While the man page usbipd.8 already informs the user on which
kernel module has to be used on server side, the man page usbip.8
does not provide any equivalent information on client side.
Also, it could be hard for a newbie to identify the proper usbip
client kernel module, due to the name "vhci-hcd" that has no
immediate assonance with usbip.
Add in usbip.8 the command to add the module vhci-hcd, similarly
as it's already present in usbipd.8 for usbip-host.
While there, rephrase the description of the command "usbip list
--remote=server".
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
--
v1->v2: rephrase the description of command "usbip list ..."
fix a typo in commit message
Link: https://lore.kernel.org/r/2da8fc9e34440c1fa5f9007baaa3921767cdec50.1593090874.git.borneo.antonio@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, if the kernel is configured incorrectly or if it crashes before any
kunit tests are run, kunit finishes without error, reporting
that 0 test cases were run.
To fix this, an error is shown when the tap header is not found, which
indicates that kunit was not able to run at all.
Signed-off-by: Uriel Guajardo <urielguajardo@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Commit 8b59cd81dc ("kbuild: ensure full rebuild when the compiler is
updated") introduced a new CONFIG option CONFIG_CC_VERSION_TEXT. On my
system, this is set to "gcc (GCC) 10.1.0" which breaks KUnit config
parsing which did not like the spaces in the string.
Fix this by updating the regex to allow strings containing spaces.
Fixes: 8b59cd81dc ("kbuild: ensure full rebuild when the compiler is updated")
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Changeset 1eecbcdca2 ("docs: move protection-keys.rst to the core-api book")
from Jun 7, 2019 converted protection-keys.txt file to ReST.
A recent change at protection_keys.c partially reverted such
changeset, causing it to point to a non-existing file:
- * Tests x86 Memory Protection Keys (see Documentation/core-api/protection-keys.rst)
+ * Tests Memory Protection Keys (see Documentation/vm/protection-keys.txt)
It sounds to me that the changeset that introduced such change
4645e3563673 ("selftests/vm/pkeys: rename all references to pkru to a generic name")
could also have other side effects, as it sounds that it was not
generated against uptream code, but, instead, against a version
older than Jun 7, 2019.
Fixes: 4645e3563673 ("selftests/vm/pkeys: rename all references to pkru to a generic name")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/cf65aa052669f55b9dc976a5c8026aef5840741d.1592895969.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
We use OUTPUT directory as TMPOUT for checking no-pie option.
Since commit f2f02ebd8f ("kbuild: improve cc-option to clean up all
temporary files") when building powerpc/ from selftests directory, the
OUTPUT directory points to powerpc/pmu/ebb/ and gets removed when
checking for -no-pie option in try-run routine, subsequently build
fails with the following:
$ make -C powerpc
...
TARGET=ebb; BUILD_TARGET=$OUTPUT/$TARGET; mkdir -p $BUILD_TARGET; make OUTPUT=$BUILD_TARGET -k -C $TARGET all
make[2]: Entering directory '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb'
make[2]: *** No rule to make target 'Makefile'.
make[2]: Failed to remake makefile 'Makefile'.
make[2]: *** No rule to make target 'ebb.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: *** No rule to make target 'ebb_handler.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: *** No rule to make target 'trace.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: *** No rule to make target 'busy_loop.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: Target 'all' not remade because of errors.
Fix this by adding a suffix to the OUTPUT directory so that the
failure is avoided.
Fixes: 9686813f6e ("selftests/powerpc: Fix try-run when source tree is not writable")
Signed-off-by: Harish <harish@linux.ibm.com>
[mpe: Mention that commit that triggered the breakage]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200625165721.264904-1-harish@linux.ibm.com
Minor overlapping changes in xfrm_device.c, between the double
ESP trailing bug fix setting the XFRM_INIT flag and the changes
in net-next preparing for bonding encryption support.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Don't insert ESP trailer twice in IPSEC code, from Huy Nguyen.
2) The default crypto algorithm selection in Kconfig for IPSEC is out
of touch with modern reality, fix this up. From Eric Biggers.
