ':'))
+			sep = "";
+
+		if (asprintf(&new_name, "%s%su", name, sep) < 0)
 			return false;
 
 		if (evsel->name)

tools/perf/util/evsel.h

@@ -115,6 +115,7 @@ struct perf_evsel {
 	unsigned int		sample_size;
 	int			id_pos;
 	int			is_pos;
+	bool			uniquified_name;
 	bool			snapshot;
 	bool 			supported;
 	bool 			needs_swap;

tools/perf/util/machine.c

@@ -1019,13 +1019,6 @@ int machine__load_vmlinux_path(struct machine *machine, enum map_type type)
 	return ret;
 }
 
-static void map_groups__fixup_end(struct map_groups *mg)
-{
-	int i;
-	for (i = 0; i < MAP__NR_TYPES; ++i)
-		__map_groups__fixup_end(mg, i);
-}
-
 static char *get_kernel_version(const char *root_dir)
 {
 	char version[PATH_MAX];
@@ -1233,6 +1226,7 @@ int machine__create_kernel_maps(struct machine *machine)
 {
 	struct dso *kernel = machine__get_kernel(machine);
 	const char *name = NULL;
+	struct map *map;
 	u64 addr = 0;
 	int ret;
 
@@ -1259,13 +1253,25 @@ int machine__create_kernel_maps(struct machine *machine)
 			machine__destroy_kernel_maps(machine);
 			return -1;
 		}
-		machine__set_kernel_mmap(machine, addr, 0);
+
+		/* we have a real start address now, so re-order the kmaps */
+		map = machine__kernel_map(machine);
+
+		map__get(map);
+		map_groups__remove(&machine->kmaps, map);
+
+		/* assume it's the last in the kmaps */
+		machine__set_kernel_mmap(machine, addr, ~0ULL);
+
+		map_groups__insert(&machine->kmaps, map);
+		map__put(map);
 	}
 
-	/*
-	 * Now that we have all the maps created, just set the ->end of them:
-	 */
-	map_groups__fixup_end(&machine->kmaps);
+	/* update end address of the kernel map using adjacent module address */
+	map = map__next(machine__kernel_map(machine));
+	if (map)
+		machine__set_kernel_mmap(machine, addr, map->start);
+
 	return 0;
 }
 

tools/perf/util/parse-events.y

@@ -224,15 +224,15 @@ event_def: event_pmu |
 	   event_bpf_file
 
 event_pmu:
-PE_NAME opt_event_config
+PE_NAME '/' event_config '/'
 {
 	struct list_head *list, *orig_terms, *terms;
 
-	if (parse_events_copy_term_list($2, &orig_terms))
+	if (parse_events_copy_term_list($3, &orig_terms))
 		YYABORT;
 
 	ALLOC_LIST(list);
-	if (parse_events_add_pmu(_parse_state, list, $1, $2, false)) {
+	if (parse_events_add_pmu(_parse_state, list, $1, $3, false)) {
 		struct perf_pmu *pmu = NULL;
 		int ok = 0;
 		char *pattern;
@@ -262,7 +262,7 @@ PE_NAME opt_event_config
 		if (!ok)
 			YYABORT;
 	}
-	parse_events_terms__delete($2);
+	parse_events_terms__delete($3);
 	parse_events_terms__delete(orig_terms);
 	$$ = list;
 }

tools/perf/util/pmu.c

@@ -539,9 +539,10 @@ static bool pmu_is_uncore(const char *name)
 
 /*
  *  PMU CORE devices have different name other than cpu in sysfs on some
- *  platforms. looking for possible sysfs files to identify as core device.
+ *  platforms.
+ *  Looking for possible sysfs files to identify the arm core device.
  */
-static int is_pmu_core(const char *name)
+static int is_arm_pmu_core(const char *name)
 {
 	struct stat st;
 	char path[PATH_MAX];
@@ -550,12 +551,6 @@ static int is_pmu_core(const char *name)
 	if (!sysfs)
 		return 0;
 
-	/* Look for cpu sysfs (x86 and others) */
-	scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/cpu", sysfs);
-	if ((stat(path, &st) == 0) &&
-			(strncmp(name, "cpu", strlen("cpu")) == 0))
-		return 1;
-
 	/* Look for cpu sysfs (specific to arm) */
 	scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/%s/cpus",
 				sysfs, name);
@@ -586,7 +581,7 @@ char * __weak get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
  * cpuid string generated on this platform.
  * Otherwise return non-zero.
  */
-int __weak strcmp_cpuid_str(const char *mapcpuid, const char *cpuid)
+int strcmp_cpuid_str(const char *mapcpuid, const char *cpuid)
 {
 	regex_t re;
 	regmatch_t pmatch[1];
@@ -668,6 +663,7 @@ static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu)
 	struct pmu_events_map *map;
 	struct pmu_event *pe;
 	const char *name = pmu->name;
+	const char *pname;
 
 	map = perf_pmu__find_map(pmu);
 	if (!map)
@@ -686,11 +682,9 @@ static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu)
 			break;
 		}
 
