In order to cover this case, setting 'maxlen = 0', with the following
explanation:
EVIOCGKEY is executed from evdev_do_ioctl(), which is called from
evdev_ioctl_handler().
evdev_ioctl_handler() is called from 2 functions, where by code coverage,
only the first one is in use.
‘compat’ is given the value ‘0’ [1].
Thus, the condition [2] is always false.
This means ‘len’ always equals a positive number [3]
‘maxlen’ in evdev_handle_get_val [4] is defined locally in
evdev_do_ioctl() [5], and is sent in the variable 'size' [6]
[1] https://elixir.bootlin.com/linux/v6.2/source/drivers/input/evdev.c#L1281
[2] https://elixir.bootlin.com/linux/v6.2/source/drivers/input/evdev.c#L705
[3] https://elixir.bootlin.com/linux/v6.2/source/drivers/input/evdev.c#L707
[4] https://elixir.bootlin.com/linux/v6.2/source/drivers/input/evdev.c#L886
[5] https://elixir.bootlin.com/linux/v6.2/source/drivers/input/evdev.c#L1155
[6] https://elixir.bootlin.com/linux/v6.2/source/drivers/input/evdev.c#L1141
Signed-off-by: Dana Elfassy <dangel101(a)gmail.com>
---
Changes in v2:
- Added following note about the patch's dependency
This patch depends on '[v3] selftests/input: Introduce basic tests for evdev ioctls' [1] sent to the ML.
[1] https://patchwork.kernel.org/project/linux-input/patch/20230607153214.15933…
tools/testing/selftests/input/evioc-test.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/tools/testing/selftests/input/evioc-test.c b/tools/testing/selftests/input/evioc-test.c
index ad7b93fe39cf..b94de2ee5596 100644
--- a/tools/testing/selftests/input/evioc-test.c
+++ b/tools/testing/selftests/input/evioc-test.c
@@ -234,4 +234,23 @@ TEST(eviocsrep_set_repeat_settings)
selftest_uinput_destroy(uidev);
}
+TEST(eviocgkey_get_global_key_state)
+{
+ struct selftest_uinput *uidev;
+ int rep_values[2];
+ int rc;
+
+ memset(rep_values, 0, sizeof(rep_values));
+
+ rc = selftest_uinput_create_device(&uidev);
+ ASSERT_EQ(0, rc);
+ ASSERT_NE(NULL, uidev);
+
+ /* ioctl to create the scenario where len > maxlen in bits_to_user() */
+ rc = ioctl(uidev->evdev_fd, EVIOCGKEY(0), rep_values);
+ ASSERT_EQ(0, rc);
+
+ selftest_uinput_destroy(uidev);
+}
+
TEST_HARNESS_MAIN
--
2.41.0
From: Danielle Ratson <danieller(a)nvidia.com>
When mirroring to a gretap in hardware the device expects to be
programmed with the egress port and all the encapsulating headers. This
requires the driver to resolve the path the packet will take in the
software data path and program the device accordingly.
If the path cannot be resolved (in this case because of an unresolved
neighbor), then mirror installation fails until the path is resolved.
This results in a race that causes the test to sometimes fail.
Fix this by setting the neighbor's state to permanent in a couple of
tests, so that it is always valid.