3) bpftool is missing an entry for BPF_MAP_TYPE_RINGBUF, from Andrii
Nakryiko.
4) Missing init of ->frame_sz in xdp_convert_zc_to_xdp_frame(), from
Hangbin Liu.
5) Adjust packet alignment handling in ax88179_178a driver to match
what the hardware actually does. From Jeremy Kerr.
6) register_netdevice can leak in the case one of the notifiers fail,
from Yang Yingliang.
7) Use after free in ip_tunnel_lookup(), from Taehee Yoo.
8) VLAN checks in sja1105 DSA driver need adjustments, from Vladimir
Oltean.
9) tg3 driver can sleep forever when we get enough EEH errors, fix from
David Christensen.
10) Missing {READ,WRITE}_ONCE() annotations in various Intel ethernet
drivers, from Ciara Loftus.
11) Fix scanning loop break condition in of_mdiobus_register(), from
Florian Fainelli.
12) MTU limit is incorrect in ibmveth driver, from Thomas Falcon.
13) Endianness fix in mlxsw, from Ido Schimmel.
14) Use after free in smsc95xx usbnet driver, from Tuomas Tynkkynen.
15) Missing bridge mrp configuration validation, from Horatiu Vultur.
16) Fix circular netns references in wireguard, from Jason A. Donenfeld.
17) PTP initialization on recovery is not done properly in qed driver,
from Alexander Lobakin.
18) Endian conversion of L4 ports in filters of cxgb4 driver is wrong,
from Rahul Lakkireddy.
19) Don't clear bound device TX queue of socket prematurely otherwise we
get problems with ktls hw offloading, from Tariq Toukan.
20) ipset can do atomics on unaligned memory, fix from Russell King.
21) Align ethernet addresses properly in bridging code, from Thomas
Martitz.
22) Don't advertise ipv4 addresses on SCTP sockets having ipv6only set,
from Marcelo Ricardo Leitner.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (149 commits)
rds: transport module should be auto loaded when transport is set
sch_cake: fix a few style nits
sch_cake: don't call diffserv parsing code when it is not needed
sch_cake: don't try to reallocate or unshare skb unconditionally
ethtool: fix error handling in linkstate_prepare_data()
wil6210: account for napi_gro_receive never returning GRO_DROP
hns: do not cast return value of napi_gro_receive to null
socionext: account for napi_gro_receive never returning GRO_DROP
wireguard: receive: account for napi_gro_receive never returning GRO_DROP
vxlan: fix last fdb index during dump of fdb with nhid
sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket
tc-testing: avoid action cookies with odd length.
bpf: tcp: bpf_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT
tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT
net: dsa: sja1105: fix tc-gate schedule with single element
net: dsa: sja1105: recalculate gating subschedule after deleting tc-gate rules
net: dsa: sja1105: unconditionally free old gating config
net: dsa: sja1105: move sja1105_compose_gating_subschedule at the top
net: macb: free resources on failure path of at91ether_open()
net: macb: call pm_runtime_put_sync on failure path
...
Update odd length cookie hexstrings in csum.json, tunnel_key.json and
bpf.json to be even length to comply with check enforced in commit
0149dabf2a1b ("tc: m_actions: check cookie hexstring len") in iproute2.
Signed-off-by: Briana Oursler <briana.oursler@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Apply the fix from:
"tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT"
to the BPF implementation of TCP CUBIC congestion control.
Repeating the commit description here for completeness:
Mirja Kuehlewind reported a bug in Linux TCP CUBIC Hystart, where
Hystart HYSTART_DELAY mechanism can exit Slow Start spuriously on an
ACK when the minimum rtt of a connection goes down. From inspection it
is clear from the existing code that this could happen in an example
like the following:
o The first 8 RTT samples in a round trip are 150ms, resulting in a
curr_rtt of 150ms and a delay_min of 150ms.
o The 9th RTT sample is 100ms. The curr_rtt does not change after the
first 8 samples, so curr_rtt remains 150ms. But delay_min can be
lowered at any time, so delay_min falls to 100ms. The code executes
the HYSTART_DELAY comparison between curr_rtt of 150ms and delay_min
of 100ms, and the curr_rtt is declared far enough above delay_min to
force a (spurious) exit of Slow start.
