Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

5 files changed, 341 insertions, 0 deletions

diff --git a/tools/perf/tests/shell/lib/coresight.sh b/tools/perf/tests/shell/lib/coresight.sh
new file mode 100644
index 000000000..45a147725
--- /dev/null
+++ b/tools/perf/tests/shell/lib/coresight.sh
@@ -0,0 +1,132 @@
+# SPDX-License-Identifier: GPL-2.0
+# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
+
+# This is sourced from a driver script so no need for #!/bin... etc. at the
+# top - the assumption below is that it runs as part of sourcing after the
+# test sets up some basic env vars to say what it is.
+
+# This currently works with ETMv4 / ETF not any other packet types at thi
+# point. This will need changes if that changes.
+
+# perf record options for the perf tests to use
+PERFRECMEM="-m ,16M"
+PERFRECOPT="$PERFRECMEM -e cs_etm//u"
+
+TOOLS=$(dirname $0)
+DIR="$TOOLS/$TEST"
+BIN="$DIR/$TEST"
+# If the test tool/binary does not exist and is executable then skip the test
+if ! test -x "$BIN"; then exit 2; fi
+DATD="."
+# If the data dir env is set then make the data dir use that instead of ./
+if test -n "$PERF_TEST_CORESIGHT_DATADIR"; then
+	DATD="$PERF_TEST_CORESIGHT_DATADIR";
+fi
+# If the stat dir env is set then make the data dir use that instead of ./
+STATD="."
+if test -n "$PERF_TEST_CORESIGHT_STATDIR"; then
+	STATD="$PERF_TEST_CORESIGHT_STATDIR";
+fi
+
+# Called if the test fails - error code 1
+err() {
+	echo "$1"
+	exit 1
+}
+
+# Check that some statistics from our perf
+check_val_min() {
+	STATF="$4"
+	if test "$2" -lt "$3"; then
+		echo ", FAILED" >> "$STATF"
+		err "Sanity check number of $1 is too low ($2 < $3)"
+	fi
+}
+
+perf_dump_aux_verify() {
+	# Some basic checking that the AUX chunk contains some sensible data
+	# to see that we are recording something and at least a minimum
+	# amount of it. We should almost always see Fn packets in just about
+	# anything but certainly we will see some trace info and async
+	# packets
+	DUMP="$DATD/perf-tmp-aux-dump.txt"
+	perf report --stdio --dump -i "$1" | \
+		grep -o -e I_ATOM_F -e I_ASYNC -e I_TRACE_INFO > "$DUMP"
+	# Simply count how many of these packets we find to see that we are
+	# producing a reasonable amount of data - exact checks are not sane
+	# as this is a lossy process where we may lose some blocks and the
+	# compiler may produce different code depending on the compiler and
+	# optimization options, so this is rough just to see if we're
+	# either missing almost all the data or all of it
+	ATOM_FX_NUM=`grep I_ATOM_F "$DUMP" | wc -l`
+	ASYNC_NUM=`grep I_ASYNC "$DUMP" | wc -l`
+	TRACE_INFO_NUM=`grep I_TRACE_INFO "$DUMP" | wc -l`
+	rm -f "$DUMP"
+
+	# Arguments provide minimums for a pass
+	CHECK_FX_MIN="$2"
+	CHECK_ASYNC_MIN="$3"
+	CHECK_TRACE_INFO_MIN="$4"
+
+	# Write out statistics, so over time you can track results to see if
+	# there is a pattern - for example we have less "noisy" results that
+	# produce more consistent amounts of data each run, to see if over
+	# time any techinques to  minimize data loss are having an effect or
+	# not
+	STATF="$STATD/stats-$TEST-$DATV.csv"
+	if ! test -f "$STATF"; then
+		echo "ATOM Fx Count, Minimum, ASYNC Count, Minimum, TRACE INFO Count, Minimum" > "$STATF"
+	fi
+	echo -n "$ATOM_FX_NUM, $CHECK_FX_MIN, $ASYNC_NUM, $CHECK_ASYNC_MIN, $TRACE_INFO_NUM, $CHECK_TRACE_INFO_MIN" >> "$STATF"
+
+	# Actually check to see if we passed or failed.
