Compiling rxtimestamp.c generates error messages due to
non-existing declaration for write() library call.
Add missing unistd.h include to provide the declaration and
silence the error.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull perf fixes from Thomas Gleixner:
"A pile of perf updates:
- Fix broken sanity check in the /proc/sys/kernel/perf_cpu_time_max_percent
write handler
- Cure a perf script crash which caused by an unitinialized data
structure
- Highlight the hottest instruction in perf top and not a random one
- Cure yet another clang issue when building perf python
- Handle topology entries with no CPU correctly in the tools
- Handle perf data which contains both tracepoints and performance
counter entries correctly.
- Add a missing NULL pointer check in perf ordered_events_free()"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf script: Fix crash when processing recorded stat data
perf top: Fix wrong hottest instruction highlighted
perf tools: Handle TOPOLOGY headers with no CPU
perf python: Remove -fstack-clash-protection when building with some clang versions
perf core: Fix perf_proc_update_handler() bug
perf script: Fix crash with printing mixed trace point and other events
perf ordered_events: Fix crash in ordered_events__free
Jonathan writes:
First set of IIO fixes for the 5.0 cycle.
Been a busy month, so these are rather later than they should have been.
* atlas-ph-sensor:
- Temperature scale didn't correspond to the ABI.
* axp288:
- A few different fixes around the TS-pin handling.
* ti-ads8688
- Not enough space in the buffer used to build the scan to allow for
the timestamp.
* tools - iio_generic_buffer
- Make num_loops signed so that we really are running for ever
rather than just a long time when we specify -1.
* tag 'iio-fixes-5.0a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
iio: ti-ads8688: Update buffer allocation for timestamps
tools: iio: iio_generic_buffer: make num_loops signed
iio: adc: axp288: Fix TS-pin handling
iio: chemical: atlas-ph-sensor: correct IIO_TEMP values to millicelsius
Alexei Starovoitov says:
====================
pull-request: bpf-next 2019-02-01
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) introduce bpf_spin_lock, from Alexei.
2) convert xdp samples to libbpf, from Maciej.
3) skip verifier tests for unsupported program/map types, from Stanislav.
4) powerpc64 JIT support for BTF line info, from Sandipan.
5) assorted fixed, from Valdis, Jesper, Jiong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei Starovoitov says:
====================
pull-request: bpf 2019-01-31
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) disable preemption in sender side of socket filters, from Alexei.
2) fix two potential deadlocks in syscall bpf lookup and prog_register,
from Martin and Alexei.
3) fix BTF to allow typedef on func_proto, from Yonghong.
4) two bpftool fixes, from Jiri and Paolo.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The global variable RET needs to be initialized before each call to
log_test. This test case sets it once before running the tests, but then
calls log_tests for every individual test. Thus a failure in one of the
tests causes spurious failures in follow-up tests as well.
Fix by moving the initialization of RET from test_all() to
full_test_span_gre_dir_acl(), a function that implements the test.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This test sets up mirroring such that it mirrors all overlay traffic.
That includes ARP, which causes occasional miscounts and spurious
failures. Ignore ARP explicitly to avoid these problems.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This test relies on routing in the primary traffic path, but neglects to
enable forwarding. Do so.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After one LAG slave is downed and another upped, it takes a while for
the neighbor on a bridge to time out and get renegotiated. The test does
prompt update of FDB entries by arpinging. But because the neighbor
still references another address, offloading is not possible, and some
packets may end up not being mirrored.
To force the neighbor renegotiation, simply flush the neighbor table at
the bridge.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ARP or ND traffic can cause spurious migration of FDB back to $swp3.
Mirroring is then updated in accordance with the change, and mirrored
packets are seen at h3, causing a failure.
Detect the case of this spurious roaming, and retry the test.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The untagged egress test sets up mirroring to {,ip6}gretap such that the
underlay goes through a bridge. Then VLAN flags are manipulated to test
that the traffic leaves the bridge 802.1q-tagged or not, as appropriate.
However, when a neighbor expires at the time that the bridge VLAN is
configured as PVID and egress untagged, the following discovery process
can't finish, because the IP address on H3 is still at the VLAN-tagged
netdevice. This manifests by occasional failures where only several of
the 10 required packets get through.
Therefore, when reconfiguring the VLAN flags, move the IP address to the
appropriate device in the H3 VRF.
In addition to that, take this opportunity to embed an ASCII art diagram
to make the topology move obvious.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When running in an environment with poor performance (such as a
simulator), processing mirrored packets can take a while. Evaluating the
condition too soon leads to spurious "seen 9, expected 10" failures as
the last packet doesn't have enough time to get mirrored and the mirror
to arrive and bump the observed counters.
Wait for one ping interval before evaluating the test.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When running in a simulator, the TTL change takes a while to settle and
during this time the performance of the packet processing is lowered.