-		if (!is_pmu_core(name)) {
-			/* check for uncore devices */
-			if (pe->pmu == NULL)
-				continue;
-			if (strncmp(pe->pmu, name, strlen(pe->pmu)))
+		if (!is_arm_pmu_core(name)) {
+			pname = pe->pmu ? pe->pmu : "cpu";
+			if (strncmp(pname, name, strlen(pname)))
 				continue;
 		}
 

tools/testing/selftests/bpf/test_progs.c

@@ -1139,7 +1139,7 @@ static void test_stacktrace_build_id(void)
 
 	assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")
 	       == 0);
-	assert(system("./urandom_read if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0);
+	assert(system("./urandom_read") == 0);
 	/* disable stack trace collection */
 	key = 0;
 	val = 1;
@@ -1189,7 +1189,7 @@ static void test_stacktrace_build_id(void)
 	} while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0);
 
 	CHECK(build_id_matches < 1, "build id match",
-	      "Didn't find expected build ID from the map");
+	      "Didn't find expected build ID from the map\n");
 
 disable_pmu:
 	ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);

tools/testing/selftests/firmware/Makefile

@@ -4,6 +4,7 @@
 all:
 
 TEST_PROGS := fw_run_tests.sh
+TEST_FILES := fw_fallback.sh fw_filesystem.sh fw_lib.sh
 
 include ../lib.mk
 

tools/testing/selftests/firmware/fw_lib.sh

@@ -154,11 +154,13 @@ test_finish()
 	if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
 		echo "$OLD_TIMEOUT" >/sys/class/firmware/timeout
 	fi
-	if [ "$OLD_FWPATH" = "" ]; then
-		OLD_FWPATH=" "
-	fi
 	if [ "$TEST_REQS_FW_SET_CUSTOM_PATH" = "yes" ]; then
-		echo -n "$OLD_FWPATH" >/sys/module/firmware_class/parameters/path
+		if [ "$OLD_FWPATH" = "" ]; then
+			# A zero-length write won't work; write a null byte
+			printf '\000' >/sys/module/firmware_class/parameters/path
+		else
+			echo -n "$OLD_FWPATH" >/sys/module/firmware_class/parameters/path
+		fi
 	fi
 	if [ -f $FW ]; then
 		rm -f "$FW"

tools/testing/selftests/firmware/fw_run_tests.sh

@@ -66,5 +66,5 @@ if [ -f $FW_FORCE_SYSFS_FALLBACK ]; then
 	run_test_config_0003
 else
 	echo "Running basic kernel configuration, working with your config"
-	run_test
+	run_tests
 fi

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc

@@ -29,7 +29,7 @@ do_reset
 
 echo "Test extended error support"
 echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger
-echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_wakeup/trigger &>/dev/null
+! echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_wakeup/trigger 2> /dev/null
 if ! grep -q "ERROR:" events/sched/sched_wakeup/hist; then
     fail "Failed to generate extended error in histogram"
 fi

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-multi-actions-accept.tc

@@ -0,0 +1,44 @@
+#!/bin/sh
+# description: event trigger - test multiple actions on hist trigger
+
+
+do_reset() {
+    reset_trigger
+    echo > set_event
+    clear_trace
+}
+
+fail() { #msg
+    do_reset
+    echo $1
+    exit_fail
+}
+
+if [ ! -f set_event ]; then
+    echo "event tracing is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+    echo "synthetic event is not supported"
+    exit_unsupported
+fi
+
+clear_synthetic_events
+reset_tracer
+do_reset
+
+echo "Test multiple actions on hist trigger"
+echo 'wakeup_latency u64 lat; pid_t pid' >> synthetic_events
+TRIGGER1=events/sched/sched_wakeup/trigger
+TRIGGER2=events/sched/sched_switch/trigger
+
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' > $TRIGGER1
+echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 if next_comm=="cyclictest"' >> $TRIGGER2
+echo 'hist:keys=next_pid:onmatch(sched.sched_wakeup).wakeup_latency(sched.sched_switch.$wakeup_lat,next_pid) if next_comm=="cyclictest"' >> $TRIGGER2
+echo 'hist:keys=next_pid:onmatch(sched.sched_wakeup).wakeup_latency(sched.sched_switch.$wakeup_lat,prev_pid) if next_comm=="cyclictest"' >> $TRIGGER2
+echo 'hist:keys=next_pid if next_comm=="cyclictest"' >> $TRIGGER2
+
+do_reset
+
+exit 0

tools/testing/selftests/lib.mk

@@ -20,10 +20,10 @@ all: $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES)
 
