linux.git/tools/testing, branch v4.11-rc7 Linux kernel source tree Merge tag 'powerpc-4.11-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2017-04-08T18:06:12+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-04-08T18:06:12+00:00 894ca30cf6ddf891aa17c39a4b8d511c0a8cf2e9 Pull powerpc fixes from Michael Ellerman: "Some more powerpc fixes for 4.11: Headed to stable: - disable HFSCR[TM] if TM is not supported, fixes a potential host kernel crash triggered by a hostile guest, but only in configurations that no one uses - don't try to fix up misaligned load-with-reservation instructions - fix flush_(d|i)cache_range() called from modules on little endian kernels - add missing global TLB invalidate if cxl is active - fix missing preempt_disable() in crc32c-vpmsum And a fix for selftests build changes that went in this release: - selftests/powerpc: Fix standalone powerpc build Thanks to: Benjamin Herrenschmidt, Frederic Barrat, Oliver O'Halloran, Paul Mackerras" * tag 'powerpc-4.11-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable() powerpc/mm: Add missing global TLB invalidate if cxl is active powerpc/64: Fix flush_(d|i)cache_range() called from modules powerpc: Don't try to fix up misaligned load-with-reservation instructions powerpc: Disable HFSCR[TM] if TM is not supported selftests/powerpc: Fix standalone powerpc build 
Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 4.11:

  Headed to stable:

   - disable HFSCR[TM] if TM is not supported, fixes a potential host
     kernel crash triggered by a hostile guest, but only in
     configurations that no one uses

   - don't try to fix up misaligned load-with-reservation instructions

   - fix flush_(d|i)cache_range() called from modules on little endian
     kernels

   - add missing global TLB invalidate if cxl is active

   - fix missing preempt_disable() in crc32c-vpmsum

  And a fix for selftests build changes that went in this release:

   - selftests/powerpc: Fix standalone powerpc build

  Thanks to: Benjamin Herrenschmidt, Frederic Barrat, Oliver O'Halloran,
  Paul Mackerras"

* tag 'powerpc-4.11-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable()
  powerpc/mm: Add missing global TLB invalidate if cxl is active
  powerpc/64: Fix flush_(d|i)cache_range() called from modules
  powerpc: Don't try to fix up misaligned load-with-reservation instructions
  powerpc: Disable HFSCR[TM] if TM is not supported
  selftests/powerpc: Fix standalone powerpc build
bpf: add various verifier test cases for self-tests 2017-04-01T19:36:37+00:00 Daniel Borkmann daniel@iogearbox.net 2017-03-31T00:24:04+00:00 02ea80b1850e48abbce77878896229d7cc5cb230 Add a couple of test cases, for example, probing for xadd on a spilled pointer to packet and map_value_adj register, various other map_value_adj tests including the unaligned load/store, and trying out pointer arithmetic on map_value_adj register itself. For the unaligned load/store, we need to figure out whether the architecture has efficient unaligned access and need to mark affected tests accordingly. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add a couple of test cases, for example, probing for xadd on a spilled
pointer to packet and map_value_adj register, various other map_value_adj
tests including the unaligned load/store, and trying out pointer arithmetic
on map_value_adj register itself. For the unaligned load/store, we need
to figure out whether the architecture has efficient unaligned access and
need to mark affected tests accordingly.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
selftests/powerpc: Fix standalone powerpc build 2017-03-27T04:11:44+00:00 Michael Ellerman mpe@ellerman.id.au 2017-03-27T04:11:44+00:00 2db2c250dd3d1e74a50d4ab5f44c44ca5cb4e42b The changes to enable building with a separate output directory, in commit a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT") broke building the powerpc selftests on their own, eg: $ cd tools/testing/selftests/powerpc; make It was partially fixed in commit e53aff45c490 ("selftests: lib.mk Fix individual test builds"), which defined OUTPUT for standalone tests. But that only defines OUTPUT within the Makefile, the value is not exported so sub-shells can't see it. We could export OUTPUT, but it's actually cleaner to just expand the value of OUTPUT before we invoke the shell. Fixes: a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
The changes to enable building with a separate output directory, in
commit a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT") broke
building the powerpc selftests on their own, eg:

 $ cd tools/testing/selftests/powerpc; make

It was partially fixed in commit e53aff45c490 ("selftests: lib.mk Fix
individual test builds"), which defined OUTPUT for standalone tests. But
that only defines OUTPUT within the Makefile, the value is not exported
so sub-shells can't see it. We could export OUTPUT, but it's actually
cleaner to just expand the value of OUTPUT before we invoke the shell.

