Andrii Nakryiko [Fri, 29 Mar 2024 19:04:10 +0000 (12:04 -0700)]
selftests/bpf: make multi-uprobe tests work in RELEASE=1 mode
When BPF selftests are built in RELEASE=1 mode with -O2 optimization
level, uprobe_multi binary, called from multi-uprobe tests is optimized
to the point that all the thousands of target uprobe_multi_func_XXX
functions are eliminated, breaking tests.
So ensure they are preserved by using weak attribute.
But, actually, compiling uprobe_multi binary with -O2 takes a really
long time, and is quite useless (it's not a benchmark). So in addition
to ensuring that uprobe_multi_func_XXX functions are preserved, opt-out
of -O2 explicitly in Makefile and stick to -O0. This saves a lot of
compilation time.
With -O2, just recompiling uprobe_multi:
$ touch uprobe_multi.c
$ time make RELEASE=1 -j90
make RELEASE=1 -j90 291.66s user 2.54s system 99% cpu 4:55.52 total
With -O0:
$ touch uprobe_multi.c
$ time make RELEASE=1 -j90
make RELEASE=1 -j90 22.40s user 1.91s system 99% cpu 24.355 total
bpf: Avoid kfree_rcu() under lock in bpf_lpm_trie.
syzbot reported the following lock sequence:
cpu 2:
grabs timer_base lock
spins on bpf_lpm lock
cpu 1:
grab rcu krcp lock
spins on timer_base lock
cpu 0:
grab bpf_lpm lock
spins on rcu krcp lock
bpf_lpm lock can be the same.
timer_base lock can also be the same due to timer migration.
but rcu krcp lock is always per-cpu, so it cannot be the same lock.
Hence it's a false positive.
To avoid lockdep complaining move kfree_rcu() after spin_unlock.
Martin KaFai Lau [Fri, 29 Mar 2024 02:04:25 +0000 (19:04 -0700)]
Merge branch 'Use start_server and connect_fd_to_fd'
Geliang Tang says:
====================
Simplify bpf_tcp_ca test by using connect_fd_to_fd and start_server
helpers.
v4:
- Matt reminded me that I shouldn't send a square-to patch to BPF (thanks),
so I update them into two patches in v4.
v3:
- split v2 as two patches as Daniel suggested.
- The patch "selftests/bpf: Use start_server in bpf_tcp_ca" is merged
by Daniel (thanks), but I forgot to drop 'settimeo(lfd, 0)' in it, so
I send a squash-to patch to fix this.
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Geliang Tang [Tue, 26 Mar 2024 10:03:39 +0000 (18:03 +0800)]
selftests/bpf: Drop settimeo in do_test
settimeo is invoked in start_server() and in connect_fd_to_fd() already,
no need to invoke settimeo(lfd, 0) and settimeo(fd, 0) in do_test()
anymore. This patch drops them.
Geliang Tang [Tue, 26 Mar 2024 10:03:38 +0000 (18:03 +0800)]
selftests/bpf: Use connect_fd_to_fd in bpf_tcp_ca
To simplify the code, use BPF selftests helper connect_fd_to_fd() in
bpf_tcp_ca.c instead of open-coding it. This helper is defined in
network_helpers.c, and exported in network_helpers.h, which is already
included in bpf_tcp_ca.c.
It is due to the "void *key" (r2) passed to the helper. bpf allows uninit
stack memory access for bpf prog with the right privileges. This patch
uses kmsan_unpoison_memory() to mark the stack as initialized.
This should address different syzbot reports on the uninit "void *key"
argument during map_{lookup,delete}_elem.
====================
bpf: Fix a couple of test failures with LTO kernel
With a LTO kernel built with clang, with one of earlier version of kernel,
I encountered two test failures, ksyms and kprobe_multi_bench_attach/kernel.
Now with latest bpf-next, only kprobe_multi_bench_attach/kernel failed.
But it is possible in the future ksyms selftest may fail again.
Both test failures are due to static variable/function renaming
due to cross-file inlining. For Ksyms failure, the solution is
to strip .llvm.<hash> suffixes for symbols in /proc/kallsyms before
comparing against the ksym in bpf program.
For kprobe_multi_bench_attach/kernel failure, the solution is
to either provide names in /proc/kallsyms to the kernel or
ignore those names who have .llvm.<hash> suffix since the kernel
sym name comparison is against /proc/kallsyms.
Please see each individual patches for details.
Changelogs:
v2 -> v3:
- no need to check config file, directly so strstr with '.llvm.'.
- for kprobe_multi_bench with syms, instead of skipping the syms,
consult /proc/kallyms to find corresponding names.
- add a test with populating addrs to the kernel for kprobe
multi attach.
v1 -> v2:
- Let libbpf handle .llvm.<hash suffixes since it may impact
bpf program ksym.
====================
Yonghong Song [Tue, 26 Mar 2024 04:15:23 +0000 (21:15 -0700)]
selftests/bpf: Add a kprobe_multi subtest to use addrs instead of syms
Get addrs directly from available_filter_functions_addrs and
send to the kernel during kprobe_multi_attach. This avoids
consultation of /proc/kallsyms. But available_filter_functions_addrs
is introduced in 6.5, i.e., it is introduced recently,
so I skip the test if the kernel does not support it.
Yonghong Song [Tue, 26 Mar 2024 04:15:18 +0000 (21:15 -0700)]
selftests/bpf: Fix kprobe_multi_bench_attach test failure with LTO kernel
In my locally build clang LTO kernel (enabling CONFIG_LTO and
CONFIG_LTO_CLANG_THIN), kprobe_multi_bench_attach/kernel subtest
failed like:
test_kprobe_multi_bench_attach:PASS:get_syms 0 nsec
test_kprobe_multi_bench_attach:PASS:kprobe_multi_empty__open_and_load 0 nsec
libbpf: prog 'test_kprobe_empty': failed to attach: No such process
test_kprobe_multi_bench_attach:FAIL:bpf_program__attach_kprobe_multi_opts unexpected error: -3
#117/1 kprobe_multi_bench_attach/kernel:FAIL
There are multiple symbols in /sys/kernel/debug/tracing/available_filter_functions
are renamed in /proc/kallsyms due to cross file inlining. One example is for
static function __access_remote_vm in mm/memory.c.
In a non-LTO kernel, we have the following call stack:
ptrace_access_vm (global, kernel/ptrace.c)
access_remote_vm (global, mm/memory.c)
__access_remote_vm (static, mm/memory.c)
With LTO kernel, it is possible that access_remote_vm() is inlined by
ptrace_access_vm(). So we end up with the following call stack:
ptrace_access_vm (global, kernel/ptrace.c)
__access_remote_vm (static, mm/memory.c)
The compiler renames __access_remote_vm to __access_remote_vm.llvm.<hash>
to prevent potential name collision.
The kernel bpf_kprobe_multi_link_attach() and ftrace_lookup_symbols() try
to find addresses based on /proc/kallsyms, hence the current test failed
with LTO kenrel.
This patch consulted /proc/kallsyms to find the corresponding entries
for the ksym and this solved the issue.
Refactor trace helper function load_kallsyms_local() such that
it invokes a common function with a compare function as input.
The common function will be used later for other local functions.
Yonghong Song [Tue, 26 Mar 2024 04:14:58 +0000 (21:14 -0700)]
libbpf: Handle <orig_name>.llvm.<hash> symbol properly
With CONFIG_LTO_CLANG_THIN enabled, with some of previous
version of kernel code base ([1]), I hit the following
error:
test_ksyms:PASS:kallsyms_fopen 0 nsec
test_ksyms:FAIL:ksym_find symbol 'bpf_link_fops' not found
#118 ksyms:FAIL
The reason is that 'bpf_link_fops' is renamed to
bpf_link_fops.llvm.8325593422554671469
Due to cross-file inlining, the static variable 'bpf_link_fops'
in syscall.c is used by a function in another file. To avoid
potential duplicated names, the llvm added suffix
'.llvm.<hash>' ([2]) to 'bpf_link_fops' variable.
Such renaming caused a problem in libbpf if 'bpf_link_fops'
is used in bpf prog as a ksym but 'bpf_link_fops' does not
match any symbol in /proc/kallsyms.
To fix this issue, libbpf needs to understand that suffix '.llvm.<hash>'
is caused by clang lto kernel and to process such symbols properly.
With latest bpf-next code base built with CONFIG_LTO_CLANG_THIN,
I cannot reproduce the above failure any more. But such an issue
could happen with other symbols or in the future for bpf_link_fops symbol.
I could not easily create a selftest to test newly-added
libbpf functionality with a static C test since I do not know
which symbol is cross-file inlined. But based on my particular kernel,
the following test change can run successfully.
