This is to match ipv4 behaviour, see __ip_sock_set_tos()
implementation.
Technically for ipv6 this might not be required because normally we
do not allow tclass to influence routing, yet the cli tooling does
support it:
lpk11:~# ip -6 rule add pref 5 tos 45 lookup 5
lpk11:~# ip -6 rule
5: from all tos 0x45 lookup 5
and in general dscp/tclass based routing does make sense.
We already have cases where dscp can affect vlan priority and/or
transmit queue (especially on wifi).
So let's just make things match. Easier to reason about and no harm.
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20211123223208.1117871-1-zenczykowski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is to match ipv4 behaviour, see __ip_sock_set_tos()
implementation at ipv4/ip_sockglue.c:579
void __ip_sock_set_tos(struct sock *sk, int val)
{
if (sk->sk_type == SOCK_STREAM) {
val &= ~INET_ECN_MASK;
val |= inet_sk(sk)->tos & INET_ECN_MASK;
}
if (inet_sk(sk)->tos != val) {
inet_sk(sk)->tos = val;
sk->sk_priority = rt_tos2priority(val);
sk_dst_reset(sk);
}
}
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211123223154.1117794-1-zenczykowski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A CAP_NET_RAW capable process can already spoof (on transmit) anything
it desires via raw packet sockets... There is no good reason to not
allow it to also be able to play routing tricks on packets from its
own normal sockets.
There is a desire to be able to use SO_MARK for routing table selection
(via ip rule fwmark) from within a user process without having to run
it as root. Granting it CAP_NET_RAW is much less dangerous than
CAP_NET_ADMIN (CAP_NET_RAW doesn't permit persistent state change,
while CAP_NET_ADMIN does - by for example allowing the reconfiguration
of the routing tables and/or bringing up/down devices).
Let's keep CAP_NET_ADMIN for persistent state changes,
while using CAP_NET_RAW for non-configuration related stuff.
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20211123203715.193413-1-zenczykowski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
CAP_NET_ADMIN is and should continue to be about configuring the
system as a whole, not about configuring per-socket or per-packet
parameters.
Sending and receiving raw packets is what CAP_NET_RAW is all about.
It can already send packets with any VLAN tag, and any IPv4 TOS
mark, and any IPv6 TCLASS mark, simply by virtue of building
such a raw packet. Not to mention using any protocol and source/
/destination ip address/port tuple.
These are the fields that networking gear uses to prioritize packets.
Hence, a CAP_NET_RAW process is already capable of affecting traffic
prioritization after it hits the wire. This change makes it capable
of affecting traffic prioritization even in the host at the nic and
before that in the queueing disciplines (provided skb->priority is
actually being used for prioritization, and not the TOS/TCLASS field)
Hence it makes sense to allow a CAP_NET_RAW process to set the
priority of sockets and thus packets it sends.
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20211123203702.193221-1-zenczykowski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Marek Behún says:
====================
phylink resolve fixes
With information from me and my nagging, Russell has produced two fixes
for phylink, which add code that triggers another phylink_resolve() from
phylink_resolve(), if certain conditions are met:
interface is being changed
or
link is down and previous link was up
These are needed because sometimes the PCS callbacks may provide stale
values if link / speed / ...
====================
Link: https://lore.kernel.org/r/20211123154403.32051-1-kabel@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On mv88e6xxx 1G/2.5G PCS, the SerDes register 4.2001.2 has the following
description:
This register bit indicates when link was lost since the last
read. For the current link status, read this register
back-to-back.
Thus to get current link state, we need to read the register twice.
But doing that in the link change interrupt handler would lead to
potentially ignoring link down events, which we really want to avoid.
Thus this needs to be solved in phylink's resolve, by retriggering
another resolve in the event when PCS reports link down and previous
link was up, and by re-reading PCS state if the previous link was down.
The wrong value is read when phylink requests change from sgmii to
2500base-x mode, and link won't come up. This fixes the bug.
Fixes: 9525ae8395 ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On PHY state change the phylink_resolve() function can read stale
information from the MAC and report incorrect link speed and duplex to
the kernel message log.