The fix here is simple: allow every RTT sample in a round trip to
lower the curr_rtt.
Fixes: 6de4a9c430 ("bpf: tcp: Add bpf_cubic example")
Reported-by: Mirja Kuehlewind <mirja.kuehlewind@ericsson.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net, they are:
1) Unaligned atomic access in ipset, from Russell King.
2) Missing module description, from Rob Gill.
3) Patches to fix a module unload causing NULL pointer dereference in
xtables, from David Wilder. For the record, I posting here his cover
letter explaining the problem:
A crash happened on ppc64le when running ltp network tests triggered by
"rmmod iptable_mangle".
See previous discussion in this thread:
https://lists.openwall.net/netdev/2020/06/03/161 .
In the crash I found in iptable_mangle_hook() that
state->net->ipv4.iptable_mangle=NULL causing a NULL pointer dereference.
net->ipv4.iptable_mangle is set to NULL in +iptable_mangle_net_exit() and
called when ip_mangle modules is unloaded. A rmmod task was found running
in the crash dump. A 2nd crash showed the same problem when running
"rmmod iptable_filter" (net->ipv4.iptable_filter=NULL).
To fix this I added .pre_exit hook in all iptable_foo.c. The pre_exit will
un-register the underlying hook and exit would do the table freeing. The
netns core does an unconditional +synchronize_rcu after the pre_exit hooks
insuring no packets are in flight that have picked up the pointer before
completing the un-register.
These patches include changes for both iptables and ip6tables.
We tested this fix with ltp running iptables01.sh and iptables01.sh -6 a
loop for 72 hours.
4) Add a selftest for conntrack helper assignment, from Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Define attach_type_name in common.c instead of main.h so it is only
defined once. This leads to a slight decrease in the binary size of
bpftool.
Before:
text data bss dec hex filename
399024 11168 1573160 1983352 1e4378 bpftool
After:
text data bss dec hex filename
398256 10880 1573160 1982296 1e3f58 bpftool
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200624143154.13145-1-tklauser@distanz.ch
Define prog_type_name in prog.c instead of main.h so it is only defined
once. This leads to a slight decrease in the binary size of bpftool.
Before:
text data bss dec hex filename
401032 11936 1573160 1986128 1e4e50 bpftool
After:
text data bss dec hex filename
399024 11168 1573160 1983352 1e4378 bpftool
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200624143124.12914-1-tklauser@distanz.ch
Refactor bpf_iter_ipv6_route.c and bpf_iter_netlink.c
so net macros, originally from various include/linux header
files, are moved to a new header file
bpf_tracing_net.h. The goal is to improve reuse so
networking tracing programs do not need to
copy these macros every time they use them.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230817.3988962-1-yhs@fb.com
Commit b9f4c01f3e ("selftest/bpf: Make bpf_iter selftest
compilable against old vmlinux.h") and Commit dda18a5c0b
("selftests/bpf: Convert bpf_iter_test_kern{3, 4}.c to define
own bpf_iter_meta") redefined newly introduced types
in bpf programs so the bpf program can still compile
properly with old kernels although loading may fail.
Since this patch set introduced new types and the same
workaround is needed, so let us move the workaround
to a separate header file so they do not clutter
bpf programs.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230816.3988656-1-yhs@fb.com
The helper is used in tracing programs to cast a socket
pointer to a tcp6_sock pointer.
The return value could be NULL if the casting is illegal.
A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added
so the verifier is able to deduce proper return types for the helper.
Different from the previous BTF_ID based helpers,
the bpf_skc_to_tcp6_sock() argument can be several possible
btf_ids. More specifically, all possible socket data structures
with sock_common appearing in the first in the memory layout.
This patch only added socket types related to tcp and udp.
All possible argument btf_id and return value btf_id
for helper bpf_skc_to_tcp6_sock() are pre-calculcated and
cached. In the future, it is even possible to precompute
these btf_id's at kernel build time.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com
check that 'nft ... ct helper set <foo>' works:
1. configure ftp helper via nft and assign it to
connections on port 2121
2. check with 'conntrack -L' that the next connection
has the ftp helper attached to it.
