RTL8723BS is often used in ARM boards, so add ability to bind it
using device tree.
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Add binding document for bluetooth part of RTL8723BS/RTL8723CS
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Vladimir Oltean says:
====================
This series adds support for boards where DSA switches of multiple types
are cascaded together. Actually this type of setup was brought up before
on netdev, and it looks like utilizing disjoint trees is the way to go:
https://lkml.org/lkml/2019/7/7/225
The trouble with disjoint trees (prior to this patch series) is that only
bridging of ports within the same hardware switch can be offloaded.
After scratching my head for a while, it looks like the easiest way to
support hardware bridging between different DSA trees is to bridge their
DSA masters and extend the crosschip bridging operations.
I have given some thought to bridging the DSA masters with the slaves
themselves, but given the hardware topology described in the commit
message of patch 4/4, virtually any number (and combination) of bridges
(forwarding domains) can be created on top of those 3x4-port front-panel
switches. So it becomes a lot less obvious, when the front-panel ports
are enslaved to more than 1 bridge, which bridge should the DSA masters
be enslaved to.
So the least awkward approach was to just create a completely separate
bridge for the DSA masters, whose entire purpose is to permit hardware
forwarding between the discrete switches beneath it.
This is a direct resend of v3, which was deferred due to lack of review.
In the meantime Florian has reviewed and tested some of them.
v1 was submitted here:
https://patchwork.ozlabs.org/project/netdev/cover/20200429161952.17769-1-olteanv@gmail.com/
v2 was submitted here:
https://patchwork.ozlabs.org/project/netdev/cover/20200430202542.11797-1-olteanv@gmail.com/
v3 was submitted here:
https://patchwork.ozlabs.org/project/netdev/cover/20200503221228.10928-1-olteanv@gmail.com/
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sja1105 uses dsa_8021q for DSA tagging, a format which is VLAN at heart
and which is compatible with cascading. A complete description of this
tagging format is in net/dsa/tag_8021q.c, but a quick summary is that
each external-facing port tags incoming frames with a unique pvid, and
this special VLAN is transmitted as tagged towards the inside of the
system, and as untagged towards the exterior. The tag encodes the switch
id and the source port index.
This means that cross-chip bridging for dsa_8021q only entails adding
the dsa_8021q pvids of one switch to the RX filter of the other
switches. Everything else falls naturally into place, as long as the
bottom-end of ports (the leaves in the tree) is comprised exclusively of
dsa_8021q-compatible (i.e. sja1105 switches). Otherwise, there would be
a chance that a front-panel switch transmits a packet tagged with a
dsa_8021q header, header which it wouldn't be able to remove, and which
would hence "leak" out.
The only use case I tested (due to lack of board availability) was when
the sja1105 switches are part of disjoint trees (however, this doesn't
change the fact that multiple sja1105 switches still need unique switch
identifiers in such a system). But in principle, even "true" single-tree
setups (with DSA links) should work just as fine, except for a small
change which I can't test: dsa_towards_port should be used instead of
dsa_upstream_port (I made the assumption that the routing port that any
sja1105 should use towards its neighbours is the CPU port. That might
not hold true in other setups).
