[ Upstream commit 1a251f52cf ]
This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics. The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.
These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:
- trivial duplicated macro definitions have been removed
Note that 'trivial' here means that it's obviously kernel code that
already included all the major kernel headers, and thus gets the new
generic MIN/MAX macros automatically.
- non-trivial duplicated macro definitions are guarded with #ifndef
This is the "yes, they define their own versions, but no, the include
situation is not entirely obvious, and maybe they don't get the
generic version automatically" case.
- strange use case #1
A couple of drivers decided that the way they want to describe their
versioning is with
#define MAJ 1
#define MIN 2
#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)
which adds zero value and I just did my Alexander the Great
impersonation, and rewrote that pointless Gordian knot as
#define DRV_VERSION "1.2"
instead.
- strange use case #2
A couple of drivers thought that it's a good idea to have a random
'MIN' or 'MAX' define for a value or index into a table, rather than
the traditional macro that takes arguments.
These values were re-written as C enum's instead. The new
function-line macros only expand when followed by an open
parenthesis, and thus don't clash with enum use.
Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.
Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab00ddd802 upstream.
When running mm selftest to verify mm patches, 'compaction_test' case
failed on an x86 server with 1TB memory. And the root cause is that it
has too much free memory than what the test supports.
The test case tries to allocate 100000 huge pages, which is about 200 GB
for that x86 server, and when it succeeds, it expects it's large than 1/3
of 80% of the free memory in system. This logic only works for platform
with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false
alarm for others.
Fix it by changing the fixed page number to self-adjustable number
according to the real number of free memory.
Link: https://lkml.kernel.org/r/20250423103645.2758-1-feng.tang@linux.alibaba.com
Fixes: bd67d5c15c ("Test compaction of mlocked memory")
Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
Acked-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@inux.alibaba.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sri Jayaramappa <sjayaram@akamai.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9c02223e2d ]
Currently if the filesystem for the cgroups version it wants to use is not
mounted charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh tests
will attempt to mount it on the hard coded path /dev/cgroup/memory,
deleting that directory when the test finishes. This will fail if there
is not a preexisting directory at that path, and since the directory is
deleted subsequent runs of the test will fail. Instead of relying on this
hard coded directory name use mktemp to generate a temporary directory to
use as a mountpoint, fixing both the assumption and the disruption caused
by deleting a preexisting directory.
This means that if the relevant cgroup filesystem is not already mounted
then we rely on having coreutils (which provides mktemp) installed. I
suspect that many current users are relying on having things automounted
by default, and given that the script relies on bash it's probably not an
unreasonable requirement.
Link: https://lkml.kernel.org/r/20250404-kselftest-mm-cgroup2-detection-v1-1-3dba6d32ba8c@kernel.org
Fixes: 209376ed2a ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 76503e1fa1 ]
The hmm2 double_map test was failing due to an incorrect buffer->mirror
size. The buffer->mirror size was 6, while buffer->ptr size was 6 *
PAGE_SIZE. The test failed because the kernel's copy_to_user function was
attempting to copy a 6 * PAGE_SIZE buffer to buffer->mirror. Since the
size of buffer->mirror was incorrect, copy_to_user failed.
This patch corrects the buffer->mirror size to 6 * PAGE_SIZE.
Test Result without this patch
==============================
# RUN hmm2.hmm2_device_private.double_map ...
# hmm-tests.c:1680:double_map:Expected ret (-14) == 0 (0)
# double_map: Test terminated by assertion
# FAIL hmm2.hmm2_device_private.double_map
not ok 53 hmm2.hmm2_device_private.double_map
Test Result with this patch
===========================
# RUN hmm2.hmm2_device_private.double_map ...
# OK hmm2.hmm2_device_private.double_map
ok 53 hmm2.hmm2_device_private.double_map
Link: https://lkml.kernel.org/r/20240927050752.51066-1-donettom@linux.ibm.com
Fixes: fee9f6d1b8 ("mm/hmm/test: add selftests for HMM")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c41a701d18 ]
Currently, running the charge_reserved_hugetlb.sh selftest we can
sometimes observe something like:
$ ./charge_reserved_hugetlb.sh -cgroup-v2
...
write_result is 0
After write:
hugetlb_usage=0
reserved_usage=10485760
killing write_to_hugetlbfs
Received 2.
Deleting the memory
Detach failure: Invalid argument
umount: /mnt/huge: target is busy.
Both cases are issues in the test.
While the unmount error seems to be racy, it will make the test fail:
$ ./run_vmtests.sh -t hugetlb
...
