As reported by Byeonguk, the bad_words test in verifier_bits_iter.c
occasionally fails on s390 host. Quoting Ilya's explanation:
s390 kernel runs in a completely separate address space, there is no
user/kernel split at TASK_SIZE. The same address may be valid in both
the kernel and the user address spaces, there is no way to tell by
looking at it. The config option related to this property is
ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
Also, unfortunately, 0 is a valid address in the s390 kernel address
space.
Fix the issue by using -4095 as the bad address for bits iterator, as
suggested by Ilya. Verify that bpf_iter_bits_new() returns -EINVAL for
NULL address and -EFAULT for bad address.
Fixes: ebafc1e535 ("selftests/bpf: Add three test cases for bits_iter")
Reported-by: Byeonguk Jeong <jungbu2855@gmail.com>
Closes: https://lore.kernel.org/bpf/ZycSXwjH4UTvx-Cn@ub22/
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20241105043057.3371482-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Disable strict aliasing, as has been done in the kernel proper for decades
(literally since before git history) to fix issues where gcc will optimize
away loads in code that looks 100% correct, but is _technically_ undefined
behavior, and thus can be thrown away by the compiler.
E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long)
pointer to a u64 (unsigned long long) pointer when setting PMCR.N via
u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores
the result and uses the original PMCR.
The issue is most easily observed by making set_pmcr_n() noinline and
wrapping the call with printf(), e.g. sans comments, for this code:
printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n);
set_pmcr_n(&pmcr, pmcr_n);
printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n);
gcc-13 generates:
0000000000401c90 <set_pmcr_n>:
401c90: f9400002 ldr x2, [x0]
401c94: b3751022 bfi x2, x1, #11, #5
401c98: f9000002 str x2, [x0]
401c9c: d65f03c0 ret
0000000000402660 <test_create_vpmu_vm_with_pmcr_n>:
402724: aa1403e3 mov x3, x20
402728: aa1503e2 mov x2, x21
40272c: aa1603e0 mov x0, x22
402730: aa1503e1 mov x1, x21
402734: 940060ff bl 41ab30 <_IO_printf>
402738: aa1403e1 mov x1, x20
40273c: 910183e0 add x0, sp, #0x60
402740: 97fffd54 bl 401c90 <set_pmcr_n>
402744: aa1403e3 mov x3, x20
402748: aa1503e2 mov x2, x21
40274c: aa1503e1 mov x1, x21
402750: aa1603e0 mov x0, x22
402754: 940060f7 bl 41ab30 <_IO_printf>
with the value stored in [sp + 0x60] ignored by both printf() above and
in the test proper, resulting in a false failure due to vcpu_set_reg()
simply storing the original value, not the intended value.
$ ./vpmu_counter_access
Random seed: 0x6b8b4567
orig = 3040, next = 3040, want = 0
orig = 3040, next = 3040, want = 0
==== Test Assertion Failure ====
aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr)
pid=71578 tid=71578 errno=9 - Bad file descriptor
1 0x400673: run_access_test at vpmu_counter_access.c:522
2 (inlined by) main at vpmu_counter_access.c:643
3 0x4132d7: __libc_start_call_main at libc-start.o:0
4 0x413653: __libc_start_main at ??:0
5 0x40106f: _start at ??:0
Failed to update PMCR.N to 0 (received: 6)
Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if
set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n()
is inlined in its sole caller.
Cc: stable@vger.kernel.org
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912
Signed-off-by: Sean Christopherson <seanjc@google.com>
The loop in test_create_guest_memfd_invalid() that is supposed to test
that nothing is accepted as a valid flag to KVM_CREATE_GUEST_MEMFD was
initializing `flag` as 0 instead of BIT(0). This caused the loop to
immediately exit instead of iterating over BIT(0), BIT(1), ... .
Fixes: 8a89efd434 ("KVM: selftests: Add basic selftest for guest_memfd()")
Signed-off-by: Patrick Roy <roypat@amazon.co.uk>
Reviewed-by: James Gowans <jgowans@amazon.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20241024095956.3668818-1-roypat@amazon.co.uk
Signed-off-by: Sean Christopherson <seanjc@google.com>
The Memory Bandwidth Allocation (MBA) test iterates through all possible
MBA allocations, from 10% (ALLOCATION_MIN) to 100% (ALLOCATION_MAX) with
increments of 10% (ALLOCATION_STEP) at each iteration. During each
iteration the test measures the actual memory bandwidth NUM_OF_RUNS times
to determine the impact of MBA on actual memory bandwidth.