Fixes: a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
bpf: improve verifier packet range checks 2017-03-25T03:51:28+00:00 Alexei Starovoitov ast@fb.com 2017-03-24T22:57:33+00:00 b1977682a3858b5584ffea7cfb7bd863f68db18d llvm can optimize the 'if (ptr > data_end)' checks to be in the order slightly different than the original C code which will confuse verifier. Like: if (ptr + 16 > data_end) return TC_ACT_SHOT; // may be followed by if (ptr + 14 > data_end) return TC_ACT_SHOT; while llvm can see that 'ptr' is valid for all 16 bytes, the verifier could not. Fix verifier logic to account for such case and add a test. Reported-by: Huapeng Zhou <hzhou@fb.com> Fixes: 969bf05eb3ce ("bpf: direct packet access") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
llvm can optimize the 'if (ptr > data_end)' checks to be in the order
slightly different than the original C code which will confuse verifier.
Like:
if (ptr + 16 > data_end)
  return TC_ACT_SHOT;
// may be followed by
if (ptr + 14 > data_end)
  return TC_ACT_SHOT;
while llvm can see that 'ptr' is valid for all 16 bytes,
the verifier could not.
Fix verifier logic to account for such case and add a test.

Reported-by: Huapeng Zhou <hzhou@fb.com>
Fixes: 969bf05eb3ce ("bpf: direct packet access")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf: fix hashmap extra_elems logic 2017-03-22T21:12:18+00:00 Alexei Starovoitov ast@fb.com 2017-03-22T02:05:04+00:00 8c290e60fa2a51806159522331c9ed41252a8fb3 In both kmalloc and prealloc mode the bpf_map_update_elem() is using per-cpu extra_elems to do atomic update when the map is full. There are two issues with it. The logic can be misused, since it allows max_entries+num_cpus elements to be present in the map. And alloc_extra_elems() at map creation time can fail percpu alloc for large map values with a warn: WARNING: CPU: 3 PID: 2752 at ../mm/percpu.c:892 pcpu_alloc+0x119/0xa60 illegal size (32824) or align (8) for percpu allocation The fixes for both of these issues are different for kmalloc and prealloc modes. For prealloc mode allocate extra num_possible_cpus elements and store their pointers into extra_elems array instead of actual elements. Hence we can use these hidden(spare) elements not only when the map is full but during bpf_map_update_elem() that replaces existing element too. That also improves performance, since pcpu_freelist_pop/push is avoided. Unfortunately this approach cannot be used for kmalloc mode which needs to kfree elements after rcu grace period. Therefore switch it back to normal kmalloc even when full and old element exists like it was prior to commit 6c9059817432 ("bpf: pre-allocate hash map elements"). Add tests to check for over max_entries and large map values. Reported-by: Dave Jones <davej@codemonkey.org.uk> Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In both kmalloc and prealloc mode the bpf_map_update_elem() is using
per-cpu extra_elems to do atomic update when the map is full.
There are two issues with it. The logic can be misused, since it allows
max_entries+num_cpus elements to be present in the map. And alloc_extra_elems()
at map creation time can fail percpu alloc for large map values with a warn:
WARNING: CPU: 3 PID: 2752 at ../mm/percpu.c:892 pcpu_alloc+0x119/0xa60
illegal size (32824) or align (8) for percpu allocation

The fixes for both of these issues are different for kmalloc and prealloc modes.
For prealloc mode allocate extra num_possible_cpus elements and store
their pointers into extra_elems array instead of actual elements.
Hence we can use these hidden(spare) elements not only when the map is full
but during bpf_map_update_elem() that replaces existing element too.
That also improves performance, since pcpu_freelist_pop/push is avoided.
Unfortunately this approach cannot be used for kmalloc mode which needs
to kfree elements after rcu grace period. Therefore switch it back to normal
kmalloc even when full and old element exists like it was prior to
commit 6c9059817432 ("bpf: pre-allocate hash map elements").