# [FAIL]
not ok 10 charge_reserved_hugetlb.sh -cgroup-v2 # exit=32
The issue is that we are not waiting for the write_to_hugetlbfs process to
quit. So it might still have a hugetlbfs file open, about which umount is
not happy. Fix that by making "killall" wait for the process to quit.
The other error ("Detach failure: Invalid argument") does not seem to
result in a test error, but is misleading. Turns out write_to_hugetlbfs.c
unconditionally tries to cleanup using shmdt(), even when we only
mmap()'ed a hugetlb file. Even worse, shmaddr is never even set for the
SHM case. Fix that as well.
With this change it seems to work as expected.
Link: https://lkml.kernel.org/r/20240821123115.2068812-1-david@redhat.com
Fixes: 29750f71a9 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d4202e66a4 ]
Patch series "Fixes for compaction_test", v2.
The compaction_test memory selftest introduces fragmentation in memory
and then tries to allocate as many hugepages as possible. This series
addresses some problems.
On Aarch64, if nr_hugepages == 0, then the test trivially succeeds since
compaction_index becomes 0, which is less than 3, due to no division by
zero exception being raised. We fix that by checking for division by
zero.
Secondly, correctly set the number of hugepages to zero before trying
to set a large number of them.
Now, consider a situation in which, at the start of the test, a non-zero
number of hugepages have been already set (while running the entire
selftests/mm suite, or manually by the admin). The test operates on 80%
of memory to avoid OOM-killer invocation, and because some memory is
already blocked by hugepages, it would increase the chance of OOM-killing.
Also, since mem_free used in check_compaction() is the value before we
set nr_hugepages to zero, the chance that the compaction_index will
be small is very high if the preset nr_hugepages was high, leading to a
bogus test success.
This patch (of 3):
Currently, if at runtime we are not able to allocate a huge page, the test
will trivially pass on Aarch64 due to no exception being raised on
division by zero while computing compaction_index. Fix that by checking
for nr_hugepages == 0. Anyways, in general, avoid a division by zero by
exiting the program beforehand. While at it, fix a typo, and handle the
case where the number of hugepages may overflow an integer.
Link: https://lkml.kernel.org/r/20240521074358.675031-1-dev.jain@arm.com
Link: https://lkml.kernel.org/r/20240521074358.675031-2-dev.jain@arm.com
Fixes: bd67d5c15c ("Test compaction of mlocked memory")
Signed-off-by: Dev Jain <dev.jain@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sri Jayaramappa <sjayaram@akamai.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 0d29b474fb which is
commit 91b80cc5b3 upstream.
map_hugetlb.c:18:10: fatal error: vm_util.h: No such file or directory
18 | #include "vm_util.h"
| ^~~~~~~~~~~
compilation terminated.
vm_util.h is not present in 5.15.y, as commit:642bc52aed9c ("selftests:
vm: bring common functions to a new file") is not present in stable
kernels <=6.1.y
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
commit e89908201e upstream.
ARRAY_SIZE is defined in several selftests. Remove definitions from
individual test files and include header file for the define instead.
ARRAY_SIZE define is added in a separate patch to prepare for this
change.
Remove ARRAY_SIZE from vm tests and pickup the one defined in
kselftest.h.
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: Kyle Huey <me@kylehuey.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e8b9989597.
The upstream commit 9c85a9bae2 ("selftest/vm: verify mmap addr in
mremap_test") was backported as commit a17404fcbf ("selftest/vm:
verify mmap addr in mremap_test"). Repeated backport introduced the
duplicate of function get_mmap_min_addr to the file breakign the vm
selftest build.
Fixes: e8b9989597 ("selftest/vm: verify mmap addr in mremap_test")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 0b4e16093e.
The upstream commit 18d609daa5 ("selftest/vm: verify remap destination
address in mremap_test") was backported as commit 2688d967ec
("selftest/vm: verify remap destination address in mremap_test").
Repeated backport introduced the duplicate of function
is_remap_region_valid to the file breakign the vm selftest build.
