From nobody Sun Oct 5 23:54:47 2025 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 546E3288C16; Tue, 29 Jul 2025 10:29:02 +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=1753784942; cv=none; b=mj1Xr9+x75Z2kVJxq1uCNDkVV1n1GpsKmBN8jm4vQQePzX0t+J3SlXpIXE2VDXeAhyASUhprV9+5TT6AZLcAx0qjtbe7Ai6kJi9a9N1R4M6Wl0yPYqgKNfEL5RONGPdDEIrSNJUVTq75AWO8IVEjuLJ3Z+7Sa6ZdpAqV+YrAdTA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753784942; c=relaxed/simple; bh=oE3MjIoq7PdzWxxy/FqOc+ixaBdp6bBF/6oQYdRPSBU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WIc5R8+sekMw0nc1M2Li/SgRKTwNKIb3fivWRCWX95khNtvRLreSwmM2TSdEi8sL9I51AUVlnv+JJdD4qe4N0uOLRkbOKPcExj3ffjRRqKvcq+EMeEUXUqX4ltSHhfXPSq+WT/of3WHzTSkClnT3Nqsp5m8TcffpM8D83zgB2aI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a42U5aG5; 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="a42U5aG5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F78DC4CEEF; Tue, 29 Jul 2025 10:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753784941; bh=oE3MjIoq7PdzWxxy/FqOc+ixaBdp6bBF/6oQYdRPSBU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a42U5aG5a3fObGpx09e13vzlH8lWFxPtU3jQ9W6k96sXIjw38o+IqjNYzqZtTENk6 yGK+6RAQOaU4nKzQ8pDHasG6tqGANgcWrLG+oRde7haZ38J9LxP9Z0HzJ3cMwiqLBQ y015CVcacFqd+j0OOXXZ71fgADmsb2NCF+wl/rwk2ezbaERYPFre5ILI3eHdmKE17r EaIfP/zvGSgNXsyfmJST6LXZcQnHaYceMqDsGo3yO/NT2qEm0LoMCHQ+XYVlmJAnHu 4KKz+3+HaC1aiuNdFnlZsGi3VIUzZ8j2Q+bdgQcMDkwRGweiyIkrjlbxRGyAZTPPVb kdInU15FKBnNw== 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 04/10] ftrace: Add modify_ftrace_direct_hash function Date: Tue, 29 Jul 2025 12:28:07 +0200 Message-ID: <20250729102813.1531457-5-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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Adding modify_ftrace_direct_hash function that modifies all entries (ip -> direct) provided in hash argument. The difference to current unregister_ftrace_direct is - hash argument that allows to modify multiple ip -> direct entries at once 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 | 58 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 7ff6004498c0..8761765d9abc 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -528,6 +528,7 @@ int modify_ftrace_direct_nolock(struct ftrace_ops *ops,= unsigned long addr); =20 int register_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash= *hash); int unregister_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_ha= sh *hash); +int modify_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *= hash, bool do_direct_lock); =20 void ftrace_stub_direct_tramp(void); =20 @@ -565,6 +566,11 @@ int unregister_ftrace_direct_hash(struct ftrace_ops *o= ps, struct ftrace_hash *ha return -ENODEV; } =20 +int modify_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *= hash, bool do_direct_lock) +{ + 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 d761237ec70f..755d5550ac44 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6440,6 +6440,64 @@ int unregister_ftrace_direct_hash(struct ftrace_ops = *ops, struct ftrace_hash *ha } EXPORT_SYMBOL_GPL(unregister_ftrace_direct_hash); =20 +int modify_ftrace_direct_hash(struct ftrace_ops *ops, struct ftrace_hash *= hash, bool do_direct_lock) +{ + struct ftrace_func_entry *entry, *tmp; + static struct ftrace_ops tmp_ops =3D { + .func =3D ftrace_stub, + .flags =3D FTRACE_OPS_FL_STUB, + }; + unsigned long size, i; + int err; + + 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 =3D=3D EMPTY_HASH) + return -EINVAL; + + if (do_direct_lock) + mutex_lock(&direct_mutex); + + /* Enable the tmp_ops to have the same functions as the direct ops */ + ftrace_ops_init(&tmp_ops); + tmp_ops.func_hash =3D ops->func_hash; + + err =3D register_ftrace_function_nolock(&tmp_ops); + if (err) + goto unlock; + + /* + * Now the ftrace_ops_list_func() is called to do the direct callers. + * We can safely change the direct functions attached to each entry. + */ + mutex_lock(&ftrace_lock); + + size =3D 1 << hash->size_bits; + for (i =3D 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + tmp =3D __ftrace_lookup_ip(direct_functions, entry->ip); + if (!tmp) + continue; + tmp->direct =3D entry->direct; + } + } + + mutex_unlock(&ftrace_lock); + + /* Removing the tmp_ops will add the updated direct callers to the functi= ons */ + unregister_ftrace_function(&tmp_ops); + +unlock: + if (do_direct_lock) + mutex_unlock(&direct_mutex); + return err; +} +EXPORT_SYMBOL_GPL(modify_ftrace_direct_hash); + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ =20 /** --=20 2.50.1