Also add a test for auto-assign (old behaviour).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pull virtio fixes from Michael Tsirkin:
"Fixes all over the place.
This includes a couple of tests that I would normally defer, but since
they have already been helpful in catching some bugs, don't build for
any users at all, and having them upstream makes life easier for
everyone, I think it's ok even at this late stage"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
tools/virtio: Use tools/include/list.h instead of stubs
tools/virtio: Reset index in virtio_test --reset.
tools/virtio: Extract virtqueue initialization in vq_reset
tools/virtio: Use __vring_new_virtqueue in virtio_test.c
tools/virtio: Add --reset
tools/virtio: Add --batch=random option
tools/virtio: Add --batch option
virtio-mem: add memory via add_memory_driver_managed()
virtio-mem: silence a static checker warning
vhost_vdpa: Fix potential underflow in vhost_vdpa_mmap()
vdpa: fix typos in the comments for __vdpa_alloc_device()
Pull thread fix from Christian Brauner:
"This fixes a regression introduced with 303cc571d1 ("nsproxy: attach
to namespaces via pidfds").
The LTP testsuite reported a regression where users would now see
EBADF returned instead of EINVAL when an fd was passed that referred
to an open file but the file was not a namespace file.
Fix this by continuing to report EINVAL and add a regression test"
* tag 'for-linus-2020-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
tests: test for setns() EINVAL regression
nsproxy: restore EINVAL for non-namespace file descriptor
This patch adds support of SO_KEEPALIVE flag and TCP related options
to bpf_setsockopt() routine. This is helpful if we want to enable or tune
TCP keepalive for applications which don't do it in the userspace code.
v3:
- update kernel-doc in uapi (Nikita Vetoshkin <nekto0n@yandex-team.ru>)
v4:
- update kernel-doc in tools too (Alexei Starovoitov)
- add test to selftests (Alexei Starovoitov)
Signed-off-by: Dmitry Yakunin <zeil@yandex-team.ru>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200620153052.9439-3-zeil@yandex-team.ru
./test_progs-no_alu32 -t get_stack_raw_tp
fails due to:
52: (85) call bpf_get_stack#67
53: (bf) r8 = r0
54: (bf) r1 = r8
55: (67) r1 <<= 32
56: (c7) r1 s>>= 32
; if (usize < 0)
57: (c5) if r1 s< 0x0 goto pc+26
R0=inv(id=0,smax_value=800) R1_w=inv(id=0,umax_value=800,var_off=(0x0; 0x3ff)) R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R8_w=inv(id=0,smax_value=800) R9=inv800
; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
58: (1f) r9 -= r8
; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
59: (bf) r2 = r7
60: (0f) r2 += r1
regs=1 stack=0 before 52: (85) call bpf_get_stack#67
; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
61: (bf) r1 = r6
62: (bf) r3 = r9
63: (b7) r4 = 0
64: (85) call bpf_get_stack#67
R0=inv(id=0,smax_value=800) R1_w=ctx(id=0,off=0,imm=0) R2_w=map_value(id=0,off=0,ks=4,vs=1600,umax_value=800,var_off=(0x0; 0x3ff),s32_max_value=1023,u32_max_value=1023) R3_w=inv(id=0,umax_value=9223372036854776608)
R3 unbounded memory access, use 'var &= const' or 'if (var < const)'
In the C code:
usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
if (usize < 0)
return 0;
ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
if (ksize < 0)
return 0;
We used to have problem with pointer arith in R2.
Now it's a problem with two integers in R3.
'if (usize < 0)' is comparing R1 and makes it [0,800], but R8 stays [-inf,800].
Both registers represent the same 'usize' variable.
Then R9 -= R8 is doing 800 - [-inf, 800]
so the result of "max_len - usize" looks unbounded to the verifier while
it's obvious in C code that "max_len - usize" should be [0, 800].