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Somewhat similar to dsa_tree_find, dsa_switch_find returns a dsa_switch
structure pointer by searching for its tree index and switch index (the
parameters from dsa,member). To be used, for example, by drivers who
implement .crosschip_bridge_join and need a reference to the other
switch indicated to by the tree_index and sw_index arguments.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
One way of utilizing DSA is by cascading switches which do not all have
compatible taggers. Consider the following real-life topology:
+---------------------------------------------------------------+
| LS1028A |
| +------------------------------+ |
| | DSA master for Felix | |
| |(internal ENETC port 2: eno2))| |
| +------------+------------------------------+-------------+ |
| | Felix embedded L2 switch | |
| | | |
| | +--------------+ +--------------+ +--------------+ | |
| | |DSA master for| |DSA master for| |DSA master for| | |
| | | SJA1105 1 | | SJA1105 2 | | SJA1105 3 | | |
| | |(Felix port 1)| |(Felix port 2)| |(Felix port 3)| | |
+--+-+--------------+---+--------------+---+--------------+--+--+
+-----------------------+ +-----------------------+ +-----------------------+
| SJA1105 switch 1 | | SJA1105 switch 2 | | SJA1105 switch 3 |
+-----+-----+-----+-----+ +-----+-----+-----+-----+ +-----+-----+-----+-----+
|sw1p0|sw1p1|sw1p2|sw1p3| |sw2p0|sw2p1|sw2p2|sw2p3| |sw3p0|sw3p1|sw3p2|sw3p3|
+-----+-----+-----+-----+ +-----+-----+-----+-----+ +-----+-----+-----+-----+
The above can be described in the device tree as follows (obviously not
complete):
mscc_felix {
dsa,member = <0 0>;
ports {
port@4 {
ethernet = <&enetc_port2>;
};
};
};
sja1105_switch1 {
dsa,member = <1 1>;
ports {
port@4 {
ethernet = <&mscc_felix_port1>;
};
};
};
sja1105_switch2 {
dsa,member = <2 2>;
ports {
port@4 {
ethernet = <&mscc_felix_port2>;
};
};
};
sja1105_switch3 {
dsa,member = <3 3>;
ports {
port@4 {
ethernet = <&mscc_felix_port3>;
};
};
};
Basically we instantiate one DSA switch tree for every hardware switch
in the system, but we still give them globally unique switch IDs (will
come back to that later). Having 3 disjoint switch trees makes the
tagger drivers "just work", because net devices are registered for the
3 Felix DSA master ports, and they are also DSA slave ports to the ENETC
port. So packets received on the ENETC port are stripped of their
stacked DSA tags one by one.
Currently, hardware bridging between ports on the same sja1105 chip is
possible, but switching between sja1105 ports on different chips is
handled by the software bridge. This is fine, but we can do better.
In fact, the dsa_8021q tag used by sja1105 is compatible with cascading.
In other words, a sja1105 switch can correctly parse and route a packet
containing a dsa_8021q tag. So if we could enable hardware bridging on
the Felix DSA master ports, cross-chip bridging could be completely
offloaded.
Such as system would be used as follows:
ip link add dev br0 type bridge && ip link set dev br0 up
for port in sw0p0 sw0p1 sw0p2 sw0p3 \
sw1p0 sw1p1 sw1p2 sw1p3 \
sw2p0 sw2p1 sw2p2 sw2p3; do
ip link set dev $port master br0
done
The above makes switching between ports on the same row be performed in
hardware, and between ports on different rows in software. Now assume
the Felix switch ports are called swp0, swp1, swp2. By running the
following extra commands:
ip link add dev br1 type bridge && ip link set dev br1 up
for port in swp0 swp1 swp2; do
ip link set dev $port master br1
done
the CPU no longer sees packets which traverse sja1105 switch boundaries
and can be forwarded directly by Felix. The br1 bridge would not be used
for any sort of traffic termination.
For this to work, we need to give drivers an opportunity to listen for
bridging events on DSA trees other than their own, and pass that other
tree index as argument. I have made the assumption, for the moment, that
the other existing DSA notifiers don't need to be broadcast to other
trees. That assumption might turn out to be incorrect. But in the
meantime, introduce a dsa_broadcast function, similar in purpose to
dsa_port_notify, which is used only by the bridging notifiers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 8db0a2ee2c ("net: bridge: reject DSA-enabled master netdevices
as bridge members") added a special check in br_if.c in order to check
for a DSA master network device with a tagging protocol configured. This
was done because back then, such devices, once enslaved in a bridge
would become inoperative and would not pass DSA tagged traffic anymore
due to br_handle_frame returning RX_HANDLER_CONSUMED.
But right now we have valid use cases which do require bridging of DSA
masters. One such example is when the DSA master ports are DSA switch
ports themselves (in a disjoint tree setup). This should be completely
equivalent, functionally speaking, from having multiple DSA switches
hanging off of the ports of a switchdev driver. So we should allow the
enslaving of DSA tagged master network devices.
Instead of the regular br_handle_frame(), install a new function
br_handle_frame_dummy() on these DSA masters, which returns
RX_HANDLER_PASS in order to call into the DSA specific tagging protocol
handlers, and lift the restriction from br_add_if.
Suggested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Suggested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Huazhong Tan says:
====================
net: hns3: misc updates for -next
This patchset includes some misc updates for the HNS3 ethernet driver.
#1 & #2 add two cleanups.
#3 provides an interface for the client to query the CMDQ's status.
#4 adds a little optimization about debugfs.
#5 prevents 1000M auto-negotiation off setting.
