linux-stable.git/tools/testing/selftests/vm, branch v5.17.7 Linux kernel stable tree selftest/vm: verify remap destination address in mremap_test 2022-05-12T10:32:43+00:00 Sidhartha Kumar sidhartha.kumar@oracle.com 2022-04-21T23:35:52+00:00 0f9ac350c07795b3e7e6ba2362cf601e1b585fb5 [ Upstream commit 18d609daa546c919fd36b62a7b510c18de4b4af8 ] Because mremap does not have a MAP_FIXED_NOREPLACE flag, it can destroy existing mappings. This causes a segfault when regions such as text are remapped and the permissions are changed. Verify the requested mremap destination address does not overlap any existing mappings by using mmap's MAP_FIXED_NOREPLACE flag. Keep incrementing the destination address until a valid mapping is found or fail the current test once the max address is reached. Link: https://lkml.kernel.org/r/20220420215721.4868-2-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> 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 18d609daa546c919fd36b62a7b510c18de4b4af8 ]

Because mremap does not have a MAP_FIXED_NOREPLACE flag, it can destroy
existing mappings.  This causes a segfault when regions such as text are
remapped and the permissions are changed.

Verify the requested mremap destination address does not overlap any
existing mappings by using mmap's MAP_FIXED_NOREPLACE flag.  Keep
incrementing the destination address until a valid mapping is found or
fail the current test once the max address is reached.

Link: https://lkml.kernel.org/r/20220420215721.4868-2-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
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>
selftest/vm: verify mmap addr in mremap_test 2022-05-12T10:32:43+00:00 Sidhartha Kumar sidhartha.kumar@oracle.com 2022-04-21T23:35:49+00:00 77463d49e03b4b5587012c127d78297dc1e3b10b [ Upstream commit 9c85a9bae267f6b5e5e374d0d023bbbe9db096d3 ] Avoid calling mmap with requested addresses that are less than the system's mmap_min_addr. When run as root, mmap returns EACCES when trying to map addresses < mmap_min_addr. This is not one of the error codes for the condition to retry the mmap in the test. Rather than arbitrarily retrying on EACCES, don't attempt an mmap until addr > vm.mmap_min_addr. Add a munmap call after an alignment check as the mappings are retained after the retry and can reach the vm.max_map_count sysctl. Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> 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 9c85a9bae267f6b5e5e374d0d023bbbe9db096d3 ]

Avoid calling mmap with requested addresses that are less than the
system's mmap_min_addr.  When run as root, mmap returns EACCES when
trying to map addresses < mmap_min_addr.  This is not one of the error
codes for the condition to retry the mmap in the test.

Rather than arbitrarily retrying on EACCES, don't attempt an mmap until
addr > vm.mmap_min_addr.

Add a munmap call after an alignment check as the mappings are retained
after the retry and can reach the vm.max_map_count sysctl.

Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
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>
selftest/vm: verify remap destination address in mremap_test 2022-05-09T07:16:28+00:00 Sidhartha Kumar sidhartha.kumar@oracle.com 2022-04-21T23:35:52+00:00 373c331da4ab83d98c745accd6c1743c7f604f77 [ Upstream commit 18d609daa546c919fd36b62a7b510c18de4b4af8 ] Because mremap does not have a MAP_FIXED_NOREPLACE flag, it can destroy existing mappings. This causes a segfault when regions such as text are remapped and the permissions are changed. Verify the requested mremap destination address does not overlap any existing mappings by using mmap's MAP_FIXED_NOREPLACE flag. Keep incrementing the destination address until a valid mapping is found or fail the current test once the max address is reached. Link: https://lkml.kernel.org/r/20220420215721.4868-2-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> 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 18d609daa546c919fd36b62a7b510c18de4b4af8 ]

Because mremap does not have a MAP_FIXED_NOREPLACE flag, it can destroy
existing mappings.  This causes a segfault when regions such as text are
remapped and the permissions are changed.

Verify the requested mremap destination address does not overlap any
existing mappings by using mmap's MAP_FIXED_NOREPLACE flag.  Keep
incrementing the destination address until a valid mapping is found or
fail the current test once the max address is reached.