+	check_val_min "ATOM_FX" "$ATOM_FX_NUM" "$CHECK_FX_MIN" "$STATF"
+	check_val_min "ASYNC" "$ASYNC_NUM" "$CHECK_ASYNC_MIN" "$STATF"
+	check_val_min "TRACE_INFO" "$TRACE_INFO_NUM" "$CHECK_TRACE_INFO_MIN" "$STATF"
+	echo ", Ok" >> "$STATF"
+}
+
+perf_dump_aux_tid_verify() {
+	# Specifically crafted test will produce a list of Tread ID's to
+	# stdout that need to be checked to  see that they have had trace
+	# info collected in AUX blocks in the perf data. This will go
+	# through all the TID's that are listed as CID=0xabcdef and see
+	# that all the Thread IDs the test tool reports are  in the perf
+	# data AUX chunks
+
+	# The TID test tools will print a TID per stdout line that are being
+	# tested
+	TIDS=`cat "$2"`
+	# Scan the perf report to find the TIDs that are actually CID in hex
+	# and build a list of the ones found
+	FOUND_TIDS=`perf report --stdio --dump -i "$1" | \
+			grep -o "CID=0x[0-9a-z]\+" | sed 's/CID=//g' | \
+			uniq | sort | uniq`
+	# No CID=xxx found - maybe your kernel is reporting these as
+	# VMID=xxx so look there
+	if test -z "$FOUND_TIDS"; then
+		FOUND_TIDS=`perf report --stdio --dump -i "$1" | \
+				grep -o "VMID=0x[0-9a-z]\+" | sed 's/VMID=//g' | \
+				uniq | sort | uniq`
+	fi
+
+	# Iterate over the list of TIDs that the test says it has and find
+	# them in the TIDs found in the perf report
+	MISSING=""
+	for TID2 in $TIDS; do
+		FOUND=""
+		for TIDHEX in $FOUND_TIDS; do
+			TID=`printf "%i" $TIDHEX`
+			if test "$TID" -eq "$TID2"; then
+				FOUND="y"
+				break
+			fi
+		done
+		if test -z "$FOUND"; then
+			MISSING="$MISSING $TID"
+		fi
+	done
+	if test -n "$MISSING"; then
+		err "Thread IDs $MISSING not found in perf AUX data"
+	fi
+}
diff --git a/tools/perf/tests/shell/lib/perf_json_output_lint.py b/tools/perf/tests/shell/lib/perf_json_output_lint.py
new file mode 100644
index 000000000..d90f8d102
--- /dev/null
+++ b/tools/perf/tests/shell/lib/perf_json_output_lint.py
@@ -0,0 +1,96 @@
+#!/usr/bin/python
+# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+# Basic sanity check of perf JSON output as specified in the man page.
+
+import argparse
+import sys
+import json
+
+ap = argparse.ArgumentParser()
+ap.add_argument('--no-args', action='store_true')
+ap.add_argument('--interval', action='store_true')
+ap.add_argument('--system-wide-no-aggr', action='store_true')
+ap.add_argument('--system-wide', action='store_true')
+ap.add_argument('--event', action='store_true')
+ap.add_argument('--per-core', action='store_true')
+ap.add_argument('--per-thread', action='store_true')
+ap.add_argument('--per-die', action='store_true')
+ap.add_argument('--per-node', action='store_true')
+ap.add_argument('--per-socket', action='store_true')
+args = ap.parse_args()
+
+Lines = sys.stdin.readlines()
+
+def isfloat(num):
+  try:
+    float(num)
+    return True
+  except ValueError:
+    return False
+
+
+def isint(num):
+  try:
+    int(num)
+    return True
+  except ValueError:
+    return False
+
+def is_counter_value(num):
+  return isfloat(num) or num == '<not counted>' or num == '<not supported>'
+
+def check_json_output(expected_items):
+  if expected_items != -1:
+    for line in Lines:
+      if 'failed' not in line:
+        count = 0
+        count = line.count(',')
+        if count != expected_items and count >= 1 and count <= 3 and 'metric-value' in line:
+          # Events that generate >1 metric may have isolated metric
+          # values and possibly other prefixes like interval, core and
+          # aggregate-number.
+          continue
+        if count != expected_items:
+          raise RuntimeError(f'wrong number of fields. counted {count} expected {expected_items}'
+                             f' in \'{line}\'')
+  checks = {
+      'aggregate-number': lambda x: isfloat(x),
+      'core': lambda x: True,
+      'counter-value': lambda x: is_counter_value(x),
+      'cgroup': lambda x: True,
+      'cpu': lambda x: isint(x),
+      'die': lambda x: True,
+      'event': lambda x: True,
+      'event-runtime': lambda x: isfloat(x),
+      'interval': lambda x: isfloat(x),
+      'metric-unit': lambda x: True,
+      'metric-value': lambda x: isfloat(x),
+      'node': lambda x: True,
+      'pcnt-running': lambda x: isfloat(x),
+      'socket': lambda x: True,
+      'thread': lambda x: True,
+      'unit': lambda x: True,
+  }
+  input = '[\n' + ','.join(Lines) + '\n]'
+  for item in json.loads(input):
+    for key, value in item.items():
+      if key not in checks:
+        raise RuntimeError(f'Unexpected key: key={key} value={value}')
+      if not checks[key](value):
+        raise RuntimeError(f'Check failed for: key={key} value={value}')
+
+
+try:
+  if args.no_args or args.system_wide or args.event:
+    expected_items = 6
+  elif args.interval or args.per_thread or args.system_wide_no_aggr:
+    expected_items = 7
+  elif args.per_core or args.per_socket or args.per_node or args.per_die:
+    expected_items = 8
+  else:
+    # If no option is specified, don't check the number of items.