Example with a Marvell 88X3310 PHY connected to a SerDes port on Marvell
88E6393X switch:
- PHY driver triggers state change due to PHY interface mode being
changed from 10gbase-r to 2500base-x due to copper change in speed
from 10Gbps to 2.5Gbps, but the PHY itself either hasn't yet changed
its interface to the host, or the interrupt about loss of SerDes link
hadn't arrived yet (there can be a delay of several milliseconds for
this), so we still think that the 10gbase-r mode is up
- phylink_resolve()
- phylink_mac_pcs_get_state()
- this fills in speed=10g link=up
- interface mode is updated to 2500base-x but speed is left at 10Gbps
- phylink_major_config()
- interface is changed to 2500base-x
- phylink_link_up()
- mv88e6xxx_mac_link_up()
- .port_set_speed_duplex()
- speed is set to 10Gbps
- reports "Link is Up - 10Gbps/Full" to dmesg
Afterwards when the interrupt finally arrives for mv88e6xxx, another
resolve is forced in which we get the correct speed from
phylink_mac_pcs_get_state(), but since the interface is not being
changed anymore, we don't call phylink_major_config() but only
phylink_mac_config(), which does not set speed/duplex anymore.
To fix this, we need to force the link down and trigger another resolve
on PHY interface change event.
Fixes: 9525ae8395 ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Usage of phy_ethtool_get_link_ksettings() in the link status change
handler isn't needed, and in combination with the referenced change
it results in a deadlock. Simply remove the call and replace it with
direct access to phydev->speed. The duplex argument of
lan743x_phy_update_flowcontrol() isn't used and can be removed.
Fixes: c10a485c3d ("phy: phy_ethtool_ksettings_get: Lock the phy for consistency")
Reported-by: Alessandro B Maurici <abmaurici@gmail.com>
Tested-by: Alessandro B Maurici <abmaurici@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/40e27f76-0ba3-dcef-ee32-a78b9df38b0f@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix warning reported by bot.
Make sure hash is init to 0 and fix wrong logic for hash_type in
qca8k_lag_can_offload.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: def975307c ("net: dsa: qca8k: add LAG support")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20211123154446.31019-1-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Even if firmware fails to recognize the plugged-in port module type,
allow reading port module EEPROM anyway. This helps in obtaining
necessary diagnostics information for debugging and analysis.
Signed-off-by: Manoj Malviya <manojmalviya@chelsio.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Link: https://lore.kernel.org/r/1637682437-31407-1-git-send-email-rahul.lakkireddy@chelsio.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
While testing BIG TCP patch series, I was expecting that TCP_RR workloads
with 80KB requests/answers would send one 80KB TSO packet,
then being received as a single GRO packet.
It turns out this was not happening, and the root cause was that
cubic Hystart ACK train was triggering after a few (2 or 3) rounds of RPC.
Hystart was wrongly setting CWND/SSTHRESH to 30, while my RPC
needed a budget of ~20 segments.
Ideally these TCP_RR flows should not exit slow start.
Cubic Hystart should reset itself at each round, instead of assuming
every TCP flow is a bulk one.
Note that even after this patch, Hystart can still trigger, depending
on scheduling artifacts, but at a higher CWND/SSTHRESH threshold,
keeping optimal TSO packet sizes.
Tested:
ip link set dev eth0 gro_ipv6_max_size 131072 gso_ipv6_max_size 131072
nstat -n; netperf -H ... -t TCP_RR -l 5 -- -r 80000,80000 -K cubic; nstat|egrep "Ip6InReceives|Hystart|Ip6OutRequests"
Before:
8605
Ip6InReceives 87541 0.0
Ip6OutRequests 129496 0.0
TcpExtTCPHystartTrainDetect 1 0.0
TcpExtTCPHystartTrainCwnd 30 0.0
After:
8760
Ip6InReceives 88514 0.0
Ip6OutRequests 87975 0.0
Fixes: ae27e98a51 ("[TCP] CUBIC v2.3")
Co-developed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Link: https://lore.kernel.org/r/20211123202535.1843771-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cited commit converted simple_strtoul() to kstrtoul() as suggested by
the former's documentation. However, it also forced all the inputs to be
decimal resulting in user space breakage.
Fix by setting the base to '0' so that the base is automatically
detected.
