Add selftest cases that validate bpftool's expected behavior when
accessing maps protected from modification via security_bpf_map.
The test includes a BPF program attached to security_bpf_map with two maps:
- A protected map that only allows read-only access
- An unprotected map that allows full access
The test script attaches the BPF program to security_bpf_map and
verifies that for the bpftool map command:
- Read access works on both maps
- Write access fails on the protected map
- Write access succeeds on the unprotected map
- These behaviors remain consistent when the maps are pinned
Signed-off-by: Slava Imameev <slava.imameev@crowdstrike.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20250620151812.13952-2-slava.imameev@crowdstrike.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Constant PATH_MAX is used in function unpriv_helpers.c:open_config().
This constant is provided by include file <limits.h>.
The dependency was added by commit [1], which does not include
<limits.h> directly, relying instead on <limits.h> being included from
zlib.h -> zconf.h.
As it turns out, this is not the case for all systems, e.g. on
Fedora 41 zlib 1.3.1 is used, and there <limits.h> is not included
from zconf.h. Hence, there is a compilation error on Fedora 41.
[1] commit fc2915bb8b ("selftests/bpf: More precise cpu_mitigations state detection")
Fixes: fc2915bb8b ("selftests/bpf: More precise cpu_mitigations state detection")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/r/20250618093134.3078870-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The underlying lookup_user_key() function uses a signed 32 bit integer
for key serial numbers because legitimate serial numbers are positive
(and > 3) and keyrings are negative. Using a u32 for the keyring in
the bpf function doesn't currently cause any conversion problems but
will start to trip the signed to unsigned conversion warnings when the
kernel enables them, so convert the argument to signed (and update the
tests accordingly) before it acquires more users.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/r/84cdb0775254d297d75e21f577089f64abdfbd28.camel@HansenPartnership.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
test_progs and test_verifier binaries execute unpriv tests under the
following conditions:
- unpriv BPF is enabled;
- CPU mitigations are enabled (see [1] for details).
The detection of the "mitigations enabled" state is performed by
unpriv_helpers.c:get_mitigations_off() via inspecting kernel boot
command line, looking for a parameter "mitigations=off".
Such detection scheme won't work for certain configurations,
e.g. when CONFIG_CPU_MITIGATIONS is disabled and boot parameter is
not supplied.
Miss-detection leads to test_progs executing tests meant to be run
only with mitigations enabled, e.g.
verifier_and.c:known_subreg_with_unknown_reg(), and reporting false
failures.
Internally, verifier sets bpf_verifier_env->bypass_spec_{v1,v4}
basing on the value returned by kernel/cpu.c:cpu_mitigations_off().
This function is backed by a variable kernel/cpu.c:cpu_mitigations.
This state is not fully introspect-able via sysfs. The closest proxy
is /sys/devices/system/cpu/vulnerabilities/spectre_v1, but it reports
"vulnerable" state only if mitigations are disabled *and* current cpu
is vulnerable, while verifier does not check cpu state.
There are only two ways the kernel/cpu.c:cpu_mitigations can be set:
- via boot parameter;
- via CONFIG_CPU_MITIGATIONS option.
This commit updates unpriv_helpers.c:get_mitigations_off() to scan
/boot/config-$(uname -r) and /proc/config.gz for
CONFIG_CPU_MITIGATIONS value in addition to boot command line check.
Tested using the following configurations:
- mitigations enabled (unpriv tests are enabled)
- mitigations disabled via boot cmdline (unpriv tests skipped)
- mitigations disabled via CONFIG_CPU_MITIGATIONS
(unpriv tests skipped)
[1] https://lore.kernel.org/bpf/20231025031144.5508-1-laoar.shao@gmail.com/
Reported-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250617005710.1066165-2-eddyz87@gmail.com
With gcc14, when building with RELEASE=1, I hit four below compilation
failure:
Error 1:
In file included from test_loader.c:6:
test_loader.c: In function ‘run_subtest’: test_progs.h:194:17:
error: ‘retval’ may be used uninitialized in this function
[-Werror=maybe-uninitialized]
194 | fprintf(stdout, ##format); \
| ^~~~~~~
test_loader.c:958:13: note: ‘retval’ was declared here
958 | int retval, err, i;
| ^~~~~~
The uninitialized var 'retval' actually could cause incorrect result.
Error 2:
In function ‘test_fd_array_cnt’:
prog_tests/fd_array.c:71:14: error: ‘btf_id’ may be used uninitialized in this
function [-Werror=maybe-uninitialized]
71 | fd = bpf_btf_get_fd_by_id(id);
| ^~~~~~~~~~~~~~~~~~~~~~~~
prog_tests/fd_array.c:302:15: note: ‘btf_id’ was declared here
302 | __u32 btf_id;
| ^~~~~~
Changing ASSERT_GE to ASSERT_EQ can fix the compilation error. Otherwise,
there is no functionality change.
Error 3:
prog_tests/tailcalls.c: In function ‘test_tailcall_hierarchy_count’:
prog_tests/tailcalls.c:1402:23: error: ‘fentry_data_fd’ may be used uninitialized
in this function [-Werror=maybe-uninitialized]
1402 | err = bpf_map_lookup_elem(fentry_data_fd, &i, &val);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The code is correct. The change intends to silence gcc errors.