This patch fixed the issue in libbpf such that
the suffix '.llvm.<hash>' will be ignored during comparison of
bpf prog ksym vs. symbols in /proc/kallsyms, this resolved the issue.
Currently, only static variables in /proc/kallsyms are checked
with '.llvm.<hash>' suffix since in bpf programs function ksyms
with '.llvm.<hash>' suffix are most likely kfunc's and unlikely
to be cross-file inlined.
Note that currently kernel does not support gcc build with lto.
Yonghong Song [Tue, 26 Mar 2024 04:14:53 +0000 (21:14 -0700)]
libbpf: Mark libbpf_kallsyms_parse static function
Currently libbpf_kallsyms_parse() function is declared as a global
function but actually it is not a API and there is no external
users in bpftool/bpf-selftests. So let us mark the function as
static.
Yonghong Song [Tue, 26 Mar 2024 04:14:48 +0000 (21:14 -0700)]
selftests/bpf: Replace CHECK with ASSERT macros for ksyms test
Replace CHECK with ASSERT macros for ksyms tests.
This test failed earlier with clang lto kernel, but the
issue is gone with latest code base. But replacing
CHECK with ASSERT still improves code as ASSERT is
preferred in selftests.
Martin KaFai Lau [Fri, 22 Mar 2024 19:14:33 +0000 (12:14 -0700)]
selftests/bpf: Test loading bpf-tcp-cc prog calling the kernel tcp-cc kfuncs
This patch adds a test to ensure all static tcp-cc kfuncs is visible to
the struct_ops bpf programs. It is checked by successfully loading
the struct_ops programs calling these tcp-cc kfuncs.
This patch needs to enable the CONFIG_TCP_CONG_DCTCP and
the CONFIG_TCP_CONG_BBR.
Martin KaFai Lau [Fri, 22 Mar 2024 19:14:32 +0000 (12:14 -0700)]
bpf: Remove CONFIG_X86 and CONFIG_DYNAMIC_FTRACE guard from the tcp-cc kfuncs
The commit 7aae231ac93b ("bpf: tcp: Limit calling some tcp cc functions to CONFIG_DYNAMIC_FTRACE")
added CONFIG_DYNAMIC_FTRACE guard because pahole was only generating
btf for ftrace-able functions. The ftrace filter had already been
removed from pahole, so the CONFIG_DYNAMIC_FTRACE guard can be
removed.
The commit 569c484f9995 ("bpf: Limit static tcp-cc functions in the .BTF_ids list to x86")
has added CONFIG_X86 guard because it failed the powerpc arch which
prepended a "." to the local static function, so "cubictcp_init" becomes
".cubictcp_init". "__bpf_kfunc" has been added to kfunc
since then and it uses the __unused compiler attribute.
There is an existing
"__bpf_kfunc static u32 bpf_kfunc_call_test_static_unused_arg(u32 arg, u32 unused)"
test in bpf_testmod.c to cover the static kfunc case.
cross compile on ppc64 with CONFIG_DYNAMIC_FTRACE disabled:
> readelf -s vmlinux | grep cubictcp_
56938: c00000000144fd00 184 FUNC LOCAL DEFAULT 2 cubictcp_cwnd_event [<localentry>: 8]
56939: c00000000144fdb8 200 FUNC LOCAL DEFAULT 2 cubictcp_recalc_[...] [<localentry>: 8]
56940: c00000000144fe80 296 FUNC LOCAL DEFAULT 2 cubictcp_init [<localentry>: 8]
56941: c00000000144ffa8 228 FUNC LOCAL DEFAULT 2 cubictcp_state [<localentry>: 8]
56942: c00000000145008c 1908 FUNC LOCAL DEFAULT 2 cubictcp_cong_avoid [<localentry>: 8]
56943: c000000001450800 1644 FUNC LOCAL DEFAULT 2 cubictcp_acked [<localentry>: 8]
Yafang Shao [Wed, 27 Mar 2024 03:20:22 +0000 (11:20 +0800)]
bpf: Mitigate latency spikes associated with freeing non-preallocated htab
Following the recent upgrade of one of our BPF programs, we encountered
significant latency spikes affecting other applications running on the same
host. After thorough investigation, we identified that these spikes were
primarily caused by the prolonged duration required to free a
non-preallocated htab with approximately 2 million keys.
Notably, our kernel configuration lacks the presence of CONFIG_PREEMPT. In
scenarios where kernel execution extends excessively, other threads might
be starved of CPU time, resulting in latency issues across the system. To
mitigate this, we've adopted a proactive approach by incorporating
cond_resched() calls within the kernel code. This ensures that during
lengthy kernel operations, the scheduler is invoked periodically to provide
opportunities for other threads to execute.
====================
bench: fast in-kernel triggering benchmarks
Remove "legacy" triggering benchmarks which rely on syscalls (and thus syscall
overhead is a noticeable part of benchmark, unfortunately). Replace them with
faster versions that rely on triggering BPF programs in-kernel through another
simple "driver" BPF program. See patch #2 with comparison results.
raw_tp/tp/fmodret benchmarks required adding a simple kfunc in kernel to be
able to trigger a simple tracepoint from BPF program (plus it is also allowed
to be replaced by fmod_ret programs). This limits raw_tp/tp/fmodret benchmarks
to new kernels only, but it keeps bench tool itself very portable and most of
other benchmarks will still work on wide variety of kernels without the need
to worry about building and deploying custom kernel module. See patches #5
and #6 for details.
v1->v2:
- move new TP closer to BPF test run code;
- rename/move kfunc and register it for fmod_rets (Alexei);
- limit --trig-batch-iters param to [1, 1000] (Alexei).
====================
Utilize bpf_modify_return_test_tp() kfunc to have a fast way to trigger
tp/raw_tp/fmodret programs from another BPF program, which gives us
comparable batched benchmarks to (batched) kprobe/fentry benchmarks.
We don't switch kprobe/fentry batched benchmarks to this kfunc to make
bench tool usable on older kernels as well.
Add a simple bpf_modify_return_test_tp() kfunc, available to all program
types, that is useful for various testing and benchmarking scenarios, as
it allows to trigger most tracing BPF program types from BPF side,
allowing to do complex testing and benchmarking scenarios.
It is also attachable to for fmod_ret programs, making it a good and
simple way to trigger fmod_ret program under test/benchmark.
Instead of front-loading all possible benchmarking BPF programs for
trigger benchmarks, explicitly specify which BPF programs are used by
specific benchmark and load only it.
This allows to be more flexible in supporting older kernels, where some
program types might not be possible to load (e.g., those that rely on
newly added kfunc).
Andrii Nakryiko [Tue, 26 Mar 2024 16:21:48 +0000 (09:21 -0700)]
selftests/bpf: remove syscall-driven benchs, keep syscall-count only
Remove "legacy" benchmarks triggered by syscalls in favor of newly added
in-kernel/batched benchmarks. Drop -batched suffix now as well.
Next patch will restore "feature parity" by adding back
tp/raw_tp/fmodret benchmarks based on in-kernel kfunc approach.
Existing kprobe/fentry triggering benchmarks have 1-to-1 mapping between
one syscall execution and BPF program run. While we use a fast
get_pgid() syscall, syscall overhead can still be non-trivial.
This patch adds kprobe/fentry set of benchmarks significantly amortizing
the cost of syscall vs actual BPF triggering overhead. We do this by
employing BPF_PROG_TEST_RUN command to trigger "driver" raw_tp program
which does a tight parameterized loop calling cheap BPF helper
(bpf_get_numa_node_id()), to which kprobe/fentry programs are
attached for benchmarking.
This way 1 bpf() syscall causes N executions of BPF program being
benchmarked. N defaults to 100, but can be adjusted with
--trig-batch-iters CLI argument.
For comparison we also implement a new baseline program that instead of
triggering another BPF program just does N atomic per-CPU counter
increments, establishing the limit for all other types of program within
this batched benchmarking setup.
Taking the final set of benchmarks added in this patch set (including
tp/raw_tp/fmodret, added in later patch), and keeping for now "legacy"
syscall-driven benchmarks, we can capture all triggering benchmarks in
one place for comparison, before we remove the legacy ones (and rename
xxx-batched into just xxx).
Note how xxx-batch variants are measured with significantly higher
throughput, even though it's exactly the same in-kernel overhead. As
such, results can be compared only between benchmarks of the same kind
(syscall vs batched):
Note also that syscall-count is setting a theoretical limit for
syscall-triggered benchmarks, while kernel-count is setting similar
limits for batch variants. usermode-count is a happy and unachievable
case of user space counting without doing any syscalls, and is mostly
the measure of CPU speed for such a trivial benchmark.
