Commit Graph

21016 Commits

Author SHA1 Message Date
Thomas Weißschuh
1d57346474 selftests/nolibc: error out on linker warnings
If the linker emits warnings these should abort the build.
Otherwise they will be swallowed by run-tests.sh and not shown.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-11-22 12:35:12 +01:00
Thomas Weißschuh
682bf67529 selftests/nolibc: use lld to link loongarch binaries
LLVM 21 switched to -mcmodel=medium for LoongArch64 compilations.
This code model uses R_LARCH_ECALL36 relocations which might not be
supported by GNU ld which to nolibc testsuite uses by default.
ld will not resolve the relocation and all function calls will end up
as busy loops.

Use lld instead.

We can not switch to lld for all LLVM builds, as it does not support all
necessary architectures.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
2025-11-22 12:35:02 +01:00
Puranjay Mohan
cf49ec5705 selftests: bpf: Add tests for unbalanced rcu_read_lock
As verifier now supports nested rcu critical sections, add new test
cases to make sure unbalanced usage of rcu_read_lock()/unlock() is
rejected.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251117200411.25563-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 18:34:59 -08:00
Puranjay Mohan
4167096cb9 bpf: support nested rcu critical sections
Currently, nested rcu critical sections are rejected by the verifier and
rcu_lock state is managed by a boolean variable. Add support for nested
rcu critical sections by make active_rcu_locks a counter similar to
active_preempt_locks. bpf_rcu_read_lock() increments this counter and
bpf_rcu_read_unlock() decrements it, MEM_RCU -> PTR_UNTRUSTED transition
happens when active_rcu_locks drops to 0.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251117200411.25563-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 18:34:59 -08:00
Eduard Zingerman
8f7cf305a1 bpf: test the correct stack liveness of tail calls
A new test is added: caller_stack_write_tail_call tests that the live
stack is correctly tracked for a tail call.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Link: https://lore.kernel.org/r/20251119160355.1160932-5-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 17:45:30 -08:00
Martin Teichmann
978da762ea bpf: test the proper verification of tail calls
Three tests are added:

- invalidate_pkt_pointers_by_tail_call checks that one can use the
  packet pointer after a tail call. This was originally possible
  and also poses not problems, but was made impossible by 1a4607ffba.

- invalidate_pkt_pointers_by_static_tail_call tests a corner case
  found by Eduard Zingerman during the discussion of the original fix,
  which was broken in that fix.

- subprog_result_tail_call tests that precision propagation works
  correctly across tail calls. This did not work before.

Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251119160355.1160932-3-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 17:45:30 -08:00
Xing Guo
b7f7d76d6e selftests/bpf: Update test_tag to use sha256
commit 603b441623 ("bpf: Update the bpf_prog_calc_tag to use SHA256")
changed digest of prog_tag to SHA256 but forgot to update tests
correspondingly. Fix it.

Fixes: 603b441623 ("bpf: Update the bpf_prog_calc_tag to use SHA256")
Signed-off-by: Xing Guo <higuoxing@gmail.com>
Link: https://lore.kernel.org/r/20251121061458.3145167-1-higuoxing@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 16:56:08 -08:00
Matt Bobrowski
ae24fc8a16 selftests/bpf: Improve reliability of test_perf_branches_no_hw()
Currently, test_perf_branches_no_hw() relies on the busy loop within
test_perf_branches_common() being slow enough to allow at least one
perf event sample tick to occur before starting to tear down the
backing perf event BPF program. With a relatively small fixed
iteration count of 1,000,000, this is not guaranteed on modern fast
CPUs, resulting in the test run to subsequently fail with the
following:

bpf_testmod.ko is already unloaded.
Loading bpf_testmod.ko...
Successfully loaded bpf_testmod.ko.
test_perf_branches_common:PASS:test_perf_branches_load 0 nsec
test_perf_branches_common:PASS:attach_perf_event 0 nsec
test_perf_branches_common:PASS:set_affinity 0 nsec
check_good_sample:PASS:output not valid 0 nsec
check_good_sample:PASS:read_branches_size 0 nsec
check_good_sample:PASS:read_branches_stack 0 nsec
check_good_sample:PASS:read_branches_stack 0 nsec
check_good_sample:PASS:read_branches_global 0 nsec
check_good_sample:PASS:read_branches_global 0 nsec
check_good_sample:PASS:read_branches_size 0 nsec
test_perf_branches_no_hw:PASS:perf_event_open 0 nsec
test_perf_branches_common:PASS:test_perf_branches_load 0 nsec
test_perf_branches_common:PASS:attach_perf_event 0 nsec
test_perf_branches_common:PASS:set_affinity 0 nsec
check_bad_sample:FAIL:output not valid no valid sample from prog
Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED
Successfully unloaded bpf_testmod.ko.

On a modern CPU (i.e. one with a 3.5 GHz clock rate), executing 1
million increments of a volatile integer can take significantly less
than 1 millisecond. If the spin loop and detachment of the perf event
BPF program elapses before the first 1 ms sampling interval elapses,
the perf event will never end up firing. Fix this by bumping the loop
iteration counter a little within test_perf_branches_common(), along
with ensuring adding another loop termination condition which is
directly influenced by the backing perf event BPF program
executing. Notably, a concious decision was made to not adjust the
sample_freq value as that is just not a reliable way to go about
fixing the problem. It effectively still leaves the race window open.

Fixes: 67306f84ca ("selftests/bpf: Add bpf_read_branch_records() selftest")
Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20251119143540.2911424-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 16:49:16 -08:00
Matt Bobrowski
27746aaf1b selftests/bpf: skip test_perf_branches_hw() on unsupported platforms
Gracefully skip the test_perf_branches_hw subtest on platforms that
do not support LBR or require specialized perf event attributes
to enable branch sampling.

For example, AMD's Milan (Zen 3) supports BRS rather than traditional
LBR. This requires specific configurations (attr.type = PERF_TYPE_RAW,
attr.config = RETIRED_TAKEN_BRANCH_INSTRUCTIONS) that differ from the
generic setup used within this test. Notably, it also probably doesn't
hold much value to special case perf event configurations for selected
micro architectures.

Fixes: 67306f84ca ("selftests/bpf: Add bpf_read_branch_records() selftest")
Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20251120142059.2836181-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 16:47:58 -08:00
Puranjay Mohan
d8774a3623 selftests: bpf: Enable gotox tests from arm64
arm64 JIT now supports gotox instruction and jumptables, so run tests in
verifier_gotox.c for arm64.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Reviewed-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20251117130732.11107-4-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-21 16:40:21 -08:00
Hoyeon Lee
db354a1577 selftests/bpf: Use sockaddr_storage instead of sa46 in select_reuseport test
The select_reuseport selftest uses a custom sa46 union to represent
IPv4 and IPv6 addresses. This custom wrapper requires extra manual
handling for address family and field extraction.

Replace sa46 with sockaddr_storage and update the helper functions to
operate on native socket structures. This simplifies the code and
removes unnecessary custom address-handling logic. No functional
changes intended.

Reviewed-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Hoyeon Lee <hoyeon.lee@suse.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251121081332.2309838-3-hoyeon.lee@suse.com
2025-11-21 10:46:31 -08:00
Hoyeon Lee
fd6ed07a05 selftests/bpf: Use sockaddr_storage directly in cls_redirect test
The cls_redirect test uses a custom addr_port/tuple wrapper to represent
IPv4/IPv6 addresses and ports. This custom wrapper requires extra
conversion logic and specific helpers such as fill_addr_port(), which
are no longer necessary when using standard socket address structures.

