| Message ID | 20250415130910.2326537-1-devaanshk840@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: Remove tracing program restriction on map types | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply |
| bpf/vmtest-bpf-PR | fail | merge-conflict |
On Tue, Apr 15, 2025 at 06:39:07PM +0530, Devaansh Kumar wrote: > [ Upstream commit 96da3f7d489d11b43e7c1af90d876b9a2492cca8 ] > > The hash map is now fully converted to bpf_mem_alloc. Its implementation is not > allocating synchronously and not calling call_rcu() directly. It's now safe to > use non-preallocated hash maps in all types of tracing programs including > BPF_PROG_TYPE_PERF_EVENT that runs out of NMI context. > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> > Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> > Acked-by: Andrii Nakryiko <andrii@kernel.org> > Link: https://lore.kernel.org/bpf/20220902211058.60789-13-alexei.starovoitov@gmail.com > Signed-off-by: Devaansh Kumar <devaanshk840@gmail.com> > --- > kernel/bpf/verifier.c | 29 ----------------------------- > 1 file changed, 29 deletions(-) what kernel tree(s) is this for?
On Tue, 15 Apr 2025 at 18:49, Greg KH <gregkh@linuxfoundation.org> wrote:
> what kernel tree(s) is this for?
This backport is for v5.15.y stable version. My bad, I should have
mentioned it in the subject.
On Tue, Apr 15, 2025 at 6:25 AM Devaansh Kumar <devaanshk840@gmail.com> wrote: > > On Tue, 15 Apr 2025 at 18:49, Greg KH <gregkh@linuxfoundation.org> wrote: > > what kernel tree(s) is this for? > > This backport is for v5.15.y stable version. My bad, I should have > mentioned it in the subject. Nack. 5.15 doesn't have bpf_mem_alloc. This backport makes no sense.
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7049a85a78ab..77a75ccaae5e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11700,35 +11700,6 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env, { enum bpf_prog_type prog_type = resolve_prog_type(prog); - /* - * Validate that trace type programs use preallocated hash maps. - * - * For programs attached to PERF events this is mandatory as the - * perf NMI can hit any arbitrary code sequence. - * - * All other trace types using preallocated hash maps are unsafe as - * well because tracepoint or kprobes can be inside locked regions - * of the memory allocator or at a place where a recursion into the - * memory allocator would see inconsistent state. - * - * On RT enabled kernels run-time allocation of all trace type - * programs is strictly prohibited due to lock type constraints. On - * !RT kernels it is allowed for backwards compatibility reasons for - * now, but warnings are emitted so developers are made aware of - * the unsafety and can fix their programs before this is enforced. - */ - if (is_tracing_prog_type(prog_type) && !is_preallocated_map(map)) { - if (prog_type == BPF_PROG_TYPE_PERF_EVENT) { - verbose(env, "perf_event programs can only use preallocated hash map\n"); - return -EINVAL; - } - if (IS_ENABLED(CONFIG_PREEMPT_RT)) { - verbose(env, "trace type programs can only use preallocated hash map\n"); - return -EINVAL; - } - WARN_ONCE(1, "trace type BPF program uses run-time allocation\n"); - verbose(env, "trace type programs with run-time allocated hash maps are unsafe. Switch to preallocated hash maps.\n"); - } if (map_value_has_spin_lock(map)) { if (prog_type == BPF_PROG_TYPE_SOCKET_FILTER) {