After the MBA test completes all the memory bandwidth measurements are
parsed into an array. One array for resctrl Memory Bandwidth Monitoring
(MBM) measurements and one array for the Integrated Memory Controller
(iMC) measurements. Each array has a hardcoded size of 1024 that is
large enough to hold the current test data, but this hardcoded value makes
the implementation difficult to understand. It will not be clear that this
array needs to be reconsidered if any of the test parameters are changed.
Replace the magic constant as array size with the test parameters the
array size depends on.
Reported-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Closes: https://lore.kernel.org/all/45af2a8c-517d-8f0d-137d-ad0f3f6a3c68@linux.intel.com/
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The resctrl selftests drop the results from every first test run
to avoid (per comment) "inaccurate due to monitoring setup transition
phase" data. Previously inaccurate data resulted from workloads needing
some time to "settle" and also the measurements themselves to
account for earlier measurements to measure across needed timeframe.
commit da50de0a92 ("selftests/resctrl: Calculate resctrl FS derived mem
bw over sleep(1) only")
ensured that measurements accurately measure just the time frame of
interest. The default "fill_buf" benchmark since separated the buffer
prepare phase from the benchmark run phase reducing the need for the
tests themselves to accommodate the benchmark's "settle" time.
With these enhancements there are no remaining portions needing
to "settle" and the first test run can contribute to measurements.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The MBA test incrementally throttles memory bandwidth, each time
followed by a comparison between the memory bandwidth observed
by the performance counters and resctrl respectively.
While a comparison between performance counters and resctrl is
generally appropriate, they do not have an identical view of
memory bandwidth. For example RAS features or memory performance
features that generate memory traffic may drive accesses that are
counted differently by performance counters and MBM respectively,
for instance generating "overhead" traffic which is not counted
against any specific RMID. As a ratio, this different view of memory
bandwidth becomes more apparent at low memory bandwidths.
It is not practical to enable/disable the various features that
may generate memory bandwidth to give performance counters and
resctrl an identical view. Instead, do not compare performance
counters and resctrl view of memory bandwidth when the memory
bandwidth is low.
Bandwidth throttling behaves differently across platforms
so it is not appropriate to drop measurement data simply based
on the throttling level. Instead, use a threshold of 750MiB
that has been observed to support adequate comparison between
performance counters and resctrl.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
By default the MBM and MBA tests use the "fill_buf" benchmark to
read from a buffer with the goal to measure the memory bandwidth
generated by this buffer access.
Care should be taken when sizing the buffer used by the "fill_buf"
benchmark. If the buffer is small enough to fit in the cache then
it cannot be expected that the benchmark will generate much memory
bandwidth. For example, on a system with 320MB L3 cache the existing
hardcoded default of 250MB is insufficient.
Use the measured cache size to determine a buffer size that can be
expected to trigger memory access while keeping the existing default
as minimum, now renamed to MINIMUM_SPAN, that has been appropriate for
testing so far.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The CMT, MBA, and MBM tests rely on the resctrl_val() wrapper to
start and run a benchmark while providing test specific flows
via callbacks to do test specific configuration and measurements.
At a high level, the resctrl_val() flow is:
a) Start by fork()ing a child process that installs a signal
handler for SIGUSR1 that, on receipt of SIGUSR1, will
start running a benchmark.
b) Assign the child process created in (a) to the resctrl
control and monitoring group that dictates the memory and
cache allocations with which the process can run and will
contain all resctrl monitoring data of that process.
c) Once parent and child are considered "ready" (determined via
a message over a pipe) the parent signals the child (via
SIGUSR1) to start the benchmark, waits one second for the
benchmark to run, and then starts collecting monitoring data
for the tests, potentially also changing allocation
configuration depending on the various test callbacks.
A problem with the above flow is the "black box" view of the
benchmark that is combined with an arbitrarily chosen
"wait one second" before measurements start. No matter what
the benchmark does, it is given one second to initialize before
measurements start.