To workaround the problem convert ksize and usize variables from int to long.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Building bpftool yields the following complaint:
pids.c: In function 'emit_obj_refs_json':
pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow]
175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
| ~~~~~~~~~~~~~~~^~~~~~~~
In file included from pids.c:11:
main.h:141:23: note: shadowed declaration is here
141 | extern json_writer_t *json_wtr;
| ^~~~~~~~
Let's rename the variable.
v2:
- Rename the variable instead of calling the global json_wtr directly.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200623213600.16643-1-quentin@isovalent.com
The arm64 signal tests generate warnings during build since both they and
the toplevel lib.mk define a clean target:
Makefile:25: warning: overriding recipe for target 'clean'
../../lib.mk:126: warning: ignoring old recipe for target 'clean'
Since the inclusion of lib.mk is in the signal Makefile there is no
situation where this warning could be avoided so just remove the redundant
clean target.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200624104933.21125-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Run rxtimestamp as part of TEST_PROGS. Analogous to other tests, add
new rxtimestamp.sh wrapper script, so that the test runs isolated
from background traffic in a private network namespace.
Also ignore failures of test case #6 by default. This case verifies
that a receive timestamp is not reported if timestamp reporting is
enabled for a socket, but generation is disabled. Receive timestamp
generation has to be enabled globally, as no associated socket is
known yet. A background process that enables rx timestamp generation
therefore causes a false positive. Ntpd is one example that does.
Add a "--strict" option to cause failure in the event that any test
case fails, including test #6. This is useful for environments that
are known to not have such background processes.
Tested:
make -C tools/testing/selftests TARGETS="net" run_tests
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When producing the bpf-helpers.7 man page from the documentation from
the BPF user space header file, rst2man complains:
<stdin>:2636: (ERROR/3) Unexpected indentation.
<stdin>:2640: (WARNING/2) Block quote ends without a blank line; unexpected unindent.
Let's fix formatting for the relevant chunk (item list in
bpf_ringbuf_query()'s description), and for a couple other functions.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200623153935.6215-1-quentin@isovalent.com
bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't
return .text "BPF program", if it is a function storage for sub-programs.
Because of that, any CO-RE relocation in helper non-inlined functions will
fail. Fix this by searching for .text-corresponding BPF program manually.
Adjust one of bpf_iter selftest to exhibit this pattern.
Fixes: ddc7c30426 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200619230423.691274-1-andriin@fb.com
Currently, if the clang-bpf-co-re feature is not available, the build
fails with e.g.
CC prog.o
prog.c:1462:10: fatal error: profiler.skel.h: No such file or directory
1462 | #include "profiler.skel.h"
| ^~~~~~~~~~~~~~~~~
This is due to the fact that the BPFTOOL_WITHOUT_SKELETONS macro is not
defined, despite BUILD_BPF_SKELS not being set. Fix this by correctly
evaluating $(BUILD_BPF_SKELS) when deciding on whether to add
-DBPFTOOL_WITHOUT_SKELETONS to CFLAGS.
Fixes: 05aca6da3b ("tools/bpftool: Generalize BPF skeleton support and generate vmlinux.h")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200623103710.10370-1-tklauser@distanz.ch
Extend original variable-length tests with a case to catch a common
existing pattern of testing for < 0 for errors. Note because
verifier also tracks upper bounds and we know it can not be greater
than MAX_LEN here we can skip upper bound check.
In ALU64 enabled compilation converting from long->int return types
in probe helpers results in extra instruction pattern, <<= 32, s >>= 32.
The trade-off is the non-ALU64 case works. If you really care about
every extra insn (XDP case?) then you probably should be using original
int type.
In addition adding a sext insn to bpf might help the verifier in the
general case to avoid these types of tricks.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200623032224.4020118-3-andriin@fb.com
Add selftest that validates variable-length data reading and concatentation
with one big shared data array. This is a common pattern in production use for
monitoring and tracing applications, that potentially can read a lot of data,
but overall read much less. Such pattern allows to determine precisely what
amount of data needs to be sent over perfbuf/ringbuf and maximize efficiency.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200623032224.4020118-2-andriin@fb.com
Switch most of BPF helper definitions from returning int to long. These
definitions are coming from comments in BPF UAPI header and are used to
generate bpf_helper_defs.h (under libbpf) to be later included and used from
BPF programs.