As was mentioned, tp/raw_tp/fmodret require kernel-side kfunc to produce
similar benchmark, which we address in a separate patch.
Note that run_bench_trigger.sh allows to override a list of benchmarks
to run, which is very useful for performance work.
Andrii Nakryiko [Tue, 26 Mar 2024 16:21:46 +0000 (09:21 -0700)]
selftests/bpf: rename and clean up userspace-triggered benchmarks
Rename uprobe-base to more precise usermode-count (it will match other
baseline-like benchmarks, kernel-count and syscall-count). Also use
BENCH_TRIG_USERMODE() macro to define all usermode-based triggering
benchmarks, which include usermode-count and uprobe/uretprobe benchmarks.
Mykyta Yatsenko [Mon, 25 Mar 2024 15:22:10 +0000 (15:22 +0000)]
bpf: improve error message for unsupported helper
BPF verifier emits "unknown func" message when given BPF program type
does not support BPF helper. This message may be confusing for users, as
important context that helper is unknown only to current program type is
not provided.
This patch changes message to "program of this type cannot use helper "
and aligns dependent code in libbpf and tests. Any suggestions on
improving/changing this message are welcome.
Anton Protopopov [Tue, 26 Mar 2024 10:17:41 +0000 (10:17 +0000)]
selftests/bpf: Add BPF_FIB_LOOKUP_MARK tests
This patch extends the fib_lookup test suite by adding a few test
cases for each IP family to test the new BPF_FIB_LOOKUP_MARK flag
to the bpf_fib_lookup:
* Test destination IP address selection with and without a mark
and/or the BPF_FIB_LOOKUP_MARK flag set
Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240326101742.17421-3-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Anton Protopopov [Tue, 26 Mar 2024 10:17:40 +0000 (10:17 +0000)]
bpf: Add support for passing mark with bpf_fib_lookup
Extend the bpf_fib_lookup() helper by making it to utilize mark if
the BPF_FIB_LOOKUP_MARK flag is set. In order to pass the mark the
four bytes of struct bpf_fib_lookup are used, shared with the
output-only smac/dmac fields.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: David Ahern <dsahern@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240326101742.17421-2-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
====================
ravb: Support describing the MDIO bus
This series adds support to the binding and driver of the Renesas
Ethernet AVB to described the MDIO bus. Currently the driver uses
the OF node of the device itself when registering the MDIO bus.
This forces any MDIO bus properties the MDIO core should react on
to be set on the device OF node. This is confusing and none of
the MDIO bus properties are described in the Ethernet AVB bindings.
Patch 1/2 extends the bindings with an optional mdio child-node
to the device that can be used to contain the MDIO bus settings.
While patch 2/2 changes the driver to use this node (if present)
when registering the MDIO bus.
If the new optional mdio child-node is not present the driver
fallback to the old behavior and uses the device OF node like before.
This change is fully backward compatible with existing usage
of the bindings.
====================
Niklas Söderlund [Mon, 25 Mar 2024 15:34:51 +0000 (16:34 +0100)]
ravb: Add support for an optional MDIO mode
The driver used the DT node of the device itself when registering the
MDIO bus. While this works, it creates a problem: it forces any MDIO bus
properties to also be set on the devices DT node. This mixes the
properties of two distinctly different things and is confusing.
This change adds support for an optional mdio node to be defined as a
child to the device DT node. The child node can then be used to describe
MDIO bus properties that the MDIO core can act on when registering the
bus.
If no mdio child node is found the driver fallback to the old behavior
and register the MDIO bus using the device DT node. This change is
backward compatible with old bindings in use.
Niklas Söderlund [Mon, 25 Mar 2024 15:34:50 +0000 (16:34 +0100)]
dt-bindings: net: renesas,etheravb: Add optional MDIO bus node
The Renesas Ethernet AVB bindings do not allow the MDIO bus to be
described. This has not been needed as only a single PHY is
supported and no MDIO bus properties have been needed.
Add an optional mdio node to the binding which allows the MDIO bus to be
described and allow bus properties to be set.
Jakub Kicinski [Fri, 29 Mar 2024 01:03:45 +0000 (18:03 -0700)]
Merge branch 'selftests-fixes-for-kernel-ci'
Petr Machata says:
====================
selftests: Fixes for kernel CI
As discussed on the bi-weekly call on Jan 30, and in mailing around
kernel CI effort, some changes are desirable in the suite of forwarding
selftests the better to work with the CI tooling. Namely:
- The forwarding selftests use a configuration file where names of
interfaces are defined and various variables can be overridden. There
is also forwarding.config.sample that users can use as a template to
refer to when creating the config file. What happens a fair bit is
that users either do not know about this at all, or simply forget, and
are confused by cryptic failures about interfaces that cannot be
created.
In patches #1 - #3 have lib.sh just be the single source of truth with
regards to which variables exist. That includes the topology variables
which were previously only in the sample file, and any "tweak
variables", such as what tools to use, sleep times, etc.
forwarding.config.sample then becomes just a placeholder with a couple
examples. Unless specific HW should be exercised, or specific tools
used, the defaults are usually just fine.
- Several net/forwarding/ selftests (and one net/ one) cannot be run on
veth pairs, they need an actual HW interface to run on. They are
generic in the sense that any capable HW should pass them, which is
why they have been put to net/forwarding/ as opposed to drivers/net/,
but they do not generalize to veth. The fact that these tests are in
net/forwarding/, but still complaining when run, is confusing.
In patches #4 - #6 move these tests to a new directory
drivers/net/hw.
- The following patches extend the codebase to handle well test results
other than pass and fail.
Patch #7 is preparatory. It converts several log_test_skip to XFAIL,
so that tests do not spuriously end up returning non-0 when they
are not supposed to.
In patches #8 - #10, introduce some missing ksft constants, then support
having those constants in RET, and then finally in EXIT_STATUS.
- The traffic scheduler tests generate a large amount of network traffic
to test the behavior of the scheduler. This demands a relatively
high-performance computer. On slow machines, such as with a debugging
kernel, the test would spuriously fail.
It can still be useful to "go through the motions" though, to possibly
catch bugs in setup of the scheduler graph and passing packets around.
Thus we still want to run the tests, just with lowered demands.
To that end, in patches #11 - #12, introduce an environment variable
KSFT_MACHINE_SLOW, with obvious meaning. Tests can then make checks
more lenient, such as mark failures as XFAIL. A helper, xfail_on_slow,
is provided to mark performance-sensitive parts of the selftest.
- In patch #13, use a similar mechanism to mark a NH group stats
selftest to XFAIL HW stats tests when run on VETH pairs.
- All these changes complicate the hitherto straightforward logging and
checking logic, so in patch #14, add a selftest that checks this
functionality in lib.sh.
v1 (vs. an RFC circulated through linux-kselftest):
- Patch #9:
- Clarify intended usage by s/set_ret/ret_set_ksft_status/,
s/nret/ksft_status/
====================
Petr Machata [Tue, 26 Mar 2024 16:54:41 +0000 (17:54 +0100)]
selftests: forwarding: Add a test for testing lib.sh functionality
Rerunning various scenarios to make sure lib.sh changes do not impact the
observable behavior is no fun. Add a selftest at least for the bare basics
-- the mechanics of setting RET, retmsg, and EXIT_STATUS.
Since the selftest itself uses lib.sh, it would be possible to break lib.sh
in such a way that invalidates result of the selftest. Since the metatest
only uses the bare basics (just pass/fail), hopefully such fundamental
breakages would be noticed.
Petr Machata [Tue, 26 Mar 2024 16:54:40 +0000 (17:54 +0100)]
selftests: forwarding: router_mpath_nh_lib: Don't skip, xfail on veth
When the NH group stats tests are currently run on a veth topology, the
HW-stats leg of each test is SKIP'ped. But kernel networking CI interprets
skips as a sign that tooling is missing, and prompts maintainer
investigation. Lack of capability to pass a test should be expressed as
XFAIL.
Selftests that require HW should normally be put in drivers/net/hw, but
doing so for the NH counter selftests would just lead to a lot of
duplicity.
So instead, introduce a helper, xfail_on_veth(), which can be used to mark
selftests that should XFAIL instead of FAILing when run on a veth topology.
On non-veth topology, they don't do anything.
Use the helper in the HW-stats part of router_mpath_nh_lib selftest.
Petr Machata [Tue, 26 Mar 2024 16:54:39 +0000 (17:54 +0100)]
selftests: forwarding: Mark performance-sensitive tests
When run on a slow machine, the scheduler traffic tests can be expected to
fail, and should be reported as XFAIL in that case. Therefore run these
tests through the perf_sensitive wrapper.