The default benchmark "fill_buf" consists of two parts,
first it prepares a buffer (allocate, initialize, then flush), then it
reads from the buffer (in unpredictable ways) until terminated.
Depending on the system and the size of the buffer, the first "prepare"
part may not be complete by the time the one second delay expires. Test
measurements may thus start before the work needing to be measured runs.
Split the default benchmark into its "prepare" and "runtime" parts and
simplify the resctrl_val() wrapper while doing so. This same split
cannot be done for the user provided benchmark (without a user
interface change), so the current behavior is maintained for user
provided benchmark.
Assign the test itself to the control and monitoring group and run the
"prepare" part of the benchmark in this context, ensuring it runs with
required cache and memory bandwidth allocations. With the benchmark
preparation complete it is only needed to fork() the "runtime" part
of the benchmark (or entire user provided benchmark).
Keep the "wait one second" delay before measurements start. For the
default "fill_buf" benchmark this time now covers only the "runtime"
portion that needs to be measured. For the user provided benchmark this
delay maintains current behavior.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The benchmark used during the CMT, MBM, and MBA tests can be provided by
the user via (-b) parameter, if not provided the default "fill_buf"
benchmark is used. The user is additionally able to override
any of the "fill_buf" default parameters when running the tests with
"-b fill_buf <fill_buf parameters>".
The "fill_buf" parameters are managed as an array of strings. Using an
array of strings is complex because it requires transformations to/from
strings at every producer and consumer. This is made worse for the
individual tests where the default benchmark parameters values may not
be appropriate and additional data wrangling is required. For example,
the CMT test duplicates the entire array of strings in order to replace
one of the parameters.
More issues appear when combining the usage of an array of strings with
the use case of user overriding default parameters by specifying
"-b fill_buf <parameters>". This use case is fragile with opportunities
to trigger a SIGSEGV because of opportunities for NULL pointers to exist
in the array of strings. For example, by running below (thus by specifying
"fill_buf" should be used but all parameters are NULL):
$ sudo resctrl_tests -t mbm -b fill_buf
Replace the "array of strings" parameters used for "fill_buf" with
new struct fill_buf_param that contains the "fill_buf" parameters that
can be used directly without transformations to/from strings. Two
instances of struct fill_buf_param may exist at any point in time:
* If the user provides new parameters to "fill_buf", the
user parameter structure (struct user_params) will point to a
fully initialized and immutable struct fill_buf_param
containing the user provided parameters.
* If "fill_buf" is the benchmark that should be used by a test,
then the test parameter structure (struct resctrl_val_param)
will point to a fully initialized struct fill_buf_param. The
latter may contain (a) the user provided parameters verbatim,
(b) user provided parameters adjusted to be appropriate for
the test, or (c) the default parameters for "fill_buf" that
is appropriate for the test if the user did not provide
"fill_buf" parameters nor an alternate benchmark.
The existing behavior of CMT test is to use test defined value for the
buffer size even if the user provides another value via command line.
This behavior is maintained since the test requires that the buffer size
matches the size of the cache allocated, and the amount of cache
allocated can instead be changed by the user with the "-n" command line
parameter.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The MBM and MBA resctrl selftests run a benchmark during which
it takes measurements of read memory bandwidth via perf.
Code exists to support measurements of write memory bandwidth
but there exists no path with which this code can execute.
While code exists for write memory bandwidth measurement
there has not yet been a use case for it. Remove this unused code.
Rename relevant functions to include "read" so that it is clear
that it relates only to memory bandwidth reads, while renaming
the functions also add consistency by changing the "membw"
instances to more prevalent "mem_bw".
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The CMT, MBM, and MBA tests rely on a benchmark to generate
memory traffic. By default this is the "fill_buf" benchmark that
can be replaced via the "-b" command line argument.
The original intent of the "-b" command line parameter was
to replace the default "fill_buf" benchmark, but the implementation
also exposes an alternative use case where the "fill_buf" parameters
itself can be modified. One of the parameters to "fill_buf" is the
"operation" that can be either "read" or "write" and indicates
whether the "fill_buf" should use "read" or "write" operations on the
allocated buffer.
While replacing "fill_buf" default parameters is technically possible,
replacing the default "read" parameter with "write" is not supported
because the MBA and MBM tests only measure "read" operations. The
"read" operation is also most appropriate for the CMT test that aims
to use the benchmark to allocate into the cache.