In actual in-kernel implementation, all the helpers are defined as returning
u64, but due to some historical reasons, most of them are actually defined as
returning int in UAPI (usually, to return 0 on success, and negative value on
error).
This actually causes Clang to quite often generate sub-optimal code, because
compiler believes that return value is 32-bit, and in a lot of cases has to be
up-converted (usually with a pair of 32-bit bit shifts) to 64-bit values,
before they can be used further in BPF code.
Besides just "polluting" the code, these 32-bit shifts quite often cause
problems for cases in which return value matters. This is especially the case
for the family of bpf_probe_read_str() functions. There are few other similar
helpers (e.g., bpf_read_branch_records()), in which return value is used by
BPF program logic to record variable-length data and process it. For such
cases, BPF program logic carefully manages offsets within some array or map to
read variable-length data. For such uses, it's crucial for BPF verifier to
track possible range of register values to prove that all the accesses happen
within given memory bounds. Those extraneous zero-extending bit shifts,
inserted by Clang (and quite often interleaved with other code, which makes
the issues even more challenging and sometimes requires employing extra
per-variable compiler barriers), throws off verifier logic and makes it mark
registers as having unknown variable offset. We'll study this pattern a bit
later below.
Another common pattern is to check return of BPF helper for non-zero state to
detect error conditions and attempt alternative actions in such case. Even in
this simple and straightforward case, this 32-bit vs BPF's native 64-bit mode
quite often leads to sub-optimal and unnecessary extra code. We'll look at
this pattern as well.
Clang's BPF target supports two modes of code generation: ALU32, in which it
is capable of using lower 32-bit parts of registers, and no-ALU32, in which
only full 64-bit registers are being used. ALU32 mode somewhat mitigates the
above described problems, but not in all cases.
This patch switches all the cases in which BPF helpers return 0 or negative
error from returning int to returning long. It is shown below that such change
in definition leads to equivalent or better code. No-ALU32 mode benefits more,
but ALU32 mode doesn't degrade or still gets improved code generation.
Another class of cases switched from int to long are bpf_probe_read_str()-like
helpers, which encode successful case as non-negative values, while still
returning negative value for errors.
In all of such cases, correctness is preserved due to two's complement
encoding of negative values and the fact that all helpers return values with
32-bit absolute value. Two's complement ensures that for negative values
higher 32 bits are all ones and when truncated, leave valid negative 32-bit
value with the same value. Non-negative values have upper 32 bits set to zero
and similarly preserve value when high 32 bits are truncated. This means that
just casting to int/u32 is correct and efficient (and in ALU32 mode doesn't
require any extra shifts).
To minimize the chances of regressions, two code patterns were investigated,
as mentioned above. For both patterns, BPF assembly was analyzed in
ALU32/NO-ALU32 compiler modes, both with current 32-bit int return type and
new 64-bit long return type.
Case 1. Variable-length data reading and concatenation. This is quite
ubiquitous pattern in tracing/monitoring applications, reading data like
process's environment variables, file path, etc. In such case, many pieces of
string-like variable-length data are read into a single big buffer, and at the
end of the process, only a part of array containing actual data is sent to
user-space for further processing. This case is tested in test_varlen.c
selftest (in the next patch). Code flow is roughly as follows:
void *payload = &sample->payload;
u64 len;
len = bpf_probe_read_kernel_str(payload, MAX_SZ1, &source_data1);
if (len <= MAX_SZ1) {
payload += len;
sample->len1 = len;
}
len = bpf_probe_read_kernel_str(payload, MAX_SZ2, &source_data2);
if (len <= MAX_SZ2) {
payload += len;
sample->len2 = len;
}
/* and so on */
sample->total_len = payload - &sample->payload;
/* send over, e.g., perf buffer */
There could be two variations with slightly different code generated: when len
is 64-bit integer and when it is 32-bit integer. Both variations were analysed.