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The 802.3 specification does not specify the behavior of
auto-negotiation off with 1000M in PHY. Therefore, some PHY
compatibility issues occur. This patch forbids the setting of
this unreasonable mode by ethtool in driver.
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch optimizes the judgment of the input parameters of dump ncl
config by checking the number and value of the input parameters apart.
It's clearer and more reasonable.
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch provides a new interface for the client to query
whether CMDQ is ready to work.
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
According to the UM, command 0x0B03 and 0x0B13 are used to
query the statistics about TX and RX, not the status, so
modifies the unsuitable macro name of these two command.
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
HCLGE_MISC_VECTOR_INT_STS and HCLGE_VECTOR_PF_OTHER_INT_STS_REG
both represent the misc interrupt status register(0x20800), so
removes HCLGE_VECTOR_PF_OTHER_INT_STS_REG and replaces it with
HCLGE_MISC_VECTOR_INT_STS.
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Andrew Lunn says:
====================
Ethernet Cable test support
any copper Ethernet PHY have support for performing diagnostics of
the cable. Are the cable shorted, broken, not plugged into anything at
the other end? And they can report roughly how far along the cable any
fault is.
Add infrastructure in ethtool and phylib support for triggering a
cable test and reporting the results. The Marvell 1G PHY driver is
then extended to make use of this infrastructure.
For testing, a modified ethtool(1) can be found here:
https://github.com/lunn/ethtool.git feature/cable-test-v4. This also
contains extra code for TDR dump, which will be added to the kernel in
a later patch series.
Thanks to Chris Healy for extensive testing.
v2:
See individual patches but:
Remove _REPLY messages
Change length into a u32
Grammar fixes
Rename functions for consistency
Extack for cable test already running
Remove ethnl_cable_test_act_ops
Add status attributes
Rename pairs from numbers to letters
v3:
See individual patches but:
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY from documentation
Remove unused cable_test_get_policy
Fixed example in document
Add ETHTOOL_A_CABLE_NEST_* enum
Add ETHTOOL_MSG_CABLE_TEST_NTF to documentation
Poison phydev->skb
Return -EMSGSIZE when ethnl_bcastmsg_put() fails
Return valid error code when nla_nest_start() fails
Use u8 for results
Actually put u32 length into message
s/mavell/marvell/g
Remove include of <uapi/linux/ethtool_netlink.h>
EMSGSIZE when ethnl_bcastmsg_put() fails
Print an error message on failure, since this is a void function.
v4:
See individual patches but:
Remove unwanted blank line
ENOTSUPP->EOPNOTSUPP
Move EINVAL->EMSGSIZE fix to correct patch
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Given that it takes time to run a cable test, send a notify message at
the start, as well as when it is completed.
v3:
EMSGSIZE when ethnl_bcastmsg_put() fails
Print an error message on failure, since this is a void function.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since running a cable test is disruptive, put the interface into
operative state testing while the test is running.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The Marvell PHYs have a couple of different register sets for
performing cable tests. Page 7 provides the simplest to use.
v3:
s/mavell/marvell/g
Remove include of <uapi/linux/ethtool_netlink.h>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The PHY drivers can use these helpers for reporting the results. The
results get translated into netlink attributes which are added to the
pre-allocated skbuf.
v3:
Poison phydev->skb
Return -EMSGSIZE when ethnl_bcastmsg_put() fails
Return valid error code when nla_nest_start() fails
Use u8 for results
Actually put u32 length into message
v4:
s/ENOTSUPP/EOPNOTSUPP/g
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Provide infrastructure for PHY drivers to report the cable test
results. A netlink skb is associated to the phydev. Helpers will be
added which can add results to this skb. Once the test has finished
the results are sent to user space.
When netlink ethtool is not part of the kernel configuration stubs are
provided. It is also impossible to trigger a cable test, so the error
code returned by the alloc function is of no consequence.
v2:
Include the status complete in the netlink notification message
v4:
Replace -EINVAL with -EMSGSIZE
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Make some helpers for building ethtool netlink messages available
outside the compilation unit, so they can be used for building
messages which are not simple get/set.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add the attributes needed to report cable test results to userspace.