Avoid any potential inconsistencies between test and measurement by
removing code for unsupported "write" operations to the buffer.
Ignore any attempt from user space to enable this unsupported test
configuration, instead always use read operations.
Keep the initialization of the, now unused, "fill_buf" parameters
to reserve these parameter positions since it has been exposed as an API.
Future parameter additions cannot use these parameter positions.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The CMT, MBM, and MBA tests rely on a benchmark that runs while
the test makes changes to needed configuration (for example memory
bandwidth allocation) and takes needed measurements. By default
the "fill_buf" benchmark is used and by default (via its
"once = false" setting) "fill_buf" is configured to run until
terminated after the test completes.
An unintended consequence of enabling the user to override the
benchmark also enables the user to change parameters to the
"fill_buf" benchmark. This enables the user to set "fill_buf" to
only cycle through the buffer once (by setting "once = true")
and thus breaking the CMT, MBA, and MBM tests that expect
workload/interference to be reflected by their measurements.
Prevent user space from changing the "once" parameter and ensure
that it is always false for the CMT, MBA, and MBM tests.
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Within mba_setup() the programmed bandwidth delay value starts
at the maximum (100, or rather ALLOCATION_MAX) and progresses
towards ALLOCATION_MIN by decrementing with ALLOCATION_STEP.
The programmed bandwidth delay should never be negative, so
representing it with an unsigned int is most appropriate. This
may introduce confusion because of the "allocation > ALLOCATION_MAX"
check used to check wraparound of the subtraction.
Modify the mba_setup() flow to start at the minimum, ALLOCATION_MIN,
and incrementally, with ALLOCATION_STEP steps, adjust the
bandwidth delay value. This avoids wraparound while making the purpose
of "allocation > ALLOCATION_MAX" clear and eliminates the
need for the "allocation < ALLOCATION_MIN" check.
Reported-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Closes: https://lore.kernel.org/lkml/1903ac13-5c9c-ef8d-78e0-417ac34a971b@linux.intel.com/
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
resctrl selftests discover system properties via a variety of sysfs files.
The MBM and MBA tests need to discover the event and umask with which to
configure the performance event used to measure read memory bandwidth.
This is done by parsing the contents of
/sys/bus/event_source/devices/uncore_imc_<imc instance>/events/cas_count_read
Similarly, the resctrl selftests discover the cache size via
/sys/bus/cpu/devices/cpu<id>/cache/index<index>/size.
Take care to do bounds checking when using fscanf() to read the
contents of files into a string buffer because by default fscanf() assumes
arbitrarily long strings. If the file contains more bytes than the array
can accommodate then an overflow will occur.
Provide a maximum field width to the conversion specifier to protect
against array overflow. The maximum is one less than the array size because
string input stores a terminating null byte that is not covered by the
maximum field width.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The MBM and MBA tests need to discover the event and umask with which to
configure the performance event used to measure read memory bandwidth.
This is done by parsing the
/sys/bus/event_source/devices/uncore_imc_<imc instance>/events/cas_count_read
file for each iMC instance that contains the formatted
output: "event=<event>,umask=<umask>"
Parsing of cas_count_read contents is done by initializing an array of
MAX_TOKENS elements with tokens (deliminated by "=,") from this file.
Remove the unnecessary append of a delimiter to the string needing to be
parsed. Per the strtok() man page: "delimiter bytes at the start or end of
the string are ignored". This has no impact on the token placement within
the array.
After initialization, the actual event and umask is determined by
parsing the tokens directly following the "event" and "umask" tokens
respectively.
Iterating through the array up to index "i < MAX_TOKENS" but then
accessing index "i + 1" risks array overrun during the final iteration.
Avoid array overrun by ensuring that the index used within for
loop will always be valid.
Fixes: 1d3f08687d ("selftests/resctrl: Read memory bandwidth from perf IMC counter and from resctrl file system")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
alloc_buffer() allocates and initializes (with random data) a
buffer of requested size. The initialization starts from the beginning
of the allocated buffer and incrementally assigns sizeof(uint64_t) random
data to each cache line. The initialization uses the size of the
buffer to control the initialization flow, decrementing the amount of
buffer needing to be initialized after each iteration.