Fixes: 35c31d5c323f ("selftests: forwarding: Test mirror-to-gretap w/ UL 802.1d")
Fixes: 239e754af854 ("selftests: forwarding: Test mirror-to-gretap w/ UL 802.1q")
Signed-off-by: Danielle Ratson <danieller(a)nvidia.com>
Reviewed-by: Petr Machata <petrm(a)nvidia.com>
Signed-off-by: Petr Machata <petrm(a)nvidia.com>
---
.../testing/selftests/net/forwarding/mirror_gre_bridge_1d.sh | 4 ++++
.../testing/selftests/net/forwarding/mirror_gre_bridge_1q.sh | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1d.sh b/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1d.sh
index c5095da7f6bf..aec752a22e9e 100755
--- a/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1d.sh
+++ b/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1d.sh
@@ -93,12 +93,16 @@ cleanup()
test_gretap()
{
+ ip neigh replace 192.0.2.130 lladdr $(mac_get $h3) \
+ nud permanent dev br2
full_test_span_gre_dir gt4 ingress 8 0 "mirror to gretap"
full_test_span_gre_dir gt4 egress 0 8 "mirror to gretap"
}
test_ip6gretap()
{
+ ip neigh replace 2001:db8:2::2 lladdr $(mac_get $h3) \
+ nud permanent dev br2
full_test_span_gre_dir gt6 ingress 8 0 "mirror to ip6gretap"
full_test_span_gre_dir gt6 egress 0 8 "mirror to ip6gretap"
}
diff --git a/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1q.sh b/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1q.sh
index 9ff22f28032d..0cf4c47a46f9 100755
--- a/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1q.sh
+++ b/tools/testing/selftests/net/forwarding/mirror_gre_bridge_1q.sh
@@ -90,12 +90,16 @@ cleanup()
test_gretap()
{
+ ip neigh replace 192.0.2.130 lladdr $(mac_get $h3) \
+ nud permanent dev br1
full_test_span_gre_dir gt4 ingress 8 0 "mirror to gretap"
full_test_span_gre_dir gt4 egress 0 8 "mirror to gretap"
}
test_ip6gretap()
{
+ ip neigh replace 2001:db8:2::2 lladdr $(mac_get $h3) \
+ nud permanent dev br1
full_test_span_gre_dir gt6 ingress 8 0 "mirror to ip6gretap"
full_test_span_gre_dir gt6 egress 0 8 "mirror to ip6gretap"
}
--
2.40.1
When calling socket lookup from L2 (tc, xdp), VRF boundaries aren't
respected. This patchset fixes this by regarding the incoming device's
VRF attachment when performing the socket lookups from tc/xdp.
The first two patches are coding changes which factor out the tc helper's
logic which was shared with cg/sk_skb (which operate correctly).
This refactoring is needed in order to avoid affecting the cgroup/sk_skb
flows as there does not seem to be a strict criteria for discerning which
flow the helper is called from based on the net device or packet
information.
The third patch contains the actual bugfix.
The fourth patch adds bpf tests for these lookup functions.
---
v6: - Remove redundant IS_ENABLED as suggested by Daniel Borkmann
- Declare net_device variable and use it as suggested by Daniel Borkmann
v5: Use reverse xmas tree indentation
v4: - Move dev_sdif() to include/linux/netdevice.h as suggested by Stanislav Fomichev
- Remove SYS and SYS_NOFAIL duplicate definitions
v3: - Rename bpf_l2_sdif() to dev_sdif() as suggested by Stanislav Fomichev
- Added xdp tests as suggested by Daniel Borkmann
- Use start_server() to avoid duplicate code as suggested by Stanislav Fomichev
v2: Fixed uninitialized var in test patch (4).
Gilad Sever (4):
bpf: factor out socket lookup functions for the TC hookpoint.
bpf: Call __bpf_sk_lookup()/__bpf_skc_lookup() directly via TC
hookpoint
bpf: fix bpf socket lookup from tc/xdp to respect socket VRF bindings
selftests/bpf: Add vrf_socket_lookup tests
include/linux/netdevice.h | 9 +
net/core/filter.c | 141 ++++++--
.../bpf/prog_tests/vrf_socket_lookup.c | 312 ++++++++++++++++++
.../selftests/bpf/progs/vrf_socket_lookup.c | 88 +++++
4 files changed, 526 insertions(+), 24 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/vrf_socket_lookup.c
create mode 100644 tools/testing/selftests/bpf/progs/vrf_socket_lookup.c
--
2.34.1
The mlxsw driver currently makes the assumption that the user applies
configuration in a bottom-up manner. Thus netdevices need to be added to
the bridge before IP addresses are configured on that bridge or SVI added
on top of it. Enslaving a netdevice to another netdevice that already has
uppers is in fact forbidden by mlxsw for this reason. Despite this safety,
it is rather easy to get into situations where the offloaded configuration
is just plain wrong.
