linux-stable.git/tools, branch v5.6.13 Linux kernel stable tree objtool: Fix stack offset tracking for indirect CFAs 2020-05-14T05:59:27+00:00 Josh Poimboeuf jpoimboe@redhat.com 2020-04-25T10:03:00+00:00 af9e6058a354c6959e754e6f61727d7952d9504c commit d8dd25a461e4eec7190cb9d66616aceacc5110ad upstream. When the current frame address (CFA) is stored on the stack (i.e., cfa->base == CFI_SP_INDIRECT), objtool neglects to adjust the stack offset when there are subsequent pushes or pops. This results in bad ORC data at the end of the ENTER_IRQ_STACK macro, when it puts the previous stack pointer on the stack and does a subsequent push. This fixes the following unwinder warning: WARNING: can't dereference registers at 00000000f0a6bdba for ip interrupt_entry+0x9f/0xa0 Fixes: 627fce14809b ("objtool: Add ORC unwind table generation") Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Dave Jones <dsj@fb.com> Reported-by: Steven Rostedt <rostedt@goodmis.org> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Joe Mario <jmario@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/853d5d691b29e250333332f09b8e27410b2d9924.1587808742.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d8dd25a461e4eec7190cb9d66616aceacc5110ad upstream.

When the current frame address (CFA) is stored on the stack (i.e.,
cfa->base == CFI_SP_INDIRECT), objtool neglects to adjust the stack
offset when there are subsequent pushes or pops.  This results in bad
ORC data at the end of the ENTER_IRQ_STACK macro, when it puts the
previous stack pointer on the stack and does a subsequent push.

This fixes the following unwinder warning:

  WARNING: can't dereference registers at 00000000f0a6bdba for ip interrupt_entry+0x9f/0xa0

Fixes: 627fce14809b ("objtool: Add ORC unwind table generation")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Dave Jones <dsj@fb.com>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Joe Mario <jmario@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/853d5d691b29e250333332f09b8e27410b2d9924.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
iocost: protect iocg->abs_vdebt with iocg->waitq.lock 2020-05-14T05:59:25+00:00 Tejun Heo tj@kernel.org 2020-05-04T23:27:54+00:00 0c44725e4f1e77a59f00d6941c3dbc8d3a8c6dd4 commit 0b80f9866e6bbfb905140ed8787ff2af03652c0c upstream. abs_vdebt is an atomic_64 which tracks how much over budget a given cgroup is and controls the activation of use_delay mechanism. Once a cgroup goes over budget from forced IOs, it has to pay it back with its future budget. The progress guarantee on debt paying comes from the iocg being active - active iocgs are processed by the periodic timer, which ensures that as time passes the debts dissipate and the iocg returns to normal operation. However, both iocg activation and vdebt handling are asynchronous and a sequence like the following may happen. 1. The iocg is in the process of being deactivated by the periodic timer. 2. A bio enters ioc_rqos_throttle(), calls iocg_activate() which returns without anything because it still sees that the iocg is already active. 3. The iocg is deactivated. 4. The bio from #2 is over budget but needs to be forced. It increases abs_vdebt and goes over the threshold and enables use_delay. 5. IO control is enabled for the iocg's subtree and now IOs are attributed to the descendant cgroups and the iocg itself no longer issues IOs. This leaves the iocg with stuck abs_vdebt - it has debt but inactive and no further IOs which can activate it. This can end up unduly punishing all the descendants cgroups. The usual throttling path has the same issue - the iocg must be active while throttled to ensure that future event will wake it up - and solves the problem by synchronizing the throttling path with a spinlock. abs_vdebt handling is another form of overage handling and shares a lot of characteristics including the fact that it isn't in the hottest path. This patch fixes the above and other possible races by strictly synchronizing abs_vdebt and use_delay handling with iocg->waitq.lock. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Vlad Dmitriev <vvd@fb.com> Cc: stable@vger.kernel.org # v5.4+ Fixes: e1518f63f246 ("blk-iocost: Don't let merges push vtime into the future") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0b80f9866e6bbfb905140ed8787ff2af03652c0c upstream.