The size of the buffer is stored in an unsigned (size_t) variable s64
and the test "s64 > 0" is used to decide if initialization is complete.
The problem is that decrementing the buffer size may wrap around
if the buffer size is not divisible by "CL_SIZE / sizeof(uint64_t)"
resulting in the "s64 > 0" test being true and memory beyond the buffer
"initialized".
Use a signed value for the buffer size to support all buffer sizes.
Fixes: a2561b12fe ("selftests/resctrl: Add built in benchmark")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
By default the MBM test uses the "fill_buf" benchmark to keep reading
from a buffer with size DEFAULT_SPAN while measuring memory bandwidth.
User space can provide an alternate benchmark or amend the size of
the buffer "fill_buf" should use.
Analysis of the MBM measurements do not require that a buffer be used
and thus do not require knowing the size of the buffer if it was used
during testing. Even so, the buffer size is printed as informational
as part of the MBM test results. What is printed as buffer size is
hardcoded as DEFAULT_SPAN, even if the test relied on another benchmark
(that may or may not use a buffer) or if user space amended the buffer
size.
Ensure that accurate buffer size is printed when using "fill_buf"
benchmark and omit the buffer size information if another benchmark
is used.
Fixes: ecdbb911f2 ("selftests/resctrl: Add MBM test")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Fix following sparse warnings:
tools/testing/selftests/resctrl/resctrl_val.c:47:6: warning: symbol 'membw_initialize_perf_event_attr' was not declared. Should it be static?
tools/testing/selftests/resctrl/resctrl_val.c:64:6: warning: symbol 'membw_ioctl_perf_event_ioc_reset_enable' was not declared. Should it be
static?
tools/testing/selftests/resctrl/resctrl_val.c:70:6: warning: symbol 'membw_ioctl_perf_event_ioc_disable' was not declared. Should it be static?
tools/testing/selftests/resctrl/resctrl_val.c:81:6: warning: symbol 'get_event_and_umask' was not declared. Should it be static?
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Ensure that trusted PTR_TO_BTF_ID accesses perform PROBE_MEM handling in
raw_tp program. Without the previous fix, this selftest crashes the
kernel due to a NULL-pointer dereference. Also ensure that dead code
elimination does not kick in for checks on the pointer.
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241104171959.2938862-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Arguments to a raw tracepoint are tagged as trusted, which carries the
semantics that the pointer will be non-NULL. However, in certain cases,
a raw tracepoint argument may end up being NULL. More context about this
issue is available in [0].
Thus, there is a discrepancy between the reality, that raw_tp arguments
can actually be NULL, and the verifier's knowledge, that they are never
NULL, causing explicit NULL checks to be deleted, and accesses to such
pointers potentially crashing the kernel.
To fix this, mark raw_tp arguments as PTR_MAYBE_NULL, and then special
case the dereference and pointer arithmetic to permit it, and allow
passing them into helpers/kfuncs; these exceptions are made for raw_tp
programs only. Ensure that we don't do this when ref_obj_id > 0, as in
that case this is an acquired object and doesn't need such adjustment.
The reason we do mask_raw_tp_trusted_reg logic is because other will
recheck in places whether the register is a trusted_reg, and then
consider our register as untrusted when detecting the presence of the
PTR_MAYBE_NULL flag.
To allow safe dereference, we enable PROBE_MEM marking when we see loads
into trusted pointers with PTR_MAYBE_NULL.
While trusted raw_tp arguments can also be passed into helpers or kfuncs
where such broken assumption may cause issues, a future patch set will
tackle their case separately, as PTR_TO_BTF_ID (without PTR_TRUSTED) can
already be passed into helpers and causes similar problems. Thus, they
are left alone for now.
It is possible that these checks also permit passing non-raw_tp args
that are trusted PTR_TO_BTF_ID with null marking. In such a case,
allowing dereference when pointer is NULL expands allowed behavior, so
won't regress existing programs, and the case of passing these into
helpers is the same as above and will be dealt with later.
Also update the failure case in tp_btf_nullable selftest to capture the
new behavior, as the verifier will no longer cause an error when
directly dereference a raw tracepoint argument marked as __nullable.