Link: https://lkml.kernel.org/r/20220420215721.4868-2-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
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>
selftest/vm: verify mmap addr in mremap_test 2022-05-09T07:16:28+00:00 Sidhartha Kumar sidhartha.kumar@oracle.com 2022-04-21T23:35:49+00:00 2d93e9af7a96db716257353c1b2d2be5e628398b [ Upstream commit 9c85a9bae267f6b5e5e374d0d023bbbe9db096d3 ] Avoid calling mmap with requested addresses that are less than the system's mmap_min_addr. When run as root, mmap returns EACCES when trying to map addresses < mmap_min_addr. This is not one of the error codes for the condition to retry the mmap in the test. Rather than arbitrarily retrying on EACCES, don't attempt an mmap until addr > vm.mmap_min_addr. Add a munmap call after an alignment check as the mappings are retained after the retry and can reach the vm.max_map_count sysctl. Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> 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 9c85a9bae267f6b5e5e374d0d023bbbe9db096d3 ]

Avoid calling mmap with requested addresses that are less than the
system's mmap_min_addr.  When run as root, mmap returns EACCES when
trying to map addresses < mmap_min_addr.  This is not one of the error
codes for the condition to retry the mmap in the test.

Rather than arbitrarily retrying on EACCES, don't attempt an mmap until
addr > vm.mmap_min_addr.

Add a munmap call after an alignment check as the mappings are retained
after the retry and can reach the vm.max_map_count sysctl.

Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
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: vm: remove dependecy from internal kernel macros 2022-04-08T11:57:49+00:00 Muhammad Usama Anjum usama.anjum@collabora.com 2022-01-19T10:15:31+00:00 ce99e83551b1ba020dc6be8a96594068abf3e530 [ Upstream commit 681696862bc1823595c05960a83766d1aa965c17 ] The defination of swap() is used from kernel's internal header when this test is built in source tree. The build fails when this test is built out of source tree as defination of swap() isn't found. Selftests shouldn't depend on kernel's internal header files. They can only depend on uapi header files. Add the defination of swap() to fix the build error: gcc -Wall -I/linux_mainline2/build/usr/include -no-pie userfaultfd.c -lrt -lpthread -o /linux_mainline2/build/kselftest/vm/userfaultfd userfaultfd.c: In function ‘userfaultfd_stress’: userfaultfd.c:1530:3: warning: implicit declaration of function ‘swap’; did you mean ‘swab’? [-Wimplicit-function-declaration] 1530 | swap(area_src, area_dst); | ^~~~ | swab /usr/bin/ld: /tmp/cclUUH7V.o: in function `userfaultfd_stress': userfaultfd.c:(.text+0x4d64): undefined reference to `swap' /usr/bin/ld: userfaultfd.c:(.text+0x4d82): undefined reference to `swap' collect2: error: ld returned 1 exit status Fixes: 2c769ed7137a ("tools/testing/selftests/vm/userfaultfd.c: use swap() to make code cleaner") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 681696862bc1823595c05960a83766d1aa965c17 ]

The defination of swap() is used from kernel's internal header when this
test is built in source tree. The build fails when this test is built
out of source tree as defination of swap() isn't found. Selftests
shouldn't depend on kernel's internal header files. They can only depend
on uapi header files. Add the defination of swap() to fix the build
error:

	gcc -Wall  -I/linux_mainline2/build/usr/include -no-pie    userfaultfd.c -lrt -lpthread -o /linux_mainline2/build/kselftest/vm/userfaultfd
	userfaultfd.c: In function ‘userfaultfd_stress’:
	userfaultfd.c:1530:3: warning: implicit declaration of function ‘swap’; did you mean ‘swab’? [-Wimplicit-function-declaration]
	 1530 |   swap(area_src, area_dst);
	      |   ^~~~
	      |   swab
	/usr/bin/ld: /tmp/cclUUH7V.o: in function `userfaultfd_stress':
	userfaultfd.c:(.text+0x4d64): undefined reference to `swap'
	/usr/bin/ld: userfaultfd.c:(.text+0x4d82): undefined reference to `swap'
	collect2: error: ld returned 1 exit status

Fixes: 2c769ed7137a ("tools/testing/selftests/vm/userfaultfd.c: use swap() to make code cleaner")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests, x86: fix how check_cc.sh is being invoked 2022-04-08T11:57:41+00:00 Guillaume Tucker guillaume.tucker@collabora.com 2022-03-22T21:41:44+00:00 8c88b263c9a2ed13e5bc71477fb2323ce394ca0f [ Upstream commit ef696f93ed9778d570bd5ac58414421cdd4f1aab ] The $(CC) variable used in Makefiles could contain several arguments such as "ccache gcc". These need to be passed as a single string to check_cc.sh, otherwise only the first argument will be used as the compiler command. Without quotes, the $(CC) variable is passed as distinct arguments which causes the script to fail to build trivial programs. Fix this by adding quotes around $(CC) when calling check_cc.sh to pass the whole string as a single argument to the script even if it has several words such as "ccache gcc". Link: https://lkml.kernel.org/r/d0d460d7be0107a69e3c52477761a6fe694c1840.1646991629.git.guillaume.tucker@collabora.com Fixes: e9886ace222e ("selftests, x86: Rework x86 target architecture detection") Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com> Tested-by: "kernelci.org bot" <bot@kernelci.org> Reviewed-by: Guenter Roeck <groeck@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> 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 ef696f93ed9778d570bd5ac58414421cdd4f1aab ]

The $(CC) variable used in Makefiles could contain several arguments
such as "ccache gcc".  These need to be passed as a single string to
check_cc.sh, otherwise only the first argument will be used as the
compiler command.  Without quotes, the $(CC) variable is passed as
distinct arguments which causes the script to fail to build trivial
programs.