The resulting instability leads to ping sending more packets as it
assumes some have been dropped. This then leads to regular spurious
failures as more packets than expected are observed.
Sleep a bit to give the system time to stabilize.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current ping intervals are too short for running mirroring tests in
simulator. This leads to ping sending a follow-up ping before the reply
arrives, thus sending more than the requested 10 ICMP requests. This
traffic is seen at the counters, and causes spurious failures.
Bump interval and timeout numbers 5x in mirroring tests to address the
spurious failures.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current ping intervals are too short for running mirroring tests in
simulator. This leads to ping sending a follow-up ping before the reply
arrives, thus sending more than the requested 10 ICMP requests. Those
are mirrored, and over a certain threshold the test case run is
considered a failure, because too much traffic is observed.
Bump interval and timeout numbers 5x in mirroring tests to address the
spurious failures.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current timeout (2 seconds) proved to be too low for some (emulated)
systems where we run the tests.
Make the timeout configurable and default to 5 seconds.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change most tests to TLS 1.3, while adding tests for previous TLS 1.2
behavior.
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Wire up support for 256 bit keys from the setsockopt to the crypto
framework
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we have a dedicated netlink attributes for xdp setup on a
particular interface, it is now possible to retrieve the program id that
is currently attached to the interface. The use case is targeted for
sample xdp programs, which will store the program id just after loading
bpf program onto iface. On shutdown, the sample will make sure that it
can unload the program by querying again the iface and verifying that
both program id's matches.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
XDP samples are mostly cooperating with eBPF maps through their file
descriptors. In case of a eBPF program that contains multiple maps it
might be tiresome to iterate through them and call bpf_map__fd for each
one. Add a helper mostly based on bpf_object__find_map_by_name, but
instead of returning the struct bpf_map pointer, return map fd.
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add C based test that runs 4 bpf programs in parallel
that update the same hash and array maps.
And another 2 threads that read from these two maps
via lookup(key, value, BPF_F_LOCK) api
to make sure the user space sees consistent value in both
hash and array elements while user space races with kernel bpf progs.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
add bpf_spin_lock C based test that requires latest llvm with BTF support
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
add bpf_spin_lock tests to test_verifier.c that don't require
latest llvm with BTF support
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Previously, bpf_num_possible_cpus() had a bug when calculating a
number of possible CPUs in the case of sparse CPU allocations, as
it was considering only the first range or element of
/sys/devices/system/cpu/possible.
E.g. in the case of "0,2-3" (CPU 1 is not available), the function
returned 1 instead of 3.
This patch fixes the function by making it parse all CPU ranges and
elements.
Signed-off-by: Martynas Pumputis <m@lambda.lt>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull kselftest fixes from Shuah Khan:
"This consists of run-time fixes to cpu-hotplug, and seccomp tests,
compile fixes to ir, net, and timers Makefiles"
* tag 'linux-kselftest-5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: timers: use LDLIBS instead of LDFLAGS
selftests: net: use LDLIBS instead of LDFLAGS
selftests/seccomp: Enhance per-arch ptrace syscall skip tests
selftests: Use lirc.h from kernel tree, not from system
selftests: cpu-hotplug: fix case where CPUs offline > CPUs present
We don't have this helper if the kernel was compiled without
CONFIG_BPF_EVENTS. Setting prog_type to BPF_PROG_TYPE_TRACEPOINT
let's verifier correctly skip this test based on the missing
prog_type support in the kernel.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Use recently introduced bpf_probe_map_type() to skip tests in the
test_verifier if map creation (create_map) fails. It's handled
explicitly for each fixup, i.e. if bpf_create_map returns negative fd,
we probe the kernel for the appropriate map support and skip the
test is map type is not supported.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Use recently introduced bpf_probe_prog_type() to skip tests in the
test_verifier() if bpf_verify_program() fails. The skipped test is
indicated in the output.
Example:
...
679/p bpf_get_stack return R0 within range SKIP (unsupported program
type 5)
680/p ld_abs: invalid op 1 OK
...
Summary: 863 PASSED, 165 SKIPPED, 3 FAILED
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Use recently introduced bpf_probe_map_type() to skip test_sockmap()
if map creation fails. The skipped test is indicated in the output.