The reports are expected to be per twisted pair. A nested property per
pair can report the result of the cable test. A nested property can
also report the length of the cable to any fault.
v2:
Grammar fixes
Change length from u16 to u32
s/DEV/HEADER/g
Add status attributes
Rename pairs from numbers to letters.
v3:
Fixed example in document
Add ETHTOOL_A_CABLE_NEST_* enum
Add ETHTOOL_MSG_CABLE_TEST_NTF to documentation
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add new ethtool netlink calls to trigger the starting of a PHY cable
test.
Add Kconfig'ury to ETHTOOL_NETLINK so that PHYLIB is not a module when
ETHTOOL_NETLINK is builtin, which would result in kernel linking errors.
v2:
Remove unwanted white space change
Remove ethnl_cable_test_act_ops and use doit handler
Rename cable_test_set_policy cable_test_act_policy
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY
v3:
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY from documentation
Remove unused cable_test_get_policy
Add Reviewed-by tags
v4:
Remove unwanted blank line
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some PHYs are not capable of generating interrupts when a cable test
finished. They do however support interrupts for normal operations,
like link up/down. As such, the PHY state machine would normally not
poll the PHY.
Add support for indicating the PHY state machine must poll the PHY
when performing a cable test.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Running a cable test is desruptive to normal operation of the PHY and
can take a 5 to 10 seconds to complete. The RTNL lock cannot be held
for this amount of time, and add a new state to the state machine for
running a cable test.
The driver is expected to implement two functions. The first is used
to start a cable test. Once the test has started, it should return.
The second function is called once per second, or on interrupt to
check if the cable test is complete, and to allow the PHY to report
the status.
v2:
Rename phy_cable_test_abort to phy_abort_cable_test
Return different extack when already running test
Use phy_init_hw() to reset the PHY
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The variable status is being initializeed with a value that is never read
and it is being updated later with a new value. The initialization
is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The variable ret is being initializeed with a value that is never read
and it is being updated later with a new value. The initialization
is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The variable ret is being initializeed with a value that is never read
and it is being updated later with a new value. The initialization
is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In the current codes, the octeontx2 uses its own method to allocate
the pool buffers, but there are some issues in this implementation.
1. We have to run the otx2_get_page() for each allocation cycle and
this is pretty error prone. As I can see there is no invocation
of the otx2_get_page() in otx2_pool_refill_task(), this will leave
the allocated pages have the wrong refcount and may be freed wrongly.
2. It wastes memory. For example, if we only receive one packet in a
NAPI RX cycle, and then allocate a 2K buffer with otx2_alloc_rbuf()
to refill the pool buffers and leave the remain area of the allocated
page wasted. On a kernel with 64K page, 62K area is wasted.
IMHO it is really unnecessary to implement our own method for the
buffers allocate, we can reuse the napi_alloc_frag() to simplify
our code.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
runqslower doesn't specify include path for uapi/bpf.h. This causes the
following warning:
In file included from runqslower.c:10:
.../tools/testing/selftests/bpf/tools/include/bpf/bpf.h:234:38:
warning: 'enum bpf_stats_type' declared inside parameter list will not
be visible outside of this definition or declaration
234 | LIBBPF_API int bpf_enable_stats(enum bpf_stats_type type);
Fix this by adding -I tools/includ/uapi to the Makefile.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yonghong Song says:
====================
Motivation:
The current way to dump kernel data structures mostly:
1. /proc system
2. various specific tools like "ss" which requires kernel support.
3. drgn
The dropback for the first two is that whenever you want to dump more, you
need change the kernel. For example, Martin wants to dump socket local
storage with "ss". Kernel change is needed for it to work ([1]).
This is also the direct motivation for this work.
drgn ([2]) solves this proble nicely and no kernel change is not needed.
But since drgn is not able to verify the validity of a particular pointer value,
it might present the wrong results in rare cases.
In this patch set, we introduce bpf iterator. Initial kernel changes are
still needed for interested kernel data, but a later data structure change
will not require kernel changes any more. bpf program itself can adapt
to new data structure changes. This will give certain flexibility with
guaranteed correctness.
In this patch set, kernel seq_ops is used to facilitate iterating through
kernel data, similar to current /proc and many other lossless kernel
dumping facilities. In the future, different iterators can be
implemented to trade off losslessness for other criteria e.g. no
repeated object visits, etc.
User Interface:
1. Similar to prog/map/link, the iterator can be pinned into a
path within a bpffs mount point.
2. The bpftool command can pin an iterator to a file
bpftool iter pin <bpf_prog.o> <path>
3. Use `cat <path>` to dump the contents.
Use `rm -f <path>` to remove the pinned iterator.
