Remove x86's mmio_warning_test, as it is unnecessarily complex (there's no
reason to fork, spawn threads, initialize srand(), etc..), unnecessarily
restrictive (triggering triple fault is not unique to Intel CPUs without
unrestricted guest), and provides no meaningful coverage beyond what
basic fuzzing can achieve (running a vCPU with garbage is fuzzing's bread
and butter).
That the test has *all* of the above flaws is not coincidental, as the
code was copy+pasted almost verbatim from the syzkaller reproducer that
originally found the KVM bug (which has long since been fixed).
Cc: Michal Luczaj <mhal@rbox.co>
Link: https://groups.google.com/g/syzkaller/c/lHfau8E3SOE
Link: https://lore.kernel.org/r/20230815220030.560372-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add yet another macro to the VM/vCPU ioctl() framework to detect when an
ioctl() failed because KVM killed/bugged the VM, i.e. when there was
nothing wrong with the ioctl() itself. If KVM kills a VM, e.g. by way of
a failed KVM_BUG_ON(), all subsequent VM and vCPU ioctl()s will fail with
-EIO, which can be quite misleading and ultimately waste user/developer
time.
Use KVM_CHECK_EXTENSION on KVM_CAP_USER_MEMORY to detect if the VM is
dead and/or bug, as KVM doesn't provide a dedicated ioctl(). Using a
heuristic is obviously less than ideal, but practically speaking the logic
is bulletproof barring a KVM change, and any such change would arguably
break userspace, e.g. if KVM returns something other than -EIO.
Without the detection, tearing down a bugged VM yields a cryptic failure
when deleting memslots:
==== Test Assertion Failure ====
lib/kvm_util.c:689: !ret
pid=45131 tid=45131 errno=5 - Input/output error
1 0x00000000004036c3: __vm_mem_region_delete at kvm_util.c:689
2 0x00000000004042f0: kvm_vm_free at kvm_util.c:724 (discriminator 12)
3 0x0000000000402929: race_sync_regs at sync_regs_test.c:193
4 0x0000000000401cab: main at sync_regs_test.c:334 (discriminator 6)
5 0x0000000000416f13: __libc_start_call_main at libc-start.o:?
6 0x000000000041855f: __libc_start_main_impl at ??:?
7 0x0000000000401d40: _start at ??:?
KVM_SET_USER_MEMORY_REGION failed, rc: -1 errno: 5 (Input/output error)
Which morphs into a more pointed error message with the detection:
==== Test Assertion Failure ====
lib/kvm_util.c:689: false
pid=80347 tid=80347 errno=5 - Input/output error
1 0x00000000004039ab: __vm_mem_region_delete at kvm_util.c:689 (discriminator 5)
2 0x0000000000404660: kvm_vm_free at kvm_util.c:724 (discriminator 12)
3 0x0000000000402ac9: race_sync_regs at sync_regs_test.c:193
4 0x0000000000401cb7: main at sync_regs_test.c:334 (discriminator 6)
5 0x0000000000418263: __libc_start_call_main at libc-start.o:?
6 0x00000000004198af: __libc_start_main_impl at ??:?
7 0x0000000000401d90: _start at ??:?
KVM killed/bugged the VM, check the kernel log for clues
Suggested-by: Michal Luczaj <mhal@rbox.co>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Colton Lewis <coltonlewis@google.com>
Link: https://lore.kernel.org/r/20231108010953.560824-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop _kvm_ioctl(), _vm_ioctl(), and _vcpu_ioctl(), as they are no longer
used by anything other than the no-underscores variants (and may have
never been used directly). The single-underscore variants were never
intended to be a "feature", they were a stopgap of sorts to ease the
conversion to pretty printing ioctl() names when reporting errors.
Opportunistically add a comment explaining when to use __KVM_IOCTL_ERROR()
versus KVM_IOCTL_ERROR(). The single-underscore macros were subtly
ensuring that the name of the ioctl() was printed on error, i.e. it's all
too easy to overlook the fact that using __KVM_IOCTL_ERROR() is
intentional.
Link: https://lore.kernel.org/r/20231108010953.560824-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Using -MD without -MP causes build failures when a header file is deleted
or moved. With -MP, the compiler will emit phony targets for the header
files it lists as dependencies, and the Makefiles won't refuse to attempt
to rebuild a C unit which no longer includes the deleted header.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/9fc8b5395321abbfcaf5d78477a9a7cd350b08e4.camel@infradead.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Pass MAGIC_TOKEN to __TEST_REQUIRE() when printing the help message about
needing to pass a magic value to manually run the NX hugepages test,
otherwise the help message will contain garbage.