Error 4: (this error only happens on arm64)
In file included from prog_tests/log_buf.c:4:
prog_tests/log_buf.c: In function ‘bpf_prog_load_log_buf’:
./test_progs.h:390:22: error: ‘log_buf’ may be used uninitialized [-Werror=maybe-uninitialized]
390 | int ___err = libbpf_get_error(___res); \
| ^~~~~~~~~~~~~~~~~~~~~~~~
prog_tests/log_buf.c:158:14: note: in expansion of macro ‘ASSERT_OK_PTR’
158 | if (!ASSERT_OK_PTR(log_buf, "log_buf_alloc"))
| ^~~~~~~~~~~~~
In file included from selftests/bpf/tools/include/bpf/bpf.h:32,
from ./test_progs.h:36:
selftests/bpf/tools/include/bpf/libbpf_legacy.h:113:17:
note: by argument 1 of type ‘const void *’ to ‘libbpf_get_error’ declared here
113 | LIBBPF_API long libbpf_get_error(const void *ptr);
| ^~~~~~~~~~~~~~~~
Adding a pragma to disable maybe-uninitialized fixed the issue.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250617044956.2686668-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A test case to check if both branches of jset are explored when
computing program CFG.
At 'if r1 & 0x7 ...':
- register 'r2' is computed alive only if jump branch of jset
instruction is followed;
- register 'r0' is computed alive only if fallthrough branch of jset
instruction is followed.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250613175331.3238739-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds a new field mem_peak / "Peak memory (MiB)" field to a
set of gathered statistics. The field is intended as an estimate for
peak verifier memory consumption for processing of a given program.
Mechanically stat is collected as follows:
- At the beginning of handle_verif_mode() a new cgroup is created
and veristat process is moved into this cgroup.
- At each program load:
- bpf_object__load() is split into bpf_object__prepare() and
bpf_object__load() to avoid accounting for memory allocated for
maps;
- before bpf_object__load():
- a write to "memory.peak" file of the new cgroup is used to reset
cgroup statistics;
- updated value is read from "memory.peak" file and stashed;
- after bpf_object__load() "memory.peak" is read again and
difference between new and stashed values is used as a metric.
If any of the above steps fails veristat proceeds w/o collecting
mem_peak information for a program, reporting mem_peak as -1.
While memcg provides data in bytes (converted from pages), veristat
converts it to megabytes to avoid jitter when comparing results of
different executions.
The change has no measurable impact on veristat running time.
A correlation between "Peak states" and "Peak memory" fields provides
a sanity check for gathered statistics, e.g. a sample of data for
sched_ext programs:
Program Peak states Peak memory (MiB)
------------------------ ----------- -----------------
lavd_select_cpu 2153 44
lavd_enqueue 1982 41
lavd_dispatch 3480 28
layered_dispatch 1417 17
layered_enqueue 760 11
lavd_cpu_offline 349 6
lavd_cpu_online 349 6
lavd_init 394 6
rusty_init 350 5
layered_select_cpu 391 4
...
rusty_stopping 134 1
arena_topology_node_init 170 0
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250613072147.3938139-3-eddyz87@gmail.com
On arm64 with 64KB page size, the selftest xdp_do_redirect failed like
below:
...
test_xdp_do_redirect:PASS:pkt_count_tc 0 nsec
test_max_pkt_size:PASS:prog_run_max_size 0 nsec
test_max_pkt_size:FAIL:prog_run_too_big unexpected prog_run_too_big: actual -28 != expected -22
With 64KB page size, the xdp frame size will be much bigger so
the existing test will fail.
Adjust various parameters so the test can also work on 64K page size.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250612035042.2208630-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When running BPF selftests on arm64 with a 64K page size, I encountered
the following two test failures:
sockmap_basic/sockmap skb_verdict change tail:FAIL
tc_change_tail:FAIL
With further debugging, I identified the root cause in the following
kernel code within __bpf_skb_change_tail():
u32 max_len = BPF_SKB_MAX_LEN;
u32 min_len = __bpf_skb_min_len(skb);
int ret;
if (unlikely(flags || new_len > max_len || new_len < min_len))
return -EINVAL;
With a 4K page size, new_len = 65535 and max_len = 16064, the function
returns -EINVAL. However, With a 64K page size, max_len increases to
261824, allowing execution to proceed further in the function. This is
because BPF_SKB_MAX_LEN scales with the page size and larger page sizes
result in higher max_len values.
Updating the new_len parameter in both tests based on actual kernel
page size resolved both failures.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250612035037.2207911-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The bpf selftest xdp_adjust_tail/xdp_adjust_frags_tail_grow failed on
arm64 with 64KB page:
xdp_adjust_tail/xdp_adjust_frags_tail_grow:FAIL
In bpf_prog_test_run_xdp(), the xdp->frame_sz is set to 4K, but later on
when constructing frags, with 64K page size, the frag data_len could
be more than 4K. This will cause problems in bpf_xdp_frags_increase_tail().