[0]: https://lore.kernel.org/bpf/ZrCZS6nisraEqehw@jlelli-thinkpadt14gen4.remote.csb
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Fixes: 3f00c52393 ("bpf: Allow trusted pointers to be passed to KF_TRUSTED_ARGS kfuncs")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241104171959.2938862-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
pkey_sighandler_tests.c makes raw syscalls using its own helper,
syscall_raw(). One of those syscalls is clone, which is problematic
as every architecture has a different opinion on the order of its
arguments.
To complete arm64 support, we therefore add an appropriate
implementation in syscall_raw(), and introduce a clone_raw() helper
that shuffles arguments as needed for each arch.
Having done this, we enable building pkey_sighandler_tests for arm64
in the Makefile.
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20241029144539.111155-6-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
pkey_sighandler_tests.c currently hardcodes x86 PKRU encodings. The
first step towards running those tests on arm64 is to abstract away
the pkey register values.
Since those tests want to deny access to all keys except a few,
we have each arch define PKEY_REG_ALLOW_NONE, the pkey register value
denying access to all keys. We then use the existing set_pkey_bits()
helper to grant access to specific keys.
Because pkeys may also remove the execute permission on arm64, we
need to be a little careful: all code is mapped with pkey 0, and we
need it to remain executable. pkey_reg_restrictive_default() is
introduced for that purpose: the value it returns prevents RW access
to all pkeys, but retains X permission for pkey 0.
test_pkru_preserved_after_sigusr1() only checks that the pkey
register value remains unchanged after a signal is delivered, so the
particular value is irrelevant. We enable pkey 0 and a few more
arbitrary keys in the smallest range available on all architectures
(8 keys on arm64).
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20241029144539.111155-5-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
There are similar checks for covering locks, references, RCU read
sections and preempt_disable sections in 3 places in the verifer, i.e.
for tail calls, bpf_ld_[abs, ind], and exit path (for BPF_EXIT and
bpf_throw). Unify all of these into a common check_resource_leak
function to avoid code duplication.
Also update the error strings in selftests to the new ones in the same
change to ensure clean bisection.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241103225940.1408302-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add 3 tests to check for the expected behaviour of
qdisc_tree_reduce_backlog in special scenarios.
- The first test checks if the qdisc class is notified of deletion for
major handle 'ffff:'.
- The second test checks the same as the first test but with 'ffff:' as the root
qdisc.
- The third test checks if everything works if ingress is active.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20241101143148.1218890-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-10-31
We've added 13 non-merge commits during the last 16 day(s) which contain
a total of 16 files changed, 710 insertions(+), 668 deletions(-).
The main changes are:
1) Optimize and homogenize bpf_csum_diff helper for all archs and also
add a batch of new BPF selftests for it, from Puranjay Mohan.
2) Rewrite and migrate the test_tcp_check_syncookie.sh BPF selftest
into test_progs so that it can be run in BPF CI, from Alexis Lothoré.
3) Two BPF sockmap selftest fixes, from Zijian Zhang.
4) Small XDP synproxy BPF selftest cleanup to remove IP_DF check,
from Vincent Li.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
selftests/bpf: Add a selftest for bpf_csum_diff()
selftests/bpf: Don't mask result of bpf_csum_diff() in test_verifier
bpf: bpf_csum_diff: Optimize and homogenize for all archs
net: checksum: Move from32to16() to generic header
selftests/bpf: remove xdp_synproxy IP_DF check
selftests/bpf: remove test_tcp_check_syncookie
selftests/bpf: test MSS value returned with bpf_tcp_gen_syncookie
selftests/bpf: add ipv4 and dual ipv4/ipv6 support in btf_skc_cls_ingress
selftests/bpf: get rid of global vars in btf_skc_cls_ingress
selftests/bpf: add missing ns cleanups in btf_skc_cls_ingress
selftests/bpf: factorize conn and syncookies tests in a single runner
selftests/bpf: Fix txmsg_redir of test_txmsg_pull in test_sockmap
selftests/bpf: Fix msg_verify_data in test_sockmap
====================
Link: https://patch.msgid.link/20241031221543.108853-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Extend netcons_basic selftest to verify the userdata functionality by:
1. Creating a test key in the userdata configfs directory
2. Writing a known value to the key
3. Validating the key-value pair appears in the captured network output
This ensures the userdata feature is properly tested during selftests.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20241029090030.1793551-3-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since 135225a363 timekeeping_cycles_to_ns() handles large offsets which
would lead to 64bit multiplication overflows correctly. It's also protected
against negative motion of the clocksource unconditionally, which was
exclusive to x86 before.
timekeeping_advance() handles large offsets already correctly.