Petr Machata [Tue, 26 Mar 2024 16:54:38 +0000 (17:54 +0100)]
selftests: forwarding: Support for performance sensitive tests
Several tests in the suite use large amounts of traffic to e.g. cause
congestion and evaluate RED or shaper performance. These tests will not run
well on a slow machine, be it one with heavy debug kernel, or a VM, or e.g.
a single-board computer. Allow users to specify an environment variable,
KSFT_MACHINE_SLOW=yes, to indicate that the tests are being run on one such
machine.
Performance sensitive tests can then use a new helper, xfail_on_slow(), to
mark parts of the test that are sensitive to low-performance machines.
The helper can be used to just mark the whole suite, like so:
xfail_on_slow tests_run
... or, on the other side of the granularity spectrum, to override
individual checks:
Petr Machata [Tue, 26 Mar 2024 16:54:37 +0000 (17:54 +0100)]
selftests: forwarding: Convert log_test() to recognize RET values
In a previous patch, the interpretation of RET value was changed to mean
the kselftest framework constant with the test outcome: $ksft_pass,
$ksft_xfail, etc.
Update log_test() to recognize the various possible RET values.
Then have EXIT_STATUS track the RET value of the current test. This differs
subtly from the way RET tracks the value: while for RET we want to
recognize XFAIL as a separate status, for purposes of exit code, we want to
to conflate XFAIL and PASS, because they both communicate non-failure. Thus
add a new helper, ksft_exit_status_merge().
With this log_test_skip() and log_test_xfail() can be reexpressed as thin
wrappers around log_test.
Petr Machata [Tue, 26 Mar 2024 16:54:36 +0000 (17:54 +0100)]
selftests: forwarding: Have RET track kselftest framework constants
The variable RET keeps track of whether the test under execution has so far
failed or not. Currently it works in binary fashion: zero means everything
is fine, non-zero means something failed. log_test() then uses the value to
given a human-readable message.
In order to allow log_test() to report skips and xfails, the semantics of
RET need to be more fine-grained. Therefore have RET value be one of
kselftest framework constants: $ksft_fail, $ksft_xfail, etc.
The current logic in check_err() is such that first non-zero value of RET
trumps all those that follow. But that is not right when RET has more
fine-grained value semantics. Different outcomes have different weights.
The results of PASS and XFAIL are mostly the same: they both communicate a
test that did not go wrong. SKIP communicates lack of tooling, which the
user should go and try to fix, and as such should not be overridden by the
passes. So far, the higher-numbered statuses can be considered weightier.
But FAIL should be the weightiest.
Add a helper, ksft_status_merge(), which merges two statuses in a way that
respects the above conditions. Express it in a generic manner, because exit
status merge is subtly different, and we want to reuse the same logic.
Use the new helper when setting RET in check_err().
Re-express check_fail() in terms of check_err() to avoid duplication.
Petr Machata [Tue, 26 Mar 2024 16:54:35 +0000 (17:54 +0100)]
selftests: lib: Define more kselftest exit codes
The following patches will operate with more exit codes besides
ksft_skip. Add them here.
Additionally, move a duplicated skip exit code definition from
forwarding/tc_tunnel_key.sh. Keep a similar duplicate in
forwarding/devlink_lib.sh, because even though lib.sh will have
been sourced in all cases where devlink_lib is, the inclusion is not
visible in the file itself, and relying on it would be confusing.
The SKIP return should be used for cases where tooling of the machine under
test is lacking. For cases where HW is lacking, the appropriate outcome is
XFAIL.
This is the case with ethtool_rmon and mlxsw_lib. For these, introduce a
new helper, log_test_xfail().
Do the same for router_mpath_nh_lib. Note that it will be fixed using a
more reusable way in a following patch.
For the two resource_scale selftests, the log should simply not be written,
because there is no problem.
Petr Machata [Tue, 26 Mar 2024 16:54:33 +0000 (17:54 +0100)]
selftests: forwarding: Ditch skip_on_veth()
Since the selftests that are not supposed to run on veth pairs are now in
their own dedicated directory, the skip_on_veth logic can go away. Drop it
from the selftests, and from lib.sh.
Petr Machata [Tue, 26 Mar 2024 16:54:32 +0000 (17:54 +0100)]
selftests: forwarding: Move several selftests
The tests in net/forwarding are generally expected to be HW-independent.
There are however several tests that, while not depending on any HW in
particular, nevertheless depend on being used on HW interfaces. Placing
these selftests to net/forwarding is confusing, because the selftest will
just report it can't be run on veth pairs. At the same time, placing them
to a particular driver's selftests subdirectory would be wrong.
Instead, add a new directory, drivers/net/hw, where these generic but HW
independent selftests should be placed. Move over several such tests
including one helper library.
Since typically these tests will not be expected to run, omit the directory
drivers/net/hw from the TARGETS list in selftests/Makefile. Retain a
Makefile in the new directory itself, so that a user can make -C into that
directory and act on those tests explicitly.
Cc: Roger Quadros <rogerq@kernel.org> Cc: Tobias Waldekranz <tobias@waldekranz.com> Cc: Danielle Ratson <danieller@nvidia.com> Cc: Davide Caratti <dcaratti@redhat.com> Cc: Johannes Nixdorf <jnixdorf-oss@avm.de> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Petr Machata <petrm@nvidia.com> Link: https://lore.kernel.org/r/e11dae1f62703059e9fc2240004288ac7cc15756.1711464583.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Petr Machata [Tue, 26 Mar 2024 16:54:31 +0000 (17:54 +0100)]
selftests: forwarding: ipip_lib: Do not import lib.sh
This library is always sourced in the context where lib.sh has already been
sourced as well. Therefore drop the explicit sourcing and expect the client
to already have done it. This will simplify moving some of the clients to a
different directory.
That any sort of customization is possible at all, let alone how it should
be done, is currently not at all clear. Document the whats and hows in
README.
Petr Machata [Tue, 26 Mar 2024 16:54:29 +0000 (17:54 +0100)]
selftests: forwarding.config.sample: Move overrides to lib.sh
forwarding.config.sample, net/lib.sh and net/forwarding/lib.sh contain
definitions and redefinitions of some of the same variables. The overlap
between net/forwarding/lib.sh and forwarding.config.sample is especially
large. This duplication is a potential source of confusion and problems.
It would be overall less error prone if each variable were defined in one
place only. In this patch set, that place is the library itself. Therefore
move all comments from forwarding.config.sample to net/forwarding/lib.sh.
Move over also a definition of TC_FLAG, which was missing from lib.sh
entirely.
Additionally, add to lib.sh a default definition of the topology variables.
The logic behind this is that forgetting to specify forwarding.config was a
frequent source of frustration for the selftest users. But really, most of
the time the default veth based topology is just fine. We considered just
sourcing forwarding.config.sample instead if forwarding.config is not
available, but this is a cleaner solution.
That means the syntax of the forwarding.config.sample override has to
change to an array assignment, so that the whole variable is overwritten,
not just individual keys, which could leave the value of some keys
unchanged. Do the same in lib.sh for any cut'n'pasters out there.
The config file is then given a sort of carte blanche to redefine whatever
variables it sees fit from the libraries. This is described in a comment in
the file. Only a handful of variables are left behind, to illustrate the
customization.
The fact that the variables are now missing from forwarding.config.sample,
and therefore would miss from forwarding.config derived from that file as
well, should not change anything. This is just the sample file. Users that
keep their own forwarding.config would retain it as before.
The only observable change is introduction of TC_FLAG to lib.sh, because
now the filters would not be attempted to install to HW datapath. For veth
pairs this does not change anything. For HW deployments, users presumably
have forwarding.config with this value overridden.
The current syntax of X=${X:=X} first evaluates the ${X:=Y} expression,
which either uses the existing value of $X if there is one, or uses the
value of "Y" as a fallback, and assigns it to X. The expression is then
replaced with the now-current value of $X. Assigning that value to X once
more is meaningless.
So avoid the outer X=... bit, and instead express the same idea though the
do-nothing ":" built-in as : "${X:=Y}". This also cleans up the block
nicely and makes it more readable.
Linus Torvalds [Thu, 28 Mar 2024 20:09:37 +0000 (13:09 -0700)]
Merge tag 'net-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from bpf, WiFi and netfilter.