Before:
# ip link add name br0 type bridge vlan_filtering 1
# echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
bash: echo: write error: Invalid argument
After:
# ip link add name br0 type bridge vlan_filtering 1
# echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
# echo $?
0
Fixes: 520fbdf7fb ("net/bridge: replace simple_strtoul to kstrtol")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20211124101122.3321496-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Eric Dumazet says:
====================
gro: remove redundant rcu_read_lock
Recent trees got an increase of rcu_read_{lock|unlock} costs,
it is time to get rid of the not needed pairs.
====================
Link: https://lore.kernel.org/r/20211123225608.2155163-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All gro_complete() handlers are called from napi_gro_complete()
while rcu_read_lock() has been called.
There is no point stacking more rcu_read_lock()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All gro_receive() handlers are called from dev_gro_receive()
while rcu_read_lock() has been called.
There is no point stacking more rcu_read_lock()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update the B53 Ethernet switch section to contain
drivers/net/dsa/bcm_sf2*.
Reported-by: Russell King (Oracle) <linux@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20211123222422.3745485-1-f.fainelli@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The following warning is fixed, by removing the unused resource size:
drivers/net/ethernet/engleder/tsnep_main.c:1155:21-24:
WARNING: Suspicious code. resource_size is maybe missing with io
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://lore.kernel.org/r/20211124205225.13985-1-gerhard@engleder-embedded.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Remove .owner field if calls are used which set it automatically
Eliminate the following coccicheck warning:
./drivers/net/ethernet/engleder/tsnep_main.c:1263:3-8: No need to set
.owner here. The core will do it.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://lore.kernel.org/r/1637721384-70836-2-git-send-email-yang.lee@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stefan Schmidt says:
====================
pull-request: ieee802154 for net 2021-11-24
A fix from Alexander which has been brought up various times found by
automated checkers. Make sure values are in u32 range.
* tag 'ieee802154-for-net-2021-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan:
net: ieee802154: handle iftypes as u32
====================
Link: https://lore.kernel.org/r/20211124150934.3670248-1-stefan@datenfreihafen.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Make microwatt_get_random_darn() static, because it can be.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211118004415.1706863-1-mpe@ellerman.id.au
When taking watchdog actions, printing messages, comparing and
re-setting wd_smp_last_reset_tb, etc., read TB close to the point of use
and under wd_smp_lock or printing lock (if applicable).
This should keep timebase mostly monotonic with kernel log messages, and
could prevent (in theory) a laggy CPU updating wd_smp_last_reset_tb to
something a long way in the past, and causing other CPUs to appear to be
stuck.
These additional TB reads are all slowpath (lockup has been detected),
so performance does not matter.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-5-npiggin@gmail.com
There is a deadlock with the console_owner lock and the wd_smp_lock:
CPU x takes the console_owner lock
CPU y takes a watchdog timer interrupt and takes __wd_smp_lock
CPU x takes a soft-NMI interrupt, detects deadlock, spins on __wd_smp_lock
CPU y detects deadlock, tries to print something and spins on console_owner
-> deadlock
Change the watchdog locking scheme so wd_smp_lock protects the watchdog
internal data, but "reporting" (printing, issuing NMI IPIs, taking any
action outside of watchdog) uses a non-waiting exclusion. If a CPU detects
a problem but can not take the reporting lock, it just returns because
something else is already reporting. It will try again at some point.
Typically hard lockup watchdog report usefulness is not impacted due to
failure to spewing a large enough amount of data in as short a time as
possible, but by messages getting garbled.
Laurent debugged this and found the deadlock, and this patch is based on
his general approach to avoid expensive operations while holding the lock.
With the addition of the reporting exclusion.
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
[np: rework to add reporting exclusion update changelog]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-4-npiggin@gmail.com
Most updates to wd_smp_cpus_pending are under lock except the watchdog
interrupt bit clear.
This can race with non-atomic RMW updates to the mask under lock, which
can happen in two instances:
Firstly, if another CPU detects this one is stuck, removes it from the
mask, mask becomes empty and is re-filled with non-atomic stores. This
is okay because it would re-fill the mask with this CPU's bit clear
anyway (because this CPU is now stuck), so it doesn't matter that the
bit clear update got "lost". Add a comment for this.