Example:
test_sockmap SKIP (unsupported map type BPF_MAP_TYPE_SOCKMAP)
Fork 1024 tasks to 'test_update_delete'
...
test_sockmap SKIP (unsupported map type BPF_MAP_TYPE_SOCKMAP)
Fork 1024 tasks to 'test_update_delete'
...
test_maps: OK, 2 SKIPPED
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Ensure that the bug is fixed and we no longer have C-TCAM spill for two
keys that differ only in delta.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With recent fix in C-TCAM spillage for delta masks, the test stops to be
falsely positive. So fix it not to use delta by adding src_ip bits to the
masks. Alongside with that, use C-TCAM spill trace to see when the
spillage actually happens.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow to specify number of trace hits and move helpers
to the beginning of the file.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds the promised selftest for binderfs. It will verify the following
things:
- binderfs mounting works
- binder device allocation works
- performing a binder ioctl() request through a binderfs device works
- binder device removal works
- binder-control removal fails
- binderfs unmounting works
The tests are performed both privileged and unprivileged. The latter
verifies that binderfs behaves correctly in user namespaces.
Cc: Todd Kjos <tkjos@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed one test_btf raw test such that typedef func_proto
is permitted now.
Fixes: 78a2540e89 ("tools/bpf: Add tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC")
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull networking fixes from David Miller:
1) Need to save away the IV across tls async operations, from Dave
Watson.
2) Upon successful packet processing, we should liberate the SKB with
dev_consume_skb{_irq}(). From Yang Wei.
3) Only apply RX hang workaround on effected macb chips, from Harini
Katakam.
4) Dummy netdev need a proper namespace assigned to them, from Josh
Elsasser.
5) Some paths of nft_compat run lockless now, and thus we need to use a
proper refcnt_t. From Florian Westphal.
6) Avoid deadlock in mlx5 by doing IRQ locking, from Moni Shoua.
7) netrom does not refcount sockets properly wrt. timers, fix that by
using the sock timer API. From Cong Wang.
8) Fix locking of inexact inserts of xfrm policies, from Florian
Westphal.
9) Missing xfrm hash generation bump, also from Florian.
10) Missing of_node_put() in hns driver, from Yonglong Liu.
11) Fix DN_IFREQ_SIZE, from Johannes Berg.
12) ip6mr notifier is invoked during traversal of wrong table, from Nir
Dotan.
13) TX promisc settings not performed correctly in qed, from Manish
Chopra.
14) Fix OOB access in vhost, from Jason Wang.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
MAINTAINERS: Add entry for XDP (eXpress Data Path)
net: set default network namespace in init_dummy_netdev()
net: b44: replace dev_kfree_skb_xxx by dev_consume_skb_xxx for drop profiles
net: caif: call dev_consume_skb_any when skb xmit done
net: 8139cp: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: macb: Apply RXUBR workaround only to versions with errata
net: ti: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: apple: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: amd8111e: replace dev_kfree_skb_irq by dev_consume_skb_irq
net: alteon: replace dev_kfree_skb_irq by dev_consume_skb_irq
net: tls: Fix deadlock in free_resources tx
net: tls: Save iv in tls_rec for async crypto requests
vhost: fix OOB in get_rx_bufs()
qed: Fix stack out of bounds bug
qed: Fix system crash in ll2 xmit
qed: Fix VF probe failure while FLR
qed: Fix LACP pdu drops for VFs
qed: Fix bug in tx promiscuous mode settings
net: i825xx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
netfilter: ipt_CLUSTERIP: fix warning unused variable cn
...
With the default SPEC_STORE_BYPASS_SECCOMP/SPEC_STORE_BYPASS_PRCTL mode,
the TIF_SSBD bit will be inherited when a new task is fork'ed or cloned.
It will also remain when a new program is execve'ed.
Only certain class of applications (like Java) that can run on behalf of
multiple users on a single thread will require disabling speculative store
bypass for security purposes. Those applications will call prctl(2) at
startup time to disable SSB. They won't rely on the fact the SSB might have
been disabled. Other applications that don't need SSBD will just move on
without checking if SSBD has been turned on or not.
The fact that the TIF_SSBD is inherited across execve(2) boundary will
cause performance of applications that don't need SSBD but their
predecessors have SSBD on to be unwittingly impacted especially if they
write to memory a lot.
To remedy this problem, a new PR_SPEC_DISABLE_NOEXEC argument for the
PR_SET_SPECULATION_CTRL option of prctl(2) is added to allow applications
to specify that the SSBD feature bit on the task structure should be
cleared whenever a new program is being execve'ed.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: https://lkml.kernel.org/r/1547676096-3281-1-git-send-email-longman@redhat.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-01-29
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Teach verifier dead code removal, this also allows for optimizing /
removing conditional branches around dead code and to shrink the
resulting image. Code store constrained architectures like nfp would
have hard time doing this at JIT level, from Jakub.
2) Add JMP32 instructions to BPF ISA in order to allow for optimizing
code generation for 32-bit sub-registers. Evaluation shows that this
can result in code reduction of ~5-20% compared to 64 bit-only code
generation. Also add implementation for most JITs, from Jiong.
3) Add support for __int128 types in BTF which is also needed for
vmlinux's BTF conversion to work, from Yonghong.