That means the value of CONFIG_DEBUG_TIMEKEEPING which analyzed these cases
is very close to zero. Remove all of it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20241031120328.536010148@linutronix.de
Pull Kselftest fixes from Shuah Khan:
- fix syntax error in frequency calculation arithmetic expression in
intel_pstate run.sh
- add missing cpupower dependency check intel_pstate run.sh
- fix idmap_mount_tree_invalid test failure due to incorrect argument
- fix watchdog-test run leaving the watchdog timer enabled causing
system reboot. With this fix, the test disables the watchdog timer
when it gets terminated with SIGTERM, SIGKILL, and SIGQUIT in
addition to SIGINT
* tag 'linux_kselftest-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests/watchdog-test: Fix system accidentally reset after watchdog-test
selftests/intel_pstate: check if cpupower is installed
selftests/intel_pstate: fix operand expected error
selftests/mount_setattr: fix idmap_mount_tree_invalid failed to run
Pull cxl fixes from Ira Weiny:
"The bulk of these fixes center around an initialization order bug
reported by Gregory Price and some additional fall out from the
debugging effort.
In summary, cxl_acpi and cxl_mem race and previously worked because of
a bus_rescan_devices() while testing without modules built in.
Unfortunately with modules built in the rescan would fail due to the
cxl_port driver being registered late via the build order. Furthermore
it was found bus_rescan_devices() did not guarantee a probe barrier
which CXL was expecting. Additional fixes to cxl-test and decoder
allocation came along as they were found in this debugging effort.
The other fixes are pretty minor but one affects trace point data seen
by user space.
Summary:
- Fix crashes when running with cxl-test code
- Fix Trace DRAM Event Record field decodes
- Fix module/built in initialization order errors
- Fix use after free on decoder shutdowns
- Fix out of order decoder allocations
- Improve cxl-test to better reflect real world systems"
* tag 'cxl-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/test: Improve init-order fidelity relative to real-world systems
cxl/port: Prevent out-of-order decoder allocation
cxl/port: Fix use-after-free, permit out-of-order decoder shutdown
cxl/acpi: Ensure ports ready at cxl_acpi_probe() return
cxl/port: Fix cxl_bus_rescan() vs bus_rescan_devices()
cxl/port: Fix CXL port initialization order when the subsystem is built-in
cxl/events: Fix Trace DRAM Event Record
cxl/core: Return error when cxl_endpoint_gather_bandwidth() handles a non-PCI device
There exist compiler flags supported by GCC but not supported by Clang
(e.g. -specs=...). Currently, these cannot be passed to BPF selftests
builds, even when building with GCC, as some binaries (urandom_read and
liburandom_read.so) are always built with Clang and the unsupported
flags make the compilation fail (as -Werror is turned on).
Add -Wno-unused-command-line-argument to these rules to suppress such
errors.
This allows to do things like:
$ CFLAGS="-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1" \
make -C tools/testing/selftests/bpf
Without this patch, the compilation would fail with:
[...]
clang: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument]
make: *** [Makefile:273: /bpf-next/tools/testing/selftests/bpf/liburandom_read.so] Error 1
[...]
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/2d349e9d5eb0a79dd9ff94b496769d64e6ff7654.1730449390.git.vmalik@redhat.com
The new subtest runs with bpf_prog_test_run_opts() as a syscall prog.
It iterates the kmem_cache using bpf_for_each loop and count the number
of entries. Finally it checks it with the number of entries from the
regular iterator.
$ ./vmtest.sh -- ./test_progs -t kmem_cache_iter
...
#130/1 kmem_cache_iter/check_task_struct:OK
#130/2 kmem_cache_iter/check_slabinfo:OK
#130/3 kmem_cache_iter/open_coded_iter:OK
#130 kmem_cache_iter:OK
Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED
Also simplify the code by using attach routine of the skeleton.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241030222819.1800667-2-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Verify that KVM's supported XCR0 includes AVX (and earlier features) when
running the SEV-ES VMSA XSAVE test. In practice, the issue will likely
never pop up, since KVM support for AVX predates KVM support for SEV-ES,
but checking for KVM support makes the requirement more obvious.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Now that CR4.OSXSAVE and XCR0 are setup by default, drop the manual
enabling from the SEV smoke test that validates FPU state can be
transferred into the VMSA.