Secondly, if another CPU detects a different CPU is stuck and removes it
from the pending mask with a non-atomic store to bytes which also
include the bit of this CPU. This case can result in the bit clear being
lost and the end result being the bit is set. This should be so rare it
hardly matters, but to make things simpler to reason about just avoid
the non-atomic access for that case.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-3-npiggin@gmail.com
It is possible for all CPUs to miss the pending cpumask becoming clear,
and then nobody resetting it, which will cause the lockup detector to
stop working. It will eventually expire, but watchdog_smp_panic will
avoid doing anything if the pending mask is clear and it will never be
reset.
Order the cpumask clear vs the subsequent test to close this race.
Add an extra check for an empty pending mask when the watchdog fires and
finds its bit still clear, to try to catch any other possible races or
bugs here and keep the watchdog working. The extra test in
arch_touch_nmi_watchdog is required to prevent the new warning from
firing off.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Debugged-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-2-npiggin@gmail.com
Provide API documentation for rtas_busy_delay_time(), explaining why we
return the same value for 9900 and -2.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211117060259.957178-3-nathanl@linux.ibm.com
Generally RTAS cannot block, and in PAPR it is required to return control
to the OS within a few tens of microseconds. In order to support operations
which may take longer to complete, many RTAS primitives can return
intermediate -2 ("busy") or 990x ("extended delay") values, which indicate
that the OS should reattempt the same call with the same arguments at some
point in the future.
Current versions of PAPR are less than clear about this, but the intended
meanings of these values in more detail are:
RTAS_BUSY (-2): RTAS has suspended a potentially long-running operation in
order to meet its latency obligation and give the OS the opportunity to
perform other work. RTAS can resume making progress as soon as the OS
reattempts the call.
RTAS_EXTENDED_DELAY_{MIN...MAX} (9900-9905): RTAS must wait for an external
event to occur or for internal contention to resolve before it can complete
the requested operation. The value encodes a non-binding hint as to roughly
how long the OS should wait before calling again, but the OS is allowed to
reattempt the call sooner or even immediately.
Linux of course must take its own CPU scheduling obligations into account
when handling these statuses; e.g. a task which receives an RTAS_BUSY
status should check whether to reschedule before it attempts the RTAS call
again to avoid starving other tasks.
rtas_busy_delay() is a helper function that "consumes" a busy or extended
delay status. Common usage:
int rc;
do {
rc = rtas_call(rtas_token("some-function"), ...);
} while (rtas_busy_delay(rc));
/* convert rc to Linux error value, etc */
If rc is a busy or extended delay status, the caller can rely on
rtas_busy_delay() to perform an appropriate sleep or reschedule and return
nonzero. Other statuses are handled normally by the caller.
The current implementation of rtas_busy_delay() both oversleeps and
overuses the CPU:
* It performs msleep() for all 990x and even when no delay is
suggested (-2), but this is understood to actually sleep for two jiffies
minimum in practice (20ms with HZ=100). 9900 (1ms) and 9901 (10ms)
appear to be the most common extended delay statuses, and the
oversleeping measurably lengthens DLPAR operations, which perform
many RTAS calls.
* It does not sleep on 990x unless need_resched() is true, causing code
like the loop above to needlessly retry, wasting CPU time.
Alter the logic to align better with the intended meanings:
* When passed RTAS_BUSY, perform cond_resched() and return without
sleeping. The caller should reattempt immediately
* Always sleep when passed an extended delay status, using usleep_range()
for precise shorter sleeps. Limit the sleep time to one second even
though there are higher architected values.
Change rtas_busy_delay()'s return type to bool to better reflect its usage,
and add kernel-doc.
rtas_busy_delay_time() is unchanged, even though it "incorrectly" returns 1
for RTAS_BUSY. There are users of that API with open-coded delay loops in
sensitive contexts that will have to be taken on an individual basis.
Brief results for addition and removal of 5GB memory on a small P9 PowerVM
partition follow. Load was generated with stress-ng --cpu N. For add,
elapsed time is greatly reduced without significant change in the number of
RTAS calls or time spent on CPU. For remove, elapsed time is modestly
reduced, with significant reductions in RTAS calls and time spent on CPU.