abs_vdebt is an atomic_64 which tracks how much over budget a given cgroup
is and controls the activation of use_delay mechanism. Once a cgroup goes
over budget from forced IOs, it has to pay it back with its future budget.
The progress guarantee on debt paying comes from the iocg being active -
active iocgs are processed by the periodic timer, which ensures that as time
passes the debts dissipate and the iocg returns to normal operation.

However, both iocg activation and vdebt handling are asynchronous and a
sequence like the following may happen.

1. The iocg is in the process of being deactivated by the periodic timer.

2. A bio enters ioc_rqos_throttle(), calls iocg_activate() which returns
   without anything because it still sees that the iocg is already active.

3. The iocg is deactivated.

4. The bio from #2 is over budget but needs to be forced. It increases
   abs_vdebt and goes over the threshold and enables use_delay.

5. IO control is enabled for the iocg's subtree and now IOs are attributed
   to the descendant cgroups and the iocg itself no longer issues IOs.

This leaves the iocg with stuck abs_vdebt - it has debt but inactive and no
further IOs which can activate it. This can end up unduly punishing all the
descendants cgroups.

The usual throttling path has the same issue - the iocg must be active while
throttled to ensure that future event will wake it up - and solves the
problem by synchronizing the throttling path with a spinlock. abs_vdebt
handling is another form of overage handling and shares a lot of
characteristics including the fact that it isn't in the hottest path.

This patch fixes the above and other possible races by strictly
synchronizing abs_vdebt and use_delay handling with iocg->waitq.lock.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vlad Dmitriev <vvd@fb.com>
Cc: stable@vger.kernel.org # v5.4+
Fixes: e1518f63f246 ("blk-iocost: Don't let merges push vtime into the future")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wireguard: socket: remove errant restriction on looping to self 2020-05-14T05:59:20+00:00 Jason A. Donenfeld Jason@zx2c4.com 2020-05-06T21:33:03+00:00 df364086a8c965a453b4a68f6cc2d6f981eda11a [ Upstream commit b673e24aad36981f327a6570412ffa7754de8911 ] It's already possible to create two different interfaces and loop packets between them. This has always been possible with tunnels in the kernel, and isn't specific to wireguard. Therefore, the networking stack already needs to deal with that. At the very least, the packet winds up exceeding the MTU and is discarded at that point. So, since this is already something that happens, there's no need to forbid the not very exceptional case of routing a packet back to the same interface; this loop is no different than others, and we shouldn't special case it, but rather rely on generic handling of loops in general. This also makes it easier to do interesting things with wireguard such as onion routing. At the same time, we add a selftest for this, ensuring that both onion routing works and infinite routing loops do not crash the kernel. We also add a test case for wireguard interfaces nesting packets and sending traffic between each other, as well as the loop in this case too. We make sure to send some throughput-heavy traffic for this use case, to stress out any possible recursion issues with the locks around workqueues. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit b673e24aad36981f327a6570412ffa7754de8911 ]

It's already possible to create two different interfaces and loop
packets between them. This has always been possible with tunnels in the
kernel, and isn't specific to wireguard. Therefore, the networking stack
already needs to deal with that. At the very least, the packet winds up
exceeding the MTU and is discarded at that point. So, since this is
already something that happens, there's no need to forbid the not very
exceptional case of routing a packet back to the same interface; this
loop is no different than others, and we shouldn't special case it, but
rather rely on generic handling of loops in general. This also makes it
easier to do interesting things with wireguard such as onion routing.

At the same time, we add a selftest for this, ensuring that both onion
routing works and infinite routing loops do not crash the kernel. We
also add a test case for wireguard interfaces nesting packets and
sending traffic between each other, as well as the loop in this case
too. We make sure to send some throughput-heavy traffic for this use
case, to stress out any possible recursion issues with the locks around
workqueues.

Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
selftests: net: tcp_mmap: fix SO_RCVLOWAT setting 2020-05-14T05:59:18+00:00 Eric Dumazet edumazet@google.com 2020-05-06T16:21:15+00:00 9ee28b1c107cad5c6270dbab36591621199bc7d3 [ Upstream commit a84724178bd7081cf3bd5b558616dd6a9a4ca63b ] Since chunk_size is no longer an integer, we can not use it directly as an argument of setsockopt(). This patch should fix tcp_mmap for Big Endian kernels. Fixes: 597b01edafac ("selftests: net: avoid ptl lock contention in tcp_mmap") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Arjun Roy <arjunroy@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a84724178bd7081cf3bd5b558616dd6a9a4ca63b ]

Since chunk_size is no longer an integer, we can not
use it directly as an argument of setsockopt().

This patch should fix tcp_mmap for Big Endian kernels.

Fixes: 597b01edafac ("selftests: net: avoid ptl lock contention in tcp_mmap")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
selftests: net: tcp_mmap: clear whole tcp_zerocopy_receive struct 2020-05-14T05:59:18+00:00 Eric Dumazet edumazet@google.com 2020-05-06T03:51:06+00:00 c8c0bc59a7544d2b1e3d910a0622d2de836dfcba [ Upstream commit bf5525f3a8e3248be5aa5defe5aaadd60e1c1ba1 ] We added fields in tcp_zerocopy_receive structure, so make sure to clear all fields to not pass garbage to the kernel. We were lucky because recent additions added 'out' parameters, still we need to clean our reference implementation, before folks copy/paste it. Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.") Fixes: 33946518d493 ("tcp-zerocopy: Return sk_err (if set) along with tcp receive zerocopy.") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Arjun Roy <arjunroy@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit bf5525f3a8e3248be5aa5defe5aaadd60e1c1ba1 ]

We added fields in tcp_zerocopy_receive structure,
so make sure to clear all fields to not pass garbage to the kernel.

We were lucky because recent additions added 'out' parameters,
still we need to clean our reference implementation, before folks
copy/paste it.

Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.")
Fixes: 33946518d493 ("tcp-zerocopy: Return sk_err (if set) along with tcp receive zerocopy.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tools/runqslower: Ensure own vmlinux.h is picked up first 2020-05-10T08:32:51+00:00 Andrii Nakryiko andriin@fb.com 2020-04-22T01:24:07+00:00 549e321c9468f0084ae0239c3668dae10a6220e1 [ Upstream commit dfc55ace9939e1e8703ad37ddbba41aaa31cc0cb ] Reorder include paths to ensure that runqslower sources are picking up vmlinux.h, generated by runqslower's own Makefile. When runqslower is built from selftests/bpf, due to current -I$(BPF_INCLUDE) -I$(OUTPUT) ordering, it might pick up not-yet-complete vmlinux.h, generated by selftests Makefile, which could lead to compilation errors like [0]. So ensure that -I$(OUTPUT) goes first and rely on runqslower's Makefile own dependency chain to ensure vmlinux.h is properly completed before source code relying on it is compiled. [0] https://travis-ci.org/github/libbpf/libbpf/jobs/677905925 Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200422012407.176303-1-andriin@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dfc55ace9939e1e8703ad37ddbba41aaa31cc0cb ]

Reorder include paths to ensure that runqslower sources are picking up
vmlinux.h, generated by runqslower's own Makefile. When runqslower is built
from selftests/bpf, due to current -I$(BPF_INCLUDE) -I$(OUTPUT) ordering, it
might pick up not-yet-complete vmlinux.h, generated by selftests Makefile,
which could lead to compilation errors like [0]. So ensure that -I$(OUTPUT)
goes first and rely on runqslower's Makefile own dependency chain to ensure
vmlinux.h is properly completed before source code relying on it is compiled.