Fix this by adding quotes around $(CC) when calling check_cc.sh to pass
the whole string as a single argument to the script even if it has
several words such as "ccache gcc".

Link: https://lkml.kernel.org/r/d0d460d7be0107a69e3c52477761a6fe694c1840.1646991629.git.guillaume.tucker@collabora.com
Fixes: e9886ace222e ("selftests, x86: Rework x86 target architecture detection")
Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Tested-by: "kernelci.org bot" <bot@kernelci.org>
Reviewed-by: Guenter Roeck <groeck@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
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: vm: fix clang build error multiple output files 2022-03-17T18:02:13+00:00 Yosry Ahmed yosryahmed@google.com 2022-03-16T23:15:12+00:00 1c4debc443ef7037dcb7c4f08c33b9caebd21d2e When building the vm selftests using clang, some errors are seen due to having headers in the compilation command: clang -Wall -I ../../../../usr/include -no-pie gup_test.c ../../../../mm/gup_test.h -lrt -lpthread -o .../tools/testing/selftests/vm/gup_test clang: error: cannot specify -o when generating multiple output files make[1]: *** [../lib.mk:146: .../tools/testing/selftests/vm/gup_test] Error 1 Rework to add the header files to LOCAL_HDRS before including ../lib.mk, since the dependency is evaluated in '$(OUTPUT)/%:%.c $(LOCAL_HDRS)' in file lib.mk. Link: https://lkml.kernel.org/r/20220304000645.1888133-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
When building the vm selftests using clang, some errors are seen due to
having headers in the compilation command:

  clang -Wall -I ../../../../usr/include  -no-pie    gup_test.c ../../../../mm/gup_test.h -lrt -lpthread -o .../tools/testing/selftests/vm/gup_test
  clang: error: cannot specify -o when generating multiple output files
  make[1]: *** [../lib.mk:146: .../tools/testing/selftests/vm/gup_test] Error 1

Rework to add the header files to LOCAL_HDRS before including ../lib.mk,
since the dependency is evaluated in '$(OUTPUT)/%:%.c $(LOCAL_HDRS)' in
file lib.mk.

Link: https://lkml.kernel.org/r/20220304000645.1888133-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kselftest/vm: fix tests build with old libc 2022-03-05T19:08:32+00:00 Chengming Zhou zhouchengming@bytedance.com 2022-03-05T04:29:04+00:00 b773827e361952b3f53ac6fa4c4e39ccd632102e The error message when I build vm tests on debian10 (GLIBC 2.28): userfaultfd.c: In function `userfaultfd_pagemap_test': userfaultfd.c:1393:37: error: `MADV_PAGEOUT' undeclared (first use in this function); did you mean `MADV_RANDOM'? if (madvise(area_dst, test_pgsize, MADV_PAGEOUT)) ^~~~~~~~~~~~ MADV_RANDOM This patch includes these newer definitions from UAPI linux/mman.h, is useful to fix tests build on systems without these definitions in glibc sys/mman.h. Link: https://lkml.kernel.org/r/20220227055330.43087-2-zhouchengming@bytedance.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The error message when I build vm tests on debian10 (GLIBC 2.28):

    userfaultfd.c: In function `userfaultfd_pagemap_test':
    userfaultfd.c:1393:37: error: `MADV_PAGEOUT' undeclared (first use
    in this function); did you mean `MADV_RANDOM'?
      if (madvise(area_dst, test_pgsize, MADV_PAGEOUT))
                                         ^~~~~~~~~~~~
                                         MADV_RANDOM

This patch includes these newer definitions from UAPI linux/mman.h, is
useful to fix tests build on systems without these definitions in glibc
sys/mman.h.

