From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4D086CAC5AC for ; Tue, 23 Sep 2025 21:52:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=QX45tuaO5WXNN+CTHbEijBgzmNBMNeLxfeOXCA93uSM=; b=IT+RGf0Yo/xyBThIxXlO1qCzOw FECaRfFRmsM3usOWhxe9/XbuIwfLHPLHFg63AV/iCy5KXwCXm1nIQJjmvezNwk9Doosxqted36ni7 mk2+qHdW/cSrM/i8L+YcFRvQUNt0pCtWxbFHunmrbx+dmsTco/vH8vxpbpocCl/yzYAa3+UvzIY4H ma092lbRU1lBfI/ZnYZnHx4OTJB2ej+9DleRh5MmRtT/tZ8gpo8xrCi7MXj8uBWR2QMOr8w5DbN1i yQVw+OI/d1cvmrUq55r116jZF797iMkwHK3lf+P4lxVbs52d0pnpz7XYpFT+o+wcHjMiMr+lFSsEU fLDDtqVg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v1Aw5-0000000F0yM-1Jwz; Tue, 23 Sep 2025 21:52:33 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v1Aw4-0000000F0xi-0LVO for linux-arm-kernel@lists.infradead.org; Tue, 23 Sep 2025 21:52:32 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 7FCBB60292; Tue, 23 Sep 2025 21:52:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E5A7C4CEF5; Tue, 23 Sep 2025 21:52:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758664351; bh=BULakDdKw0A4NZGkv919IsMp+rW5CmZOYDx2mdUjOFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bbPDkg8x5vH27VfUoF+koTvyt23ssm+a7u9uXZl1YlS2HNFgfS/7XXfJJcS36jBK+ jbI0CCQwFbtQmwdOyJUvQVRVRLOnaomAwjKVnHzJlEMNZ7MsqpA/Hi9F/qxuFUNWVx iZqOyoV41gMhmdN2/QBQgUO8pTSfw2YthTD/82vNjswNC9ftWo3DzQDeriMn8V51WJ 4QUpXkEpfQZ9mRg7szIgWPrpYfg3LfGY59rOM9URqQDQTBOYCpp4RwL10WqZlRfHgb 0PPOBNd2hpo/yAWgbRVCF8pm1SDCpjwqIQqAJxTL2hpp7trEedJx/XLhPz0U5mZ02H Q1QkPGTs/N0Bw== From: Jiri Olsa To: Steven Rostedt , Florent Revest , Mark Rutland Cc: 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 Subject: [PATCH 3/9] ftrace: Add unregister_ftrace_direct_hash function Date: Tue, 23 Sep 2025 23:51:41 +0200 Message-ID: <20250923215147.1571952-4-jolsa@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250923215147.1571952-1-jolsa@kernel.org> References: <20250923215147.1571952-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Adding unregister_ftrace_direct_hash function that unregisters all entries (ip -> direct) provided in hash argument. The difference to current unregister_ftrace_direct is - hash argument that allows to unregister multiple ip -> direct entries at once - we can call unregister_ftrace_direct_hash multiple times on the same ftrace_ops object, becase we do not need to unregister all entries at once, we can do it gradualy with the help of ftrace_update_ops function This change will allow us to have simple ftrace_ops for all bpf direct interface users in following changes. Signed-off-by: Jiri Olsa --- include/linux/ftrace.h | 6 +++ kernel/trace/ftrace.c | 98 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 104 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 2705c292341a..55f5ead5d4ff 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -527,6 +527,7 @@ int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr); int register_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash); +int unregister_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash); void ftrace_stub_direct_tramp(void); @@ -559,6 +560,11 @@ int register_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash return -ENODEV; } +int unregister_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash) +{ + return -ENODEV; +} + /* * This must be implemented by the architecture. * It is the way the ftrace direct_ops helper, when called diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 06528af2281f..ab5739f72933 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6329,6 +6329,104 @@ int register_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash } EXPORT_SYMBOL_GPL(register_ftrace_direct_hash); +/** + * 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; + + size = 1 << b->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &b->buckets[i], hlist) { + del = __ftrace_lookup_ip(sub, entry->ip); + if (WARN_ON_ONCE(!del)) + goto error; + remove_hash_entry(sub, del); + kfree(del); + } + } + return sub; + + error: + free_ftrace_hash(sub); + return NULL; +} + +int unregister_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash) +{ + struct ftrace_hash *new_hash = NULL, *filter_hash = NULL, *free_hash = NULL; + struct ftrace_func_entry *del, *entry; + unsigned long size, i; + int err = -EINVAL; + + if (!hash_count(hash)) + return 0; + 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); + + /* Make sure requested entries are already registered. */ + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + del = __ftrace_lookup_ip(direct_functions, entry->ip); + if (!del || del->direct != entry->direct) + goto out_unlock; + } + } + + err = -ENOMEM; + filter_hash = hash_sub(ops->func_hash->filter_hash, hash); + if (!filter_hash) + goto out_unlock; + + new_hash = hash_sub(direct_functions, hash); + if (!new_hash) + goto out_unlock; + + /* If there's nothing left, we need to unregister the ops. */ + if (ftrace_hash_empty(filter_hash)) { + err = unregister_ftrace_function(ops); + /* cleanup for possible another register call */ + ops->func = NULL; + ops->trampoline = 0; + ftrace_free_filter(ops); + ops->func_hash->filter_hash = NULL; + } else { + err = ftrace_update_ops(ops, filter_hash, EMPTY_HASH); + } + + free_hash = direct_functions; + rcu_assign_pointer(direct_functions, new_hash); + + out_unlock: + mutex_unlock(&direct_mutex); + + if (free_hash && free_hash != EMPTY_HASH) + call_rcu_tasks(&free_hash->rcu, register_ftrace_direct_cb); + if (filter_hash) + free_ftrace_hash(filter_hash); + + return err; +} +EXPORT_SYMBOL_GPL(unregister_ftrace_direct_hash); + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ /** -- 2.51.0