  [0] https://travis-ci.org/github/libbpf/libbpf/jobs/677905925

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200422012407.176303-1-andriin@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests/ipc: Fix test failure seen after initial test run 2020-05-10T08:32:43+00:00 Tyler Hicks tyhicks@linux.microsoft.com 2020-04-13T20:21:45+00:00 8079acfe5b45d5601a399ba4e938ed75d8dc68c2 [ Upstream commit b87080eab4c1377706c113fc9c0157f19ea8fed1 ] After successfully running the IPC msgque test once, subsequent runs result in a test failure: $ sudo ./run_kselftest.sh TAP version 13 1..1 # selftests: ipc: msgque # Failed to get stats for IPC queue with id 0 # Failed to dump queue: -22 # Bail out! # # Pass 0 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0 not ok 1 selftests: ipc: msgque # exit=1 The dump_queue() function loops through the possible message queue index values using calls to msgctl(kern_id, MSG_STAT, ...) where kern_id represents the index value. The first time the test is ran, the initial index value of 0 is valid and the test is able to complete. The index value of 0 is not valid in subsequent test runs and the loop attempts to try index values of 1, 2, 3, and so on until a valid index value is found that corresponds to the message queue created earlier in the test. The msgctl() syscall returns -1 and sets errno to EINVAL when invalid index values are used. The test failure is caused by incorrectly comparing errno to -EINVAL when cycling through possible index values. Fix invalid test failures on subsequent runs of the msgque test by correctly comparing errno values to a non-negated EINVAL. Fixes: 3a665531a3b7 ("selftests: IPC message queue copy feature test") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b87080eab4c1377706c113fc9c0157f19ea8fed1 ]

After successfully running the IPC msgque test once, subsequent runs
result in a test failure:

  $ sudo ./run_kselftest.sh
  TAP version 13
  1..1
  # selftests: ipc: msgque
  # Failed to get stats for IPC queue with id 0
  # Failed to dump queue: -22
  # Bail out!
  # # Pass 0 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
  not ok 1 selftests: ipc: msgque # exit=1

The dump_queue() function loops through the possible message queue index
values using calls to msgctl(kern_id, MSG_STAT, ...) where kern_id
represents the index value. The first time the test is ran, the initial
index value of 0 is valid and the test is able to complete. The index
value of 0 is not valid in subsequent test runs and the loop attempts to
try index values of 1, 2, 3, and so on until a valid index value is
found that corresponds to the message queue created earlier in the test.

The msgctl() syscall returns -1 and sets errno to EINVAL when invalid
index values are used. The test failure is caused by incorrectly
comparing errno to -EINVAL when cycling through possible index values.

Fix invalid test failures on subsequent runs of the msgque test by
correctly comparing errno values to a non-negated EINVAL.

Fixes: 3a665531a3b7 ("selftests: IPC message queue copy feature test")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Revert "Kernel selftests: tpm2: check for tpm support" 2020-05-10T08:32:43+00:00 Jarkko Sakkinen jarkko.sakkinen@linux.intel.com 2020-04-12T14:23:07+00:00 b668423c13b012e6e14b2faf4e9da6c544d70fbb [ Upstream commit aaa2d92efe1f972567f1691b423ab8dc606ab3a9 ] This reverts commit b32694cd0724d4ceca2c62cc7c3d3a8d1ffa11fc. The original comment was neither reviewed nor tested. Thus, this the *only* possible action to take. Cc: Nikita Sobolev <Nikita.Sobolev@synopsys.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aaa2d92efe1f972567f1691b423ab8dc606ab3a9 ]

This reverts commit b32694cd0724d4ceca2c62cc7c3d3a8d1ffa11fc.

The original comment was neither reviewed nor tested. Thus, this the
*only* possible action to take.