4. The anonymous iterator can be created as well.
Please see patch #19 andd #20 for bpf programs and bpf iterator
output examples.
Note that certain iterators are namespace aware. For example,
task and task_file targets only iterate through current pid namespace.
ipv6_route and netlink will iterate through current net namespace.
Please see individual patches for implementation details.
Performance:
The bpf iterator provides in-kernel aggregation abilities
for kernel data. This can greatly improve performance
compared to e.g., iterating all process directories under /proc.
For example, I did an experiment on my VM with an application forking
different number of tasks and each forked process opening various number
of files. The following is the result with the latency with unit of microseconds:
# of forked tasks # of open files # of bpf_prog calls # latency (us)
100 100 11503 7586
1000 1000 1013203 709513
10000 100 1130203 764519
The number of bpf_prog calls may be more than forked tasks multipled by
open files since there are other tasks running on the system.
The bpf program is a do-nothing program. One millions of bpf calls takes
less than one second.
Although the initial motivation is from Martin's sk_local_storage,
this patch didn't implement tcp6 sockets and sk_local_storage.
The /proc/net/tcp6 involves three types of sockets, timewait,
request and tcp6 sockets. Some kind of type casting or other
mechanism is needed to handle all these socket types in one
bpf program. This will be addressed in future work.
Currently, we do not support kernel data generated under module.
This requires some BTF work.
More work for more iterators, e.g., tcp, udp, bpf_map elements, etc.
Changelog:
v3 -> v4:
- in bpf_seq_read(), if start() failed with an error, return that
error to user space (Andrii)
- in bpf_seq_printf(), if reading kernel memory failed for
%s and %p{i,I}{4,6}, set buffer to empty string or address 0.
Documented this behavior in uapi header (Andrii)
- fix a few error handling issues for bpftool (Andrii)
- A few other minor fixes and cosmetic changes.
v2 -> v3:
- add bpf_iter_unreg_target() to unregister a target, used in the
error path of the __init functions.
- handle err != 0 before handling overflow (Andrii)
- reference count "task" for task_file target (Andrii)
- remove some redundancy for bpf_map/task/task_file targets
- add bpf_iter_unreg_target() in ip6_route_cleanup()
- Handling "%%" format in bpf_seq_printf() (Andrii)
- implement auto-attach for bpf_iter in libbpf (Andrii)
- add macros offsetof and container_of in bpf_helpers.h (Andrii)
- add tests for auto-attach and program-return-1 cases
- some other minor fixes
v1 -> v2:
- removed target_feature, using callback functions instead
- checking target to ensure program specified btf_id supported (Martin)
- link_create change with new changes from Andrii
- better handling of btf_iter vs. seq_file private data (Martin, Andrii)
- implemented bpf_seq_read() (Andrii, Alexei)
- percpu buffer for bpf_seq_printf() (Andrii)
- better syntax for BPF_SEQ_PRINTF macro (Andrii)
- bpftool fixes (Quentin)
- a lot of other fixes
RFC v2 -> v1:
- rename bpfdump to bpf_iter
- use bpffs instead of a new file system
- use bpf_link to streamline and simplify iterator creation.
References:
[1]: https://lore.kernel.org/bpf/20200225230427.1976129-1-kafai@fb.com
[2]: https://github.com/osandov/drgn
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The added test includes the following subtests:
- test verifier change for btf_id_or_null
- test load/create_iter/read for
ipv6_route/netlink/bpf_map/task/task_file
- test anon bpf iterator
- test anon bpf iterator reading one char at a time
- test file bpf iterator
- test overflow (single bpf program output not overflow)
- test overflow (single bpf program output overflows)
- test bpf prog returning 1
The ipv6_route tests the following verifier change
- access fields in the variable length array of the structure.
The netlink load tests the following verifier change
- put a btf_id ptr value in a stack and accessible to
tracing/iter programs.
The anon bpf iterator also tests link auto attach through skeleton.
$ test_progs -n 2
#2/1 btf_id_or_null:OK
#2/2 ipv6_route:OK
#2/3 netlink:OK
#2/4 bpf_map:OK
#2/5 task:OK
#2/6 task_file:OK
#2/7 anon:OK
#2/8 anon-read-one-char:OK
#2/9 file:OK
#2/10 overflow:OK
#2/11 overflow-e2big:OK
#2/12 prog-ret-1:OK
#2 bpf_iter:OK
Summary: 1/12 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175923.2477637-1-yhs@fb.com
The implementation is arbitrary, just to show how the bpf programs
can be written for bpf_map/task/task_file. They can be costomized
for specific needs.
