linux.git/tools/testing, branch v4.19.39 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git net/sched: act_sample: fix divide by zero in the traffic path 2019-04-17T06:38:41+00:00 Davide Caratti dcaratti@redhat.com 2019-04-04T10:31:35+00:00 15c0770e2e83aa43cfa851be5edef81b06fcdf3f [ Upstream commit fae2708174ae95d98d19f194e03d6e8f688ae195 ] the control path of 'sample' action does not validate the value of 'rate' provided by the user, but then it uses it as divisor in the traffic path. Validate it in tcf_sample_init(), and return -EINVAL with a proper extack message in case that value is zero, to fix a splat with the script below: # tc f a dev test0 egress matchall action sample rate 0 group 1 index 2 # tc -s a s action sample total acts 1 action order 0: sample rate 1/0 group 1 pipe index 2 ref 1 bind 1 installed 19 sec used 19 sec Action statistics: Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 # ping 192.0.2.1 -I test0 -c1 -q divide error: 0000 [#1] SMP PTI CPU: 1 PID: 6192 Comm: ping Not tainted 5.1.0-rc2.diag2+ #591 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:tcf_sample_act+0x9e/0x1e0 [act_sample] Code: 6a f1 85 c0 74 0d 80 3d 83 1a 00 00 00 0f 84 9c 00 00 00 4d 85 e4 0f 84 85 00 00 00 e8 9b d7 9c f1 44 8b 8b e0 00 00 00 31 d2 <41> f7 f1 85 d2 75 70 f6 85 83 00 00 00 10 48 8b 45 10 8b 88 08 01 RSP: 0018:ffffae320190ba30 EFLAGS: 00010246 RAX: 00000000b0677d21 RBX: ffff8af1ed9ec000 RCX: 0000000059a9fe49 RDX: 0000000000000000 RSI: 000000000c7e33b7 RDI: ffff8af23daa0af0 RBP: ffff8af1ee11b200 R08: 0000000074fcaf7e R09: 0000000000000000 R10: 0000000000000050 R11: ffffffffb3088680 R12: ffff8af232307f80 R13: 0000000000000003 R14: ffff8af1ed9ec000 R15: 0000000000000000 FS: 00007fe9c6d2f740(0000) GS:ffff8af23da80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff6772f000 CR3: 00000000746a2004 CR4: 00000000001606e0 Call Trace: tcf_action_exec+0x7c/0x1c0 tcf_classify+0x57/0x160 __dev_queue_xmit+0x3dc/0xd10 ip_finish_output2+0x257/0x6d0 ip_output+0x75/0x280 ip_send_skb+0x15/0x40 raw_sendmsg+0xae3/0x1410 sock_sendmsg+0x36/0x40 __sys_sendto+0x10e/0x140 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x60/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe [...] Kernel panic - not syncing: Fatal exception in interrupt Add a TDC selftest to document that 'rate' is now being validated. Reported-by: Matteo Croce <mcroce@redhat.com> Fixes: 5c5670fae430 ("net/sched: Introduce sample tc action") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Acked-by: Yotam Gigi <yotam.gi@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fae2708174ae95d98d19f194e03d6e8f688ae195 ]

the control path of 'sample' action does not validate the value of 'rate'
provided by the user, but then it uses it as divisor in the traffic path.
Validate it in tcf_sample_init(), and return -EINVAL with a proper extack
message in case that value is zero, to fix a splat with the script below:

 # tc f a dev test0 egress matchall action sample rate 0 group 1 index 2
 # tc -s a s action sample
 total acts 1

         action order 0: sample rate 1/0 group 1 pipe
          index 2 ref 1 bind 1 installed 19 sec used 19 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
 # ping 192.0.2.1 -I test0 -c1 -q