This commit replaces addr_port/tuple with the standard sockaddr_storage
so test handles address families and ports using native socket types.
It removes the custom helper, eliminates redundant casts, and simplifies
the setup helpers without functional changes. set_up_conn() and
build_input() now take src/dst sockaddr_storage directly.

Reviewed-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Hoyeon Lee <hoyeon.lee@suse.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251121081332.2309838-2-hoyeon.lee@suse.com
2025-11-21 10:46:01 -08:00
Yosry Ahmed
d2e50389ab KVM: selftests: Make sure vm->vpages_mapped is always up-to-date
Call paths leading to __virt_pg_map() are currently:
(a) virt_pg_map() -> virt_arch_pg_map() -> __virt_pg_map()
(b) virt_map_level() -> __virt_pg_map()

For (a), calls to virt_pg_map() from kvm_util.c make sure they update
vm->vpages_mapped, but other callers do not. Move the sparsebit_set()
call into virt_pg_map() to make sure all callers are captured.

For (b), call sparsebit_set_num() from virt_map_level().

It's tempting to have a single the call inside __virt_pg_map(), however:
- The call path in (a) is not x86-specific, while (b) is. Moving the
  call into __virt_pg_map() would require doing something similar for
  other archs implementing virt_pg_map().

- Future changes will reusue __virt_pg_map() for nested PTEs, which should
  not update vm->vpages_mapped, i.e. a triple underscore version that does
  not update vm->vpages_mapped would need to be provided.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-12-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-21 10:17:05 -08:00
Yosry Ahmed
1de4dc15ba KVM: selftests: Stop using __virt_pg_map() directly in tests
Replace __virt_pg_map() calls in tests by high-level equivalent
functions, removing some loops in the process.

No functional change intended.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-11-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-21 10:15:14 -08:00
Janosch Frank
8e8678e740 KVM: s390: Add capability that forwards operation exceptions
Setting KVM_CAP_S390_USER_OPEREXEC will forward all operation
exceptions to user space. This also includes the 0x0000 instructions
managed by KVM_CAP_S390_USER_INSTR0. It's helpful if user space wants
to emulate instructions which do not (yet) have an opcode.

While we're at it refine the documentation for
KVM_CAP_S390_USER_INSTR0.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-21 10:26:03 +01:00
Daniel Zahka
8be656cfb9 selftest: netdevsim: test devlink default params
Test querying default values and resetting to default values for
netdevsim devlink params.

This should cover the basic paths of interest: driverinit and
non-driverinit cmodes, as well as bool and non-bool value
type. Default param values of type bool are encoded with u8 netlink
type as opposed to flag type, so that userspace can distinguish
"not-present" from false.

Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20251119025038.651131-7-daniel.zahka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 19:01:23 -08:00
Gustavo Luiz Duarte
5ad9945341 netconsole: Increase MAX_USERDATA_ITEMS
Increase MAX_USERDATA_ITEMS from 16 to 256 entries now that the userdata
buffer is allocated dynamically.

The previous limit of 16 was necessary because the buffer was statically
allocated for all targets. With dynamic allocation, we can support more
entries without wasting memory on targets that don't use userdata.

This allows users to attach more metadata to their netconsole messages,
which is useful for complex debugging and logging scenarios.

Also update the testcase accordingly.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20251119-netconsole_dynamic_extradata-v3-4-497ac3191707@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:47:18 -08:00
Jakub Kicinski
bd28e5bddc selftests: net: remove old setup_* scripts
gro.sh and toeplitz.sh used to source in one of two setup scripts
depending on whether the test was expected to be run against
veth or a real device. veth testing is replaced by netdevsim
and existing "remote endpoint" support in our Python tests.
Add a script which sets up loopback mode.