Fixes: 0b4e16093e ("selftest/vm: verify remap destination address in mremap_test")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 41c240099f ]
The tools/testing/selftests/vm/Makefile uses the variable TARGETS
internally to generate a list of platform-specific binary build targets
suffixed with _{32,64}. When building the selftests using its own
Makefile directly, such as via the following command run in a kernel tree:
One receives an error such as the following:
make: Entering directory '/root/linux/tools/testing/selftests'
make --no-builtin-rules ARCH=x86 -C ../../.. headers_install
make[1]: Entering directory '/root/linux'
INSTALL ./usr/include
make[1]: Leaving directory '/root/linux'
make[1]: Entering directory '/root/linux/tools/testing/selftests/vm'
make[1]: *** No rule to make target 'vm.c', needed by '/root/linux/tools/testing/selftests/vm/vm_64'. Stop.
make[1]: Leaving directory '/root/linux/tools/testing/selftests/vm'
make: *** [Makefile:175: all] Error 2
make: Leaving directory '/root/linux/tools/testing/selftests'
The TARGETS variable passed to tools/testing/selftests/Makefile collides
with the TARGETS used in tools/testing/selftests/vm/Makefile, so rename
the latter to VMTARGETS, eliminating the collision with no functional
change.
Link: https://lkml.kernel.org/r/20220504213454.1282532-1-jsavitz@redhat.com
Fixes: f21fda8f64 ("selftests: vm: pkeys: fix multilib builds for x86")
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Acked-by: Nico Pache <npache@redhat.com>
Cc: Joel Savitz <jsavitz@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 18d609daa5 ]
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 9c85a9bae2 ]
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 18d609daa5 ]
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 9c85a9bae2 ]
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 1c4debc443 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b773827e36 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 209376ed2a ]
The hugetlb cgroup reservation test charge_reserved_hugetlb.sh assume
that no cgroup filesystems are mounted before running the test. That is
not true in many cases. As a result, the test fails to run. Fix that
by querying the current cgroup mount setting and using the existing
cgroup setup instead before attempting to freshly mount a cgroup
filesystem.
Similar change is also made for hugetlb_reparenting_test.sh as well,
though it still has problem if cgroup v2 isn't used.
The patched test scripts were run on a centos 8 based system to verify
that they ran properly.
Link: https://lkml.kernel.org/r/20220106201359.1646575-1-longman@redhat.com
Fixes: 29750f71a9 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Mina Almasry <almasrymina@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.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>
commit 87c01d57fa upstream.
hmm_range_fault() can be used instead of get_user_pages() for devices
which allow faulting however unlike get_user_pages() it will return an
error when used on a VM_MIXEDMAP range.
To make hmm_range_fault() more closely match get_user_pages() remove
this restriction. This requires dealing with the !ARCH_HAS_PTE_SPECIAL
case in hmm_vma_handle_pte(). Rather than replicating the logic of
vm_normal_page() call it directly and do a check for the zero pfn
similar to what get_user_pages() currently does.
Also add a test to hmm selftest to verify functionality.
Link: https://lkml.kernel.org/r/20211104012001.2555676-1-apopple@nvidia.com
Fixes: da4c3c735e ("mm/hmm/mirror: helper to snapshot CPU page table")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f5c7329718 ]
Currently, userfaultfd selftest for hugetlb as run from run_vmtests.sh
or any environment where there are 'just enough' hugetlb pages will
always fail with:
testing events (fork, remap, remove):
ERROR: UFFDIO_COPY error: -12 (errno=12, line=616)
The ENOMEM error code implies there are not enough hugetlb pages.
However, there are free hugetlb pages but they are all reserved. There
is a basic problem with the way the test allocates hugetlb pages which
has existed since the test was originally written.
Due to the way 'cleanup' was done between different phases of the test,
this issue was masked until recently. The issue was uncovered by commit
8ba6e86408 ("userfaultfd/selftests: reinitialize test context in each
test").
For the hugetlb test, src and dst areas are allocated as PRIVATE
mappings of a hugetlb file. This means that at mmap time, pages are
reserved for the src and dst areas. At the start of event testing (and
other tests) the src area is populated which results in allocation of
huge pages to fill the area and consumption of reserves associated with
the area. Then, a child is forked to fault in the dst area. Note that
the dst area was allocated in the parent and hence the parent owns the
reserves associated with the mapping. The child has normal access to
the dst area, but can not use the reserves created/owned by the parent.
Thus, if there are no other huge pages available allocation of a page
for the dst by the child will fail.
Fix by not creating reserves for the dst area. In this way the child
can use free (non-reserved) pages.
Also, MAP_PRIVATE of a file only makes sense if you are interested in
the contents of the file before making a COW copy. The test does not do
this. So, just use MAP_ANONYMOUS | MAP_HUGETLB to create an anonymous
hugetlb mapping. There is no need to create a hugetlb file in the
non-shared case.