Cc: Nikita Sobolev <Nikita.Sobolev@synopsys.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: vm: Fix 64-bit test builds for powerpc64le 2020-05-10T08:32:43+00:00 Sandipan Das sandipan@linux.ibm.com 2020-01-30T07:01:19+00:00 c03b7f4d2422eaf50f843511ba5f22e764879692 [ Upstream commit 963e3e9c9a127013eb4d3c82eb997068b1adbb89 ] Some tests are built only for 64-bit systems. This makes sure that these tests are built for both big and little endian variants of powerpc64. Fixes: 7549b3364201 ("selftests: vm: Build/Run 64bit tests only on 64bit arch") Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 963e3e9c9a127013eb4d3c82eb997068b1adbb89 ]

Some tests are built only for 64-bit systems. This makes
sure that these tests are built for both big and little
endian variants of powerpc64.

Fixes: 7549b3364201 ("selftests: vm: Build/Run 64bit tests only on 64bit arch")
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests: vm: Do not override definition of ARCH 2020-05-10T08:32:43+00:00 Sandipan Das sandipan@linux.ibm.com 2020-01-30T07:01:18+00:00 036b7355ea0b6574d470b9d1a1f3b001801fd8ad [ Upstream commit 24c3f063c57b2a8ae21b259bcfa7690e2eb56dd9 ] Independent builds of the vm selftests is currently broken because commit 7549b3364201 ("selftests: vm: Build/Run 64bit tests only on 64bit arch") overrides the value of ARCH with the machine name from uname. This does not always match the architecture names used for tasks like header installation. E.g. for building tests on powerpc64, we need ARCH=powerpc and not ARCH=ppc64 or ARCH=ppc64le. Otherwise, the build fails as shown below. $ uname -m ppc64le $ make -C tools/testing/selftests/vm make: Entering directory '/home/sandipan/linux/tools/testing/selftests/vm' make --no-builtin-rules ARCH=ppc64le -C ../../../.. headers_install make[1]: Entering directory '/home/sandipan/linux' Makefile:653: arch/ppc64le/Makefile: No such file or directory make[1]: *** No rule to make target 'arch/ppc64le/Makefile'. Stop. make[1]: Leaving directory '/home/sandipan/linux' ../lib.mk:50: recipe for target 'khdr' failed make: *** [khdr] Error 2 make: Leaving directory '/home/sandipan/linux/tools/testing/selftests/vm' Fixes: 7549b3364201 ("selftests: vm: Build/Run 64bit tests only on 64bit arch") Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 24c3f063c57b2a8ae21b259bcfa7690e2eb56dd9 ]

Independent builds of the vm selftests is currently broken because
commit 7549b3364201 ("selftests: vm: Build/Run 64bit tests only on
64bit arch") overrides the value of ARCH with the machine name from
uname. This does not always match the architecture names used for
tasks like header installation.

E.g. for building tests on powerpc64, we need ARCH=powerpc
and not ARCH=ppc64 or ARCH=ppc64le. Otherwise, the build
fails as shown below.

  $ uname -m
  ppc64le

  $ make -C tools/testing/selftests/vm
  make: Entering directory '/home/sandipan/linux/tools/testing/selftests/vm'
  make --no-builtin-rules ARCH=ppc64le -C ../../../.. headers_install
  make[1]: Entering directory '/home/sandipan/linux'
  Makefile:653: arch/ppc64le/Makefile: No such file or directory
  make[1]: *** No rule to make target 'arch/ppc64le/Makefile'.  Stop.
  make[1]: Leaving directory '/home/sandipan/linux'
  ../lib.mk:50: recipe for target 'khdr' failed
  make: *** [khdr] Error 2
  make: Leaving directory '/home/sandipan/linux/tools/testing/selftests/vm'

Fixes: 7549b3364201 ("selftests: vm: Build/Run 64bit tests only on 64bit arch")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>