To fix the failure, the xdp->frame_sz is set to be PAGE_SIZE so kernel
can test different page size properly. With the kernel change, the user
space and bpf prog needs adjustment. Currently, the MAX_SKB_FRAGS default
value is 17, so for 4K page, the maximum packet size will be less than 68K.
To test 64K page, a bigger maximum packet size than 68K is desired. So two
different functions are implemented for subtest xdp_adjust_frags_tail_grow.
Depending on different page size, different data input/output sizes are used
to adapt with different page size.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250612035032.2207498-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The test case absent_mark_in_the_middle_state is equivalent of the
following C program:
1: r8 = bpf_get_prandom_u32();
2: r6 = -32;
3: bpf_iter_num_new(&fp[-8], 0, 10);
4: if (unlikely(bpf_get_prandom_u32()))
5: r6 = -31;
6: for (;;) {
7: if (!bpf_iter_num_next(&fp[-8]))
8: break;
9: if (unlikely(bpf_get_prandom_u32()))
10: *(u64 *)(fp + r6) = 7;
11: }
12: bpf_iter_num_destroy(&fp[-8]);
13: return 0;
W/o a fix that instructs verifier to ignore branches count for loop
entries verification proceeds as follows:
- 1-4, state is {r6=-32,fp-8=active};
- 6, checkpoint A is created with {r6=-32,fp-8=active};
- 7, checkpoint B is created with {r6=-32,fp-8=active},
push state {r6=-32,fp-8=active} from 7 to 9;
- 8,12,13, {r6=-32,fp-8=drained}, exit;
- pop state with {r6=-32,fp-8=active} from 7 to 9;
- 9, push state {r6=-32,fp-8=active} from 9 to 10;
- 6, checkpoint C is created with {r6=-32,fp-8=active};
- 7, checkpoint A is hit, no precision propagated for r6 to C;
- pop state {r6=-32,fp-8=active} from 9 to 10;
- 10, state is {r6=-31,fp-8=active}, r6 is marked as read and precise,
these marks are propagated to checkpoints A and B (but not C, as
it is not the parent of current state;
- 6, {r6=-31,fp-8=active} checkpoint C is hit, because r6 is not
marked precise for this checkpoint;
- the program is accepted, despite a possibility of unaligned u64
stack access at offset -31.
The test case absent_mark_in_the_middle_state2 is similar except the
following change:
r8 = bpf_get_prandom_u32();
r6 = -32;
bpf_iter_num_new(&fp[-8], 0, 10);
if (unlikely(bpf_get_prandom_u32())) {
r6 = -31;
+ jump_into_loop:
+ goto +0;
+ goto loop;
+ }
+ if (unlikely(bpf_get_prandom_u32()))
+ goto jump_into_loop;
+ loop:
for (;;) {
if (!bpf_iter_num_next(&fp[-8]))
break;
if (unlikely(bpf_get_prandom_u32()))
*(u64 *)(fp + r6) = 7;
}
bpf_iter_num_destroy(&fp[-8])
return 0
The goal is to check that read/precision marks are propagated to
checkpoint created at 'goto +0' that resides outside of the loop.
The test case absent_mark_in_the_middle_state3 is a bit different and
is equivalent to the C program below:
int absent_mark_in_the_middle_state3(void)
{
bpf_iter_num_new(&fp[-8], 0, 10)
loop1(-32, &fp[-8])
loop1_wrapper(&fp[-8])
bpf_iter_num_destroy(&fp[-8])
}
int loop1(num, iter)
{
while (bpf_iter_num_next(iter)) {
if (unlikely(bpf_get_prandom_u32()))
*(fp + num) = 7;
}
return 0
}
int loop1_wrapper(iter)
{
r6 = -32;
if (unlikely(bpf_get_prandom_u32()))
r6 = -31;
loop1(r6, iter);
return 0;
}
The unsafe state is reached in a similar manner, but the loop is
located inside a subprogram that is called from two locations in the
main subprogram. This detail is important for exercising
bpf_scc_visit->backedges memory management.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
On arm64, the cgroup_mprog_ordering selftest failed with test_progs run
when building with clang compiler. The reason is due to socklen_t optlen
not initialized.
In kernel function do_ip_getsockopt(), we have
if (copy_from_sockptr(&len, optlen, sizeof(int)))
return -EFAULT;
if (len < 0)
return -EINVAL;
The above 'len' variable is a negative value and hence the test failed.
But the test is okay on x86_64. I checked the x86_64 asm code and I didn't
see explicit initialization of 'optlen' but its value is 0 so kernel
didn't return error. This should be a pure luck.
Fix the bug by initializing 'oplen' var properly.
Fixes: e422d5f118 ("selftests/bpf: Add two selftests for mprog API based cgroup progs")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250611162103.1623692-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This implements the core of the series and causes the verifier to fall
back to mitigating Spectre v1 using speculation barriers. The approach
was presented at LPC'24 [1] and RAID'24 [2].
If we find any forbidden behavior on a speculative path, we insert a
nospec (e.g., lfence speculation barrier on x86) before the instruction
and stop verifying the path. While verifying a speculative path, we can
furthermore stop verification of that path whenever we encounter a
nospec instruction.
