From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8AC030F556; Tue, 23 Sep 2025 21:52:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758664340; cv=none; b=KLDVKIE2Dpc6d7kNzpMIFurUxiZMscQCG1G9Ys0jsLcIOMzpoYrgYVaCdgiCf8SobAerytZhW1lQ6251aIU4azeymAxu6OZsqFQ9fC7oGik8YS+OFziIVlzI8UQYz6CtL82RR306bek+5XvJz440BFVNrbyyNY10L8/RmfALkXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758664340; c=relaxed/simple; bh=owMdIa2olCHJ3eYUyQpQ21kOHUHt5sxjjmLt+nAB5Gc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YMmB4F1mQ+uecememrMw8nIWIGn1dja9l2jHOM6gTk9Up9Kvn9nFneKebKt3Q+qordD9stUO2073YxMs4FAbhyd06D7zcmj7sTvOXjCuGXzYQZDv1f7rMtSfr64O4A2oYC0KwuvSJLUqFAI7yas3a8Z/1mTqsWOhgyea3XETKHQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G/RqXC3K; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="G/RqXC3K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE1A9C4CEF5; Tue, 23 Sep 2025 21:52:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758664340; bh=owMdIa2olCHJ3eYUyQpQ21kOHUHt5sxjjmLt+nAB5Gc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G/RqXC3KmUV/CsJGvJtZGwzPF2/7gsfLJPdooZB5WN/gLN1DiiKGgZjP4UllLkQy7 tRj1xNyIWXuw6H/dNVx6X7zF64rjQYHboNCdMyOkiixCFiFBpMQcLG65Ffii91LuXD 81Y2gWy20aCGQfNCg8AOz9VvC89cxDkWm+0y+RFuA5/DJnzKsgPTgQp0qFSB0HxOXL Q58zDHoFmrrD7A77l7gQZWGsTV+oPZQEPcMm0GX+tZ0PJGnr42my2EogblAnLk50ei litgKOD8b9mI2oso6hzd2EsX3parhlBtgRGWKnipP45cFN5H2S66gcWvYLs9EISmr3 4yC1bb25iTEDA== 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 2/9] ftrace: Add register_ftrace_direct_hash function Date: Tue, 23 Sep 2025 23:51:40 +0200 Message-ID: <20250923215147.1571952-3-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> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Adding register_ftrace_direct_hash function that registers all entries (ip -> direct) provided in hash argument. The difference to current register_ftrace_direct is - hash argument that allows to register multiple ip -> direct entries at once - we can call register_ftrace_direct_hash multiple times on the same ftrace_ops object, becase after first registration with register_ftrace_function_nolock, it uses ftrace_update_ops to update the ftrace_ops object 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 | 7 +++ kernel/trace/ftrace.c | 110 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 7ded7df6e9b5..2705c292341a 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -526,6 +526,8 @@ int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, 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); + void ftrace_stub_direct_tramp(void); #else @@ -552,6 +554,11 @@ static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned l return -ENODEV; } +int register_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 a45556257963..06528af2281f 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6219,6 +6219,116 @@ int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) return err; } EXPORT_SYMBOL_GPL(modify_ftrace_direct); + +static unsigned long hash_count(struct ftrace_hash *hash) +{ + return hash ? hash->count : 0; +} + +/** + * hash_add - adds two struct ftrace_hash 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_add(struct ftrace_hash *a, struct ftrace_hash *b) +{ + struct ftrace_func_entry *entry; + struct ftrace_hash *add; + int size, i; + + size = hash_count(a) + hash_count(b); + if (size > 32) + size = 32; + + add = alloc_and_copy_ftrace_hash(fls(size), a); + if (!add) + goto error; + + size = 1 << b->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &b->buckets[i], hlist) { + if (add_hash_entry_direct(add, entry->ip, entry->direct) == NULL) + goto error; + } + } + return add; + + error: + free_ftrace_hash(add); + return NULL; +} + +int register_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *hash) +{ + struct ftrace_hash *filter_hash = NULL, *new_hash = NULL, *free_hash = NULL; + struct ftrace_func_entry *entry; + int i, size, err = -EINVAL; + bool reg; + + if (!hash_count(hash)) + return 0; + + mutex_lock(&direct_mutex); + + /* Make sure requested entries are not already registered. */ + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + if (__ftrace_lookup_ip(direct_functions, entry->ip)) + goto out_unlock; + } + } + + filter_hash = ops->func_hash ? ops->func_hash->filter_hash : NULL; + + /* If there's nothing in filter_hash we need to register the ops. */ + reg = hash_count(filter_hash) == 0; + if (reg) { + if (ops->func || ops->trampoline) + goto out_unlock; + if (ops->flags & FTRACE_OPS_FL_ENABLED) + goto out_unlock; + } + + err = -ENOMEM; + filter_hash = hash_add(filter_hash, hash); + if (!filter_hash) + goto out_unlock; + + new_hash = hash_add(direct_functions, hash); + if (!new_hash) + goto out_unlock; + + free_hash = direct_functions; + rcu_assign_pointer(direct_functions, new_hash); + + if (reg) { + ops->func = call_direct_funcs; + ops->flags = MULTI_FLAGS; + ops->trampoline = FTRACE_REGS_ADDR; + ops->local_hash.filter_hash = filter_hash; + + err = register_ftrace_function_nolock(ops); + if (!err) + filter_hash = NULL; + } else { + err = ftrace_update_ops(ops, filter_hash, EMPTY_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(register_ftrace_direct_hash); + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ /** -- 2.51.0