Link: https://lkml.kernel.org/r/20211217172919.7861-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mina Almasry <almasrymina@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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
In RHEL's gating selftests we've encountered memory corruption in the
uffd event test even with upstream kernel:
# ./userfaultfd anon 128 4
nr_pages: 32768, nr_pages_per_cpu: 32768
bounces: 3, mode: rnd racing read, userfaults: 6240 missing (6240) 14729 wp (14729)
bounces: 2, mode: racing read, userfaults: 1444 missing (1444) 28877 wp (28877)
bounces: 1, mode: rnd read, userfaults: 6055 missing (6055) 14699 wp (14699)
bounces: 0, mode: read, userfaults: 82 missing (82) 25196 wp (25196)
testing uffd-wp with pagemap (pgsize=4096): done
testing uffd-wp with pagemap (pgsize=2097152): done
testing events (fork, remap, remove): ERROR: nr 32427 memory corruption 0 1 (errno=0, line=963)
ERROR: faulting process failed (errno=0, line=1117)
It can be easily reproduced when global thp enabled, which is the
default for RHEL.
It's also known as a side effect of commit 0db282ba2c ("selftest: use
mmap instead of posix_memalign to allocate memory", 2021-07-23), which
is imho right itself on using mmap() to make sure the addresses will be
untagged even on arm.
The problem is, for each test we allocate buffers using two
allocate_area() calls. We assumed these two buffers won't affect each
other, however they could, because mmap() could have found that the two
buffers are near each other and having the same VMA flags, so they got
merged into one VMA.
It won't be a big problem if thp is not enabled, but when thp is
agressively enabled it means when initializing the src buffer it could
accidentally setup part of the dest buffer too when there's a shared THP
that overlaps the two regions. Then some of the dest buffer won't be
able to be trapped by userfaultfd missing mode, then it'll cause memory
corruption as described.
To fix it, do release_pages() after initializing the src buffer.
Since the previous two release_pages() calls are after
uffd_test_ctx_clear() which will unmap all the buffers anyway (which is
stronger than release pages; as unmap() also tear town pgtables), drop
them as they shouldn't really be anything useful.
We can mark the Fixes tag upon 0db282ba2c as it's reported to only
happen there, however the real "Fixes" IMHO should be 8ba6e86408, as
before that commit we'll always do explicit release_pages() before
registration of uffd, and 8ba6e86408 changed that logic by adding
extra unmap/map and we didn't release the pages at the right place.
Meanwhile I don't have a solid glue anyway on whether posix_memalign()
could always avoid triggering this bug, hence it's safer to attach this
fix to commit 8ba6e86408.
Link: https://lkml.kernel.org/r/20210923232512.210092-1-peterx@redhat.com
Fixes: 8ba6e86408 ("userfaultfd/selftests: reinitialize test context in each test")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1994931
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Li Wang <liwan@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since merged pages are copied every time they need to be modified, the
write access time is different between shared and non-shared pages. Add
ksm_cow_time() function which evaluates latency of these COW breaks.
First, 4000 pages are allocated and the time, required to modify 1 byte in
every other page, is measured. After this, the pages are merged into 2000
pairs and in each pair, 1 page is modified (i.e. they are decoupled) to
detect COW breaks. The time needed to break COW of merged pages is then
compared with performance of non-shared pages.
The test is run as follows: ./ksm_tests -C
The output:
Total size: 15 MiB
Not merged pages:
Total time: 0.002185489 s
Average speed: 3202.945 MiB/s
Merged pages:
Total time: 0.004386872 s
Average speed: 1595.670 MiB/s
Link: https://lkml.kernel.org/r/1d03ee0d1b341959d4b61672c6401d498bff5652.1629386192.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When userfaultfd copy-ioctl fails since the PTE already exists, an -EEXIST
error is returned and the faulting thread is not woken. The current
userfaultfd test does not wake the faulting thread in such case. The
assumption is presumably that another thread set the PTE through copy/wp
ioctl and would wake the faulting thread or that alternatively the fault
handler would realize there is no need to "must_wait" and continue. This
is not necessarily true.
There is an assumption that the "must_wait" tests in handle_userfault()
are sufficient to provide definitive answer whether the offending PTE is
populated or not. However, userfaultfd_must_wait() test is lockless.
Consequently, concurrent calls to ptep_modify_prot_start(), for instance,
can clear the PTE and can cause userfaultfd_must_wait() to wrongly assume
it is not populated and a wait is needed.
There are therefore 3 options:
(1) Change the tests to wake on copy failure.
(2) Wake faulting thread unconditionally on zero/copy ioctls before
returning -EEXIST.
(3) Change the userfaultfd_must_wait() to hold locks.
This patch took the first approach, but the others are valid solutions
with different tradeoffs.