In file included from x86_64/nx_huge_pages_test.c:15:
x86_64/nx_huge_pages_test.c: In function ‘main’:
include/test_util.h:40:32: error: format ‘%d’ expects a matching ‘int’ argument [-Werror=format=]
40 | ksft_exit_skip("- " fmt "\n", ##__VA_ARGS__); \
| ^~~~
x86_64/nx_huge_pages_test.c:259:9: note: in expansion of macro ‘__TEST_REQUIRE’
259 | __TEST_REQUIRE(token == MAGIC_TOKEN,
| ^~~~~~~~~~~~~~
Signed-off-by: angquan yu <angquan21@gmail.com>
Link: https://lore.kernel.org/r/20231128221105.63093-1-angquan21@gmail.com
[sean: rewrite shortlog+changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
The root-only cpuset.cpus.isolated control file shows the current set
of isolated CPUs in isolated partitions. This control file is currently
exposed only with the cgroup_debug boot command line option which also
adds the ".__DEBUG__." prefix. This is actually a useful control file if
users want to find out which CPUs are currently in an isolated state by
the cpuset controller. Remove CFTYPE_DEBUG flag for this control file and
make it available by default without any prefix.
The test_cpuset_prs.sh test script and the cgroup-v2.rst documentation
file are also updated accordingly. Minor code change is also made in
test_cpuset_prs.sh to avoid false test failure when running on debug
kernel.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cleanup net namespaces and other resources if we get a SIGINT (Ctrl-C).
As user visible resources are allocated on a per test basis, it's only
required to catch this condition when (possibly) running tests.
So far calling post_suite is enough to free up anything that might
linger.
A missing keyword replacement for nsPlugin is also included.
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20231124154248.315470-5-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Same init_rng() in both tests. The function reads /dev/urandom to
initialize srand(). In case of failure, it falls back onto the
entropy in the uninitialized variable. Not sure if this is on purpose.
But failure reading urandom should be rare, so just fail hard. While
at it, convert to getrandom(). Which man 4 random suggests is simpler
and more robust.
mptcp_inq.c:525:6:
mptcp_connect.c:1131:6:
error: variable 'foo' is used uninitialized
whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
Fixes: 048d19d444 ("mptcp: add basic kselftest for mptcp")
Fixes: b51880568f ("selftests: mptcp: add inq test case")
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Willem de Bruijn <willemb@google.com>
----
When input is randomized because this is expected to meaningfully
explore edge cases, should we also add
1. logging the random seed to stdout and
2. adding a command line argument to replay from a specific seed
I can do this in net-next, if authors find it useful in this case.
Reviewed-by: Matthieu Baerts <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231124171645.1011043-5-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signedness of char is signed on x86_64, but unsigned on arm64.
Fix the warning building cmsg_sender.c on signed platforms or
forced with -fsigned-char:
msg_sender.c:455:12:
error: implicit conversion from 'int' to 'char'
changes value from 128 to -128
[-Werror,-Wconstant-conversion]
buf[0] = ICMPV6_ECHO_REQUEST;
constant ICMPV6_ECHO_REQUEST is 128.
Link: https://lwn.net/Articles/911914
Fixes: de17e305a8 ("selftests: net: cmsg_sender: support icmp and raw sockets")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20231124171645.1011043-3-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix a small compiler warning.
nr_process must be a signed long: it is assigned a signed long by
strtol() and is compared against LONG_MIN and LONG_MAX.
ipsec.c:2280:65:
error: result of comparison of constant -9223372036854775808
with expression of type 'unsigned int' is always false
[-Werror,-Wtautological-constant-out-of-range-compare]
if ((errno == ERANGE && (nr_process == LONG_MAX || nr_process == LONG_MIN))
Fixes: bc2652b7ae ("selftest/net/xfrm: Add test for ipsec tunnel")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20231124171645.1011043-2-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
With latest upstream llvm18, the following test cases failed:
$ ./test_progs -j
#13/2 bpf_cookie/multi_kprobe_link_api:FAIL
#13/3 bpf_cookie/multi_kprobe_attach_api:FAIL
#13 bpf_cookie:FAIL
#77 fentry_fexit:FAIL
#78/1 fentry_test/fentry:FAIL
#78 fentry_test:FAIL
#82/1 fexit_test/fexit:FAIL
#82 fexit_test:FAIL
#112/1 kprobe_multi_test/skel_api:FAIL
#112/2 kprobe_multi_test/link_api_addrs:FAIL
[...]