In guest_code_xsave(), explicitly set the Requested-Feature Bitmask (RFBM)
to exactly XFEATURE_MASK_X87_AVX instead of relying on the host side of
things to enable only X87_AVX features in guest XCR0. I.e. match the RFBM
for the host XSAVE.
Link: https://lore.kernel.org/r/20241003234337.273364-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Now that KVM selftests enable all supported XCR0 features by default, add
a testcase to the XCR0 vs. CPUID test to verify that the guest can disable
everything except the legacy FPU in XCR0, and then re-enable the full
feature set, which is kinda sorta what the test did before XCR0 was setup
by default.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
To play nice with compilers generating AVX instructions, set CR4.OSXSAVE
and configure XCR0 by default when creating selftests vCPUs. Some distros
have switched gcc to '-march=x86-64-v3' by default, and while it's hard to
find a CPU which doesn't support AVX today, many KVM selftests fail with
==== Test Assertion Failure ====
lib/x86_64/processor.c:570: Unhandled exception in guest
pid=72747 tid=72747 errno=4 - Interrupted system call
Unhandled exception '0x6' at guest RIP '0x4104f7'
due to selftests not enabling AVX by default for the guest. The failure
is easy to reproduce elsewhere with:
$ make clean && CFLAGS='-march=x86-64-v3' make -j && ./x86_64/kvm_pv_test
E.g. gcc-13 with -march=x86-64-v3 compiles this chunk from selftests'
kvm_fixup_exception():
regs->rip = regs->r11;
regs->r9 = regs->vector;
regs->r10 = regs->error_code;
into this monstronsity (which is clever, but oof):
405313: c4 e1 f9 6e c8 vmovq %rax,%xmm1
405318: 48 89 68 08 mov %rbp,0x8(%rax)
40531c: 48 89 e8 mov %rbp,%rax
40531f: c4 c3 f1 22 c4 01 vpinsrq $0x1,%r12,%xmm1,%xmm0
405325: 49 89 6d 38 mov %rbp,0x38(%r13)
405329: c5 fa 7f 45 00 vmovdqu %xmm0,0x0(%rbp)
Alternatively, KVM selftests could explicitly restrict the compiler to
-march=x86-64-v2, but odds are very good that punting on AVX enabling will
simply result in tests that "need" AVX doing their own thing, e.g. there
are already three or so additional cleanups that can be done on top.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Closes: https://lore.kernel.org/all/20240920154422.2890096-1-vkuznets@redhat.com
Reviewed-and-tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Rework the CR4/CPUID sync test to clear CR4.OSXSAVE, do CPUID, and restore
CR4.OSXSAVE in assembly, so that there is zero chance of AVX instructions
being executed while CR4.OSXSAVE is disabled. This will allow enabling
CR4.OSXSAVE by default for selftests vCPUs as a general means of playing
nice with AVX instructions.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Mask off OSPKE and OSXSAVE, which are toggled based on corresponding CR4
enabling bits, when comparing vCPU CPUID against KVM's supported CPUID.
This will allow setting OSXSAVE by default when creating vCPUs, without
causing test failures (KVM doesn't enumerate OSXSAVE=1).
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
When comparing vCPU CPUID entries against KVM's supported CPUID, mask off
only the dynamic fields/bits instead of skipping the entire entry.
Precisely masking bits isn't meaningfully more difficult than skipping
entire entries, and will be necessary to maintain test coverage when a
future commit enables OSXSAVE by default, i.e. makes one bit in all of
CPUID.0x1 dynamic.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Expand and rename the feature MSRs test to verify KVM's ABI and quirk
for initializing feature MSRs.
Exempt VM_CR{0,4}_FIXED1 from most tests as KVM intentionally takes full
control of the MSRs, e.g. to prevent L1 from running L2 with bogus CR0
and/or CR4 values.
Link: https://lore.kernel.org/r/20240802185511.305849-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