Over the course of the following several patchsets, mlxsw code is going to
be adjusted to diminish the space of wrongly offloaded configurations.
Ideally the offload state will reflect the actual state, regardless of the
sequence of operation used to construct that state.
Several selftests build configurations that will not be offloadable in the
future on some systems. The reason is that what will get offloaded is the
actual configuration, not the configuration steps.
For example, when a port is added to a bridge that has an IP address, that
bridge will get a RIF, which it would not have with the current code. But
on Nvidia Spectrum-1 machines, MAC addresses of all RIFs need to have the
same prefix, which the bridge will violate. The RIF thus couldn't be
created, and the enslavement is therefore canceled, because it would lead
to an unoffloadable configuration. This breaks some selftests.
In this patchset, adjust selftests to avoid the configurations that mlxsw
would be incapable of offloading, while maintaining relevance with regards
to the feature that is being tested. There are generally two cases of
fixes:
- Disabling IPv6 autogen on bridges that do not participate in routing,
either because of the abovementioned requirement to keep the same MAC
prefix on all in-HW router interfaces, or, on 802.1ad bridges, because
in-HW router interfaces are not supported at all.
- Setting the bridge MAC address to what it will become after the first
member port is attached, so that the in-HW router interface is created
with a supported MAC address.
The patchset is then split thus:
- Patches #1-#7 adjust generic selftests
- Patches #8-#16 adjust mlxsw-specific selftests
Petr Machata (16):
selftests: forwarding: q_in_vni: Disable IPv6 autogen on bridges
selftests: forwarding: dual_vxlan_bridge: Disable IPv6 autogen on
bridges
selftests: forwarding: skbedit_priority: Disable IPv6 autogen on a
bridge
selftests: forwarding: pedit_dsfield: Disable IPv6 autogen on a bridge
selftests: forwarding: mirror_gre_*: Disable IPv6 autogen on bridges
selftests: forwarding: mirror_gre_*: Use port MAC for bridge address
selftests: forwarding: router_bridge: Use port MAC for bridge address
selftests: mlxsw: q_in_q_veto: Disable IPv6 autogen on bridges
selftests: mlxsw: extack: Disable IPv6 autogen on bridges
selftests: mlxsw: mirror_gre_scale: Disable IPv6 autogen on a bridge
selftests: mlxsw: qos_dscp_bridge: Disable IPv6 autogen on a bridge
selftests: mlxsw: qos_ets_strict: Disable IPv6 autogen on bridges
selftests: mlxsw: qos_mc_aware: Disable IPv6 autogen on bridges
selftests: mlxsw: spectrum: q_in_vni_veto: Disable IPv6 autogen on a
bridge
selftests: mlxsw: vxlan: Disable IPv6 autogen on bridges
selftests: mlxsw: one_armed_router: Use port MAC for bridge address
.../selftests/drivers/net/mlxsw/extack.sh | 24 ++++++++---
.../drivers/net/mlxsw/mirror_gre_scale.sh | 1 +
.../drivers/net/mlxsw/one_armed_router.sh | 3 +-
.../drivers/net/mlxsw/q_in_q_veto.sh | 8 ++++
.../drivers/net/mlxsw/qos_dscp_bridge.sh | 1 +
.../drivers/net/mlxsw/qos_ets_strict.sh | 8 +++-
.../drivers/net/mlxsw/qos_mc_aware.sh | 2 +
.../net/mlxsw/spectrum/q_in_vni_veto.sh | 1 +
.../selftests/drivers/net/mlxsw/vxlan.sh | 41 ++++++++++++++-----
.../net/forwarding/dual_vxlan_bridge.sh | 1 +
.../net/forwarding/mirror_gre_bound.sh | 1 +
.../net/forwarding/mirror_gre_bridge_1d.sh | 3 +-
.../forwarding/mirror_gre_bridge_1d_vlan.sh | 3 +-
.../forwarding/mirror_gre_bridge_1q_lag.sh | 3 +-
.../net/forwarding/mirror_topo_lib.sh | 1 +
.../selftests/net/forwarding/pedit_dsfield.sh | 4 +-
.../selftests/net/forwarding/q_in_vni.sh | 1 +
.../selftests/net/forwarding/router_bridge.sh | 3 +-
.../net/forwarding/skbedit_priority.sh | 4 +-
19 files changed, 88 insertions(+), 25 deletions(-)
--
2.40.1
If we get an unexpected signal during a signal test log a bit more data to
aid diagnostics.
