Commit c27cea4416 ("rcu: Re-implement RCU Tasks Trace in terms of SRCU-fast")
broke map_kptr selftest since it removed the function we were kprobing.
Use a new kfunc that invokes call_rcu_tasks_trace and sets a program
provided pointer to an integer to 1. Technically this can be unsafe if
the memory being written to from the callback disappears, but this is
just for usage in a test where we ensure we spin until we see the value
to be set to 1, so it's ok.
Reported-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Fixes: c27cea4416 ("rcu: Re-implement RCU Tasks Trace in terms of SRCU-fast")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260211185747.3630539-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new selftest suite `exe_ctx` to verify the accuracy of the
bpf_in_task(), bpf_in_hardirq(), and bpf_in_serving_softirq() helpers
introduced in bpf_experimental.h.
Testing these execution contexts deterministically requires crossing
context boundaries within a single CPU. To achieve this, the test
implements a "Trigger-Observer" pattern using bpf_testmod:
1. Trigger: A BPF syscall program calls a new bpf_testmod kfunc
bpf_kfunc_trigger_ctx_check().
2. Task to HardIRQ: The kfunc uses irq_work_queue() to trigger a
self-IPI on the local CPU.
3. HardIRQ to SoftIRQ: The irq_work handler calls a dummy function
(observed by BPF fentry) and then schedules a tasklet to
transition into SoftIRQ context.
The user-space runner ensures determinism by pinning itself to CPU 0
before execution, forcing the entire interrupt chain to remain on a
single core. Dummy noinline functions with compiler barriers are
added to bpf_testmod.c to serve as stable attachment points for
fentry programs. A retry loop is used in user-space to wait for the
asynchronous SoftIRQ to complete.
Note that testing on s390x is avoided because supporting those helpers
purely in BPF on s390x is not possible at this point.
Reviewed-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Changwoo Min <changwoo@igalia.com>
Link: https://lore.kernel.org/r/20260125115413.117502-3-changwoo@igalia.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Test BPF_PROG_ASSOC_STRUCT_OPS command that associates a BPF program
with a struct_ops. The test follows the same logic in commit
ba7000f1c3 ("selftests/bpf: Test multi_st_ops and calling kfuncs from
different programs"), but instead of using map id to identify a specific
struct_ops, this test uses the new BPF command to associate a struct_ops
with a program.
The test consists of two sets of almost identical struct_ops maps and BPF
programs associated with the map. Their only difference is the unique
value returned by bpf_testmod_multi_st_ops::test_1().
The test first loads the programs and associates them with struct_ops
maps. Then, it exercises the BPF programs. They will in turn call kfunc
bpf_kfunc_multi_st_ops_test_1_prog_arg() to trigger test_1() of the
associated struct_ops map, and then check if the right unique value is
returned.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20251203233748.668365-5-ameryhung@gmail.com
The selftests build four kernel modules which use copy-pasted Makefile
targets. This is a bit messy, and doesn't scale so well when we add more
modules, so let's consolidate these rules into a single rule generated
for each module name, and move the module sources into a single
directory.
To avoid parallel builds of the different modules stepping on each
other's toes during the 'modpost' phase of the Kbuild 'make modules',
the module files should really be a grouped target. However, make only
added explicit support for grouped targets in version 4.3, which is
newer than the minimum version supported by the kernel. However, make
implicitly treats pattern matching rules with multiple targets as a
grouped target, so we can work around this by turning the rule into a
pattern matching target. We do this by replacing '.ko' with '%ko' in the
targets with subst().
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/bpf/20241204-bpf-selftests-mod-compile-v5-1-b96231134a49@redhat.com