#112 kprobe_multi_test:FAIL
#356/17 test_global_funcs/global_func17:FAIL
#356 test_global_funcs:FAIL
Further analysis shows llvm upstream patch [1] is responsible for the above
failures. For example, for function bpf_fentry_test7() in net/bpf/test_run.c,
without [1], the asm code is:
0000000000000400 <bpf_fentry_test7>:
400: f3 0f 1e fa endbr64
404: e8 00 00 00 00 callq 0x409 <bpf_fentry_test7+0x9>
409: 48 89 f8 movq %rdi, %rax
40c: c3 retq
40d: 0f 1f 00 nopl (%rax)
... and with [1], the asm code is:
0000000000005d20 <bpf_fentry_test7.specialized.1>:
5d20: e8 00 00 00 00 callq 0x5d25 <bpf_fentry_test7.specialized.1+0x5>
5d25: c3 retq
... and <bpf_fentry_test7.specialized.1> is called instead of <bpf_fentry_test7>
and this caused test failures for #13/#77 etc. except #356.
For test case #356/17, with [1] (progs/test_global_func17.c)), the main prog
looks like:
0000000000000000 <global_func17>:
0: b4 00 00 00 2a 00 00 00 w0 = 0x2a
1: 95 00 00 00 00 00 00 00 exit
... which passed verification while the test itself expects a verification
failure.
Let us add 'barrier_var' style asm code in both places to prevent function
specialization which caused selftests failure.
[1] https://github.com/llvm/llvm-project/pull/72903
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231127050342.1945270-1-yonghong.song@linux.dev
Pull arm64 fixes from Catalin Marinas:
- Fix "rodata=on" not disabling "rodata=full" on arm64
- Add arm64 make dependency between vmlinuz.efi and Image, leading to
occasional build failures previously (with parallel building)
- Add newline to the output formatting of the za-fork kselftest
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: add dependency between vmlinuz.efi and Image
kselftest/arm64: Fix output formatting for za-fork
arm64: mm: Fix "rodata=on" when CONFIG_RODATA_FULL_DEFAULT_ENABLED=y
Add a few test that validate BPF verifier's lazy approach to validating
global subprogs.
We check that global subprogs that are called transitively through
another global subprog is validated.
We also check that invalid global subprog is not validated, if it's not
called from the main program.
And we also check that main program is always validated first, before
any of the subprogs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231124035937.403208-4-andrii@kernel.org
Slightly change BPF verifier logic around eagerness and order of global
subprog validation. Instead of going over every global subprog eagerly
and validating it before main (entry) BPF program is verified, turn it
around. Validate main program first, mark subprogs that were called from
main program for later verification, but otherwise assume it is valid.
Afterwards, go over marked global subprogs and validate those,
potentially marking some more global functions as being called. Continue
this process until all (transitively) callable global subprogs are
validated. It's a BFS traversal at its heart and will always converge.
This is an important change because it allows to feature-gate some
subprograms that might not be verifiable on some older kernel, depending
on supported set of features.
E.g., at some point, global functions were allowed to accept a pointer
to memory, which size is identified by user-provided type.
Unfortunately, older kernels don't support this feature. With BPF CO-RE
approach, the natural way would be to still compile BPF object file once
and guard calls to this global subprog with some CO-RE check or using
.rodata variables. That's what people do to guard usage of new helpers
or kfuncs, and any other new BPF-side feature that might be missing on
old kernels.
That's currently impossible to do with global subprogs, unfortunately,
because they are eagerly and unconditionally validated. This patch set
aims to change this, so that in the future when global funcs gain new
features, those can be guarded using BPF CO-RE techniques in the same
fashion as any other new kernel feature.
Two selftests had to be adjusted in sync with these changes.
test_global_func12 relied on eager global subprog validation failing
before main program failure is detected (unknown return value). Fix by
making sure that main program is always valid.
verifier_subprog_precision's parent_stack_slot_precise subtest relied on
verifier checkpointing heuristic to do a checkpoint at instruction #5,
but that's no longer true because we don't have enough jumps validated
before reaching insn #5 due to global subprogs being validated later.
Other than that, no changes, as one would expect.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231124035937.403208-3-andrii@kernel.org
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf.