 divide error: 0000 [#1] SMP PTI
 CPU: 1 PID: 6192 Comm: ping Not tainted 5.1.0-rc2.diag2+ #591
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_sample_act+0x9e/0x1e0 [act_sample]
 Code: 6a f1 85 c0 74 0d 80 3d 83 1a 00 00 00 0f 84 9c 00 00 00 4d 85 e4 0f 84 85 00 00 00 e8 9b d7 9c f1 44 8b 8b e0 00 00 00 31 d2 <41> f7 f1 85 d2 75 70 f6 85 83 00 00 00 10 48 8b 45 10 8b 88 08 01
 RSP: 0018:ffffae320190ba30 EFLAGS: 00010246
 RAX: 00000000b0677d21 RBX: ffff8af1ed9ec000 RCX: 0000000059a9fe49
 RDX: 0000000000000000 RSI: 000000000c7e33b7 RDI: ffff8af23daa0af0
 RBP: ffff8af1ee11b200 R08: 0000000074fcaf7e R09: 0000000000000000
 R10: 0000000000000050 R11: ffffffffb3088680 R12: ffff8af232307f80
 R13: 0000000000000003 R14: ffff8af1ed9ec000 R15: 0000000000000000
 FS:  00007fe9c6d2f740(0000) GS:ffff8af23da80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fff6772f000 CR3: 00000000746a2004 CR4: 00000000001606e0
 Call Trace:
  tcf_action_exec+0x7c/0x1c0
  tcf_classify+0x57/0x160
  __dev_queue_xmit+0x3dc/0xd10
  ip_finish_output2+0x257/0x6d0
  ip_output+0x75/0x280
  ip_send_skb+0x15/0x40
  raw_sendmsg+0xae3/0x1410
  sock_sendmsg+0x36/0x40
  __sys_sendto+0x10e/0x140
  __x64_sys_sendto+0x24/0x30
  do_syscall_64+0x60/0x210
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [...]
  Kernel panic - not syncing: Fatal exception in interrupt

Add a TDC selftest to document that 'rate' is now being validated.

Reported-by: Matteo Croce <mcroce@redhat.com>
Fixes: 5c5670fae430 ("net/sched: Introduce sample tc action")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Yotam Gigi <yotam.gi@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests/bpf: skip verifier tests for unsupported program types 2019-04-05T20:33:13+00:00 Stanislav Fomichev sdf@google.com 2019-01-28T17:21:16+00:00 118d38a3577f7728278f6afda8436af05a6bec7f [ Upstream commit 8184d44c9a577a2f1842ed6cc844bfd4a9981d8e ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8184d44c9a577a2f1842ed6cc844bfd4a9981d8e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: skip seccomp get_metadata test if not real root 2019-04-05T20:33:07+00:00 Tycho Andersen tycho@tycho.ws 2019-01-19T00:12:15+00:00 c63cc8d1487c3a15baa03c016a4b4344cbd0137d [ Upstream commit 3aa415dd2128e478ea3225b59308766de0e94d6b ] The get_metadata() test requires real root, so let's skip it if we're not real root. Note that I used XFAIL here because that's what the test does later if CONFIG_CHEKCKPOINT_RESTORE happens to not be enabled. After looking at the code, there doesn't seem to be a nice way to skip tests defined as TEST(), since there's no return code (I tried exit(KSFT_SKIP), but that didn't work either...). So let's do it this way to be consistent, and easier to fix when someone comes along and fixes it. Signed-off-by: Tycho Andersen <tycho@tycho.ws> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Shuah Khan <shuah@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3aa415dd2128e478ea3225b59308766de0e94d6b ]

The get_metadata() test requires real root, so let's skip it if we're not
real root.

Note that I used XFAIL here because that's what the test does later if
CONFIG_CHEKCKPOINT_RESTORE happens to not be enabled. After looking at the
code, there doesn't seem to be a nice way to skip tests defined as TEST(),
since there's no return code (I tried exit(KSFT_SKIP), but that didn't work
either...). So let's do it this way to be consistent, and easier to fix
when someone comes along and fixes it.