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
tools/testing/selftests/arm64/signal/test_signals_utils.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.c b/tools/testing/selftests/arm64/signal/test_signals_utils.c
index 40be8443949d..0dc948db3a4a 100644
--- a/tools/testing/selftests/arm64/signal/test_signals_utils.c
+++ b/tools/testing/selftests/arm64/signal/test_signals_utils.c
@@ -249,7 +249,8 @@ static void default_handler(int signum, siginfo_t *si, void *uc)
fprintf(stderr, "-- Timeout !\n");
} else {
fprintf(stderr,
- "-- RX UNEXPECTED SIGNAL: %d\n", signum);
+ "-- RX UNEXPECTED SIGNAL: %d code %d address %p\n",
+ signum, si->si_code, si->si_addr);
}
default_result(current, 1);
}
---
base-commit: 44c026a73be8038f03dbdeef028b642880cf1511
change-id: 20230620-arm64-selftest-log-wrong-signal-cd8c34ae5e4f
Best regards,
--
Mark Brown <broonie(a)kernel.org>
This series adds 2 zswap related selftests that verify known and fixed
issues. A new dedicated test program (test_zswap) is proposed since
the test cases are specific to zswap and hosts specific helpers.
The first patch adds the (empty) test program, while the other 2 add an
actual test function each.
Domenico Cerasuolo (3):
selftests: cgroup: add test_zswap program
selftests: cgroup: add test_zswap with no kmem bypass test
selftests: cgroup: add zswap-memcg unwanted writeback test
tools/testing/selftests/cgroup/.gitignore | 1 +
tools/testing/selftests/cgroup/Makefile | 2 +
tools/testing/selftests/cgroup/test_zswap.c | 286 ++++++++++++++++++++
3 files changed, 289 insertions(+)
create mode 100644 tools/testing/selftests/cgroup/test_zswap.c
--
2.34.1
We want to replace iptables TPROXY with a BPF program at TC ingress.
To make this work in all cases we need to assign a SO_REUSEPORT socket
to an skb, which is currently prohibited. This series adds support for
such sockets to bpf_sk_assing. See patch 5 for details.
I did some refactoring to cut down on the amount of duplicate code. The
key to this is to use INDIRECT_CALL in the reuseport helpers. To show
that this approach is not just beneficial to TC sk_assign I removed
duplicate code for bpf_sk_lookup as well.
Changes from v1:
- Correct commit abbrev length (Kuniyuki)
- Reduce duplication (Kuniyuki)
- Add checks on sk_state (Martin)
- Split exporting inet[6]_lookup_reuseport into separate patch (Eric)
Joint work with Daniel Borkmann.