A minimal example program would look as follows:
A = true
B = true
if A goto e
f()
if B goto e
unsafe()
e: exit
There are the following speculative and non-speculative paths
(`cur->speculative` and `speculative` referring to the value of the
push_stack() parameters):
- A = true
- B = true
- if A goto e
- A && !cur->speculative && !speculative
- exit
- !A && !cur->speculative && speculative
- f()
- if B goto e
- B && cur->speculative && !speculative
- exit
- !B && cur->speculative && speculative
- unsafe()
If f() contains any unsafe behavior under Spectre v1 and the unsafe
behavior matches `state->speculative &&
error_recoverable_with_nospec(err)`, do_check() will now add a nospec
before f() instead of rejecting the program:
A = true
B = true
if A goto e
nospec
f()
if B goto e
unsafe()
e: exit
Alternatively, the algorithm also takes advantage of nospec instructions
inserted for other reasons (e.g., Spectre v4). Taking the program above
as an example, speculative path exploration can stop before f() if a
nospec was inserted there because of Spectre v4 sanitization.
In this example, all instructions after the nospec are dead code (and
with the nospec they are also dead code speculatively).
For this, it relies on the fact that speculation barriers generally
prevent all later instructions from executing if the speculation was not
correct:
* On Intel x86_64, lfence acts as full speculation barrier, not only as
a load fence [3]:
An LFENCE instruction or a serializing instruction will ensure that
no later instructions execute, even speculatively, until all prior
instructions complete locally. [...] Inserting an LFENCE instruction
after a bounds check prevents later operations from executing before
the bound check completes.
This was experimentally confirmed in [4].
* On AMD x86_64, lfence is dispatch-serializing [5] (requires MSR
C001_1029[1] to be set if the MSR is supported, this happens in
init_amd()). AMD further specifies "A dispatch serializing instruction
forces the processor to retire the serializing instruction and all
previous instructions before the next instruction is executed" [8]. As
dispatch is not specific to memory loads or branches, lfence therefore
also affects all instructions there. Also, if retiring a branch means
it's PC change becomes architectural (should be), this means any
"wrong" speculation is aborted as required for this series.
* ARM's SB speculation barrier instruction also affects "any instruction
that appears later in the program order than the barrier" [6].
* PowerPC's barrier also affects all subsequent instructions [7]:
[...] executing an ori R31,R31,0 instruction ensures that all
instructions preceding the ori R31,R31,0 instruction have completed
before the ori R31,R31,0 instruction completes, and that no
subsequent instructions are initiated, even out-of-order, until
after the ori R31,R31,0 instruction completes. The ori R31,R31,0
instruction may complete before storage accesses associated with
instructions preceding the ori R31,R31,0 instruction have been
performed
Regarding the example, this implies that `if B goto e` will not execute
before `if A goto e` completes. Once `if A goto e` completes, the CPU
should find that the speculation was wrong and continue with `exit`.
If there is any other path that leads to `if B goto e` (and therefore
`unsafe()`) without going through `if A goto e`, then a nospec will
still be needed there. However, this patch assumes this other path will
be explored separately and therefore be discovered by the verifier even
if the exploration discussed here stops at the nospec.
This patch furthermore has the unfortunate consequence that Spectre v1
mitigations now only support architectures which implement BPF_NOSPEC.
Before this commit, Spectre v1 mitigations prevented exploits by
rejecting the programs on all architectures. Because some JITs do not
implement BPF_NOSPEC, this patch therefore may regress unpriv BPF's
security to a limited extent:
* The regression is limited to systems vulnerable to Spectre v1, have
unprivileged BPF enabled, and do NOT emit insns for BPF_NOSPEC. The
latter is not the case for x86 64- and 32-bit, arm64, and powerpc
64-bit and they are therefore not affected by the regression.
According to commit a6f6a95f25 ("LoongArch, bpf: Fix jit to skip
speculation barrier opcode"), LoongArch is not vulnerable to Spectre
v1 and therefore also not affected by the regression.
* To the best of my knowledge this regression may therefore only affect
MIPS. This is deemed acceptable because unpriv BPF is still disabled
there by default. As stated in a previous commit, BPF_NOSPEC could be
implemented for MIPS based on GCC's speculation_barrier
implementation.
* It is unclear which other architectures (besides x86 64- and 32-bit,
ARM64, PowerPC 64-bit, LoongArch, and MIPS) supported by the kernel
are vulnerable to Spectre v1. Also, it is not clear if barriers are
available on these architectures. Implementing BPF_NOSPEC on these
architectures therefore is non-trivial. Searching GCC and the kernel
for speculation barrier implementations for these architectures
yielded no result.
* If any of those regressed systems is also vulnerable to Spectre v4,
the system was already vulnerable to Spectre v4 attacks based on
unpriv BPF before this patch and the impact is therefore further
limited.
As an alternative to regressing security, one could still reject
programs if the architecture does not emit BPF_NOSPEC (e.g., by removing
the empty BPF_NOSPEC-case from all JITs except for LoongArch where it
appears justified). However, this will cause rejections on these archs
that are likely unfounded in the vast majority of cases.
