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Fri, 19 Dec 2025 01:27:46 -0800 (PST) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Fri, 19 Dec 2025 10:27:45 +0100 To: Steven Rostedt Cc: Florent Revest , Mark Rutland , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Menglong Dong , Song Liu Subject: Re: [PATCHv5 bpf-next 5/9] ftrace: Add update_ftrace_direct_del function Message-ID: References: <20251215211402.353056-1-jolsa@kernel.org> <20251215211402.353056-6-jolsa@kernel.org> <20251217204814.38756224@robin> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251217204814.38756224@robin> On Wed, Dec 17, 2025 at 08:48:14PM -0500, Steven Rostedt wrote: > On Mon, 15 Dec 2025 22:13:58 +0100 > Jiri Olsa wrote: > > +/** > > + * hash_sub - substracts @b from @a and returns the result > > + * @a: struct ftrace_hash object > > + * @b: struct ftrace_hash object > > + * > > + * Returns struct ftrace_hash object on success, NULL on error. > > + */ > > +static struct ftrace_hash *hash_sub(struct ftrace_hash *a, struct ftrace_hash *b) > > +{ > > + struct ftrace_func_entry *entry, *del; > > + struct ftrace_hash *sub; > > + int size, i; > > + > > + sub = alloc_and_copy_ftrace_hash(a->size_bits, a); > > + if (!sub) > > + goto error; > > Again, this can be just return NULL; ok > > > + > > + size = 1 << b->size_bits; > > + for (i = 0; i < size; i++) { > > You can make this for (int i = 0; ...) too. ok > > > + hlist_for_each_entry(entry, &b->buckets[i], hlist) { > > + del = __ftrace_lookup_ip(sub, entry->ip); > > + if (WARN_ON_ONCE(!del)) > > + goto error; > > And you can remove the error label here too: ok > > if (WARN_ON_ONCE(!del)) { > free_ftrace_hash(sub); > return NULL; > } > > > > + remove_hash_entry(sub, del); > > + kfree(del); > > + } > > + } > > + return sub; > > + > > + error: > > + free_ftrace_hash(sub); > > + return NULL; > > +} > > + > > +int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash) > > +{ > > + struct ftrace_hash *old_direct_functions = NULL, *new_direct_functions; > > + struct ftrace_hash *old_filter_hash, *new_filter_hash = NULL; > > + struct ftrace_func_entry *del, *entry; > > One variable per line. ok > > > + unsigned long size, i; > > + int err = -EINVAL; > > + > > + if (!hash_count(hash)) > > + return -EINVAL; > > + if (check_direct_multi(ops)) > > + return -EINVAL; > > + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) > > + return -EINVAL; > > + if (direct_functions == EMPTY_HASH) > > + return -EINVAL; > > + > > + mutex_lock(&direct_mutex); > > + > > + old_filter_hash = ops->func_hash ? ops->func_hash->filter_hash : NULL; > > + > > + if (!hash_count(old_filter_hash)) > > + goto out_unlock; > > + > > + /* Make sure requested entries are already registered. */ > > + size = 1 << hash->size_bits; > > + for (i = 0; i < size; i++) { > > for (int i = 0; ...) ack thanks, jirka