Current release - regressions:
- ipv6: fix address dump when IPv6 is disabled on an interface
Current release - new code bugs:
- bpf: temporarily disable atomic operations in BPF arena
- nexthop: fix uninitialized variable in nla_put_nh_group_stats()
Previous releases - regressions:
- bpf: protect against int overflow for stack access size
- hsr: fix the promiscuous mode in offload mode
- wifi: don't always use FW dump trig
- tls: adjust recv return with async crypto and failed copy to
userspace
- tcp: properly terminate timers for kernel sockets
- ice: fix memory corruption bug with suspend and rebuild
- at803x: fix kernel panic with at8031_probe
- qeth: handle deferred cc1
Previous releases - always broken:
- bpf: fix bug in BPF_LDX_MEMSX
- netfilter: reject table flag and netdev basechain updates
- inet_defrag: prevent sk release while still in use
- wifi: pick the version of SESSION_PROTECTION_NOTIF
- wwan: t7xx: split 64bit accesses to fix alignment issues
- mlxbf_gige: call request_irq() after NAPI initialized
- hns3: fix kernel crash when devlink reload during pf
initialization"
* tag 'net-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
inet: inet_defrag: prevent sk release while still in use
Octeontx2-af: fix pause frame configuration in GMP mode
net: lan743x: Add set RFE read fifo threshold for PCI1x1x chips
net: bcmasp: Remove phy_{suspend/resume}
net: bcmasp: Bring up unimac after PHY link up
net: phy: qcom: at803x: fix kernel panic with at8031_probe
netfilter: arptables: Select NETFILTER_FAMILY_ARP when building arp_tables.c
netfilter: nf_tables: skip netdev hook unregistration if table is dormant
netfilter: nf_tables: reject table flag and netdev basechain updates
netfilter: nf_tables: reject destroy command to remove basechain hooks
bpf: update BPF LSM designated reviewer list
bpf: Protect against int overflow for stack access size
bpf: Check bloom filter map value size
bpf: fix warning for crash_kexec
selftests: netdevsim: set test timeout to 10 minutes
net: wan: framer: Add missing static inline qualifiers
mlxbf_gige: call request_irq() after NAPI initialized
tls: get psock ref after taking rxlock to avoid leak
selftests: tls: add test with a partially invalid iov
tls: adjust recv return with async crypto and failed copy to userspace
...
Florian Westphal [Tue, 26 Mar 2024 10:18:41 +0000 (11:18 +0100)]
inet: inet_defrag: prevent sk release while still in use
ip_local_out() and other functions can pass skb->sk as function argument.
If the skb is a fragment and reassembly happens before such function call
returns, the sk must not be released.
This affects skb fragments reassembled via netfilter or similar
modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline.
Eric Dumazet made an initial analysis of this bug. Quoting Eric:
Calling ip_defrag() in output path is also implying skb_orphan(),
which is buggy because output path relies on sk not disappearing.
A relevant old patch about the issue was : 8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()")
[..]
net/ipv4/ip_output.c depends on skb->sk being set, and probably to an
inet socket, not an arbitrary one.
If we orphan the packet in ipvlan, then downstream things like FQ
packet scheduler will not work properly.
We need to change ip_defrag() to only use skb_orphan() when really
needed, ie whenever frag_list is going to be used.
Eric suggested to stash sk in fragment queue and made an initial patch.
However there is a problem with this:
If skb is refragmented again right after, ip_do_fragment() will copy
head->sk to the new fragments, and sets up destructor to sock_wfree.
IOW, we have no choice but to fix up sk_wmem accouting to reflect the
fully reassembled skb, else wmem will underflow.
This change moves the orphan down into the core, to last possible moment.
As ip_defrag_offset is aliased with sk_buff->sk member, we must move the
offset into the FRAG_CB, else skb->sk gets clobbered.
This allows to delay the orphaning long enough to learn if the skb has
to be queued or if the skb is completing the reasm queue.
In the former case, things work as before, skb is orphaned. This is
safe because skb gets queued/stolen and won't continue past reasm engine.
In the latter case, we will steal the skb->sk reference, reattach it to
the head skb, and fix up wmem accouting when inet_frag inflates truesize.
Fixes: 7026b1ddb6b8 ("netfilter: Pass socket pointer down through okfn().") Diagnosed-by: Eric Dumazet <edumazet@google.com> Reported-by: xingwei lee <xrivendell7@gmail.com> Reported-by: yue sun <samsun1006219@gmail.com> Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Raju Lakkaraju [Tue, 26 Mar 2024 06:58:05 +0000 (12:28 +0530)]
net: lan743x: Add set RFE read fifo threshold for PCI1x1x chips
PCI11x1x Rev B0 devices might drop packets when receiving back to back frames
at 2.5G link speed. Change the B0 Rev device's Receive filtering Engine FIFO
threshold parameter from its hardware default of 4 to 3 dwords to prevent the
problem. Rev C0 and later hardware already defaults to 3 dwords.
net: phy: qcom: at803x: fix kernel panic with at8031_probe
On reworking and splitting the at803x driver, in splitting function of
at803x PHYs it was added a NULL dereference bug where priv is referenced
before it's actually allocated and then is tried to write to for the
is_1000basex and is_fiber variables in the case of at8031, writing on
the wrong address.
Fix this by correctly setting priv local variable only after
at803x_probe is called and actually allocates priv in the phydev struct.
Reported-by: William Wortel <wwortel@dorpstraat.com> Cc: <stable@vger.kernel.org> Fixes: 25d2ba94005f ("net: phy: at803x: move specific at8031 probe mode check to dedicated probe") Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20240325190621.2665-1-ansuelsmth@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Paolo Abeni [Thu, 28 Mar 2024 09:23:02 +0000 (10:23 +0100)]
Merge tag 'nf-24-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
Patch #1 reject destroy chain command to delete device hooks in netdev
family, hence, only delchain commands are allowed.
Patch #2 reject table flag update interference with netdev basechain
hook updates, this can leave hooks in inconsistent
registration/unregistration state.
Patch #3 do not unregister netdev basechain hooks if table is dormant.
Otherwise, splat with double unregistration is possible.
Patch #4 fixes Kconfig to allow to restore IP_NF_ARPTABLES,
from Kuniyuki Iwashima.
There are a more fixes still in progress on my side that need more work.
* tag 'nf-24-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: arptables: Select NETFILTER_FAMILY_ARP when building arp_tables.c
netfilter: nf_tables: skip netdev hook unregistration if table is dormant
netfilter: nf_tables: reject table flag and netdev basechain updates
netfilter: nf_tables: reject destroy command to remove basechain hooks
====================
Paolo Abeni [Thu, 28 Mar 2024 09:07:59 +0000 (10:07 +0100)]
Merge tag 'for-net' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:
====================
pull-request: bpf 2024-03-27
The following pull-request contains BPF updates for your *net* tree.
We've added 4 non-merge commits during the last 1 day(s) which contain
a total of 5 files changed, 26 insertions(+), 3 deletions(-).
The main changes are:
1) Fix bloom filter value size validation and protect the verifier
against such mistakes, from Andrei.
2) Fix build due to CONFIG_KEXEC_CORE/CRASH_DUMP split, from Hari.
3) Update bpf_lsm maintainers entry, from Matt.
* tag 'for-net' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: update BPF LSM designated reviewer list
bpf: Protect against int overflow for stack access size
bpf: Check bloom filter map value size
bpf: fix warning for crash_kexec
====================
Linus Torvalds [Thu, 28 Mar 2024 03:24:09 +0000 (20:24 -0700)]
Merge tag 'erofs-for-6.9-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs fixes from Gao Xiang:
- Add a new reviewer Sandeep Dhavale to build a healthier community
- Drop experimental warning for FSDAX
* tag 'erofs-for-6.9-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
MAINTAINERS: erofs: add myself as reviewer
erofs: drop experimental warning for FSDAX
netfilter: arptables: Select NETFILTER_FAMILY_ARP when building arp_tables.c
syzkaller started to report a warning below [0] after consuming the
commit 4654467dc7e1 ("netfilter: arptables: allow xtables-nft only
builds").
The change accidentally removed the dependency on NETFILTER_FAMILY_ARP
from IP_NF_ARPTABLES.
If NF_TABLES_ARP is not enabled on Kconfig, NETFILTER_FAMILY_ARP will
be removed and some code necessary for arptables will not be compiled.
$ grep -E "(NETFILTER_FAMILY_ARP|IP_NF_ARPTABLES|NF_TABLES_ARP)" .config
CONFIG_NETFILTER_FAMILY_ARP=y
# CONFIG_NF_TABLES_ARP is not set
CONFIG_IP_NF_ARPTABLES=y
$ make olddefconfig
$ grep -E "(NETFILTER_FAMILY_ARP|IP_NF_ARPTABLES|NF_TABLES_ARP)" .config
# CONFIG_NF_TABLES_ARP is not set
CONFIG_IP_NF_ARPTABLES=y
So, when nf_register_net_hooks() is called for arptables, it will
trigger the splat below.