Link: https://lkml.kernel.org/r/20210808020724.1022515-4-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are several test cases in the vm directory are still using exit 0
when they need to be skipped. Use the kselftest framework to skip code
instead so it can help us to distinguish the return status.
Criterion to filter out what should be fixed in vm directory:
grep -r "exit 0" -B1 | grep -i skip
This change might cause some false-positives if people are running these
test scripts directly and only checking their return codes, which will
change from 0 to 4. However I think the impact should be small as most of
our scripts here are already using this skip code. And there will be no
such issue if running them with the kselftest framework.
Link: https://lkml.kernel.org/r/20210823073433.37653-1-po-hsu.lin@canonical.com
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.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 x86, there is a set of instructions used to save and restore register
state collectively known as the XSAVE architecture. There are about a
dozen different features managed with XSAVE. The protection keys
register, PKRU, is one of those features.
The hardware optimizes XSAVE by tracking when the state has not changed
from its initial (init) state. In this case, it can avoid the cost of
writing state to memory (it would usually just be a bunch of 0's).
When the pkey register is 0x0 the hardware optionally choose to track the
register as being in the init state (optimize away the writes). AMD CPUs
do this more aggressively compared to Intel.
On x86, PKRU is rarely in its (very permissive) init state. Instead, the
value defaults to something very restrictive. It is not surprising that
bugs have popped up in the rare cases when PKRU reaches its init state.
Add a protection key selftest which gets the protection keys register into
its init state in a way that should work on Intel and AMD. Then, do a
bunch of pkey register reads to watch for inadvertent changes.
This adds "-mxsave" to CFLAGS for all the x86 vm selftests in order to
allow use of the XSAVE instruction __builtin functions. This will make
the builtins available on all of the vm selftests, but is expected to be
harmless.
Link: https://lkml.kernel.org/r/20210611164202.1849B712@viggo.jf.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pkey test code keeps a "shadow" of the pkey register around. This
ensures that any bugs which might write to the register can be caught more
quickly.
Generally, userspace has a good idea when the kernel is going to write to
the register. For instance, alloc_pkey() is passed a permission mask.
The caller of alloc_pkey() can update the shadow based on the return value
and the mask.
But, the kernel can also modify the pkey register in a more sneaky way.
For mprotect(PROT_EXEC) mappings, the kernel will allocate a pkey and
write the pkey register to create an execute-only mapping. The kernel
never tells userspace what key it uses for this.
This can cause the test to fail with messages like:
protection_keys_64.2: pkey-helpers.h:132: _read_pkey_reg: Assertion `pkey_reg == shadow_pkey_reg' failed.
because the shadow was not updated with the new kernel-set value.
Forcibly update the shadow value immediately after an mprotect().
Link: https://lkml.kernel.org/r/20210611164200.EF76AB73@viggo.jf.intel.com
Fixes: 6af17cf89e ("x86/pkeys/selftests: Add PROT_EXEC test")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "selftests/vm/pkeys: Bug fixes and a new test".
There has been a lot of activity on the x86 front around the XSAVE
architecture which is used to context-switch processor state (among other
things). In addition, AMD has recently joined the protection keys club by
adding processor support for PKU.
The AMD implementation helped uncover a kernel bug around the PKRU "init
state", which actually applied to Intel's implementation but was just
harder to hit. This series adds a test which is expected to help find
this class of bug both on AMD and Intel. All the work around pkeys on x86
also uncovered a few bugs in the selftest.
This patch (of 4):
The "random" pkey allocation code currently does the good old:
srand((unsigned int)time(NULL));
*But*, it unfortunately does this on every random pkey allocation.
There may be thousands of these a second. time() has a one second
resolution. So, each time alloc_random_pkey() is called, the PRNG is
*RESET* to time(). This is nasty. Normally, if you do:
srand(<ANYTHING>);
foo = rand();
bar = rand();
You'll be quite guaranteed that 'foo' and 'bar' are different. But, if
you do:
srand(1);
foo = rand();
srand(1);
bar = rand();
You are quite guaranteed that 'foo' and 'bar' are the *SAME*. The recent
"fix" effectively forced the test case to use the same "random" pkey for
the whole test, unless the test run crossed a second boundary.
Only run srand() once at program startup.
This explains some very odd and persistent test failures I've been seeing.
Link: https://lkml.kernel.org/r/20210611164153.91B76FB8@viggo.jf.intel.com
Link: https://lkml.kernel.org/r/20210611164155.192D00FF@viggo.jf.intel.com
Fixes: 6e373263ce ("selftests/vm/pkeys: fix alloc_random_pkey() to make it really random")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