With no competing workload (- before, + after):
Performance counter stats for 'bash -c echo "memory add count 20" > /sys/kernel/dlpar' (10 runs):
- 1,935 probe:rtas_call # 0.003 M/sec ( +- 0.22% )
- 609.99 msec task-clock # 0.183 CPUs utilized ( +- 0.19% )
+ 1,956 probe:rtas_call # 0.003 M/sec ( +- 0.17% )
+ 618.56 msec task-clock # 0.278 CPUs utilized ( +- 0.11% )
- 3.3322 +- 0.0670 seconds time elapsed ( +- 2.01% )
+ 2.2222 +- 0.0416 seconds time elapsed ( +- 1.87% )
Performance counter stats for 'bash -c echo "memory remove count 20" > /sys/kernel/dlpar' (10 runs):
- 6,224 probe:rtas_call # 0.008 M/sec ( +- 2.57% )
- 750.36 msec task-clock # 0.190 CPUs utilized ( +- 2.01% )
+ 843 probe:rtas_call # 0.003 M/sec ( +- 0.12% )
+ 250.66 msec task-clock # 0.068 CPUs utilized ( +- 0.17% )
- 3.9394 +- 0.0890 seconds time elapsed ( +- 2.26% )
+ 3.678 +- 0.113 seconds time elapsed ( +- 3.07% )
With all CPUs 100% busy (- before, + after):
Performance counter stats for 'bash -c echo "memory add count 20" > /sys/kernel/dlpar' (10 runs):
- 2,979 probe:rtas_call # 0.003 M/sec ( +- 0.12% )
- 1,096.62 msec task-clock # 0.105 CPUs utilized ( +- 0.10% )
+ 2,981 probe:rtas_call # 0.003 M/sec ( +- 0.22% )
+ 1,095.26 msec task-clock # 0.154 CPUs utilized ( +- 0.21% )
- 10.476 +- 0.104 seconds time elapsed ( +- 1.00% )
+ 7.1124 +- 0.0865 seconds time elapsed ( +- 1.22% )
Performance counter stats for 'bash -c echo "memory remove count 20" > /sys/kernel/dlpar' (10 runs):
- 2,702 probe:rtas_call # 0.004 M/sec ( +- 4.00% )
- 722.71 msec task-clock # 0.067 CPUs utilized ( +- 2.41% )
+ 1,246 probe:rtas_call # 0.003 M/sec ( +- 0.25% )
+ 487.73 msec task-clock # 0.049 CPUs utilized ( +- 0.20% )
- 10.829 +- 0.163 seconds time elapsed ( +- 1.51% )
+ 9.9887 +- 0.0866 seconds time elapsed ( +- 0.87% )
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211117060259.957178-2-nathanl@linux.ibm.com
Remove the pseries scanlog driver.
This code supports functions from Power4-era servers that are not present
on targets currently supported by arch/powerpc. System manuals from this
time have this description:
Scan Dump data is a set of chip data that the service processor gathers
after a system malfunction. It consists of chip scan rings, chip trace
arrays, and Scan COM (SCOM) registers. This data is stored in the
scan-log partition of the system’s Nonvolatile Random Access
Memory (NVRAM).
PowerVM partition firmware development doesn't recognize the associated
function call or property, and they don't see any references to them in
their codebase. It seems to have been specific to non-virtualized pseries.
References:
Historical Linux commit from February 2003 (interesting to note this seems
to be the source of non-GPL exports for rtas_call etc):
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=f92e361842d5251e50562b09664082dcbd0548bb
IntelliStation and pSeries docs which refer to the feature:
http://ps-2.retropc.se/basil.holloway/ALL%20PDF/380635.pdfhttp://ps-2.kev009.com/rs6000/manuals/p/p615-6C3-6E3/6C3_and_6E3_Users_Guide_SA38-0629.pdf
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210920173203.1800475-1-nathanl@linux.ibm.com
Fix the following issues reported by kernel-doc:
$ scripts/kernel-doc -v -none arch/powerpc/kernel/rtas.c
arch/powerpc/kernel/rtas.c:810: info: Scanning doc for function rtas_activate_firmware
arch/powerpc/kernel/rtas.c:818: warning: contents before sections
arch/powerpc/kernel/rtas.c:841: info: Scanning doc for function rtas_call_reentrant
arch/powerpc/kernel/rtas.c:893: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Find a specific pseries error log in an RTAS extended event log.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211116215806.928235-1-nathanl@linux.ibm.com
Today, patch_instruction() assumes that it is called exclusively on
valid addresses, and only checks that it is not called on an init
address after init section has been freed.