Now IP_NF_ARPTABLES is only enabled by IP_NF_ARPFILTER, so let's
restore the dependency on NETFILTER_FAMILY_ARP in IP_NF_ARPFILTER.
netfilter: nf_tables: skip netdev hook unregistration if table is dormant
Skip hook unregistration when adding or deleting devices from an
existing netdev basechain. Otherwise, commit/abort path try to
unregister hooks which not enabled.
Fixes: b9703ed44ffb ("netfilter: nf_tables: support for adding new devices to an existing netdev chain") Fixes: 7d937b107108 ("netfilter: nf_tables: support for deleting devices in an existing netdev chain") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_tables: reject table flag and netdev basechain updates
netdev basechain updates are stored in the transaction object hook list.
When setting on the table dormant flag, it iterates over the existing
hooks in the basechain. Thus, skipping the hooks that are being
added/deleted in this transaction, which leaves hook registration in
inconsistent state.
Reject table flag updates in combination with netdev basechain updates
in the same batch:
- Update table flags and add/delete basechain: Check from basechain update
path if there are pending flag updates for this table.
- add/delete basechain and update table flags: Iterate over the transaction
list to search for basechain updates from the table update path.
In both cases, the batch is rejected. Based on suggestion from Florian Westphal.
Fixes: b9703ed44ffb ("netfilter: nf_tables: support for adding new devices to an existing netdev chain") Fixes: 7d937b107108f ("netfilter: nf_tables: support for deleting devices in an existing netdev chain") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_tables: reject destroy command to remove basechain hooks
Report EOPNOTSUPP if NFT_MSG_DESTROYCHAIN is used to delete hooks in an
existing netdev basechain, thus, only NFT_MSG_DELCHAIN is allowed.
Fixes: 7d937b107108f ("netfilter: nf_tables: support for deleting devices in an existing netdev chain") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jakub Kicinski [Wed, 27 Mar 2024 22:39:17 +0000 (15:39 -0700)]
Merge tag 'wireless-2024-03-27' of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless
Kalle Valo says:
====================
wireless fixes for v6.9-rc2
The first fixes for v6.9. Ping-Ke Shih now maintains a separate tree
for Realtek drivers, document that in the MAINTAINERS. Plenty of fixes
for both to stack and iwlwifi. Our kunit tests were working only on um
architecture but that's fixed now.
* tag 'wireless-2024-03-27' of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: (21 commits)
MAINTAINERS: wifi: mwifiex: add Francesco as reviewer
kunit: fix wireless test dependencies
wifi: iwlwifi: mvm: include link ID when releasing frames
wifi: iwlwifi: mvm: handle debugfs names more carefully
wifi: iwlwifi: mvm: guard against invalid STA ID on removal
wifi: iwlwifi: read txq->read_ptr under lock
wifi: iwlwifi: fw: don't always use FW dump trig
wifi: iwlwifi: mvm: rfi: fix potential response leaks
wifi: mac80211: correctly set active links upon TTLM
wifi: iwlwifi: mvm: Configure the link mapping for non-MLD FW
wifi: iwlwifi: mvm: consider having one active link
wifi: iwlwifi: mvm: pick the version of SESSION_PROTECTION_NOTIF
wifi: mac80211: fix prep_connection error path
wifi: cfg80211: fix rdev_dump_mpp() arguments order
wifi: iwlwifi: mvm: disable MLO for the time being
wifi: cfg80211: add a flag to disable wireless extensions
wifi: mac80211: fix ieee80211_bss_*_flags kernel-doc
wifi: mac80211: check/clear fast rx for non-4addr sta VLAN changes
wifi: mac80211: fix mlme_link_id_dbg()
MAINTAINERS: wifi: add git tree for Realtek WiFi drivers
...
====================
Linus Torvalds [Wed, 27 Mar 2024 21:53:56 +0000 (14:53 -0700)]
Merge tag '9p-fixes-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
Pull 9p fixes from Eric Van Hensbergen:
"Two of these fix syzbot reported issues, and the other fixes a unused
variable in some configurations"
* tag '9p-fixes-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
fs/9p: fix uninitialized values during inode evict
fs/9p: remove redundant pointer v9ses
fs/9p: fix uaf in in v9fs_stat2inode_dotl
Linus Torvalds [Wed, 27 Mar 2024 20:56:41 +0000 (13:56 -0700)]
Merge tag 'for-6.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix race when reading extent buffer and 'uptodate' status is missed
by one thread (introduced in 6.5)
- do additional validation of devices using major:minor numbers
- zoned mode fixes:
- use zone-aware super block access during scrub
- fix use-after-free during device replace (found by KASAN)
- also delete zones that are 100% unusable to reclaim space
- extent unpinning fixes:
- fix extent map leak after error handling
- print correct range in error message
- error code and message updates
* tag 'for-6.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix race in read_extent_buffer_pages()
btrfs: return accurate error code on open failure in open_fs_devices()
btrfs: zoned: don't skip block groups with 100% zone unusable
btrfs: use btrfs_warn() to log message at btrfs_add_extent_mapping()
btrfs: fix message not properly printing interval when adding extent map
btrfs: fix warning messages not printing interval at unpin_extent_range()
btrfs: fix extent map leak in unexpected scenario at unpin_extent_cache()
btrfs: validate device maj:min during open
btrfs: zoned: fix use-after-free in do_zone_finish()
btrfs: zoned: use zone aware sb location for scrub
Linus Torvalds [Wed, 27 Mar 2024 20:30:48 +0000 (13:30 -0700)]
Merge tag 'mm-hotfixes-stable-2024-03-27-11-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"Various hotfixes. About half are cc:stable and the remainder address
post-6.8 issues or aren't considered suitable for backporting.
zswap figures prominently in the post-6.8 issues - folloup against the
large amount of changes we have just made to that code.
Apart from that, all over the map"
* tag 'mm-hotfixes-stable-2024-03-27-11-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
crash: use macro to add crashk_res into iomem early for specific arch
mm: zswap: fix data loss on SWP_SYNCHRONOUS_IO devices
selftests/mm: fix ARM related issue with fork after pthread_create
hexagon: vmlinux.lds.S: handle attributes section
userfaultfd: fix deadlock warning when locking src and dst VMAs
tmpfs: fix race on handling dquot rbtree
selftests/mm: sigbus-wp test requires UFFD_FEATURE_WP_HUGETLBFS_SHMEM
mm: zswap: fix writeback shinker GFP_NOIO/GFP_NOFS recursion
ARM: prctl: reject PR_SET_MDWE on pre-ARMv6
prctl: generalize PR_SET_MDWE support check to be per-arch
MAINTAINERS: remove incorrect M: tag for dm-devel@lists.linux.dev
mm: zswap: fix kernel BUG in sg_init_one
selftests: mm: restore settings from only parent process
tools/Makefile: remove cgroup target
mm: cachestat: fix two shmem bugs
mm: increase folio batch size
mm,page_owner: fix recursion
mailmap: update entry for Leonard Crestez
init: open /initrd.image with O_LARGEFILE
selftests/mm: Fix build with _FORTIFY_SOURCE
...
Matt Bobrowski [Tue, 26 Mar 2024 19:50:19 +0000 (19:50 +0000)]
bpf: update BPF LSM designated reviewer list
Adding myself in place of both Brendan and Florent as both have since
moved on from working on the BPF LSM and will no longer be devoting
their time to maintaining the BPF LSM.
Linus Torvalds [Wed, 27 Mar 2024 17:01:24 +0000 (10:01 -0700)]
Merge tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixlet from Masami Hiramatsu:
- tracing/probes: initialize a 'val' local variable with zero.
This variable is read by FETCH_OP_ST_EDATA in a loop, and is
initialized by FETCH_OP_ARG in the same loop. Since this
initialization is not obvious, smatch warns about it.
Explicitly initializing 'val' with zero fixes this warning.
* tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: probes: Fix to zero initialize a local variable
Linus Torvalds [Wed, 27 Mar 2024 16:57:30 +0000 (09:57 -0700)]
Merge tag 'execve-v6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull execve fixes from Kees Cook:
- Fix selftests to conform to the TAP output format (Muhammad Usama
Anjum)
- Fix NOMMU linux_binprm::exec pointer in auxv (Max Filippov)
- Replace deprecated strncpy usage (Justin Stitt)
- Replace another /bin/sh instance in selftests
* tag 'execve-v6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
binfmt: replace deprecated strncpy
exec: Fix NOMMU linux_binprm::exec in transfer_args_to_stack()
selftests/exec: Convert remaining /bin/sh to /bin/bash
selftests/exec: execveat: Improve debug reporting
selftests/exec: recursion-depth: conform test to TAP format output
selftests/exec: load_address: conform test to TAP format output
selftests/exec: binfmt_script: Add the overall result line according to TAP
Andrei Matei [Wed, 27 Mar 2024 02:42:45 +0000 (22:42 -0400)]
bpf: Protect against int overflow for stack access size
This patch re-introduces protection against the size of access to stack
memory being negative; the access size can appear negative as a result
of overflowing its signed int representation. This should not actually
happen, as there are other protections along the way, but we should
protect against it anyway. One code path was missing such protections
(fixed in the previous patch in the series), causing out-of-bounds array
accesses in check_stack_range_initialized(). This patch causes the
verification of a program with such a non-sensical access size to fail.