Signed-off-by: Lorenz Bauer <lmb(a)isovalent.com>
---
Daniel Borkmann (1):
selftests/bpf: Test that SO_REUSEPORT can be used with sk_assign helper
Lorenz Bauer (5):
net: export inet_lookup_reuseport and inet6_lookup_reuseport
net: document inet[6]_lookup_reuseport sk_state requirements
net: remove duplicate reuseport_lookup functions
net: remove duplicate sk_lookup helpers
bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assign
include/net/inet6_hashtables.h | 84 ++++++++-
include/net/inet_hashtables.h | 77 +++++++-
include/net/sock.h | 7 +-
include/uapi/linux/bpf.h | 3 -
net/core/filter.c | 2 -
net/ipv4/inet_hashtables.c | 69 +++++---
net/ipv4/udp.c | 73 +++-----
net/ipv6/inet6_hashtables.c | 71 +++++---
net/ipv6/udp.c | 85 +++------
tools/include/uapi/linux/bpf.h | 3 -
tools/testing/selftests/bpf/network_helpers.c | 3 +
.../selftests/bpf/prog_tests/assign_reuse.c | 197 +++++++++++++++++++++
.../selftests/bpf/progs/test_assign_reuse.c | 142 +++++++++++++++
13 files changed, 637 insertions(+), 179 deletions(-)
---
base-commit: 25085b4e9251c77758964a8e8651338972353642
change-id: 20230613-so-reuseport-e92c526173ee
Best regards,
--
Lorenz Bauer <lmb(a)isovalent.com>
*Changes in v18*
- Rebase on top of next-20230613
- Minor updates
*Changes in v17*
- Rebase on top of next-20230606
- Minor improvements in PAGEMAP_SCAN IOCTL patch
*Changes in v16*
- Fix a corner case
- Add exclusive PM_SCAN_OP_WP back
*Changes in v15*
- Build fix (Add missed build fix in RESEND)
*Changes in v14*
- Fix build error caused by #ifdef added at last minute in some configs
*Changes in v13*
- Rebase on top of next-20230414
- Give-up on using uffd_wp_range() and write new helpers, flush tlb only
once
*Changes in v12*
- Update and other memory types to UFFD_FEATURE_WP_ASYNC
- Rebaase on top of next-20230406
- Review updates
*Changes in v11*
- Rebase on top of next-20230307
- Base patches on UFFD_FEATURE_WP_UNPOPULATED
- Do a lot of cosmetic changes and review updates
- Remove ENGAGE_WP + !GET operation as it can be performed with
UFFDIO_WRITEPROTECT
*Changes in v10*
- Add specific condition to return error if hugetlb is used with wp
async
- Move changes in tools/include/uapi/linux/fs.h to separate patch
- Add documentation
*Changes in v9:*
- Correct fault resolution for userfaultfd wp async
- Fix build warnings and errors which were happening on some configs
- Simplify pagemap ioctl's code
*Changes in v8:*
- Update uffd async wp implementation
- Improve PAGEMAP_IOCTL implementation
*Changes in v7:*
- Add uffd wp async
- Update the IOCTL to use uffd under the hood instead of soft-dirty
flags
*Motivation*
The real motivation for adding PAGEMAP_SCAN IOCTL is to emulate Windows
GetWriteWatch() syscall [1]. The GetWriteWatch{} retrieves the addresses of
the pages that are written to in a region of virtual memory.
This syscall is used in Windows applications and games etc. This syscall is
being emulated in pretty slow manner in userspace. Our purpose is to
enhance the kernel such that we translate it efficiently in a better way.
Currently some out of tree hack patches are being used to efficiently
emulate it in some kernels. We intend to replace those with these patches.
So the whole gaming on Linux can effectively get benefit from this. It
means there would be tons of users of this code.
CRIU use case [2] was mentioned by Andrei and Danylo:
> Use cases for migrating sparse VMAs are binaries sanitized with ASAN,
> MSAN or TSAN [3]. All of these sanitizers produce sparse mappings of
> shadow memory [4]. Being able to migrate such binaries allows to highly
> reduce the amount of work needed to identify and fix post-migration
> crashes, which happen constantly.