Improve verification by calling kernel_text_address() instead.
kernel_text_address() already includes a verification of
initmem release.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bc683d499a411730504b132a924de0ccc2ef1f79.1636971137.git.christophe.leroy@csgroup.eu
With KUAP enabled, any kernel code which wants to access userspace
needs to be surrounded by disable-enable KUAP. But that is not
happening for BPF_PROBE_MEM load instruction. Though PPC32 does not
support read protection, considering the fact that PTR_TO_BTF_ID
(which uses BPF_PROBE_MEM mode) could either be a valid kernel pointer
or NULL but should never be a pointer to userspace address, execute
BPF_PROBE_MEM load only if addr is kernel address, otherwise set
dst_reg=0 and move on.
This will catch NULL, valid or invalid userspace pointers. Only bad
kernel pointer will be handled by BPF exception table.
[Alexei suggested for x86]
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-9-hbathini@linux.ibm.com
BPF load instruction with BPF_PROBE_MEM mode can cause a fault
inside kernel. Append exception table for such instructions
within BPF program.
Unlike other archs which uses extable 'fixup' field to pass dest_reg
and nip, BPF exception table on PowerPC follows the generic PowerPC
exception table design, where it populates both fixup and extable
sections within BPF program. fixup section contains 3 instructions,
first 2 instructions clear dest_reg (lower & higher 32-bit registers)
and last instruction jumps to next instruction in the BPF code.
extable 'insn' field contains relative offset of the instruction and
'fixup' field contains relative offset of the fixup entry. Example
layout of BPF program with extable present:
+------------------+
| |
| |
0x4020 -->| lwz r28,4(r4) |
| |
| |
0x40ac -->| lwz r3,0(r24) |
| lwz r4,4(r24) |
| |
| |
|------------------|
0x4278 -->| li r28,0 | \
| li r27,0 | | fixup entry
| b 0x4024 | /
0x4284 -->| li r4,0 |
| li r3,0 |
| b 0x40b4 |
|------------------|
0x4290 -->| insn=0xfffffd90 | \ extable entry
| fixup=0xffffffe4 | /
0x4298 -->| insn=0xfffffe14 |
| fixup=0xffffffe8 |
+------------------+
(Addresses shown here are chosen random, not real)
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-8-hbathini@linux.ibm.com
On PPC64 with KUAP enabled, any kernel code which wants to
access userspace needs to be surrounded by disable-enable KUAP.
But that is not happening for BPF_PROBE_MEM load instruction.
So, when BPF program tries to access invalid userspace address,
page-fault handler considers it as bad KUAP fault:
Kernel attempted to read user page (d0000000) - exploit attempt? (uid: 0)
Considering the fact that PTR_TO_BTF_ID (which uses BPF_PROBE_MEM
mode) could either be a valid kernel pointer or NULL but should
never be a pointer to userspace address, execute BPF_PROBE_MEM load
only if addr is kernel address, otherwise set dst_reg=0 and move on.
This will catch NULL, valid or invalid userspace pointers. Only bad
kernel pointer will be handled by BPF exception table.
[Alexei suggested for x86]
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-7-hbathini@linux.ibm.com
BPF load instruction with BPF_PROBE_MEM mode can cause a fault
inside kernel. Append exception table for such instructions
within BPF program.