This check used to exist in a more indirect way, but was inadvertendly
removed in a833a17aeac7.
Andrei Matei [Wed, 27 Mar 2024 02:42:44 +0000 (22:42 -0400)]
bpf: Check bloom filter map value size
This patch adds a missing check to bloom filter creating, rejecting
values above KMALLOC_MAX_SIZE. This brings the bloom map in line with
many other map types.
The lack of this protection can cause kernel crashes for value sizes
that overflow int's. Such a crash was caught by syzkaller. The next
patch adds more guard-rails at a lower level.
Linus Torvalds [Wed, 27 Mar 2024 16:48:47 +0000 (09:48 -0700)]
Fix build errors due to new UIO_MEM_DMA_COHERENT mess
Commit 576882ef5e7f ("uio: introduce UIO_MEM_DMA_COHERENT type")
introduced a new use-case for 'struct uio_mem' where the 'mem' field now
contains a kernel virtual address when 'memtype' is set to
UIO_MEM_DMA_COHERENT.
That in turn causes build errors, because 'mem' is of type
'phys_addr_t', and a virtual address is a pointer type. When the code
just blindly uses cast to mix the two, it caused problems when
phys_addr_t isn't the same size as a pointer - notably on 32-bit
architectures with PHYS_ADDR_T_64BIT.
The proper thing to do would probably be to use a union member, and not
have any casts, and make the 'mem' member be a union of 'mem.physaddr'
and 'mem.vaddr', based on 'memtype'.
This is not that proper thing. This is just fixing the ugly casts to be
even uglier, but at least not cause build errors on 32-bit platforms
with 64-bit physical addresses.
Hari Bathini [Tue, 19 Mar 2024 08:01:52 +0000 (13:31 +0530)]
bpf: fix warning for crash_kexec
With [1], crash dump specific code is moved out of CONFIG_KEXEC_CORE
and placed under CONFIG_CRASH_DUMP, where it is more appropriate.
And since CONFIG_KEXEC & !CONFIG_CRASH_DUMP build option is supported
with that, it led to the below warning:
"WARN: resolve_btfids: unresolved symbol crash_kexec"
We've added 38 non-merge commits during the last 13 day(s) which contain
a total of 50 files changed, 867 insertions(+), 274 deletions(-).
The main changes are:
1) Add the ability to specify and retrieve BPF cookie also for raw
tracepoint programs in order to ease migration from classic to raw
tracepoints, from Andrii Nakryiko.
2) Allow the use of bpf_get_{ns_,}current_pid_tgid() helper for all
program types and add additional BPF selftests, from Yonghong Song.
3) Several improvements to bpftool and its build, for example, enabling
libbpf logs when loading pid_iter in debug mode, from Quentin Monnet.
4) Check the return code of all BPF-related set_memory_*() functions during
load and bail out in case they fail, from Christophe Leroy.
5) Avoid a goto in regs_refine_cond_op() such that the verifier can
be better integrated into Agni tool which doesn't support backedges
yet, from Harishankar Vishwanathan.
6) Add a small BPF trie perf improvement by always inlining
longest_prefix_match, from Jesper Dangaard Brouer.
7) Small BPF selftest refactor in bpf_tcp_ca.c to utilize start_server()
helper instead of open-coding it, from Geliang Tang.
8) Improve test_tc_tunnel.sh BPF selftest to prevent client connect
before the server bind, from Alessandro Carminati.
9) Fix BPF selftest benchmark for older glibc and use syscall(SYS_gettid)
instead of gettid(), from Alan Maguire.
10) Implement a backward-compatible method for struct_ops types with
additional fields which are not present in older kernels,
from Kui-Feng Lee.
11) Add a small helper to check if an instruction is addr_space_cast
from as(0) to as(1) and utilize it in x86-64 JIT, from Puranjay Mohan.
12) Small cleanup to remove unnecessary error check in
bpf_struct_ops_map_update_elem, from Martin KaFai Lau.
13) Improvements to libbpf fd validity checks for BPF map/programs,
from Mykyta Yatsenko.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (38 commits)
selftests/bpf: Fix flaky test btf_map_in_map/lookup_update
bpf: implement insn_is_cast_user() helper for JITs
bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP
selftests/bpf: Use start_server in bpf_tcp_ca
bpf: Sync uapi bpf.h to tools directory
libbpf: Add new sec_def "sk_skb/verdict"
selftests/bpf: Mark uprobe trigger functions with nocf_check attribute
selftests/bpf: Use syscall(SYS_gettid) instead of gettid() wrapper in bench
bpf-next: Avoid goto in regs_refine_cond_op()
bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool
selftests/bpf: scale benchmark counting by using per-CPU counters
bpftool: Remove unnecessary source files from bootstrap version
bpftool: Enable libbpf logs when loading pid_iter in debug mode
selftests/bpf: add raw_tp/tp_btf BPF cookie subtests
libbpf: add support for BPF cookie for raw_tp/tp_btf programs
bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
bpf: pass whole link instead of prog when triggering raw tracepoint
bpf: flatten bpf_probe_register call chain
selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh
selftests/bpf: Add a sk_msg prog bpf_get_ns_current_pid_tgid() test
...
====================
Jakub Kicinski [Mon, 25 Mar 2024 15:56:11 +0000 (08:56 -0700)]
selftests: netdevsim: set test timeout to 10 minutes
The longest running netdevsim test, nexthop.sh, currently takes
5 min to finish. Around 260s to be exact, and 310s on a debug kernel.
The default timeout in selftest is 45sec, so we need an explicit
config. Give ourselves some headroom and use 10min.
Commit under Fixes isn't really to "blame" but prior to that
netdevsim tests weren't integrated with kselftest infra
so blaming the tests themselves doesn't seem right, either.
Fixes: 8ff25dac88f6 ("netdevsim: add Makefile for selftests") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Compilation with CONFIG_GENERIC_FRAMER disabled lead to the following
warnings:
framer.h:184:16: warning: no previous prototype for function 'framer_get' [-Wmissing-prototypes]
184 | struct framer *framer_get(struct device *dev, const char *con_id)
framer.h:184:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
184 | struct framer *framer_get(struct device *dev, const char *con_id)
framer.h:189:6: warning: no previous prototype for function 'framer_put' [-Wmissing-prototypes]
189 | void framer_put(struct device *dev, struct framer *framer)
framer.h:189:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
189 | void framer_put(struct device *dev, struct framer *framer)
Add missing 'static inline' qualifiers for these functions.
Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202403241110.hfJqeJRu-lkp@intel.com/ Fixes: 82c944d05b1a ("net: wan: Add framer framework support") Cc: stable@vger.kernel.org Signed-off-by: Herve Codina <herve.codina@bootlin.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Jakub Kicinski [Wed, 27 Mar 2024 03:54:21 +0000 (20:54 -0700)]
Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue
Tony Nguyen says:
====================
Intel Wired LAN Driver Updates 2024-03-25 (ice, ixgbe, igc)
This series contains updates to ice, ixgbe, and igc drivers.
Steven fixes incorrect casting of bitmap type for ice driver.
Jesse fixes memory corruption issue with suspend flow on ice.
Przemek adds GFP_ATOMIC flag to avoid sleeping in IRQ context for ixgbe.
Kurt Kanzenbach removes no longer valid comment on igc.
* '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue:
igc: Remove stale comment about Tx timestamping
ixgbe: avoid sleeping allocation in ixgbe_ipsec_vf_add_sa()
ice: fix memory corruption bug with suspend and rebuild
ice: Refactor FW data type and fix bitmap casting issue
====================
David Thompson [Mon, 25 Mar 2024 18:36:27 +0000 (14:36 -0400)]
mlxbf_gige: call request_irq() after NAPI initialized
The mlxbf_gige driver encounters a NULL pointer exception in
mlxbf_gige_open() when kdump is enabled. The sequence to reproduce
the exception is as follows:
a) enable kdump
b) trigger kdump via "echo c > /proc/sysrq-trigger"
c) kdump kernel executes
d) kdump kernel loads mlxbf_gige module
e) the mlxbf_gige module runs its open() as the
the "oob_net0" interface is brought up
f) mlxbf_gige module will experience an exception
during its open(), something like:
The exception happens because there is a pending RX interrupt before the
call to request_irq(RX IRQ) executes. Then, the RX IRQ handler fires
immediately after this request_irq() completes. The RX IRQ handler runs
"napi_schedule()" before NAPI is fully initialized via "netif_napi_add()"
and "napi_enable()", both which happen later in the open() logic.