Add tests to check for over max_entries and large map values.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
selftests/bpf: fix broken build, take 2 2017-03-22T01:57:58+00:00 Zi Shen Lim zlim.lnx@gmail.com 2017-03-20T06:03:14+00:00 e8f1f34a344d060eaf1918089369c4c1172a153b Merge of 'linux-kselftest-4.11-rc1': 1. Partially removed use of 'test_objs' target, breaking force rebuild of BPFOBJ, introduced in commit d498f8719a09 ("bpf: Rebuild bpf.o for any dependency update"). Update target so dependency on BPFOBJ is restored. 2. Introduced commit 2047f1d8ba28 ("selftests: Fix the .c linking rule") which fixes order of LDLIBS. Commit d02d8986a768 ("bpf: Always test unprivileged programs") added libcap dependency into CFLAGS. Use LDLIBS instead to fix linking of test_verifier. 3. Introduced commit d83c3ba0b926 ("selftests: Fix selftests build to just build, not run tests"). Reordering the Makefile allows us to remove the 'all' target. Tested both: selftests/bpf$ make and selftests$ make TARGETS=bpf on Ubuntu 16.04.2. Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Merge of 'linux-kselftest-4.11-rc1':

1. Partially removed use of 'test_objs' target, breaking force rebuild of
BPFOBJ, introduced in commit d498f8719a09 ("bpf: Rebuild bpf.o for any
dependency update").

  Update target so dependency on BPFOBJ is restored.

2. Introduced commit 2047f1d8ba28 ("selftests: Fix the .c linking rule")
which fixes order of LDLIBS.

  Commit d02d8986a768 ("bpf: Always test unprivileged programs") added
libcap dependency into CFLAGS. Use LDLIBS instead to fix linking of
test_verifier.

3. Introduced commit d83c3ba0b926 ("selftests: Fix selftests build to
just build, not run tests").

  Reordering the Makefile allows us to remove the 'all' target.

Tested both:
    selftests/bpf$ make
and
    selftests$ make TARGETS=bpf
on Ubuntu 16.04.2.

Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-15T04:31:23+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-03-15T04:31:23+00:00 ae50dfd61665086e617cc9e554a1285d52765670 Pull networking fixes from David Miller: 1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver, from Steffen Klassert. 2) Fix crashes when user tries to get_next_key on an LPM bpf map, from Alexei Starovoitov. 3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from Michal Schmidt. 4) We can get a divide by zero when TCP socket are morphed into listening state, fix from Eric Dumazet. 5) Fix socket refcounting bugs in skb_complete_wifi_ack() and skb_complete_tx_timestamp(). From Eric Dumazet. 6) Use after free in dccp_feat_activate_values(), also from Eric Dumazet. 7) Like bonding team needs to use ETH_MAX_MTU as netdev->max_mtu, from Jarod Wilson. 8) Fix use after free in vrf_xmit(), from David Ahern. 9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from Alexey Kodanev. 10) Properly check napi_complete_done() return value in order to decide whether to re-enable IRQs or not in amd-xgbe driver, from Thomas Lendacky. 11) Fix double free of hwmon device in marvell phy driver, from Andrew Lunn. 12) Don't crash on malformed netlink attributes in act_connmark, from Etienne Noss. 13) Don't remove routes with a higher metric in ipv6 ECMP route replace, from Sabrina Dubroca. 14) Don't write into a cloned SKB in ipv6 fragmentation handling, from Florian Westphal. 15) Fix routing redirect races in dccp and tcp, basically the ICMP handler can't modify the socket's cached route in it's locked by the user at this moment. From Jon Maxwell. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits) qed: Enable iSCSI Out-of-Order qed: Correct out-of-bound access in OOO history qed: Fix interrupt flags on Rx LL2 qed: Free previous connections when releasing iSCSI qed: Fix mapping leak on LL2 rx flow qed: Prevent creation of too-big u32-chains qed: Align CIDs according to DORQ requirement mlxsw: reg: Fix SPVMLR max record count mlxsw: reg: Fix SPVM max record count net: Resend IGMP memberships upon peer notification. dccp: fix memory leak during tear-down of unsuccessful connection request tun: fix premature POLLOUT notification on tun devices dccp/tcp: fix routing redirect race ucc/hdlc: fix two little issue vxlan: fix ovs support net: use net->count to check whether a netns is alive or not bridge: drop netfilter fake rtable unconditionally ipv6: avoid write to a possibly cloned skb net: wimax/i2400m: fix NULL-deref at probe isdn/gigaset: fix NULL-deref at probe ... 
Pull networking fixes from David Miller:

 1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver,
    from Steffen Klassert.

 2) Fix crashes when user tries to get_next_key on an LPM bpf map, from
    Alexei Starovoitov.

 3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from
    Michal Schmidt.

 4) We can get a divide by zero when TCP socket are morphed into
    listening state, fix from Eric Dumazet.

 5) Fix socket refcounting bugs in skb_complete_wifi_ack() and
    skb_complete_tx_timestamp(). From Eric Dumazet.

 6) Use after free in dccp_feat_activate_values(), also from Eric
    Dumazet.

 7) Like bonding team needs to use ETH_MAX_MTU as netdev->max_mtu, from
    Jarod Wilson.

 8) Fix use after free in vrf_xmit(), from David Ahern.

 9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from
    Alexey Kodanev.

10) Properly check napi_complete_done() return value in order to decide
    whether to re-enable IRQs or not in amd-xgbe driver, from Thomas
    Lendacky.

11) Fix double free of hwmon device in marvell phy driver, from Andrew
    Lunn.

12) Don't crash on malformed netlink attributes in act_connmark, from
    Etienne Noss.

13) Don't remove routes with a higher metric in ipv6 ECMP route replace,
    from Sabrina Dubroca.

14) Don't write into a cloned SKB in ipv6 fragmentation handling, from
    Florian Westphal.

15) Fix routing redirect races in dccp and tcp, basically the ICMP
    handler can't modify the socket's cached route in it's locked by the
    user at this moment. From Jon Maxwell.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits)
  qed: Enable iSCSI Out-of-Order
  qed: Correct out-of-bound access in OOO history
  qed: Fix interrupt flags on Rx LL2
  qed: Free previous connections when releasing iSCSI
  qed: Fix mapping leak on LL2 rx flow
  qed: Prevent creation of too-big u32-chains
  qed: Align CIDs according to DORQ requirement
  mlxsw: reg: Fix SPVMLR max record count
  mlxsw: reg: Fix SPVM max record count
  net: Resend IGMP memberships upon peer notification.
  dccp: fix memory leak during tear-down of unsuccessful connection request
  tun: fix premature POLLOUT notification on tun devices
  dccp/tcp: fix routing redirect race
  ucc/hdlc: fix two little issue
  vxlan: fix ovs support
  net: use net->count to check whether a netns is alive or not
  bridge: drop netfilter fake rtable unconditionally
  ipv6: avoid write to a possibly cloned skb
  net: wimax/i2400m: fix NULL-deref at probe
  isdn/gigaset: fix NULL-deref at probe
  ...
Merge tag 'powerpc-4.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2017-03-14T02:48:22+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-03-14T02:48:22+00:00 fb5fe0fd626c425ed41842c4318aa7ab6f3c2db7 Pull some more powerpc fixes from Michael Ellerman: "The main item is the addition of the Power9 Machine Check handler. This was delayed to make sure some details were correct, and is as minimal as possible. The rest is small fixes, two for the Power9 PMU, two dealing with obscure toolchain problems, two for the PowerNV IOMMU code (used by VFIO), and one to fix a crash on 32-bit machines with macio devices due to missing dma_ops. Thanks to: Alexey Kardashevskiy, Cyril Bur, Larry Finger, Madhavan Srinivasan, Nicholas Piggin" * tag 'powerpc-4.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: POWER9 machine check handler powerpc/64s: allow machine check handler to set severity and initiator powerpc/64s: fix handling of non-synchronous machine checks powerpc/pmac: Fix crash in dma-mapping.h with NULL dma_ops powerpc/powernv/ioda2: Update iommu table base on ownership change powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested selftests/powerpc: Replace stxvx and lxvx with stxvd2x/lxvd2x powerpc/perf: Handle sdar_mode for marked event in power9 powerpc/perf: Fix perf_get_data_addr() for power9 DD1 powerpc/boot: Fix zImage TOC alignment 
Pull some more powerpc fixes from Michael Ellerman:
 "The main item is the addition of the Power9 Machine Check handler.
  This was delayed to make sure some details were correct, and is as
  minimal as possible.