Link: https://lkml.kernel.org/r/20220227055330.43087-2-zhouchengming@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
selftests/vm: cleanup hugetlb file after mremap test 2022-03-05T19:08:32+00:00 Mike Kravetz mike.kravetz@oracle.com 2022-03-05T04:28:48+00:00 ff712a627f7296a42ea5d7356704525e1e909e05 The hugepage-mremap test will create a file in a hugetlb filesystem. In a default 'run_vmtests' run, the file will contain all the hugetlb pages. After the test, the file remains and there are no free hugetlb pages for subsequent tests. This causes those hugetlb tests to fail. Change hugepage-mremap to take the name of the hugetlb file as an argument. Unlink the file within the test, and just to be sure remove the file in the run_vmtests script. Link: https://lkml.kernel.org/r/20220201033459.156944-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Yosry Ahmed <yosryahmed@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The hugepage-mremap test will create a file in a hugetlb filesystem.  In
a default 'run_vmtests' run, the file will contain all the hugetlb
pages.  After the test, the file remains and there are no free hugetlb
pages for subsequent tests.  This causes those hugetlb tests to fail.

Change hugepage-mremap to take the name of the hugetlb file as an
argument.  Unlink the file within the test, and just to be sure remove
the file in the run_vmtests script.

Link: https://lkml.kernel.org/r/20220201033459.156944-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
selftest/vm: fix map_fixed_noreplace test failure 2022-02-26T17:51:17+00:00 Aneesh Kumar K.V aneesh.kumar@linux.ibm.com 2022-02-26T03:11:08+00:00 f39c58008dee7ab5fc94c3f1995a21e886801df0 On the latest RHEL the test fails due to executable mapped at 256MB address # ./map_fixed_noreplace mmap() @ 0x10000000-0x10050000 p=0xffffffffffffffff result=File exists 10000000-10010000 r-xp 00000000 fd:04 34905657 /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace 10010000-10020000 r--p 00000000 fd:04 34905657 /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace 10020000-10030000 rw-p 00010000 fd:04 34905657 /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace 10029b90000-10029bc0000 rw-p 00000000 00:00 0 [heap] 7fffbb510000-7fffbb750000 r-xp 00000000 fd:04 24534 /usr/lib64/libc.so.6 7fffbb750000-7fffbb760000 r--p 00230000 fd:04 24534 /usr/lib64/libc.so.6 7fffbb760000-7fffbb770000 rw-p 00240000 fd:04 24534 /usr/lib64/libc.so.6 7fffbb780000-7fffbb7a0000 r--p 00000000 00:00 0 [vvar] 7fffbb7a0000-7fffbb7b0000 r-xp 00000000 00:00 0 [vdso] 7fffbb7b0000-7fffbb800000 r-xp 00000000 fd:04 24514 /usr/lib64/ld64.so.2 7fffbb800000-7fffbb810000 r--p 00040000 fd:04 24514 /usr/lib64/ld64.so.2 7fffbb810000-7fffbb820000 rw-p 00050000 fd:04 24514 /usr/lib64/ld64.so.2 7fffd93f0000-7fffd9420000 rw-p 00000000 00:00 0 [stack] Error: couldn't map the space we need for the test Fix this by finding a free address using mmap instead of hardcoding BASE_ADDRESS. Link: https://lkml.kernel.org/r/20220217083417.373823-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Jann Horn <jannh@google.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
On the latest RHEL the test fails due to executable mapped at 256MB
address

     # ./map_fixed_noreplace
    mmap() @ 0x10000000-0x10050000 p=0xffffffffffffffff result=File exists
    10000000-10010000 r-xp 00000000 fd:04 34905657                           /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace
    10010000-10020000 r--p 00000000 fd:04 34905657                           /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace
    10020000-10030000 rw-p 00010000 fd:04 34905657                           /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace
    10029b90000-10029bc0000 rw-p 00000000 00:00 0                            [heap]
    7fffbb510000-7fffbb750000 r-xp 00000000 fd:04 24534                      /usr/lib64/libc.so.6
    7fffbb750000-7fffbb760000 r--p 00230000 fd:04 24534                      /usr/lib64/libc.so.6
    7fffbb760000-7fffbb770000 rw-p 00240000 fd:04 24534                      /usr/lib64/libc.so.6
    7fffbb780000-7fffbb7a0000 r--p 00000000 00:00 0                          [vvar]
    7fffbb7a0000-7fffbb7b0000 r-xp 00000000 00:00 0                          [vdso]
    7fffbb7b0000-7fffbb800000 r-xp 00000000 fd:04 24514                      /usr/lib64/ld64.so.2
    7fffbb800000-7fffbb810000 r--p 00040000 fd:04 24514                      /usr/lib64/ld64.so.2
    7fffbb810000-7fffbb820000 rw-p 00050000 fd:04 24514                      /usr/lib64/ld64.so.2
    7fffd93f0000-7fffd9420000 rw-p 00000000 00:00 0                          [stack]
    Error: couldn't map the space we need for the test

Fix this by finding a free address using mmap instead of hardcoding
BASE_ADDRESS.

Link: https://lkml.kernel.org/r/20220217083417.373823-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>