 .ONESHELL:
 define RUN_TESTS
-	@export KSFT_TAP_LEVEL=`echo 1`;
-	@test_num=`echo 0`;
-	@echo "TAP version 13";
-	@for TEST in $(1); do				\
+	@export KSFT_TAP_LEVEL=`echo 1`;		\
+	test_num=`echo 0`;				\
+	echo "TAP version 13";				\
+	for TEST in $(1); do				\
 		BASENAME_TEST=`basename $$TEST`;	\
 		test_num=`echo $$test_num+1 | bc`;	\
 		echo "selftests: $$BASENAME_TEST";	\

tools/testing/selftests/net/Makefile

@@ -7,6 +7,7 @@ CFLAGS += -I../../../../usr/include/
 TEST_PROGS := run_netsocktests run_afpackettests test_bpf.sh netdevice.sh rtnetlink.sh
 TEST_PROGS += fib_tests.sh fib-onlink-tests.sh in_netns.sh pmtu.sh udpgso.sh
 TEST_PROGS += udpgso_bench.sh
+TEST_GEN_PROGS_EXTENDED := in_netns.sh
 TEST_GEN_FILES =  socket
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy
 TEST_GEN_FILES += tcp_mmap tcp_inq

tools/testing/selftests/x86/test_syscall_vdso.c

@@ -100,12 +100,19 @@ asm (
 	"	shl	$32, %r8\n"
 	"	orq	$0x7f7f7f7f, %r8\n"
 	"	movq	%r8, %r9\n"
-	"	movq	%r8, %r10\n"
-	"	movq	%r8, %r11\n"
-	"	movq	%r8, %r12\n"
-	"	movq	%r8, %r13\n"
-	"	movq	%r8, %r14\n"
-	"	movq	%r8, %r15\n"
+	"	incq	%r9\n"
+	"	movq	%r9, %r10\n"
+	"	incq	%r10\n"
+	"	movq	%r10, %r11\n"
+	"	incq	%r11\n"
+	"	movq	%r11, %r12\n"
+	"	incq	%r12\n"
+	"	movq	%r12, %r13\n"
+	"	incq	%r13\n"
+	"	movq	%r13, %r14\n"
+	"	incq	%r14\n"
+	"	movq	%r14, %r15\n"
+	"	incq	%r15\n"
 	"	ret\n"
 	"	.code32\n"
 	"	.popsection\n"
@@ -128,12 +135,13 @@ int check_regs64(void)
 	int err = 0;
 	int num = 8;
 	uint64_t *r64 = &regs64.r8;
+	uint64_t expected = 0x7f7f7f7f7f7f7f7fULL;
 
 	if (!kernel_is_64bit)
 		return 0;
 
 	do {
-		if (*r64 == 0x7f7f7f7f7f7f7f7fULL)
+		if (*r64 == expected++)
 			continue; /* register did not change */
 		if (syscall_addr != (long)&int80) {
 			/*
@@ -147,18 +155,17 @@ int check_regs64(void)
 				continue;
 			}
 		} else {
-			/* INT80 syscall entrypoint can be used by
+			/*
+			 * INT80 syscall entrypoint can be used by
 			 * 64-bit programs too, unlike SYSCALL/SYSENTER.
 			 * Therefore it must preserve R12+
 			 * (they are callee-saved registers in 64-bit C ABI).
 			 *
-			 * This was probably historically not intended,
-			 * but R8..11 are clobbered (cleared to 0).
-			 * IOW: they are the only registers which aren't
-			 * preserved across INT80 syscall.
+			 * Starting in Linux 4.17 (and any kernel that
+			 * backports the change), R8..11 are preserved.
+			 * Historically (and probably unintentionally), they
+			 * were clobbered or zeroed.
 			 */
-			if (*r64 == 0 && num <= 11)
-				continue;
 		}
 		printf("[FAIL]\tR%d has changed:%016llx\n", num, *r64);
 		err++;