+    expected_items = -1
+  check_json_output(expected_items)
+except:
+  print('Test failed for input:\n' + '\n'.join(Lines))
+  raise
diff --git a/tools/perf/tests/shell/lib/probe.sh b/tools/perf/tests/shell/lib/probe.sh
new file mode 100644
index 000000000..51e3f60ba
--- /dev/null
+++ b/tools/perf/tests/shell/lib/probe.sh
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+# Arnaldo Carvalho de Melo <acme@kernel.org>, 2017
+
+skip_if_no_perf_probe() {
+	perf probe 2>&1 | grep -q 'is not a perf-command' && return 2
+	return 0
+}
+
+skip_if_no_perf_trace() {
+	perf trace -h 2>&1 | grep -q -e 'is not a perf-command' -e 'trace command not available' && return 2
+	return 0
+}
diff --git a/tools/perf/tests/shell/lib/probe_vfs_getname.sh b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
new file mode 100644
index 000000000..ed0a3972c
--- /dev/null
+++ b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
@@ -0,0 +1,24 @@
+# Arnaldo Carvalho de Melo <acme@kernel.org>, 2017
+
+perf probe -l 2>&1 | grep -q probe:vfs_getname
+had_vfs_getname=$?
+
+cleanup_probe_vfs_getname() {
+	if [ $had_vfs_getname -eq 1 ] ; then
+		perf probe -q -d probe:vfs_getname*
+	fi
+}
+
+add_probe_vfs_getname() {
+	local verbose=$1
+	if [ $had_vfs_getname -eq 1 ] ; then
+		line=$(perf probe -L getname_flags 2>&1 | grep -E 'result.*=.*filename;' | sed -r 's/[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*/\1/')
+		perf probe -q       "vfs_getname=getname_flags:${line} pathname=result->name:string" || \
+		perf probe $verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring"
+	fi
+}
+
+skip_if_no_debuginfo() {
+	add_probe_vfs_getname -v 2>&1 | grep -E -q "^(Failed to find the path for the kernel|Debuginfo-analysis is not supported)|(file has no debug information)" && return 2
+	return 1
+}
diff --git a/tools/perf/tests/shell/lib/waiting.sh b/tools/perf/tests/shell/lib/waiting.sh
new file mode 100644
index 000000000..e7a39134a
--- /dev/null
+++ b/tools/perf/tests/shell/lib/waiting.sh
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0
+
+tenths=date\ +%s%1N
+
+# Wait for PID $1 to have $2 number of threads started
+# Time out after $3 tenths of a second or 5 seconds if $3 is ""
+wait_for_threads()
+{
+	tm_out=$3 ; [ -n "${tm_out}" ] || tm_out=50
+	start_time=$($tenths)
+	while [ -e "/proc/$1/task" ] ; do
+		th_cnt=$(find "/proc/$1/task" -mindepth 1 -maxdepth 1 -printf x | wc -c)
+		if [ "${th_cnt}" -ge "$2" ] ; then
+			return 0
+		fi
+		# Wait at most tm_out tenths of a second
+		if [ $(($($tenths) - start_time)) -ge $tm_out ] ; then
+			echo "PID $1 does not have $2 threads"
+			return 1
+		fi
+	done
+	return 1
+}
+
+# Wait for perf record -vvv 2>$2 with PID $1 to start by looking at file $2
+# It depends on capturing perf record debug message "perf record has started"
+# Time out after $3 tenths of a second or 5 seconds if $3 is ""
+wait_for_perf_to_start()
+{
+	tm_out=$3 ; [ -n "${tm_out}" ] || tm_out=50
+	echo "Waiting for \"perf record has started\" message"
+	start_time=$($tenths)
+	while [ -e "/proc/$1" ] ; do
+		if grep -q "perf record has started" "$2" ; then
+			echo OK
+			break
+		fi
+		# Wait at most tm_out tenths of a second
+		if [ $(($($tenths) - start_time)) -ge $tm_out ] ; then
+			echo "perf recording did not start"
+			return 1
+		fi
+	done
+	return 0
+}
+
+# Wait for process PID %1 to exit
+# Time out after $2 tenths of a second or 5 seconds if $2 is ""
+wait_for_process_to_exit()
+{
+	tm_out=$2 ; [ -n "${tm_out}" ] || tm_out=50
+	start_time=$($tenths)
+	while [ -e "/proc/$1" ] ; do
+		# Wait at most tm_out tenths of a second
+		if [ $(($($tenths) - start_time)) -ge $tm_out ] ; then
+			echo "PID $1 did not exit as expected"
+			return 1
+		fi
+	done
+	return 0
+}
+
+# Check if PID $1 is still running after $2 tenths of a second
+# or 0.3 seconds if $2 is ""
+is_running()
+{
+	tm_out=$2 ; [ -n "${tm_out}" ] || tm_out=3
+	start_time=$($tenths)
+	while [ -e "/proc/$1" ] ; do
+		# Check for at least tm_out tenths of a second
+		if [ $(($($tenths) - start_time)) -gt $tm_out ] ; then
+			return 0
+		fi
+	done
+	echo "PID $1 exited prematurely"
+	return 1
+}