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 46C5BC83F26 for ; Tue, 29 Jul 2025 10:36:50 +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=jQ3zIuKmYjiiVQZZvgJD4Hb48Xt4mLbw8QLpqmoGdVk=; b=e2NsHpiR3v2DGdR+UjiakUH7FU ZvZa51WzyBIc9Ga7WnKM8qABLl1CuXvgnAuu8DU4QyRIr+7StCnwfjZRUG3DP2ZbKqSK1XyuUp7k6 fS9g3GJQ8tYOT/87hOv7OUI6ffcu/X4pSjGktPov6tZcYLoIi4fh+cghzhXUA1HwthUC+hO0MGHvM eAcTfFKT0I0qpMHgpLd6Qkx3WQFc45yzNd9/t5j1S6/oMBmk+DT9mr2wm9alDDJsDXziskMgPtZ03 +R3NaR6h/zt6M1Sv9lD89amHatEKeg/KtgwYmG4BqHnOAJpERux/puDepbG9CYyirJT1YJ+r7LrzB lU+lkzBg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ughhL-0000000GY4l-2PRf; Tue, 29 Jul 2025 10:36:43 +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 1ughZX-0000000GWgv-3feV for linux-arm-kernel@lists.infradead.org; Tue, 29 Jul 2025 10:28:40 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 51AC1601EC; Tue, 29 Jul 2025 10:28:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33CB7C4CEEF; Tue, 29 Jul 2025 10:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753784919; bh=PoVJYmha+F5Q+Shyh8Z6KZj91FS00Vyug/N39XeYgMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cvoNT2pkbNwrm9T3+/0Qy1iPrq8hPGDjfzb55rvDPU92Tp6ra268grQaNQUx/5YMG flGt4OoLgVr05TK/y0/MaDFjfeaCK9Nmax3CMWqKkBtEQsUomO5+nm4IinpJJAoxKo DiuxSJys3Fu7aNhh/s7CmnP1JP7ESYd+2zu8r4pwK+SC6W8TDAlos1TLXwn6yIJSw5 PLqtuv8SRR78GdCvlV+OXenW26soPrMNPSXYxcVCGLhK0yavus3sL3n35uoWAykTU2 3r2sseihRrqZPsOB0wjVMzNJ/ibme2TeBY6y8zW9RNF7faQPJ10WIm8FXw+7goiAEU yXy0ct+8CUksg== 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: [RFC 02/10] ftrace: Add register_ftrace_direct_hash function Date: Tue, 29 Jul 2025 12:28:05 +0200 Message-ID: <20250729102813.1531457-3-jolsa@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250729102813.1531457-1-jolsa@kernel.org> References: <20250729102813.1531457-1-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 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 | 123 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 130 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index b672ca15f265..e45bcc9de53b 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 5b8f565a1258..1dbb113f4e9c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6219,6 +6219,129 @@ 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; +} + +static void call_direct_funcs_hash(unsigned long ip, unsigned long pip, + struct ftrace_ops *ops, struct ftrace_regs *fregs) +{ + unsigned long addr; + + addr = ftrace_find_rec_direct(ip); + if (!addr) + return; + + arch_ftrace_set_direct_caller(fregs, addr); +} + +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; + bool reg; + + if (!hash_count(hash)) + return 0; + + mutex_lock(&direct_mutex); + + /* Make sure requested entry is 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; + } + + 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); + new_hash = NULL; + + if (reg) { + ops->func = call_direct_funcs_hash; + 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 */ /** -- 2.50.1