In the tests, some are now successful where we previously had a
false-positive (i.e., rejection). Change them to reflect where the
nospec should be inserted (using __xlated_unpriv) and modify the error
message if the nospec is able to mitigate a problem that previously
shadowed another problem (in that case __xlated_unpriv does not work,
therefore just add a comment).
Define SPEC_V1 to avoid duplicating this ifdef whenever we check for
nospec insns using __xlated_unpriv, define it here once. This also
improves readability. PowerPC can probably also be added here. However,
omit it for now because the BPF CI currently does not include a test.
Limit it to EPERM, EACCES, and EINVAL (and not everything except for
EFAULT and ENOMEM) as it already has the desired effect for most
real-world programs. Briefly went through all the occurrences of EPERM,
EINVAL, and EACCESS in verifier.c to validate that catching them like
this makes sense.
Thanks to Dustin for their help in checking the vendor documentation.
[1] https://lpc.events/event/18/contributions/1954/ ("Mitigating
Spectre-PHT using Speculation Barriers in Linux eBPF")
[2] https://arxiv.org/pdf/2405.00078 ("VeriFence: Lightweight and
Precise Spectre Defenses for Untrusted Linux Kernel Extensions")
[3] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/runtime-speculative-side-channel-mitigations.html
("Managed Runtime Speculative Execution Side Channel Mitigations")
[4] https://dl.acm.org/doi/pdf/10.1145/3359789.3359837 ("Speculator: a
tool to analyze speculative execution attacks and mitigations" -
Section 4.6 "Stopping Speculative Execution")
[5] https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/software-techniques-for-managing-speculation.pdf
("White Paper - SOFTWARE TECHNIQUES FOR MANAGING SPECULATION ON AMD
PROCESSORS - REVISION 5.09.23")
[6] https://developer.arm.com/documentation/ddi0597/2020-12/Base-Instructions/SB--Speculation-Barrier-
("SB - Speculation Barrier - Arm Armv8-A A32/T32 Instruction Set
Architecture (2020-12)")
[7] https://wiki.raptorcs.com/w/images/5/5f/OPF_PowerISA_v3.1C.pdf
("Power ISA™ - Version 3.1C - May 26, 2024 - Section 9.2.1 of Book
III")
[8] https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/40332.pdf
("AMD64 Architecture Programmer’s Manual Volumes 1–5 - Revision 4.08
- April 2024 - 7.6.4 Serializing Instructions")
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Dustin Nguyen <nguyen@cs.fau.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603212428.338473-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When reg->type is CONST_PTR_TO_MAP, it can not be null. However the
verifier explores the branches under rX == 0 in check_cond_jmp_op()
even if reg->type is CONST_PTR_TO_MAP, because it was not checked for
in reg_not_null().
Fix this by adding CONST_PTR_TO_MAP to the set of types that are
considered non nullable in reg_not_null().
An old "unpriv: cmp map pointer with zero" selftest fails with this
change, because now early out correctly triggers in
check_cond_jmp_op(), making the verification to pass.
In practice verifier may allow pointer to null comparison in unpriv,
since in many cases the relevant branch and comparison op are removed
as dead code. So change the expected test result to __success_unpriv.
Signed-off-by: Ihor Solodrai <isolodrai@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250609183024.359974-2-isolodrai@meta.com
For selftest xdp_adjust_tail/xdp_adjust_frags_tail_grow, if tested failure,
I see a long list of log output like
...
test_xdp_adjust_frags_tail_grow:PASS:9Kb+10b-untouched 0 nsec
test_xdp_adjust_frags_tail_grow:PASS:9Kb+10b-untouched 0 nsec
test_xdp_adjust_frags_tail_grow:PASS:9Kb+10b-untouched 0 nsec
test_xdp_adjust_frags_tail_grow:PASS:9Kb+10b-untouched 0 nsec
...
There are total 7374 lines of the above which is too much. Let us
only issue such logs when it is an assert failure.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250607013610.1551399-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull Compute Express Link (CXL) updates from Dave Jiang:
- Remove always true condition in cxl features code
- Add verification of CHBS length for CXL 2.0
- Ignore interleave granularity when interleave ways is 1
- Add update addressing mising MODULE_DESCRIPTION for cxl_test
- A series of cleanups/refactor to prep for AMD Zen5 translate code
- Clean %pa debug printk in core/hdm.c
- Documentation updates:
- Update to CXL Maturity Map
- Fixes to source linking in CXL documentation
- CXL documentation fixes, spelling corrections
- A large collection of CXL documentation for the entire CXL
subsystem, including documentation on CXL related platform and
firmware notes
- Remove redundant code of cxlctl_get_supported_features()
- Series to support CXL RAS Features
- Including "Patrol Scrub Control", "Error Check Scrub",
"Performance Maitenance" and "Memory Sparing". The series
connects CXL to EDAC.
