From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- rust/helpers/time.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 rust/helpers/time.c (limited to 'rust/helpers/time.c') diff --git a/rust/helpers/time.c b/rust/helpers/time.c new file mode 100644 index 000000000..32f495970 --- /dev/null +++ b/rust/helpers/time.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +__rust_helper void rust_helper_fsleep(unsigned long usecs) +{ + fsleep(usecs); +} + +__rust_helper ktime_t rust_helper_ktime_get_real(void) +{ + return ktime_get_real(); +} + +__rust_helper ktime_t rust_helper_ktime_get_boottime(void) +{ + return ktime_get_boottime(); +} + +__rust_helper ktime_t rust_helper_ktime_get_clocktai(void) +{ + return ktime_get_clocktai(); +} + +__rust_helper s64 rust_helper_ktime_to_us(const ktime_t kt) +{ + return ktime_to_us(kt); +} + +__rust_helper s64 rust_helper_ktime_to_ms(const ktime_t kt) +{ + return ktime_to_ms(kt); +} + +__rust_helper void rust_helper_udelay(unsigned long usec) +{ + udelay(usec); +} -- cgit v1.3.1