Andrei's defines the following uses of this code:
* it is more granular and allows us to track changed pages more
effectively. The current interface can clear dirty bits for the entire
process only. In addition, reading info about pages is a separate
operation. It means we must freeze the process to read information
about all its pages, reset dirty bits, only then we can start dumping
pages. The information about pages becomes more and more outdated,
while we are processing pages. The new interface solves both these
downsides. First, it allows us to read pte bits and clear the
soft-dirty bit atomically. It means that CRIU will not need to freeze
processes to pre-dump their memory. Second, it clears soft-dirty bits
for a specified region of memory. It means CRIU will have actual info
about pages to the moment of dumping them.
* The new interface has to be much faster because basic page filtering
is happening in the kernel. With the old interface, we have to read
pagemap for each page.
*Implementation Evolution (Short Summary)*
From the definition of GetWriteWatch(), we feel like kernel's soft-dirty
feature can be used under the hood with some additions like:
* reset soft-dirty flag for only a specific region of memory instead of
clearing the flag for the entire process
* get and clear soft-dirty flag for a specific region atomically
So we decided to use ioctl on pagemap file to read or/and reset soft-dirty
flag. But using soft-dirty flag, sometimes we get extra pages which weren't
even written. They had become soft-dirty because of VMA merging and
VM_SOFTDIRTY flag. This breaks the definition of GetWriteWatch(). We were
able to by-pass this short coming by ignoring VM_SOFTDIRTY until David
reported that mprotect etc messes up the soft-dirty flag while ignoring
VM_SOFTDIRTY [5]. This wasn't happening until [6] got introduced. We
discussed if we can revert these patches. But we could not reach to any
conclusion. So at this point, I made couple of tries to solve this whole
VM_SOFTDIRTY issue by correcting the soft-dirty implementation:
* [7] Correct the bug fixed wrongly back in 2014. It had potential to cause
regression. We left it behind.
* [8] Keep a list of soft-dirty part of a VMA across splits and merges. I
got the reply don't increase the size of the VMA by 8 bytes.
At this point, we left soft-dirty considering it is too much delicate and
userfaultfd [9] seemed like the only way forward. From there onward, we
have been basing soft-dirty emulation on userfaultfd wp feature where
kernel resolves the faults itself when WP_ASYNC feature is used. It was
straight forward to add WP_ASYNC feature in userfautlfd. Now we get only
those pages dirty or written-to which are really written in reality. (PS
There is another WP_UNPOPULATED userfautfd feature is required which is
needed to avoid pre-faulting memory before write-protecting [9].)
All the different masks were added on the request of CRIU devs to create
interface more generic and better.
[1] https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-…
[2] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com
[3] https://github.com/google/sanitizers
[4] https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm#64-bit
[5] https://lore.kernel.org/all/bfcae708-db21-04b4-0bbe-712badd03071@redhat.com
[6] https://lore.kernel.org/all/20220725142048.30450-1-peterx@redhat.com/
[7] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.…
[8] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.…
[9] https://lore.kernel.org/all/20230306213925.617814-1-peterx@redhat.com
[10] https://lore.kernel.org/all/20230125144529.1630917-1-mdanylo@google.com
* Original Cover letter from v8*
Hello,
Note:
Soft-dirty pages and pages which have been written-to are synonyms. As
kernel already has soft-dirty feature inside which we have given up to
use, we are using written-to terminology while using UFFD async WP under
the hood.
This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear
the info about page table entries. The following operations are
supported in this ioctl:
- Get the information if the pages have been written-to (PAGE_IS_WRITTEN),
file mapped (PAGE_IS_FILE), present (PAGE_IS_PRESENT) or swapped
(PAGE_IS_SWAPPED).
- Write-protect the pages (PAGEMAP_WP_ENGAGE) to start finding which
pages have been written-to.
- Find pages which have been written-to and write protect the pages
(atomic PAGE_IS_WRITTEN + PAGEMAP_WP_ENGAGE)
It is possible to find and clear soft-dirty pages entirely in userspace.