Current release - regressions:
- Revert "net: r8169: Disable multicast filter for RTL8168H and
RTL8107E"
- kselftest: rtnetlink: fix ip route command typo
Current release - new code bugs:
- s390/ism: make sure ism driver implies smc protocol in kconfig
- two build fixes for tools/net
Previous releases - regressions:
- rxrpc: couple of ACK/PING/RTT handling fixes
Previous releases - always broken:
- bpf: verify bpf_loop() callbacks as if they are called unknown
number of times
- improve stability of auto-bonding with Hyper-V
- account BPF-neigh-redirected traffic in interface statistics
Misc:
- net: fill in some more MODULE_DESCRIPTION()s"
* tag 'net-6.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
tools: ynl: fix duplicate op name in devlink
tools: ynl: fix header path for nfsd
net: ipa: fix one GSI register field width
tls: fix NULL deref on tls_sw_splice_eof() with empty record
net: axienet: Fix check for partial TX checksum
vsock/test: fix SEQPACKET message bounds test
i40e: Fix adding unsupported cloud filters
ice: restore timestamp configuration after device reset
ice: unify logic for programming PFINT_TSYN_MSK
ice: remove ptp_tx ring parameter flag
amd-xgbe: propagate the correct speed and duplex status
amd-xgbe: handle the corner-case during tx completion
amd-xgbe: handle corner-case during sfp hotplug
net: veth: fix ethtool stats reporting
octeontx2-pf: Fix ntuple rule creation to direct packet to VF with higher Rx queue than its PF
net: usb: qmi_wwan: claim interface 4 for ZTE MF290
Revert "net: r8169: Disable multicast filter for RTL8168H and RTL8107E"
net/smc: avoid data corruption caused by decline
nfc: virtual_ncidev: Add variable to check if ndev is running
dpll: Fix potential msg memleak when genlmsg_put_reply failed
...
Tune message length calculation to make this test work on machines
where 'getpagesize()' returns >32KB. Now maximum message length is not
hardcoded (on machines above it was smaller than 'getpagesize()' return
value, thus we get negative value and test fails), but calculated at
runtime and always bigger than 'getpagesize()' result. Reproduced on
aarch64 with 64KB page size.
Fixes: 5c338112e4 ("test/vsock: rework message bounds test")
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reported-by: Bogdan Marcynkov <bmarcynk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20231121211642.163474-1-avkrasnov@salutedevices.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is code in rcu_implicit_dynticks_qs() that checks for the current
grace period being halfway to the RCU CPU stall timeout, but rcutorture
currently does not test this code. This commit therefore adds a 14-second
stall to the TREE07 scenario in order to test this code given the default
RCU CPU stall warning timeout of 21 seconds.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
Daniel Borkmann says:
====================
pull-request: bpf-next 2023-11-21
We've added 85 non-merge commits during the last 12 day(s) which contain
a total of 63 files changed, 4464 insertions(+), 1484 deletions(-).
The main changes are:
1) Huge batch of verifier changes to improve BPF register bounds logic
and range support along with a large test suite, and verifier log
improvements, all from Andrii Nakryiko.
2) Add a new kfunc which acquires the associated cgroup of a task within
a specific cgroup v1 hierarchy where the latter is identified by its id,
from Yafang Shao.
3) Extend verifier to allow bpf_refcount_acquire() of a map value field
obtained via direct load which is a use-case needed in sched_ext,
from Dave Marchevsky.
4) Fix bpf_get_task_stack() helper to add the correct crosstask check
for the get_perf_callchain(), from Jordan Rome.
5) Fix BPF task_iter internals where lockless usage of next_thread()
was wrong. The rework also simplifies the code, from Oleg Nesterov.
6) Fix uninitialized tail padding via LIBBPF_OPTS_RESET, and another
fix for certain BPF UAPI structs to fix verifier failures seen
in bpf_dynptr usage, from Yonghong Song.
7) Add BPF selftest fixes for map_percpu_stats flakes due to per-CPU BPF
memory allocator not being able to allocate per-CPU pointer successfully,
from Hou Tao.
8) Add prep work around dynptr and string handling for kfuncs which
is later going to be used by file verification via BPF LSM and fsverity,
from Song Liu.
9) Improve BPF selftests to update multiple prog_tests to use ASSERT_*
macros, from Yuran Pereira.
10) Optimize LPM trie lookup to check prefixlen before walking the trie,
from Florian Lehner.
11) Consolidate virtio/9p configs from BPF selftests in config.vm file
given they are needed consistently across archs, from Manu Bretelle.