BPF assembly instructions between two successive invocations of
bpf_probe_read_kernel_str() were used to check code regressions. Results are
below, followed by short analysis. Left side is using helpers with int return
type, the right one is after the switch to long.
ALU32 + INT ALU32 + LONG
=========== ============
64-BIT (13 insns): 64-BIT (10 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: if w0 > 256 goto +9 <LBB0_4> 18: if r0 > 256 goto +6 <LBB0_4>
19: w1 = w0 19: r1 = 0 ll
20: r1 <<= 32 21: *(u64 *)(r1 + 0) = r0
21: r1 s>>= 32 22: r6 = 0 ll
22: r2 = 0 ll 24: r6 += r0
24: *(u64 *)(r2 + 0) = r1 00000000000000c8 <LBB0_4>:
25: r6 = 0 ll 25: r1 = r6
27: r6 += r1 26: w2 = 256
00000000000000e0 <LBB0_4>: 27: r3 = 0 ll
28: r1 = r6 29: call 115
29: w2 = 256
30: r3 = 0 ll
32: call 115
32-BIT (11 insns): 32-BIT (12 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: if w0 > 256 goto +7 <LBB1_4> 18: if w0 > 256 goto +8 <LBB1_4>
19: r1 = 0 ll 19: r1 = 0 ll
21: *(u32 *)(r1 + 0) = r0 21: *(u32 *)(r1 + 0) = r0
22: w1 = w0 22: r0 <<= 32
23: r6 = 0 ll 23: r0 >>= 32
25: r6 += r1 24: r6 = 0 ll
00000000000000d0 <LBB1_4>: 26: r6 += r0
26: r1 = r6 00000000000000d8 <LBB1_4>:
27: w2 = 256 27: r1 = r6
28: r3 = 0 ll 28: w2 = 256
30: call 115 29: r3 = 0 ll
31: call 115
In ALU32 mode, the variant using 64-bit length variable clearly wins and
avoids unnecessary zero-extension bit shifts. In practice, this is even more
important and good, because BPF code won't need to do extra checks to "prove"
that payload/len are within good bounds.
32-bit len is one instruction longer. Clang decided to do 64-to-32 casting
with two bit shifts, instead of equivalent `w1 = w0` assignment. The former
uses extra register. The latter might potentially lose some range information,
but not for 32-bit value. So in this case, verifier infers that r0 is [0, 256]
after check at 18:, and shifting 32 bits left/right keeps that range intact.
We should probably look into Clang's logic and see why it chooses bitshifts
over sub-register assignments for this.
NO-ALU32 + INT NO-ALU32 + LONG
============== ===============
64-BIT (14 insns): 64-BIT (10 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: r0 <<= 32 18: if r0 > 256 goto +6 <LBB0_4>
19: r1 = r0 19: r1 = 0 ll
20: r1 >>= 32 21: *(u64 *)(r1 + 0) = r0
21: if r1 > 256 goto +7 <LBB0_4> 22: r6 = 0 ll
22: r0 s>>= 32 24: r6 += r0
23: r1 = 0 ll 00000000000000c8 <LBB0_4>:
25: *(u64 *)(r1 + 0) = r0 25: r1 = r6
26: r6 = 0 ll 26: r2 = 256
28: r6 += r0 27: r3 = 0 ll
00000000000000e8 <LBB0_4>: 29: call 115
29: r1 = r6
30: r2 = 256
31: r3 = 0 ll
33: call 115
32-BIT (13 insns): 32-BIT (13 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: r1 = r0 18: r1 = r0
19: r1 <<= 32 19: r1 <<= 32
20: r1 >>= 32 20: r1 >>= 32
21: if r1 > 256 goto +6 <LBB1_4> 21: if r1 > 256 goto +6 <LBB1_4>
22: r2 = 0 ll 22: r2 = 0 ll
24: *(u32 *)(r2 + 0) = r0 24: *(u32 *)(r2 + 0) = r0
25: r6 = 0 ll 25: r6 = 0 ll
27: r6 += r1 27: r6 += r1
00000000000000e0 <LBB1_4>: 00000000000000e0 <LBB1_4>:
28: r1 = r6 28: r1 = r6
29: r2 = 256 29: r2 = 256
30: r3 = 0 ll 30: r3 = 0 ll
32: call 115 32: call 115
In NO-ALU32 mode, for the case of 64-bit len variable, Clang generates much
superior code, as expected, eliminating unnecessary bit shifts. For 32-bit
len, code is identical.