The logic in mlxbf_gige_open() must fully initialize NAPI before any calls
to request_irq() execute.
Sabrina Dubroca [Mon, 25 Mar 2024 15:56:48 +0000 (16:56 +0100)]
tls: get psock ref after taking rxlock to avoid leak
At the start of tls_sw_recvmsg, we take a reference on the psock, and
then call tls_rx_reader_lock. If that fails, we return directly
without releasing the reference.
Instead of adding a new label, just take the reference after locking
has succeeded, since we don't need it before.
Sabrina Dubroca [Mon, 25 Mar 2024 15:56:47 +0000 (16:56 +0100)]
selftests: tls: add test with a partially invalid iov
Make sure that we don't return more bytes than we actually received if
the userspace buffer was bogus. We expect to receive at least the rest
of rec1, and possibly some of rec2 (currently, we don't, but that
would be ok).
Sabrina Dubroca [Mon, 25 Mar 2024 15:56:46 +0000 (16:56 +0100)]
tls: adjust recv return with async crypto and failed copy to userspace
process_rx_list may not copy as many bytes as we want to the userspace
buffer, for example in case we hit an EFAULT during the copy. If this
happens, we should only count the bytes that were actually copied,
which may be 0.
Subtracting async_copy_bytes is correct in both peek and !peek cases,
because decrypted == async_copy_bytes + peeked for the peek case: peek
is always !ZC, and we can go through either the sync or async path. In
the async case, we add chunk to both decrypted and
async_copy_bytes. In the sync case, we add chunk to both decrypted and
peeked. I missed that in commit 6caaf104423d ("tls: fix peeking with
sync+async decryption").
Sabrina Dubroca [Mon, 25 Mar 2024 15:56:45 +0000 (16:56 +0100)]
tls: recv: process_rx_list shouldn't use an offset with kvec
Only MSG_PEEK needs to copy from an offset during the final
process_rx_list call, because the bytes we copied at the beginning of
tls_sw_recvmsg were left on the rx_list. In the KVEC case, we removed
data from the rx_list as we were copying it, so there's no need to use
an offset, just like in the normal case.
net: pin system percpu page_pools to the corresponding NUMA nodes
System page_pools are percpu and one instance can be used only on
one CPU.
%NUMA_NO_NODE is fine for allocating pages, as the PP core always
allocates local pages in this case. But for the struct &page_pool
itself, this node ID means they are allocated on the boot CPU,
which may belong to a different node than the target CPU.
Pin system page_pools to the corresponding nodes when creating,
so that all the allocated data will always be local. Use
cpu_to_mem() to account memless nodes.
Nodes != 0 win some Kpps when testing with xdp-trafficgen.
Baoquan He [Mon, 25 Mar 2024 01:50:50 +0000 (09:50 +0800)]
crash: use macro to add crashk_res into iomem early for specific arch
There are regression reports[1][2] that crashkernel region on x86_64 can't
be added into iomem tree sometime. This causes the later failure of kdump
loading.
This happened after commit 4a693ce65b18 ("kdump: defer the insertion of
crashkernel resources") was merged.
Even though, these reported issues are proved to be related to other
component, they are just exposed after above commmit applied, I still
would like to keep crashk_res and crashk_low_res being added into iomem
early as before because the early adding has been always there on x86_64
and working very well. For safety of kdump, Let's change it back.
Here, add a macro HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY to limit that
only ARCH defining the macro can have the early adding
crashk_res/_low_res into iomem. Then define
HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY on x86 to enable it.
Note: In reserve_crashkernel_low(), there's a remnant of crashk_low_res
handling which was mistakenly added back in commit 85fcde402db1 ("kexec:
split crashkernel reservation code out from crash_core.c").
[1]
[PATCH V2] x86/kexec: do not update E820 kexec table for setup_data
https://lore.kernel.org/all/Zfv8iCL6CT2JqLIC@darkstar.users.ipa.redhat.com/T/#u
[2]
Question about Address Range Validation in Crash Kernel Allocation
https://lore.kernel.org/all/4eeac1f733584855965a2ea62fa4da58@huawei.com/T/#u
Link: https://lkml.kernel.org/r/ZgDYemRQ2jxjLkq+@MiWiFi-R3L-srv Fixes: 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Huacai Chen <chenhuacai@loongson.cn> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Li Huafei <lihuafei1@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johannes Weiner [Sun, 24 Mar 2024 21:04:47 +0000 (17:04 -0400)]
mm: zswap: fix data loss on SWP_SYNCHRONOUS_IO devices
Zhongkun He reports data corruption when combining zswap with zram.
The issue is the exclusive loads we're doing in zswap. They assume
that all reads are going into the swapcache, which can assume
authoritative ownership of the data and so the zswap copy can go.
However, zram files are marked SWP_SYNCHRONOUS_IO, and faults will try to
bypass the swapcache. This results in an optimistic read of the swap data
into a page that will be dismissed if the fault fails due to races. In
this case, zswap mustn't drop its authoritative copy.
Link: https://lore.kernel.org/all/CACSyD1N+dUvsu8=zV9P691B9bVq33erwOXNTmEaUbi9DrDeJzw@mail.gmail.com/ Fixes: b9c91c43412f ("mm: zswap: support exclusive loads") Link: https://lkml.kernel.org/r/20240324210447.956973-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Zhongkun He <hezhongkun.hzk@bytedance.com> Tested-by: Zhongkun He <hezhongkun.hzk@bytedance.com> Acked-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Barry Song <baohua@kernel.org> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: <stable@vger.kernel.org> [6.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Edward Liaw [Mon, 25 Mar 2024 19:40:52 +0000 (19:40 +0000)]
selftests/mm: fix ARM related issue with fork after pthread_create
Following issue was observed while running the uffd-unit-tests selftest
on ARM devices. On x86_64 no issues were detected:
pthread_create followed by fork caused deadlock in certain cases wherein
fork required some work to be completed by the created thread. Used
synchronization to ensure that created thread's start function has started
before invoking fork.
[edliaw@google.com: refactored to use atomic_bool] Link: https://lkml.kernel.org/r/20240325194100.775052-1-edliaw@google.com Fixes: 760aee0b71e3 ("selftests/mm: add tests for RO pinning vs fork()") Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Signed-off-by: Edward Liaw <edliaw@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After the linked LLVM change, the build fails with
CONFIG_LD_ORPHAN_WARN_LEVEL="error", which happens with allmodconfig:
ld.lld: error: vmlinux.a(init/main.o):(.hexagon.attributes) is being placed in '.hexagon.attributes'
Handle the attributes section in a similar manner as arm and riscv by
adding it after the primary ELF_DETAILS grouping in vmlinux.lds.S, which
fixes the error.
Carlos Maiolino [Wed, 20 Mar 2024 12:39:59 +0000 (13:39 +0100)]
tmpfs: fix race on handling dquot rbtree
A syzkaller reproducer found a race while attempting to remove dquot
information from the rb tree.
Fetching the rb_tree root node must also be protected by the
dqopt->dqio_sem, otherwise, giving the right timing, shmem_release_dquot()
will trigger a warning because it couldn't find a node in the tree, when
the real reason was the root node changing before the search starts:
Edward Liaw [Thu, 21 Mar 2024 23:20:21 +0000 (23:20 +0000)]
selftests/mm: sigbus-wp test requires UFFD_FEATURE_WP_HUGETLBFS_SHMEM
The sigbus-wp test requires the UFFD_FEATURE_WP_HUGETLBFS_SHMEM flag for
shmem and hugetlb targets. Otherwise it is not backwards compatible with
kernels <5.19 and fails with EINVAL.
Link: https://lkml.kernel.org/r/20240321232023.2064975-1-edliaw@google.com Fixes: 73c1ea939b65 ("selftests/mm: move uffd sig/events tests into uffd unit tests") Signed-off-by: Edward Liaw <edliaw@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Peter Xu <peterx@redhat.com Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The zswap shrinker resumes the swap_writepage()s that were intercepted
by the zswap store. This will enter the block layer, and may even
enter the filesystem depending on the swap backing file.