  The rest is small fixes, two for the Power9 PMU, two dealing with
  obscure toolchain problems, two for the PowerNV IOMMU code (used by
  VFIO), and one to fix a crash on 32-bit machines with macio devices
  due to missing dma_ops.

  Thanks to:
    Alexey Kardashevskiy, Cyril Bur, Larry Finger, Madhavan Srinivasan,
    Nicholas Piggin"

* tag 'powerpc-4.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: POWER9 machine check handler
  powerpc/64s: allow machine check handler to set severity and initiator
  powerpc/64s: fix handling of non-synchronous machine checks
  powerpc/pmac: Fix crash in dma-mapping.h with NULL dma_ops
  powerpc/powernv/ioda2: Update iommu table base on ownership change
  powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested
  selftests/powerpc: Replace stxvx and lxvx with stxvd2x/lxvd2x
  powerpc/perf: Handle sdar_mode for marked event in power9
  powerpc/perf: Fix perf_get_data_addr() for power9 DD1
  powerpc/boot: Fix zImage TOC alignment
selftests/bpf: fix broken build 2017-03-13T06:48:41+00:00 Alexei Starovoitov ast@fb.com 2017-03-11T06:05:55+00:00 1da8ac7c49fb2879ba95006d8bd1095e6870ea1a Recent merge of 'linux-kselftest-4.11-rc1' tree broke bpf test build. None of the tests were building and test_verifier.c had tons of compiler errors. Fix it and add #ifdef CAP_IS_SUPPORTED to support old versions of libcap. Tested on centos 6.8 and 7 Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Recent merge of 'linux-kselftest-4.11-rc1' tree broke bpf test build.
None of the tests were building and test_verifier.c had tons of compiler errors.
Fix it and add #ifdef CAP_IS_SUPPORTED to support old versions of libcap.
Tested on centos 6.8 and 7

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
userfaultfd: selftest: vm: allow to build in vm/ directory 2017-03-10T01:01:10+00:00 Andrea Arcangeli aarcange@redhat.com 2017-03-10T00:17:14+00:00 46aa6a302b53f543f8e8b8e1714dc5e449ad36a6 linux/tools/testing/selftests/vm $ make gcc -Wall -I ../../../../usr/include compaction_test.c -lrt -o /compaction_test /usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../../x86_64-pc-linux-gnu/bin/ld: cannot open output file /compaction_test: Permission denied collect2: error: ld returned 1 exit status make: *** [../lib.mk:54: /compaction_test] Error 1 Since commit a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT") selftests/vm build fails if run from the "selftests/vm" directory, but it works in the selftests/ directory. It's quicker to be able to do a local vm-only build after a tree wipe and this patch allows for it again. Link: http://lkml.kernel.org/r/20170302173738.18994-4-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
linux/tools/testing/selftests/vm $ make

  gcc -Wall -I ../../../../usr/include     compaction_test.c -lrt -o /compaction_test
  /usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../../x86_64-pc-linux-gnu/bin/ld: cannot open output file /compaction_test: Permission denied
  collect2: error: ld returned 1 exit status
  make: *** [../lib.mk:54: /compaction_test] Error 1

Since commit a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT")
selftests/vm build fails if run from the "selftests/vm" directory, but
it works in the selftests/ directory.  It's quicker to be able to do a
local vm-only build after a tree wipe and this patch allows for it
again.

Link: http://lkml.kernel.org/r/20170302173738.18994-4-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>