* tag 'cxl-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (53 commits)
cxl/edac: Add CXL memory device soft PPR control feature
cxl/edac: Add CXL memory device memory sparing control feature
cxl/edac: Support for finding memory operation attributes from the current boot
cxl/edac: Add support for PERFORM_MAINTENANCE command
cxl/edac: Add CXL memory device ECS control feature
cxl/edac: Add CXL memory device patrol scrub control feature
cxl: Update prototype of function get_support_feature_info()
EDAC: Update documentation for the CXL memory patrol scrub control feature
cxl/features: Remove the inline specifier from to_cxlfs()
cxl/feature: Remove redundant code of get supported features
docs: ABI: Fix "firwmare" to "firmware"
cxl/Documentation: Fix typo in sysfs write_bandwidth attribute path
cxl: doc/linux/access-coordinates Update access coordinates calculation methods
cxl: docs/platform/acpi/srat Add generic target documentation
cxl: docs/platform/cdat reference documentation
Documentation: Update the CXL Maturity Map
cxl: Sync up the driver-api/cxl documentation
cxl: docs - add self-referencing cross-links
cxl: docs/allocation/hugepages
cxl: docs/allocation/reclaim
...
Pull more MM updates from Andrew Morton:
- "zram: support algorithm-specific parameters" from Sergey Senozhatsky
adds infrastructure for passing algorithm-specific parameters into
zram. A single parameter `winbits' is implemented at this time.
- "memcg: nmi-safe kmem charging" from Shakeel Butt makes memcg
charging nmi-safe, which is required by BFP, which can operate in NMI
context.
- "Some random fixes and cleanup to shmem" from Kemeng Shi implements
small fixes and cleanups in the shmem code.
- "Skip mm selftests instead when kernel features are not present" from
Zi Yan fixes some issues in the MM selftest code.
- "mm/damon: build-enable essential DAMON components by default" from
SeongJae Park reworks DAMON Kconfig to make it easier to enable
CONFIG_DAMON.
- "sched/numa: add statistics of numa balance task migration" from Libo
Chen adds more info into sysfs and procfs files to improve visibility
into the NUMA balancer's task migration activity.
- "selftests/mm: cow and gup_longterm cleanups" from Mark Brown
provides various updates to some of the MM selftests to make them
play better with the overall containing framework.
* tag 'mm-stable-2025-06-01-14-06' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (43 commits)
mm/khugepaged: clean up refcount check using folio_expected_ref_count()
selftests/mm: fix test result reporting in gup_longterm
selftests/mm: report unique test names for each cow test
selftests/mm: add helper for logging test start and results
selftests/mm: use standard ksft_finished() in cow and gup_longterm
selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled
sched/numa: add statistics of numa balance task
sched/numa: fix task swap by skipping kernel threads
tools/testing: check correct variable in open_procmap()
tools/testing/vma: add missing function stub
mm/gup: update comment explaining why gup_fast() disables IRQs
selftests/mm: two fixes for the pfnmap test
mm/khugepaged: fix race with folio split/free using temporary reference
mm: add CONFIG_PAGE_BLOCK_ORDER to select page block order
mmu_notifiers: remove leftover stub macros
selftests/mm: deduplicate test names in madv_populate
kcov: rust: add flags for KCOV with Rust
mm: rust: make CONFIG_MMU ifdefs more narrow
mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables()
mm/damon/Kconfig: enable CONFIG_DAMON by default
...
Pull more kvm updates from Paolo Bonzini:
Generic:
- Clean up locking of all vCPUs for a VM by using the *_nest_lock()
family of functions, and move duplicated code to virt/kvm/. kernel/
patches acked by Peter Zijlstra
- Add MGLRU support to the access tracking perf test
ARM fixes:
- Make the irqbypass hooks resilient to changes in the GSI<->MSI
routing, avoiding behind stale vLPI mappings being left behind. The
fix is to resolve the VGIC IRQ using the host IRQ (which is stable)
and nuking the vLPI mapping upon a routing change
- Close another VGIC race where vCPU creation races with VGIC
creation, leading to in-flight vCPUs entering the kernel w/o
private IRQs allocated
- Fix a build issue triggered by the recently added workaround for
Ampere's AC04_CPU_23 erratum
- Correctly sign-extend the VA when emulating a TLBI instruction
potentially targeting a VNCR mapping
- Avoid dereferencing a NULL pointer in the VGIC debug code, which
can happen if the device doesn't have any mapping yet
s390:
- Fix interaction between some filesystems and Secure Execution
- Some cleanups and refactorings, preparing for an upcoming big
series
x86:
- Wait for target vCPU to ack KVM_REQ_UPDATE_PROTECTED_GUEST_STATE
to fix a race between AP destroy and VMRUN
- Decrypt and dump the VMSA in dump_vmcb() if debugging enabled for
the VM
- Refine and harden handling of spurious faults
- Add support for ALLOWED_SEV_FEATURES
- Add #VMGEXIT to the set of handlers special cased for
CONFIG_RETPOLINE=y
- Treat DEBUGCTL[5:2] as reserved to pave the way for virtualizing
features that utilize those bits
- Don't account temporary allocations in sev_send_update_data()
- Add support for KVM_CAP_X86_BUS_LOCK_EXIT on SVM, via Bus Lock
Threshold
- Unify virtualization of IBRS on nested VM-Exit, and cross-vCPU
IBPB, between SVM and VMX
- Advertise support to userspace for WRMSRNS and PREFETCHI