So overall, only ALU-32 32-bit len case is more-or-less equivalent and the
difference stems from internal Clang decision, rather than compiler lacking
enough information about types.
Case 2. Let's look at the simpler case of checking return result of BPF helper
for errors. The code is very simple:
long bla;
if (bpf_probe_read_kenerl(&bla, sizeof(bla), 0))
return 1;
else
return 0;
ALU32 + CHECK (9 insns) ALU32 + CHECK (9 insns)
==================================== ====================================
0: r1 = r10 0: r1 = r10
1: r1 += -8 1: r1 += -8
2: w2 = 8 2: w2 = 8
3: r3 = 0 3: r3 = 0
4: call 113 4: call 113
5: w1 = w0 5: r1 = r0
6: w0 = 1 6: w0 = 1
7: if w1 != 0 goto +1 <LBB2_2> 7: if r1 != 0 goto +1 <LBB2_2>
8: w0 = 0 8: w0 = 0
0000000000000048 <LBB2_2>: 0000000000000048 <LBB2_2>:
9: exit 9: exit
Almost identical code, the only difference is the use of full register
assignment (r1 = r0) vs half-registers (w1 = w0) in instruction #5. On 32-bit
architectures, new BPF assembly might be slightly less optimal, in theory. But
one can argue that's not a big issue, given that use of full registers is
still prevalent (e.g., for parameter passing).
NO-ALU32 + CHECK (11 insns) NO-ALU32 + CHECK (9 insns)
==================================== ====================================
0: r1 = r10 0: r1 = r10
1: r1 += -8 1: r1 += -8
2: r2 = 8 2: r2 = 8
3: r3 = 0 3: r3 = 0
4: call 113 4: call 113
5: r1 = r0 5: r1 = r0
6: r1 <<= 32 6: r0 = 1
7: r1 >>= 32 7: if r1 != 0 goto +1 <LBB2_2>
8: r0 = 1 8: r0 = 0
9: if r1 != 0 goto +1 <LBB2_2> 0000000000000048 <LBB2_2>:
10: r0 = 0 9: exit
0000000000000058 <LBB2_2>:
11: exit
NO-ALU32 is a clear improvement, getting rid of unnecessary zero-extension bit
shifts.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200623032224.4020118-1-andriin@fb.com
Before, we took a reference to the creating netns if the new netns was
different. This caused issues with circular references, with two
wireguard interfaces swapping namespaces. The solution is to rather not
take any extra references at all, but instead simply invalidate the
creating netns pointer when that netns is deleted.
In order to prevent this from happening again, this commit improves the
rough object leak tracking by allowing it to account for created and
destroyed interfaces, aside from just peers and keys. That then makes it
possible to check for the object leak when having two interfaces take a
reference to each others' namespaces.
Fixes: e7096c131e ("net: WireGuard secure network tunnel")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These will break the build as soon as we stop disabling all warnings
when building flex and bison generated files, so add them before we do
that to keep the tree bisectable.
Noticed when building on centos:7 with NO_LIBBPF=1:
util/expr.c: In function 'key_equal':
util/expr.c:29:2: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
return !strcmp((const char *)key1, (const char *)key2);
^
util/expr.c: In function 'expr__add_id':
util/expr.c:40:3: error: implicit declaration of function 'malloc' [-Werror=implicit-function-declaration]
val_ptr = malloc(sizeof(double));
^
util/expr.c:40:13: error: incompatible implicit declaration of built-in function 'malloc' [-Werror]
val_ptr = malloc(sizeof(double));
^
util/expr.c:42:12: error: 'ENOMEM' undeclared (first use in this function)
return -ENOMEM;
^
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