4) Add a new command to bpftool in order to dump a list of BPF-related
parameters from the system or for a specific network device e.g. in
terms of available prog/map types or helper functions, from Quentin.
5) Add AF_XDP sock_diag interface for querying sockets from user
space which provides information about the RX/TX/fill/completion
rings, umem, memory usage etc, from Björn.
6) Add skb context access for skb_shared_info->gso_segs field, from Eric.
7) Add support for testing flow dissector BPF programs by extending
existing BPF_PROG_TEST_RUN infrastructure, from Stanislav.
8) Split BPF kselftest's test_verifier into various subgroups of tests
in order better deal with merge conflicts in this area, from Jakub.
9) Add support for queue/stack manipulations in bpftool, from Stanislav.
10) Document BTF, from Yonghong.
11) Dump supported ELF section names in libbpf on program load
failure, from Taeung.
12) Silence a false positive compiler warning in verifier's BTF
handling, from Peter.
13) Fix help string in bpftool's feature probing, from Prashant.
14) Remove duplicate includes in BPF kselftests, from Yue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Use existing pkt_v4 and pkt_v6 to make sure flow_keys are what we want.
Also, add new bpf_flow_load routine (and flow_dissector_load.h header)
that loads bpf_flow.o program and does all required setup.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
When prog array is updated with bpftool users often refer
to the map via the ID. Unfortunately, that's likely
to lead to confusion because prog arrays get flushed when
the last user reference is gone. If there is no other
reference bpftool will create one, update successfully
just to close the map again and have it flushed.
Warn about this case in non-JSON mode.
If the problem continues causing confusion we can remove
the support for referring to a map by ID for prog array
update completely. For now it seems like the potential
inconvenience to users who know what they're doing outweighs
the benefit.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Prog arrays don't have 'owner_prog_type' and 'owner_jited'
fields in their fdinfo when they are created. Those fields
are set and reported when first program is checked for
compatibility by bpf_prog_array_compatible().
This means that bpftool cannot expect the fields to always
be there. Currently trying to show maps on a system with
an un-owned prog array leads to a crash:
$ bpftool map show
389: prog_array name tail_call_map flags 0x0
Error: key 'owner_prog_type' not found in fdinfo
Error: key 'owner_jited' not found in fdinfo
key 4B value 4B max_entries 4 memlock 4096B
Segmentation fault (core dumped)
We pass a NULL pointer to atoi().
Remove the assumption that fdinfo keys are always present.
Add missing validations and remove the p_err() calls which
may lead to broken JSON output as caller will not propagate
the failure.
Fixes: 99a44bef58 ("tools: bpftool: add owner_prog_type and owner_jited to bpftool output")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
As for the others, check help message output to find out if devlink
supports "resource" object.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
posix_timers fails to build due to undefined reference errors:
aarch64-linaro-linux-gcc --sysroot=/build/tmp-rpb-glibc/sysroots/hikey
-O2 -pipe -g -feliminate-unused-debug-types -O3 -Wl,-no-as-needed -Wall
-DKTEST -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -lrt -lpthread
posix_timers.c
-o /build/tmp-rpb-glibc/work/hikey-linaro-linux/kselftests/4.12-r0/linux-4.12-rc7/tools/testing/selftests/timers/posix_timers
/tmp/cc1FTZzT.o: In function `check_timer_create':
/usr/src/debug/kselftests/4.12-r0/linux-4.12-rc7/tools/testing/selftests/timers/posix_timers.c:157:
undefined reference to `timer_create'
/usr/src/debug/kselftests/4.12-r0/linux-4.12-rc7/tools/testing/selftests/timers/posix_timers.c:170:
undefined reference to `timer_settime'
collect2: error: ld returned 1 exit status
It's GNU Make and linker specific.
The default Makefile rule looks like:
$(CC) $(CFLAGS) $(LDFLAGS) $@ $^ $(LDLIBS)
When linking is done by gcc itself, no issue, but when it needs to be passed
to proper ld, only LDLIBS follows and then ld cannot know what libs to link
with.
More detail:
https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html
LDFLAGS
Extra flags to give to compilers when they are supposed to invoke the linker,
‘ld’, such as -L. Libraries (-lfoo) should be added to the LDLIBS variable
instead.
LDLIBS
Library flags or names given to compilers when they are supposed to invoke the
linker, ‘ld’. LOADLIBES is a deprecated (but still supported) alternative to
LDLIBS. Non-library linker flags, such as -L, should go in the LDFLAGS
variable.
https://lkml.org/lkml/2010/2/10/362
tools/perf: libraries must come after objects
Link order matters, use LDLIBS instead of LDFLAGS to properly link against
libpthread.
Signed-off-by: Denys Dmytriyenko <denys@ti.com>
Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