- Rescan I/O APIC routes after handling EOI that needed to be
intercepted due to the old/previous routing, but not the
new/current routing
- Add a module param to control and enumerate support for device
posted interrupts
- Fix a potential overflow with nested virt on Intel systems running
32-bit kernels
- Flush shadow VMCSes on emergency reboot
- Add support for SNP to the various SEV selftests
- Add a selftest to verify fastops instructions via forced emulation
- Refine and optimize KVM's software processing of the posted
interrupt bitmap, and share the harvesting code between KVM and the
kernel's Posted MSI handler"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (93 commits)
rtmutex_api: provide correct extern functions
KVM: arm64: vgic-debug: Avoid dereferencing NULL ITE pointer
KVM: arm64: vgic-init: Plug vCPU vs. VGIC creation race
KVM: arm64: Unmap vLPIs affected by changes to GSI routing information
KVM: arm64: Resolve vLPI by host IRQ in vgic_v4_unset_forwarding()
KVM: arm64: Protect vLPI translation with vgic_irq::irq_lock
KVM: arm64: Use lock guard in vgic_v4_set_forwarding()
KVM: arm64: Mask out non-VA bits from TLBI VA* on VNCR invalidation
arm64: sysreg: Drag linux/kconfig.h to work around vdso build issue
KVM: s390: Simplify and move pv code
KVM: s390: Refactor and split some gmap helpers
KVM: s390: Remove unneeded srcu lock
s390: Remove unneeded includes
s390/uv: Improve splitting of large folios that cannot be split while dirty
s390/uv: Always return 0 from s390_wiggle_split_folio() if successful
s390/uv: Don't return 0 from make_hva_secure() if the operation was not successful
rust: add helper for mutex_trylock
RISC-V: KVM: use kvm_trylock_all_vcpus when locking all vCPUs
KVM: arm64: use kvm_trylock_all_vcpus when locking all vCPUs
x86: KVM: SVM: use kvm_lock_all_vcpus instead of a custom implementation
...
Ihor Solodrai reported selftest 'btf_tag/btf_type_tag_percpu_vmlinux_helper'
failure ([1]) during 6.16 merge window. The failure log:
...
7: (15) if r0 == 0x0 goto pc+1 ; R0=ptr_css_rstat_cpu()
; *(volatile int *)rstat; @ btf_type_tag_percpu.c:68
8: (61) r1 = *(u32 *)(r0 +0)
cannot access ptr member updated_children with moff 0 in struct css_rstat_cpu with off 0 size 4
Two changes are needed. First, 'struct cgroup_rstat_cpu' needs to be
replaced with 'struct css_rstat_cpu' to be consistent with new data
structure. Second, layout of 'css_rstat_cpu' is changed compared
to 'cgroup_rstat_cpu'. The first member becomes a pointer so
the bpf prog needs to do 8-byte load instead of 4-byte load.
[1] https://lore.kernel.org/bpf/6f688f2e-7d26-423a-9029-d1b1ef1c938a@linux.dev/
Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
Cc: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20250529201151.1787575-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The kselftest framework uses the string logged when a test result is
reported as the unique identifier for a test, using it to track test
results between runs. The gup_longterm test fails to follow this pattern,
it runs a single test function repeatedly with various parameters but each
result report is a string logging an error message which is fixed between
runs.
Since the code already logs each test uniquely before it starts refactor
to also print this to a buffer, then use that name as the test result.
This isn't especially pretty but is relatively straightforward and is a
great help to tooling.
Link: https://lkml.kernel.org/r/20250527-selftests-mm-cow-dedupe-v2-4-ff198df8e38e@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The kselftest framework uses the string logged when a test result is
reported as the unique identifier for a test, using it to track test
results between runs. The cow test completely fails to follow this
pattern, it runs test functions repeatedly with various parameters with
each result report from those functions being a string logging an error
message which is fixed between runs.
Since the code already logs each test uniquely before it starts refactor
to also print this to a buffer, then use that name as the test result.
This isn't especially pretty but is relatively straightforward and is a
great help to tooling.
Link: https://lkml.kernel.org/r/20250527-selftests-mm-cow-dedupe-v2-3-ff198df8e38e@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Several of the MM tests have a pattern of printing a description of the
test to be run then reporting the actual TAP result using a generic string
not connected to the specific test, often in a shared function used by
many tests. The name reported typically varies depending on the specific
result rather than the test too. This causes problems for tooling that
works with test results, the names reported with the results are used to
deduplicate tests and track them between runs so both duplicated names and
changing names cause trouble for things like UIs and automated bisection.
As a first step towards matching these tests better with the expectations
of kselftest provide helpers which record the test name as part of the
initial print and then use that as part of reporting a result.
This is not added as a generic kselftest helper partly because the use of
a variable to store the test name doesn't fit well with the header only
implementation of kselftest.h and partly because it's not really an
intended pattern. Ideally at some point the mm tests that use it will be
updated to not need it.