The usage is a little bit more complicated than running
the scripts used to be. Testing used to work like this:

  ./../gro.sh -i eth0 ...

now the "setup script" has to be run explicitly:

  NETIF=eth0 ./../ksft_setup_loopback.sh ./../gro.sh

But the functionality itself is retained.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-13-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:31 -08:00
Jakub Kicinski
9cf9aa77a1 selftests: drv-net: hw: convert the Toeplitz test to Python
Rewrite the existing toeplitz.sh test in Python. The conversion
is a lot less exact than the GRO one. We use Netlink APIs to
get the device RSS and IRQ information. We expect that the device
has neither RPS nor RFS configured, and set RPS up as part of
the test.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:30 -08:00
Jakub Kicinski
fdb0267d56 selftests: drv-net: add a Python version of the GRO test
Rewrite the existing gro.sh test in Python. The conversion
not exact, the changes are related to integrating the test
with our "remote endpoint" paradigm. The test now reads
the IP addresses from the user config. It resolves the MAC
address (including running over Layer 3 networks).

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:30 -08:00
Jakub Kicinski
15011a57d0 selftests: net: py: read ip link info about remote dev
We're already saving the info about the local dev in env.dev
for the tests, save remote dev as well. This is more symmetric,
env generally provides the same info for local and remote end.

While at it make sure that we reliably get the detailed info
about the local dev. nsim used to read the dev info without -d.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:29 -08:00
Jakub Kicinski
e02b52ecef selftests: net: py: support ksft ready without wait
There's a common synchronization problem when a script (Python test)
uses a C program to set up some state (usually start a receiving
process for traffic). The script needs to know when the process
has fully initialized. The inverse of the problem exists for shutting
the process down - we need a reliable way to tell the process to exit.

We added helpers to do this safely in
commit 7147713799 ("selftests: drv-net: add a way to wait for a local process")
unfortunately the two operations (wait for init, and shutdown) are
controlled by a single parameter (ksft_wait). Add support for using
ksft_ready without using the second fd for exit.

This is useful for programs which wait for a specific number of packets
to rx so exit_wait is a good match, but we still need to wait for init.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20251120021024.2944527-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:29 -08:00
Jakub Kicinski
89268f7dbc selftests: net: relocate gro and toeplitz tests to drivers/net
The GRO test can run on a real device or a veth.
The Toeplitz hash test can only run on a real device.
Move them from net/ to drivers/net/ and drivers/net/hw/ respectively.

There are two scripts which set up the environment for these tests
setup_loopback.sh and setup_veth.sh. Move those scripts to net/lib.
The paths to the setup files are a little ugly but they will be
deleted shortly.

toeplitz_client.sh is not a test in itself, but rather a helper
to send traffic, so add it to TEST_FILES rather than TEST_PROGS.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:29 -08:00
Jakub Kicinski
173227d7d6 selftests: drv-net: xdp: use variants for qstat tests
Use just-added ksft variants for XDP qstat tests.

While at it correct the number of packets, we're sending
1000 packets now.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:29 -08:00
Jakub Kicinski
6ae67f1159 selftests: net: py: add test variants
There's a lot of cases where we try to re-run the same code with
different parameters. We currently need to either use a generator
method or create a "main" case implementation which then gets called
by trivial case functions:

  def _test(x, y, z):
     ...

  def case_int():
     _test(1, 2, 3)

  def case_str():
     _test('a', 'b', 'c')

Add support for variants, similar to kselftests_harness.h and
a lot of other frameworks. Variants can be added as decorator
to test functions:

  @ksft_variants([(1, 2, 3), ('a', 'b', 'c')])
  def case(x, y, z):
     ...

ksft_run() will auto-generate case names:
  case.1_2_3
  case.a_b_c

Because the names may not always be pretty (and to avoid forcing
classes to implement case-friendly __str__()) add a wrapper class
KsftNamedVariant which lets the user specify the name for the variant.