For example, for bpf_map, the iterator prints out:
$ cat /sys/fs/bpf/my_bpf_map
id refcnt usercnt locked_vm
3 2 0 20
6 2 0 20
9 2 0 20
12 2 0 20
13 2 0 20
16 2 0 20
19 2 0 20
%%% END %%%
For task, the iterator prints out:
$ cat /sys/fs/bpf/my_task
tgid gid
1 1
2 2
....
1944 1944
1948 1948
1949 1949
1953 1953
=== END ===
For task/file, the iterator prints out:
$ cat /sys/fs/bpf/my_task_file
tgid gid fd file
1 1 0 ffffffff95c97600
1 1 1 ffffffff95c97600
1 1 2 ffffffff95c97600
....
1895 1895 255 ffffffff95c8fe00
1932 1932 0 ffffffff95c8fe00
1932 1932 1 ffffffff95c8fe00
1932 1932 2 ffffffff95c8fe00
1932 1932 3 ffffffff95c185c0
This is able to print out all open files (fd and file->f_op), so user can compare
f_op against a particular kernel file operations to find what it is.
For example, from /proc/kallsyms, we can find
ffffffff95c185c0 r eventfd_fops
so we will know tgid 1932 fd 3 is an eventfd file descriptor.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175922.2477576-1-yhs@fb.com
Currently, only one command is supported
bpftool iter pin <bpf_prog.o> <path>
It will pin the trace/iter bpf program in
the object file <bpf_prog.o> to the <path>
where <path> should be on a bpffs mount.
For example,
$ bpftool iter pin ./bpf_iter_ipv6_route.o \
/sys/fs/bpf/my_route
User can then do a `cat` to print out the results:
$ cat /sys/fs/bpf/my_route
fe800000000000000000000000000000 40 00000000000000000000000000000000 ...
00000000000000000000000000000000 00 00000000000000000000000000000000 ...
00000000000000000000000000000001 80 00000000000000000000000000000000 ...
fe800000000000008c0162fffebdfd57 80 00000000000000000000000000000000 ...
ff000000000000000000000000000000 08 00000000000000000000000000000000 ...
00000000000000000000000000000000 00 00000000000000000000000000000000 ...
The implementation for ipv6_route iterator is in one of subsequent
patches.
This patch also added BPF_LINK_TYPE_ITER to link query.
In the future, we may add additional parameters to pin command
by parameterizing the bpf iterator. For example, a map_id or pid
may be added to let bpf program only traverses a single map or task,
similar to kernel seq_file single_open().
We may also add introspection command for targets/iterators by
leveraging the bpf_iter itself.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200509175920.2477247-1-yhs@fb.com
These two helpers will be used later in bpf_iter bpf program
bpf_iter_netlink.c. Put them in bpf_helpers.h since they could
be useful in other cases.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175919.2477104-1-yhs@fb.com
Two new libbpf APIs are added to support bpf_iter:
- bpf_program__attach_iter
Given a bpf program and additional parameters, which is
none now, returns a bpf_link.
- bpf_iter_create
syscall level API to create a bpf iterator.
The macro BPF_SEQ_PRINTF are also introduced. The format
looks like:
BPF_SEQ_PRINTF(seq, "task id %d\n", pid);
This macro can help bpf program writers with
nicer bpf_seq_printf syntax similar to the kernel one.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175917.2476936-1-yhs@fb.com
Two helpers bpf_seq_printf and bpf_seq_write, are added for
writing data to the seq_file buffer.
bpf_seq_printf supports common format string flag/width/type
fields so at least I can get identical results for
netlink and ipv6_route targets.
For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW
specifically indicates a write failure due to overflow, which
means the object will be repeated in the next bpf invocation
if object collection stays the same. Note that if the object
collection is changed, depending how collection traversal is
done, even if the object still in the collection, it may not
be visited.
For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to
read kernel memory. Reading kernel memory may fail in
the following two cases:
- invalid kernel address, or
- valid kernel address but requiring a major fault
If reading kernel memory failed, the %s string will be
an empty string and %p{i,I}{4,6} will be all 0.