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: fib_tests: sleep after changing carrier. again. 2019-03-23T19:09:52+00:00 Thadeu Lima de Souza Cascardo cascardo@canonical.com 2019-02-22T10:27:41+00:00 d3f62d3eab0beff6877c2035d6a6f556f8d921a0 [ Upstream commit af548a27b158d548d41e56255e6eaca1658cc3be ] Just like commit e2ba732a1681 ("selftests: fib_tests: sleep after changing carrier"), wait one second to allow linkwatch to propagate the carrier change to the stack. There are two sets of carrier tests. The first slept after the carrier was set to off, and when the second set ran, it was likely that the linkwatch would be able to run again without much delay, reducing the likelihood of a race. However, if you run 'fib_tests.sh -t carrier' on a loop, you will quickly notice the failures. Sleeping on the second set of tests make the failures go away. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit af548a27b158d548d41e56255e6eaca1658cc3be ]

Just like commit e2ba732a1681 ("selftests: fib_tests: sleep after
changing carrier"), wait one second to allow linkwatch to propagate the
carrier change to the stack.

There are two sets of carrier tests. The first slept after the carrier
was set to off, and when the second set ran, it was likely that the
linkwatch would be able to run again without much delay, reducing the
likelihood of a race. However, if you run 'fib_tests.sh -t carrier' on a
loop, you will quickly notice the failures.

Sleeping on the second set of tests make the failures go away.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf, lpm: fix lookup bug in map_delete_elem 2019-03-23T19:09:51+00:00 Alban Crequy alban@kinvolk.io 2019-02-22T13:19:08+00:00 02f8211b75c96fdfbfb6b25601c1b363686aa38b [ Upstream commit 7c0cdf0b3940f63d9777c3fcf250a2f83859ca54 ] trie_delete_elem() was deleting an entry even though it was not matching if the prefixlen was correct. This patch adds a check on matchlen. Reproducer: $ sudo bpftool map create /sys/fs/bpf/mylpm type lpm_trie key 8 value 1 entries 128 name mylpm flags 1 $ sudo bpftool map update pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 aa bb cc dd value hex 01 $ sudo bpftool map dump pinned /sys/fs/bpf/mylpm key: 10 00 00 00 aa bb cc dd value: 01 Found 1 element $ sudo bpftool map delete pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 ff ff ff ff $ echo $? 0 $ sudo bpftool map dump pinned /sys/fs/bpf/mylpm Found 0 elements A similar reproducer is added in the selftests. Without the patch: $ sudo ./tools/testing/selftests/bpf/test_lpm_map test_lpm_map: test_lpm_map.c:485: test_lpm_delete: Assertion `bpf_map_delete_elem(map_fd, key) == -1 && errno == ENOENT' failed. Aborted With the patch: test_lpm_map runs without errors. Fixes: e454cf595853 ("bpf: Implement map_delete_elem for BPF_MAP_TYPE_LPM_TRIE") Cc: Craig Gallek <kraig@google.com> Signed-off-by: Alban Crequy <alban@kinvolk.io> Acked-by: Craig Gallek <kraig@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7c0cdf0b3940f63d9777c3fcf250a2f83859ca54 ]

trie_delete_elem() was deleting an entry even though it was not matching
if the prefixlen was correct. This patch adds a check on matchlen.

Reproducer:

$ sudo bpftool map create /sys/fs/bpf/mylpm type lpm_trie key 8 value 1 entries 128 name mylpm flags 1
$ sudo bpftool map update pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 aa bb cc dd value hex 01
$ sudo bpftool map dump pinned /sys/fs/bpf/mylpm
key: 10 00 00 00 aa bb cc dd  value: 01
Found 1 element
$ sudo bpftool map delete pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 ff ff ff ff
$ echo $?
0
$ sudo bpftool map dump pinned /sys/fs/bpf/mylpm
Found 0 elements

A similar reproducer is added in the selftests.

Without the patch:

$ sudo ./tools/testing/selftests/bpf/test_lpm_map
test_lpm_map: test_lpm_map.c:485: test_lpm_delete: Assertion `bpf_map_delete_elem(map_fd, key) == -1 && errno == ENOENT' failed.
Aborted

With the patch: test_lpm_map runs without errors.