But it isn't efficient:
- The mprotect and SIGSEGV handler for bookkeeping
- The userfaultfd wp (synchronous) with the handler for bookkeeping
Some benchmarks can be seen here[1]. This series adds features that weren't
present earlier:
- There is no atomic get soft-dirty/Written-to status and clear present in
the kernel.
- The pages which have been written-to can not be found in accurate way.
(Kernel's soft-dirty PTE bit + sof_dirty VMA bit shows more soft-dirty
pages than there actually are.)
Historically, soft-dirty PTE bit tracking has been used in the CRIU
project. The procfs interface is enough for finding the soft-dirty bit
status and clearing the soft-dirty bit of all the pages of a process.
We have the use case where we need to track the soft-dirty PTE bit for
only specific pages on-demand. We need this tracking and clear mechanism
of a region of memory while the process is running to emulate the
getWriteWatch() syscall of Windows.
*(Moved to using UFFD instead of soft-dirtyi feature to find pages which
have been written-to from v7 patch series)*:
Stop using the soft-dirty flags for finding which pages have been
written to. It is too delicate and wrong as it shows more soft-dirty
pages than the actual soft-dirty pages. There is no interest in
correcting it [2][3] as this is how the feature was written years ago.
It shouldn't be updated to changed behaviour. Peter Xu has suggested
using the async version of the UFFD WP [4] as it is based inherently
on the PTEs.
So in this patch series, I've added a new mode to the UFFD which is
asynchronous version of the write protect. When this variant of the
UFFD WP is used, the page faults are resolved automatically by the
kernel. The pages which have been written-to can be found by reading
pagemap file (!PM_UFFD_WP). This feature can be used successfully to
find which pages have been written to from the time the pages were
write protected. This works just like the soft-dirty flag without
showing any extra pages which aren't soft-dirty in reality.
The information related to pages if the page is file mapped, present and
swapped is required for the CRIU project [5][6]. The addition of the
required mask, any mask, excluded mask and return masks are also required
for the CRIU project [5].
The IOCTL returns the addresses of the pages which match the specific
masks. The page addresses are returned in struct page_region in a compact
form. The max_pages is needed to support a use case where user only wants
to get a specific number of pages. So there is no need to find all the
pages of interest in the range when max_pages is specified. The IOCTL
returns when the maximum number of the pages are found. The max_pages is
optional. If max_pages is specified, it must be equal or greater than the
vec_size. This restriction is needed to handle worse case when one
page_region only contains info of one page and it cannot be compacted.
This is needed to emulate the Windows getWriteWatch() syscall.
The patch series include the detailed selftest which can be used as an
example for the uffd async wp test and PAGEMAP_IOCTL. It shows the
interface usages as well.