Note that ksft_run's args are still supported. ksft_run splices args
and variant params together.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20251120021024.2944527-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:29 -08:00
Jakub Kicinski
80970e0fc0 selftests: net: py: extract the case generation logic
In preparation for adding test variants move the test case
collection logic to a dedicated function. New helper returns

 (function, args, name, )

tuples. The main test loop can simply run them, not much
logic or discernment needed.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251120021024.2944527-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:29 -08:00
Jakub Kicinski
5cb7b71b76 selftests: net: py: coding style improvements
We're about to add more features here and finding new issues with old
ones in place is hard. Address ruff checks:
 - bare exceptions
 - f-string with no params
 - unused import

We need to use BaseException when handling defer(), as Petr points out.
This retains the old behavior of ignoring SIGTERM while running cleanups.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20251120021024.2944527-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:19:28 -08:00
Jim Mattson
6a8818de21 KVM: selftests: Add a VMX test for LA57 nested state
Add a selftest that verifies KVM's ability to save and restore
nested state when the L1 guest is using 5-level paging and the L2
guest is using 4-level paging. Specifically, canonicality tests of
the VMCS12 host-state fields should accept 57-bit virtual addresses.

Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20251028225827.2269128-5-jmattson@google.com
[sean: rename to vmx_nested_la57_state_test to prep nested_<test> namespace]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:21:52 -08:00
Jim Mattson
ec5806639e KVM: selftests: Change VM_MODE_PXXV48_4K to VM_MODE_PXXVYY_4K
Use 57-bit addresses with 5-level paging on hardware that supports
LA57. Continue to use 48-bit addresses with 4-level paging on hardware
that doesn't support LA57.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20251028225827.2269128-4-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:59 -08:00
Jim Mattson
2103a8baf5 KVM: selftests: Use a loop to walk guest page tables
Walk the guest page tables via a loop when searching for a PTE,
instead of using unique variables for each level of the page tables.

This simplifies the code and makes it easier to support 5-level paging
in the future.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251028225827.2269128-3-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:59 -08:00
Jim Mattson
ae5b498b8d KVM: selftests: Use a loop to create guest page tables
Walk the guest page tables via a loop when creating new mappings,
instead of using unique variables for each level of the page tables.

This simplifies the code and makes it easier to support 5-level paging
in the future.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251028225827.2269128-2-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:59 -08:00
Yosry Ahmed
ff736dba47 KVM: selftests: Remove the unused argument to prepare_eptp()
eptp_memslot is unused, remove it. No functional change intended.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-10-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:57 -08:00
Yosry Ahmed
28b2dced8b KVM: selftests: Stop hardcoding PAGE_SIZE in x86 selftests
Use PAGE_SIZE instead of 4096.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-9-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:56 -08:00
Yosry Ahmed
3c40777f0e KVM: selftests: Extend vmx_tsc_adjust_test to cover SVM
Add SVM L1 code to run the nested guest, and allow the test to run with
SVM as well as VMX.

Reviewed-by: Jim Mattson <jmattson@google.com>

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-8-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:56 -08:00
Yosry Ahmed
91423b041d KVM: selftests: Extend nested_invalid_cr3_test to cover SVM
Add SVM L1 code to run the nested guest, and allow the test to run with
SVM as well as VMX.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-7-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:55 -08:00
Yosry Ahmed
4d256d00e4 KVM: selftests: Move nested invalid CR3 check to its own test
vmx_tsc_adjust_test currently verifies that a nested VMLAUNCH fails with
an invalid CR3. This is irrelevant to TSC scaling, move it to a
standalone test.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-6-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:54 -08:00
Yosry Ahmed
e6bcdd2122 KVM: selftests: Extend vmx_nested_tsc_scaling_test to cover SVM
Add SVM L1 code to run the nested guest, and allow the test to run with
SVM as well as VMX.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-5-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:54 -08:00
Yosry Ahmed
0a9eb2afa1 KVM: selftests: Extend vmx_close_while_nested_test to cover SVM
Add SVM L1 code to run the nested guest, and allow the test to run with
SVM as well as VMX.

Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-4-yosry.ahmed@linux.dev
[sean: rename to "nested_close_kvm_test" to provide nested_* sorting]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-20 16:19:53 -08:00
Ping Cheng
10c64d4ff4 selftests/hid-tablet: add ABS_DISTANCE test for stylus/pen
For pen and stylus, the ABS_Z event reports ABS_DISTANCE values
in the hid generic kernel driver. This test is to make sure that
the assignment is properly done for all pen and stylus tools.
Same as tilt, distance is an optional event.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Tatsunosuke Tobit <tatsunosuke.tobita@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
2025-11-20 22:47:14 +01:00
Lorenzo Stoakes
c7ba92bcfe testing/selftests/mm: add soft-dirty merge self-test
Assert that we correctly merge VMAs containing VM_SOFTDIRTY flags now that
we correctly handle these as sticky.

In order to do so, we have to account for the fact the pagemap interface
checks soft dirty PTEs and additionally that newly merged VMAs are marked
VM_SOFTDIRTY.

We do this by using use unfaulted anon VMAs, establishing one and clearing
references on that one, before establishing another and merging the two
before checking that soft-dirty is propagated as expected.

We check that this functions correctly with mremap() and mprotect() as
sample cases, because VMA merge of adjacent newly mapped VMAs will
automatically be made soft-dirty due to existing logic which does so.

We are therefore exercising other means of merging VMAs.

Link: https://lkml.kernel.org/r/d5a0f735783fb4f30a604f570ede02ccc5e29be9.1763399675.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Andrey Vagin <avagin@gmail.com>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:44:01 -08:00
Lorenzo Stoakes
6707915e03 mm: propagate VM_SOFTDIRTY on merge
Patch series "make VM_SOFTDIRTY a sticky VMA flag", v2.

Currently we set VM_SOFTDIRTY when a new mapping is set up (whether by
establishing a new VMA, or via merge) as implemented in __mmap_complete()
and do_brk_flags().

However, when performing a merge of existing mappings such as when
performing mprotect(), we may lose the VM_SOFTDIRTY flag.

Now we have the concept of making VMA flags 'sticky', that is that they
both don't prevent merge and, importantly, are propagated to merged VMAs,
this seems a sensible alternative to the existing special-casing of
VM_SOFTDIRTY.

We additionally add a self-test that demonstrates that this logic behaves
as expected.


This patch (of 2):

Currently we set VM_SOFTDIRTY when a new mapping is set up (whether by
establishing a new VMA, or via merge) as implemented in __mmap_complete()
and do_brk_flags().

However, when performing a merge of existing mappings such as when
performing mprotect(), we may lose the VM_SOFTDIRTY flag.

This is because currently we simply ignore VM_SOFTDIRTY for the purposes
of merge, so one VMA may possess the flag and another not, and whichever
happens to be the target VMA will be the one upon which the merge is
performed which may or may not have VM_SOFTDIRTY set.

Now we have the concept of 'sticky' VMA flags, let's make VM_SOFTDIRTY one
which solves this issue.

Additionally update VMA userland tests to propagate changes.

[akpm@linux-foundation.org: update comments, per Lorenzo]
  Link: https://lkml.kernel.org/r/0019e0b8-ee1e-4359-b5ee-94225cbe5588@lucifer.local
Link: https://lkml.kernel.org/r/cover.1763399675.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/955478b5170715c895d1ef3b7f68e0cd77f76868.1763399675.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Acked-by: Andrey Vagin <avagin@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:44:01 -08:00
SeongJae Park
675774adbe selftests/damon/sysfs.py: merge DAMON status dumping into commitment assertion
For each test case, sysfs.py makes changes to DAMON, dumps DAMON internal
status and asserts the expectation is met.  The dumping part should be the
same for all cases, so it is duplicated for each test case.  Which means
it is easy to make mistakes.  Actually a few of those duplicates are not
turning DAMON off in case of the dumping failure.  It makes following
selftests that need to turn DAMON on fails with -EBUSY.  Merge the status
dumping into commitment assertion with proper dumping failure handling, to
deduplicate and avoid the unnecessary following tests failures.