Fixes: e454cf595853 ("bpf: Implement map_delete_elem for BPF_MAP_TYPE_LPM_TRIE")
Cc: Craig Gallek <kraig@google.com>
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Acked-by: Craig Gallek <kraig@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: netfilter: add simple masq/redirect test cases 2019-03-13T21:02:37+00:00 Florian Westphal fw@strlen.de 2019-01-29T14:16:23+00:00 5c39e08fc417b91d24d243bc6d1a305e1c38fb9f [ Upstream commit 98bfc3414bda335dbd7fec58bde6266f991801d7 ] Check basic nat/redirect/masquerade for ipv4 and ipv6. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 98bfc3414bda335dbd7fec58bde6266f991801d7 ]

Check basic nat/redirect/masquerade for ipv4 and ipv6.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: netfilter: fix config fragment CONFIG_NF_TABLES_INET 2019-03-13T21:02:36+00:00 Naresh Kamboju naresh.kamboju@linaro.org 2019-01-29T06:28:35+00:00 974ed365b16455203b0fb6ef91b1aa9a07b9acde [ Upstream commit 952b72f89ae23b316da8c1021b18d0c388ad6cc4 ] In selftests the config fragment for netfilter was added as NF_TABLES_INET=y and this patch correct it as CONFIG_NF_TABLES_INET=y Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 952b72f89ae23b316da8c1021b18d0c388ad6cc4 ]

In selftests the config fragment for netfilter was added as
NF_TABLES_INET=y and this patch correct it as CONFIG_NF_TABLES_INET=y

Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf, selftests: fix handling of sparse CPU allocations 2019-03-13T21:02:36+00:00 Martynas Pumputis m@lambda.lt 2019-01-31T09:19:33+00:00 0ace0d28941b8dc91dac2edae754f48ac550ed40 [ Upstream commit 1bb54c4071f585ebef56ce8fdfe6026fa2cbcddd ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1bb54c4071f585ebef56ce8fdfe6026fa2cbcddd ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
proc: fix /proc/net/* after setns(2) 2019-03-13T21:02:32+00:00 Alexey Dobriyan adobriyan@gmail.com 2019-02-01T22:20:01+00:00 845d73be1b4cba6c353e99f79eff0f17e0d7c1d8 [ Upstream commit 1fde6f21d90f8ba5da3cb9c54ca991ed72696c43 ] /proc entries under /proc/net/* can't be cached into dcache because setns(2) can change current net namespace. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: avoid vim miscolorization] [adobriyan@gmail.com: write test, add dummy ->d_revalidate hook: necessary if /proc/net/* is pinned at setns time] Link: http://lkml.kernel.org/r/20190108192350.GA12034@avx2 Link: http://lkml.kernel.org/r/20190107162336.GA9239@avx2 Fixes: 1da4d377f943fe4194ffb9fb9c26cc58fad4dd24 ("proc: revalidate misc dentries") Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reported-by: Mateusz Stępień <mateusz.stepien@netrounds.com> Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1fde6f21d90f8ba5da3cb9c54ca991ed72696c43 ]

/proc entries under /proc/net/* can't be cached into dcache because
setns(2) can change current net namespace.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: avoid vim miscolorization]
[adobriyan@gmail.com: write test, add dummy ->d_revalidate hook: necessary if /proc/net/* is pinned at setns time]
  Link: http://lkml.kernel.org/r/20190108192350.GA12034@avx2
Link: http://lkml.kernel.org/r/20190107162336.GA9239@avx2
Fixes: 1da4d377f943fe4194ffb9fb9c26cc58fad4dd24 ("proc: revalidate misc dentries")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: Mateusz Stępień <mateusz.stepien@netrounds.com>
Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: timers: use LDLIBS instead of LDFLAGS 2019-03-13T21:02:30+00:00 Fathi Boudra fathi.boudra@linaro.org 2019-01-16T17:43:20+00:00 daf04674d08ad4962ac3e04d4a46e971c6f9c2a7 [ Upstream commit 7d4e591bc051d3382c45caaa2530969fb42ed23d ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7d4e591bc051d3382c45caaa2530969fb42ed23d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>