12) Small BPF verifier refactor to remove register_is_const(),
from Shung-Hsi Yu.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (85 commits)
selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in vmlinux
selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in bpf_obj_id
selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in bind_perm
selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in bpf_tcp_ca
selftests/bpf: reduce verboseness of reg_bounds selftest logs
bpf: bpf_iter_task_next: use next_task(kit->task) rather than next_task(kit->pos)
bpf: bpf_iter_task_next: use __next_thread() rather than next_thread()
bpf: task_group_seq_get_next: use __next_thread() rather than next_thread()
bpf: emit frameno for PTR_TO_STACK regs if it differs from current one
bpf: smarter verifier log number printing logic
bpf: omit default off=0 and imm=0 in register state log
bpf: emit map name in register state if applicable and available
bpf: print spilled register state in stack slot
bpf: extract register state printing
bpf: move verifier state printing code to kernel/bpf/log.c
bpf: move verbose_linfo() into kernel/bpf/log.c
bpf: rename BPF_F_TEST_SANITY_STRICT to BPF_F_TEST_REG_INVARIANTS
bpf: Remove test for MOVSX32 with offset=32
selftests/bpf: add iter test requiring range x range logic
veristat: add ability to set BPF_F_TEST_SANITY_STRICT flag with -r flag
...
====================
Link: https://lore.kernel.org/r/20231122000500.28126-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MEM_REGION_SLOT and MEM_REGION_GPA are not really needed in
test_invalid_memory_region_flags; the VM never runs and there are no
other slots, so it is okay to use slot 0 and place it at address
zero. This fixes compilation on architectures that do not
define them.
Fixes: 5d74316466 ("KVM: selftests: Add a memory region subtest to validate invalid flags")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In some cases verifier can't infer convergence of the bpf_loop()
iteration. E.g. for the following program:
static int cb(__u32 idx, struct num_context* ctx)
{
ctx->i++;
return 0;
}
SEC("?raw_tp")
int prog(void *_)
{
struct num_context ctx = { .i = 0 };
__u8 choice_arr[2] = { 0, 1 };
bpf_loop(2, cb, &ctx, 0);
return choice_arr[ctx.i];
}
Each 'cb' simulation would eventually return to 'prog' and reach
'return choice_arr[ctx.i]' statement. At which point ctx.i would be
marked precise, thus forcing verifier to track multitude of separate
states with {.i=0}, {.i=1}, ... at bpf_loop() callback entry.
This commit allows "brute force" handling for such cases by limiting
number of callback body simulations using 'umax' value of the first
bpf_loop() parameter.
For this, extend bpf_func_state with 'callback_depth' field.
Increment this field when callback visiting state is pushed to states
traversal stack. For frame #N it's 'callback_depth' field counts how
many times callback with frame depth N+1 had been executed.
Use bpf_func_state specifically to allow independent tracking of
callback depths when multiple nested bpf_loop() calls are present.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A set of test cases to check behavior of callback handling logic,
check if verifier catches the following situations:
- program not safe on second callback iteration;
- program not safe on zero callback iterations;
- infinite loop inside a callback.
Verify that callback logic works for bpf_loop, bpf_for_each_map_elem,
bpf_user_ringbuf_drain, bpf_find_vma.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Prior to this patch callbacks were handled as regular function calls,
execution of callback body was modeled exactly once.
This patch updates callbacks handling logic as follows:
- introduces a function push_callback_call() that schedules callback
body verification in env->head stack;
- updates prepare_func_exit() to reschedule callback body verification
upon BPF_EXIT;
- as calls to bpf_*_iter_next(), calls to callback invoking functions
are marked as checkpoints;
- is_state_visited() is updated to stop callback based iteration when
some identical parent state is found.
Paths with callback function invoked zero times are now verified first,
which leads to necessity to modify some selftests:
- the following negative tests required adding release/unlock/drop
calls to avoid previously masked unrelated error reports:
- cb_refs.c:underflow_prog
- exceptions_fail.c:reject_rbtree_add_throw
- exceptions_fail.c:reject_with_cp_reference
- the following precision tracking selftests needed change in expected
log trace:
- verifier_subprog_precision.c:callback_result_precise
(note: r0 precision is no longer propagated inside callback and
I think this is a correct behavior)
- verifier_subprog_precision.c:parent_callee_saved_reg_precise_with_callback
- verifier_subprog_precision.c:parent_stack_slot_precise_with_callback
Reported-by: Andrew Werner <awerner32@gmail.com>
Closes: https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