Link: https://lkml.kernel.org/r/20250527-selftests-mm-cow-dedupe-v2-2-ff198df8e38e@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/mm: cow and gup_longterm cleanups", v2.
The bulk of these changes modify the cow and gup_longterm tests to report
unique and stable names for each test, bringing them into line with the
expectations of tooling that works with kselftest. The string reported as
a test result is used by tooling to both deduplicate tests and track tests
between test runs, using the same string for multiple tests or changing
the string depending on test result causes problems for user interfaces
and automation such as bisection.
It was suggested that converting to use kselftest_harness.h would be a
good way of addressing this, however that really wants the set of tests to
run to be known at compile time but both test programs dynamically
enumarate the set of huge page sizes the system supports and test each.
Refactoring to handle this would be even more invasive than these changes
which are large but straightforward and repetitive.
A version of the main gup_longterm cleanup was previously sent separately,
this version factors out the helpers for logging the start of the test
since the cow test looks very similar.
This patch (of 4):
The cow and gup_longterm test programs open code something that looks a
lot like the standard ksft_finished() helper to summarise the test results
and provide an exit code, convert to use ksft_finished().
Link: https://lkml.kernel.org/r/20250527-selftests-mm-cow-dedupe-v2-0-ff198df8e38e@kernel.org
Link: https://lkml.kernel.org/r/20250527-selftests-mm-cow-dedupe-v2-1-ff198df8e38e@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When CONFIG_DAMON_SYSFS is disabled, the selftests fail with the following
outputs,
not ok 2 selftests: damon: sysfs_update_schemes_tried_regions_wss_estimation.py # exit=1
not ok 3 selftests: damon: damos_quota.py # exit=1
not ok 4 selftests: damon: damos_quota_goal.py # exit=1
not ok 5 selftests: damon: damos_apply_interval.py # exit=1
not ok 6 selftests: damon: damos_tried_regions.py # exit=1
not ok 7 selftests: damon: damon_nr_regions.py # exit=1
not ok 11 selftests: damon: sysfs_update_schemes_tried_regions_hang.py # exit=1
The root cause of this issue is that all the testcases above do not check
the sysfs interface of DAMON whether it exists or not. With this patch
applied, all the testcases above now pass successfully.
Link: https://lkml.kernel.org/r/20250531093937.1555159-1-lienze@kylinos.cn
Signed-off-by: Enze Li <lienze@kylinos.cn>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mlock2-tests test_mlock_lock() test reports two test results with an
identical string, one reporitng if it successfully locked a block of
memory and another reporting if the lock is still present after doing an
unlock (following a similar pattern to other tests in the same program).
This confuses test automation since the test string is used to deduplicate
tests, change the post unlock test to report "Unlocked" instead like the
other tests to fix this.
Link: https://lkml.kernel.org/r/20250515-selftest-mm-mlock2-dup-v1-1-963d5d7d243a@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Dev Jain <dev.jain@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull non-MM updates from Andrew Morton:
- "hung_task: extend blocking task stacktrace dump to semaphore" from
Lance Yang enhances the hung task detector.
The detector presently dumps the blocking tasks's stack when it is
blocked on a mutex. Lance's series extends this to semaphores
- "nilfs2: improve sanity checks in dirty state propagation" from
Wentao Liang addresses a couple of minor flaws in nilfs2
- "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn
fixes a couple of issues in the gdb scripts
- "Support kdump with LUKS encryption by reusing LUKS volume keys" from
Coiby Xu addresses a usability problem with kdump.
When the dump device is LUKS-encrypted, the kdump kernel may not have
the keys to the encrypted filesystem. A full writeup of this is in
the series [0/N] cover letter
- "sysfs: add counters for lockups and stalls" from Max Kellermann adds
/sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and
/sys/kernel/rcu_stall_count
- "fork: Page operation cleanups in the fork code" from Pasha Tatashin
implements a number of code cleanups in fork.c
- "scripts/gdb/symbols: determine KASLR offset on s390 during early
boot" from Ilya Leoshkevich fixes some s390 issues in the gdb
scripts
* tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits)
llist: make llist_add_batch() a static inline
delayacct: remove redundant code and adjust indentation
squashfs: add optional full compressed block caching
crash_dump, nvme: select CONFIGFS_FS as built-in
scripts/gdb/symbols: determine KASLR offset on s390 during early boot
scripts/gdb/symbols: factor out pagination_off()
scripts/gdb/symbols: factor out get_vmlinux()
kernel/panic.c: format kernel-doc comments
mailmap: update and consolidate Casey Connolly's name and email
nilfs2: remove wbc->for_reclaim handling
fork: define a local GFP_VMAP_STACK
fork: check charging success before zeroing stack
fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
fork: clean-up ifdef logic around stack allocation
kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count
kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count
x86/crash: make the page that stores the dm crypt keys inaccessible
x86/crash: pass dm crypt keys to kdump kernel
Revert "x86/mm: Remove unused __set_memory_prot()"
crash_dump: retrieve dm crypt keys in kdump kernel
...