Link: https://lkml.kernel.org/r/20251112154114.66053-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:44:01 -08:00
SeongJae Park
53298afe45 mm/damon: rename damos->filters to damos->core_filters
DAMOS filters that are handled by the ops layer are linked to
damos->ops_filters.  Owing to the ops_ prefix on the name, it is easy to
understand it is for ops layer handled filters.  The other types of
filters, which are handled by the core layer, are linked to
damos->filters.  Because of the name, it is easy to confuse the list is
there for not only core layer handled ones but all filters.  Avoid such
confusions by renaming the field to core_filters.

Link: https://lkml.kernel.org/r/20251112154114.66053-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:44:01 -08:00
Mehdi Ben Hadj Khelifa
1ec5d5810b selftests/mm/uffd: remove static address usage in shmem_allocate_area()
The current shmem_allocate_area() implementation uses a hardcoded virtual
base address (BASE_PMD_ADDR) as a hint for mmap() when creating
shmem-backed test areas.  This approach is fragile and may fail on systems
with ASLR or different virtual memory layouts, where the chosen address is
unavailable.

Replace the static base address with a dynamically reserved address range
obtained via mmap(NULL, ..., PROT_NONE).  The memfd-backed areas and their
alias are then mapped into that reserved region using MAP_FIXED,
preserving the original layout and aliasing semantics while avoiding
collisions with unrelated mappings.

This change improves robustness and portability of the test suite without
altering its behavior or coverage.

[mehdi.benhadjkhelifa@gmail.com: make cleanup code more clear, per Mike]
  Link: https://lkml.kernel.org/r/20251113142050.108638-1-mehdi.benhadjkhelifa@gmail.com
Link: https://lkml.kernel.org/r/20251111205739.420009-1-mehdi.benhadjkhelifa@gmail.com
Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Suggested-by: Mike Rapoport <rppt@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Hunter <david.hunter.linux@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:44:00 -08:00
Matthew Wilcox (Oracle)
2197bb60f8 mm: add vma_start_write_killable()
Patch series "vma_start_write_killable"", v2.

When we added the VMA lock, we made a major oversight in not adding a
killable variant.  That can run us into trouble where a thread takes the
VMA lock for read (eg handling a page fault) and then goes out to lunch
for an hour (eg doing reclaim).  Another thread tries to modify the VMA,
taking the mmap_lock for write, then attempts to lock the VMA for write. 
That blocks on the first thread, and ensures that every other page fault
now tries to take the mmap_lock for read.  Because everything's in an
uninterruptible sleep, we can't kill the task, which makes me angry.

This patchset just adds vma_start_write_killable() and converts one caller
to use it.  Most users are somewhat tricky to convert, so expect follow-up
individual patches per call-site which need careful analysis to make sure
we've done proper cleanup.


This patch (of 2):

The vma can be held read-locked for a substantial period of time, eg if
memory allocation needs to go into reclaim.  It's useful to be able to
send fatal signals to threads which are waiting for the write lock.

Link: https://lkml.kernel.org/r/20251110203204.1454057-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20251110203204.1454057-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Chris Li <chriscli@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:43:59 -08:00
Lorenzo Stoakes
c0ae966fac tools/testing/selftests/mm: add smaps visibility guard region test
Assert that we observe guard regions appearing in /proc/$pid/smaps as
expected, and when split/merge is performed too (with expected sticky
behaviour).

Also add handling for file systems which don't sanely handle mmap() VMA
merging so we don't incorrectly encounter a test failure in this
situation.

Link: https://lkml.kernel.org/r/059e62b8c67e55e6d849878206a95ea1d7c1e885.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:43:58 -08:00
Lorenzo Stoakes
89330ec897 tools/testing/selftests/mm: add MADV_COLLAPSE test case
To ensure the retract_page_tables() logic functions correctly with the
introduction of VM_MAYBE_GUARD, add a test to assert that madvise collapse
fails when guard regions are established in the collapsed range in all
cases.

