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 --- arch/powerpc/perf/hv-common.h | 47 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 arch/powerpc/perf/hv-common.h (limited to 'arch/powerpc/perf/hv-common.h') diff --git a/arch/powerpc/perf/hv-common.h b/arch/powerpc/perf/hv-common.h new file mode 100644 index 000000000..2cce17bc3 --- /dev/null +++ b/arch/powerpc/perf/hv-common.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef LINUX_POWERPC_PERF_HV_COMMON_H_ +#define LINUX_POWERPC_PERF_HV_COMMON_H_ + +#include +#include + +struct hv_perf_caps { + u16 version; + u16 collect_privileged:1, + ga:1, + expanded:1, + lab:1, + unused:12; +}; + +unsigned long hv_perf_caps_get(struct hv_perf_caps *caps); + + +#define EVENT_DEFINE_RANGE_FORMAT(name, attr_var, bit_start, bit_end) \ +PMU_FORMAT_ATTR(name, #attr_var ":" #bit_start "-" #bit_end); \ +EVENT_DEFINE_RANGE(name, attr_var, bit_start, bit_end) + +/* + * The EVENT_DEFINE_RANGE_FORMAT() macro above includes helper functions + * for the fields (eg: event_get_starting_index()). For some fields we + * need the bit-range definition, but no the helper functions. Define a + * lite version of the above macro without the helpers and silence + * compiler warnings unused static functions. + */ +#define EVENT_DEFINE_RANGE_FORMAT_LITE(name, attr_var, bit_start, bit_end) \ +PMU_FORMAT_ATTR(name, #attr_var ":" #bit_start "-" #bit_end); + +#define EVENT_DEFINE_RANGE(name, attr_var, bit_start, bit_end) \ +static u64 event_get_##name##_max(void) \ +{ \ + BUILD_BUG_ON((bit_start > bit_end) \ + || (bit_end >= (sizeof(1ull) * 8))); \ + return (((1ull << (bit_end - bit_start)) - 1) << 1) + 1; \ +} \ +static u64 event_get_##name(struct perf_event *event) \ +{ \ + return (event->attr.attr_var >> (bit_start)) & \ + event_get_##name##_max(); \ +} + +#endif -- cgit v1.3.1