linux/tools
Martin KaFai Lau 2ddef1783c bpf: Allow refcounted bpf_rb_node used in bpf_rbtree_{remove,left,right}
The bpf_rbtree_{remove,left,right} requires the root's lock to be held.
They also check the node_internal->owner is still owned by that root
before proceeding, so it is safe to allow refcounted bpf_rb_node
pointer to be used in these kfuncs.

In a bpf fq implementation which is much closer to the kernel fq,
https://lore.kernel.org/bpf/20250418224652.105998-13-martin.lau@linux.dev/,
a networking flow (allocated by bpf_obj_new) can be added to two different
rbtrees. There are cases that the flow is searched from one rbtree,
held the refcount of the flow, and then removed from another rbtree:

struct fq_flow {
	struct bpf_rb_node	fq_node;
	struct bpf_rb_node	rate_node;
	struct bpf_refcount	refcount;
	unsigned long		sk_long;
};

int bpf_fq_enqueue(...)
{
	/* ... */

	bpf_spin_lock(&root->lock);
	while (can_loop) {
		/* ... */
		if (!p)
			break;
		gc_f = bpf_rb_entry(p, struct fq_flow, fq_node);
		if (gc_f->sk_long == sk_long) {
			f = bpf_refcount_acquire(gc_f);
			break;
		}
		/* ... */
	}
	bpf_spin_unlock(&root->lock);

	if (f) {
		bpf_spin_lock(&q->lock);
		bpf_rbtree_remove(&q->delayed, &f->rate_node);
		bpf_spin_unlock(&q->lock);
	}
}

bpf_rbtree_{left,right} do not need this change but are relaxed together
with bpf_rbtree_remove instead of adding extra verifier logic
to exclude these kfuncs.

To avoid bi-sect failure, this patch also changes the selftests together.

The "rbtree_api_remove_unadded_node" is not expecting verifier's error.
The test now expects bpf_rbtree_remove(&groot, &m->node) to return NULL.
The test uses __retval(0) to ensure this NULL return value.

Some of the "only take non-owning..." failure messages are changed also.

Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-5-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-05-06 10:21:05 -07:00
..
accounting
arch x86/insn: Fix CTEST instruction decoding 2025-04-24 20:19:17 +02:00
bootconfig
bpf bpf-next-6.15 2025-03-30 12:43:03 -07:00
build perf tools changes for v6.15 2025-03-31 08:52:33 -07:00
certs
cgroup
counter
crypto
debugging taint: Add TAINT_FWCTL 2025-03-06 15:13:13 -04:00
firewire
firmware
gpio
hv
iio
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc3 2025-04-21 08:04:38 -07:00
kvm/kvm_stat
laptop
leds
lib libbpf: Improve BTF dedup handling of "identical" BTF types 2025-05-05 14:51:47 -07:00
memory-model
mm
net tools: ynl-gen: make sure we validate subtype of array-nest 2025-04-16 18:09:41 -07:00
objtool Rust fixes for v6.15 2025-04-19 10:02:43 -07:00
pcmcia
perf perf tools: Remove evsel__handle_error_quirks() 2025-04-11 09:22:49 -07:00
power Turbostat 2025.05.06 2025-04-06 12:32:43 -07:00
rcu
sched_ext sched_ext: Mark SCX_OPS_HAS_CGROUP_WEIGHT for deprecation 2025-04-08 08:53:52 -10:00
scripts tools headers: Update the syscall table with the kernel sources 2025-04-10 09:28:24 -07:00
sound
spi
testing bpf: Allow refcounted bpf_rb_node used in bpf_rbtree_{remove,left,right} 2025-05-06 10:21:05 -07:00
thermal
time
tracing tracing tooling updates for 6.15: 2025-03-27 17:03:01 -07:00
usb
verification tracing tooling updates for 6.15: 2025-03-27 17:03:01 -07:00
virtio
wmi
workqueue
writeback
Makefile tools/Makefile: Remove pci target 2025-03-08 14:35:32 +00:00