Unfortunately we cannot differentiate between e.g. 
CONFIG_READ_ONLY_THP_FOR_FS not being set vs.  a file-backed VMA having
collapse correctly disallowed, so in each instance we will get an assert
pass here.

We add an additional check to see whether guard regions are preserved
across collapse in case of a bug causing the collapse to succeed, which
will give us more data to debug with should this occur in future.

Link: https://lkml.kernel.org/r/0748beeb864525b8ddfa51adad7128dd32eb3ac4.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:43:58 -08:00
Lorenzo Stoakes
29bef05e6d tools/testing/vma: add VMA sticky userland tests
Modify existing merge new/existing userland VMA tests to assert that
sticky VMA flags behave as expected.

We do so by generating every possible permutation of VMAs being
manipulated being sticky/not sticky and asserting that VMA flags with this
property retain are retained upon merge.

Link: https://lkml.kernel.org/r/5e2c7244485867befd052f8afc8188be6a4be670.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:43:58 -08:00
Lorenzo Stoakes
ab04b530e7 mm: introduce copy-on-fork VMAs and make VM_MAYBE_GUARD one
Gather all the VMA flags whose presence implies that page tables must be
copied on fork into a single bitmap - VM_COPY_ON_FORK - and use this
rather than specifying individual flags in vma_needs_copy().

We also add VM_MAYBE_GUARD to this list, as it being set on a VMA implies
that there may be metadata contained in the page tables (that is - guard
markers) which would will not and cannot be propagated upon fork.

This was already being done manually previously in vma_needs_copy(), but
this makes it very explicit, alongside VM_PFNMAP, VM_MIXEDMAP and
VM_UFFD_WP all of which imply the same.

Note that VM_STICKY flags ought generally to be marked VM_COPY_ON_FORK too
- because equally a flag being VM_STICKY indicates that the VMA contains
metadat that is not propagated by being faulted in - i.e.  that the VMA
metadata does not fully describe the VMA alone, and thus we must propagate
whatever metadata there is on a fork.

However, for maximum flexibility, we do not make this necessarily the case
here.

Link: https://lkml.kernel.org/r/5d41b24e7bc622cda0af92b6d558d7f4c0d1bc8c.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:43:58 -08:00
Lorenzo Stoakes
64212ba02e mm: implement sticky VMA flags
It is useful to be able to designate that certain flags are 'sticky', that
is, if two VMAs are merged one with a flag of this nature and one without,
the merged VMA sets this flag.

As a result we ignore these flags for the purposes of determining VMA flag
differences between VMAs being considered for merge.

This patch therefore updates the VMA merge logic to perform this action,
with flags possessing this property being described in the VM_STICKY
bitmap.

Those flags which ought to be ignored for the purposes of VMA merge are
described in the VM_IGNORE_MERGE bitmap, which the VMA merge logic is also
updated to use.

As part of this change we place VM_SOFTDIRTY in VM_IGNORE_MERGE as it
already had this behaviour, alongside VM_STICKY as sticky flags by
implication must not disallow merge.

Ultimately it seems that we should make VM_SOFTDIRTY a sticky flag in its
own right, but this change is out of scope for this series.

The only sticky flag designated as such is VM_MAYBE_GUARD, so as a result
of this change, once the VMA flag is set upon guard region installation,
VMAs with guard ranges will now not have their merge behaviour impacted as
a result and can be freely merged with other VMAs without VM_MAYBE_GUARD
set.

Also update the comments for vma_modify_flags() to directly reference
sticky flags now we have established the concept.

We also update the VMA userland tests to account for the changes.

Link: https://lkml.kernel.org/r/22ad5269f7669d62afb42ce0c79bad70b994c58d.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 13:43:58 -08:00