Not returning error to bpf program is consistent with
what bpf_trace_printk() does for now.
bpf_seq_printf may return -EBUSY meaning that internal percpu
buffer for memory copy of strings or other pointees is
not available. Bpf program can return 1 to indicate it
wants the same object to be repeated. Right now, this should not
happen on no-RT kernels since migrate_disable(), which guards
bpf prog call, calls preempt_disable().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
Add bpf_reg_type PTR_TO_BTF_ID_OR_NULL support.
For tracing/iter program, the bpf program context
definition, e.g., for previous bpf_map target, looks like
struct bpf_iter__bpf_map {
struct bpf_iter_meta *meta;
struct bpf_map *map;
};
The kernel guarantees that meta is not NULL, but
map pointer maybe NULL. The NULL map indicates that all
objects have been traversed, so bpf program can take
proper action, e.g., do final aggregation and/or send
final report to user space.
Add btf_id_or_null_non0_off to prog->aux structure, to
indicate that if the context access offset is not 0,
set to PTR_TO_BTF_ID_OR_NULL instead of PTR_TO_BTF_ID.
This bit is set for tracing/iter program.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175912.2476576-1-yhs@fb.com
Only the tasks belonging to "current" pid namespace
are enumerated.
For task/file target, the bpf program will have access to
struct task_struct *task
u32 fd
struct file *file
where fd/file is an open file for the task.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175911.2476407-1-yhs@fb.com
This patch added netlink and ipv6_route targets, using
the same seq_ops (except show() and minor changes for stop())
for /proc/net/{netlink,ipv6_route}.
The net namespace for these targets are the current net
namespace at file open stage, similar to
/proc/net/{netlink,ipv6_route} reference counting
the net namespace at seq_file open stage.
Since module is not supported for now, ipv6_route is
supported only if the IPV6 is built-in, i.e., not compiled
as a module. The restriction can be lifted once module
is properly supported for bpf_iter.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com
Macro DEFINE_BPF_ITER_FUNC is implemented so target
can define an init function to capture the BTF type
which represents the target.
The bpf_iter_meta is a structure holding meta data, common
to all targets in the bpf program.
Additional marker functions are called before or after
bpf_seq_read() show()/next()/stop() callback functions
to help calculate precise seq_num and whether call bpf_prog
inside stop().
Two functions, bpf_iter_get_info() and bpf_iter_run_prog(),
are implemented so target can get needed information from
bpf_iter infrastructure and can run the program.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175907.2475956-1-yhs@fb.com
To produce a file bpf iterator, the fd must be
corresponding to a link_fd assocciated with a
trace/iter program. When the pinned file is
opened, a seq_file will be generated.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175906.2475893-1-yhs@fb.com
A new bpf command BPF_ITER_CREATE is added.
The anonymous bpf iterator is seq_file based.
The seq_file private data are referenced by targets.
The bpf_iter infrastructure allocated additional space
at seq_file->private before the space used by targets
to store some meta data, e.g.,
prog: prog to run
session_id: an unique id for each opened seq_file
seq_num: how many times bpf programs are queried in this session
done_stop: an internal state to decide whether bpf program
should be called in seq_ops->stop() or not
The seq_num will start from 0 for valid objects.
The bpf program may see the same seq_num more than once if
- seq_file buffer overflow happens and the same object
is retried by bpf_seq_read(), or
- the bpf program explicitly requests a retry of the
same object
Since module is not supported for bpf_iter, all target
registeration happens at __init time, so there is no
need to change bpf_iter_unreg_target() as it is used
mostly in error path of the init function at which time
no bpf iterators have been created yet.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175905.2475770-1-yhs@fb.com
bpf iterator uses seq_file to provide a lossless
way to transfer data to user space. But we want to call
bpf program after all objects have been traversed, and
bpf program may write additional data to the
seq_file buffer. The current seq_read() does not work
for this use case.
Besides allowing stop() function to write to the buffer,
the bpf_seq_read() also fixed the buffer size to one page.
If any single call of show() or stop() will emit data
more than one page to cause overflow, -E2BIG error code
will be returned to user space.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175904.2475468-1-yhs@fb.com
Added BPF_LINK_UPDATE support for tracing/iter programs.
This way, a file based bpf iterator, which holds a reference
to the link, can have its bpf program updated without
creating new files.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175902.2475262-1-yhs@fb.com