[1] https://lore.kernel.org/lkml/54d4c322-cd6e-eefd-b161-2af2b56aae24@collabora…
[2] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.…
[3] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.…
[4] https://lore.kernel.org/all/Y6Hc2d+7eTKs7AiH@x1n
[5] https://lore.kernel.org/all/YyiDg79flhWoMDZB@gmail.com/
[6] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com/
Regards,
Muhammad Usama Anjum
Muhammad Usama Anjum (4):
fs/proc/task_mmu: Implement IOCTL to get and optionally clear info
about PTEs
tools headers UAPI: Update linux/fs.h with the kernel sources
mm/pagemap: add documentation of PAGEMAP_SCAN IOCTL
selftests: mm: add pagemap ioctl tests
Peter Xu (1):
userfaultfd: UFFD_FEATURE_WP_ASYNC
Documentation/admin-guide/mm/pagemap.rst | 58 +
Documentation/admin-guide/mm/userfaultfd.rst | 35 +
fs/proc/task_mmu.c | 513 ++++++
fs/userfaultfd.c | 26 +-
include/linux/hugetlb.h | 1 +
include/linux/userfaultfd_k.h | 21 +-
include/uapi/linux/fs.h | 53 +
include/uapi/linux/userfaultfd.h | 9 +-
mm/hugetlb.c | 34 +-
mm/memory.c | 27 +-
tools/include/uapi/linux/fs.h | 53 +
tools/testing/selftests/mm/.gitignore | 2 +
tools/testing/selftests/mm/Makefile | 3 +-
tools/testing/selftests/mm/config | 1 +
tools/testing/selftests/mm/pagemap_ioctl.c | 1459 ++++++++++++++++++
tools/testing/selftests/mm/run_vmtests.sh | 4 +
16 files changed, 2275 insertions(+), 24 deletions(-)
create mode 100644 tools/testing/selftests/mm/pagemap_ioctl.c
mode change 100644 => 100755 tools/testing/selftests/mm/run_vmtests.sh
--
2.39.2
This patchset is based on the next branch of shuah/linux-kselftest.git
Tiezhu Yang (2):
selftests/vDSO: Add support for LoongArch
selftests/vDSO: Get version and name for all archs
tools/testing/selftests/vDSO/vdso_config.h | 6 ++++-
tools/testing/selftests/vDSO/vdso_test_getcpu.c | 16 +++++--------
.../selftests/vDSO/vdso_test_gettimeofday.c | 26 ++++++----------------
3 files changed, 18 insertions(+), 30 deletions(-)
--
2.1.0
When execute the following command to test clone3 on LoongArch:
# cd tools/testing/selftests/clone3 && make && ./clone3
we can see the following error info:
# [5719] Trying clone3() with flags 0x80 (size 0)
# Invalid argument - Failed to create new process
# [5719] clone3() with flags says: -22 expected 0
not ok 18 [5719] Result (-22) is different than expected (0)
This is because if CONFIG_TIME_NS is not set, but the flag
CLONE_NEWTIME (0x80) is used to clone a time namespace, it
will return -EINVAL in copy_time_ns().
If kernel does not support CONFIG_TIME_NS, /proc/self/ns/time
will be not exist, and then we should skip clone3() test with
CLONE_NEWTIME.
With this patch under !CONFIG_TIME_NS:
# cd tools/testing/selftests/clone3 && make && ./clone3
...
# Time namespaces are not supported
ok 18 # SKIP Skipping clone3() with CLONE_NEWTIME
# Totals: pass:17 fail:0 xfail:0 xpass:0 skip:1 error:0
Fixes: 515bddf0ec41 ("selftests/clone3: test clone3 with CLONE_NEWTIME")
Suggested-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Tiezhu Yang <yangtiezhu(a)loongson.cn>
---
v5:
-- Rebase on the next branch of shuah/linux-kselftest.git
to avoid potential merge conflicts due to changes in the link:
https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/c…
-- Update the commit message and send it as a single patch
Here is the v4 patch:
https://lore.kernel.org/loongarch/1685968410-5412-2-git-send-email-yangtiez…
tools/testing/selftests/clone3/clone3.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index e60cf4d..1c61e3c 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -196,7 +196,12 @@ int main(int argc, char *argv[])
CLONE3_ARGS_NO_TEST);
/* Do a clone3() in a new time namespace */
- test_clone3(CLONE_NEWTIME, 0, 0, CLONE3_ARGS_NO_TEST);
+ if (access("/proc/self/ns/time", F_OK) == 0) {
+ test_clone3(CLONE_NEWTIME, 0, 0, CLONE3_ARGS_NO_TEST);
+ } else {
+ ksft_print_msg("Time namespaces are not supported\n");
+ ksft_test_result_skip("Skipping clone3() with CLONE_NEWTIME\n");
+ }
/* Do a clone3() with exit signal (SIGCHLD) in flags */
test_clone3(SIGCHLD, 0, -EINVAL, CLONE3_ARGS_NO_TEST);
--
2.1.0