Unlike other archs which uses extable 'fixup' field to pass dest_reg
and nip, BPF exception table on PowerPC follows the generic PowerPC
exception table design, where it populates both fixup and extable
sections within BPF program. fixup section contains two instructions,
first instruction clears dest_reg and 2nd jumps to next instruction
in the BPF code. extable 'insn' field contains relative offset of
the instruction and 'fixup' field contains relative offset of the
fixup entry. Example layout of BPF program with extable present:
+------------------+
| |
| |
0x4020 -->| ld r27,4(r3) |
| |
| |
0x40ac -->| lwz r3,0(r4) |
| |
| |
|------------------|
0x4280 -->| li r27,0 | \ fixup entry
| b 0x4024 | /
0x4288 -->| li r3,0 |
| b 0x40b0 |
|------------------|
0x4290 -->| insn=0xfffffd90 | \ extable entry
| fixup=0xffffffec | /
0x4298 -->| insn=0xfffffe14 |
| fixup=0xffffffec |
+------------------+
(Addresses shown here are chosen random, not real)
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-6-hbathini@linux.ibm.com
Define and use PPC_RAW_BRANCH() macro instead of open coding it. This
macro is used while adding BPF_PROBE_MEM support.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-5-hbathini@linux.ibm.com
In case of extra_pass, usual JIT passes are always skipped. So,
extra_pass is always false while calling bpf_jit_build_body() and
can be removed.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-3-hbathini@linux.ibm.com
SEEN_STACK is unused on PowerPC. Remove it. Also, have
SEEN_TAILCALL use 0x40000000.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-2-hbathini@linux.ibm.com
The EEH recovery logic in eeh_handle_normal_event() has some pretty strange
flow control. If we remove all the actual recovery logic we're left with
the following skeleton:
if (result != PCI_ERS_RESULT_DISCONNECT) {
...
}
if (result != PCI_ERS_RESULT_DISCONNECT) {
...
}
if (result == PCI_ERS_RESULT_NONE) {
...
}
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
...
}
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
...
}
if (result == PCI_ERS_RESULT_NEED_RESET) {
...
}
if ((result == PCI_ERS_RESULT_RECOVERED) ||
(result == PCI_ERS_RESULT_NONE)) {
...
goto out;
}
/*
* unsuccessful recovery / PCI_ERS_RESULT_DISCONECTED
* handling is here.
*/
...
out:
...
Most of the "if () { ... }" blocks above change "result" to
PCI_ERS_RESULT_DISCONNECTED if an error occurs in that recovery step. This
makes the control flow a bit confusing since it breaks the early-exit
pattern that is generally used in Linux. In any case we end up handling the
error in the final else block so why not just jump there directly? Doing so
also allows us to de-indent a bunch of code.
No functional changes.
[dja: rebase on top of linux-next + my preceeding refactor,
move clearing the EEH_DEV_NO_HANDLER bit above the first goto so that
it is always clear in the error handler code as it was before.]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015070628.1331635-2-dja@axtens.net
The control flow of eeh_handle_normal_event() is a bit tricky.
Break out one of the error handling paths - rather than be in an else
block, we'll make it part of the regular body of the function and put a
'goto out;' in the true limb of the if.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015070628.1331635-1-dja@axtens.net
On POWER10, the automatic "save & restore" of interrupt context is
always available. Provide a way to deactivate it for tests or
performance.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-11-clg@kaod.org
StoreEOI is activated by default on platforms supporting the feature
(POWER10) and will be used as soon as firmware advertises its
availability. The kernel parameter provides a way to deactivate its
use. It can be still be reactivated through debugfs.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-10-clg@kaod.org
It can be used to deactivate temporarily StoreEOI for tests or
performance on platforms supporting the feature (POWER10)
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-9-clg@kaod.org
The XIVE driver under Linux uses a single interrupt priority and only
one event queue is configured per CPU. Expose the contents under
a 'xive/eqs/cpuX' debugfs file.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-8-clg@kaod.org
and remove the EQ entries output which is not very useful since only
the next two events of the queue are taken into account. We will
improve the dump of the EQ in the next patches.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-7-clg@kaod.org
and fix some compile issues when !CONFIG_DEBUG_FS.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
[mpe: Add empty stub to fix !CONFIG_DEBUG_FS build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-5-clg@kaod.org
StoreEOI (the capability to EOI with a store) requires load-after-store
ordering in some cases to be reliable. P10 introduced a new offset for
load operations to enforce correct ordering and the XIVE driver has
the required support since kernel 5.8, commit b1f9be9392
("powerpc/xive: Enforce load-after-store ordering when StoreEOI is active")
Since skiboot v7, StoreEOI support is advertised on P10 with a new flag
on the PowerNV platform. See skiboot commit 4bd7d84afe46 ("xive/p10:
Introduce a new OPAL_XIVE_IRQ_STORE_EOI2 flag"). When detected,
activate the feature.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-4-clg@kaod.org
and extend output of debugfs and xmon with addresses of the ESB
management and trigger pages.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-3-clg@kaod.org
