From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 303303F9270; Wed, 27 May 2026 11:41:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779882079; cv=none; b=XdH/3Zu571OM9WuLM37BPGvE1ARYW+kNCv5Dq4nkIaU03/0h/+I+SC1nIAEydwp2KAKVEqzo82N0FKm+L81v3vceveHFkkBXbG8hwXOabY2mJNTkbY/nlmj/2G8EvsWM3zPLokI4NpB3xxT3Htu2TdEQmA9Dc/s8YrRDuydv4Jg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779882079; c=relaxed/simple; bh=bTR4oxYA+F9NmTSwYOzfQoe0goAyxBrw88zAIRXeRTc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=b0lKQ3ofyxfNUtr9QIVt5k1pNobQ3OMLu3uuZxvRO6eVVW3WuecQKLJ1ETH6+sXNtIxAaxZuGrlPttvvn3tgPKG1zq/8kx9nMND86fuGZZvoSaKywDTQrmlRNFYkTPpCROT7Ql957mxNsDurbnADMWief8UJndqRPtB5RORLUU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Dh7B9dt1; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Dh7B9dt1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4BC91F000E9; Wed, 27 May 2026 11:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779882076; bh=DmygLWCAfWehd2T/8BJ9g5b5Ozq1qPHC3aZIFcJ8iKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Dh7B9dt1wujY2L+bMDWgPUiQNTTO/xLm57U82FLp3LDc8v0llCQ9y4uh8OlTrN26H FdZ55OAwZLd6RMe3sZeovGW5e+NFtXVwCDDEs2iW0UM7jfik/kTyQhroo9QSFbwJ8h /zLQELuuWS0QAqZOn+5oefAyKke8N/GMQ/wuXmtHER5blW97Il7caz1O6iOKeTTDHF RQyyZ3IBVF1s7P74Mo0VJoGdLrb6UlY5NeSv/rki/FL41lJyY7bv+lwDzHMTu1RU5r eCpW880U6p2B4ozMD1UwudLOHzRyZJ0hq7ETV4POPpnmNOTC/svSAtd9xkKQX7uMss Gazc8CUGBGMYw== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , Menglong Dong , Steven Rostedt Subject: [PATCHv6 bpf-next 07/29] bpf: Add bpf_trampoline_add/remove_prog functions Date: Wed, 27 May 2026 13:39:29 +0200 Message-ID: <20260527113951.46265-8-jolsa@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260527113951.46265-1-jolsa@kernel.org> References: <20260527113951.46265-1-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 Separate bpf_trampoline_add/remove_prog functions from __bpf_trampoline_link/unlink functions to be able to add/remove trampoline programs without the image being updated in following changes. No functional change is intended. Signed-off-by: Jiri Olsa --- kernel/bpf/trampoline.c | 108 +++++++++++++++++++++++----------------- 1 file changed, 61 insertions(+), 47 deletions(-) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 7661738c1bd0..70724b0d8fb8 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -820,41 +820,16 @@ static int bpf_freplace_check_tgt_prog(struct bpf_prog *tgt_prog) return 0; } -static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, - struct bpf_trampoline *tr, - struct bpf_prog *tgt_prog, - const struct bpf_trampoline_ops *ops, - void *data) +static int bpf_trampoline_add_prog(struct bpf_trampoline *tr, + struct bpf_tramp_link *link, + int cnt) { struct bpf_fsession_link *fslink = NULL; enum bpf_tramp_prog_type kind; struct bpf_tramp_link *link_exiting; struct hlist_head *prog_list; - int err = 0; - int cnt = 0, i; kind = bpf_attach_type_to_tramp(link->link.prog); - if (tr->extension_prog) - /* cannot attach fentry/fexit if extension prog is attached. - * cannot overwrite extension prog either. - */ - return -EBUSY; - - for (i = 0; i < BPF_TRAMP_MAX; i++) - cnt += tr->progs_cnt[i]; - - if (kind == BPF_TRAMP_REPLACE) { - /* Cannot attach extension if fentry/fexit are in use. */ - if (cnt) - return -EBUSY; - err = bpf_freplace_check_tgt_prog(tgt_prog); - if (err) - return err; - tr->extension_prog = link->link.prog; - return bpf_arch_text_poke(tr->func.addr, BPF_MOD_NOP, - BPF_MOD_JUMP, NULL, - link->link.prog->bpf_func); - } if (kind == BPF_TRAMP_FSESSION) { prog_list = &tr->progs_hlist[BPF_TRAMP_FENTRY]; cnt++; @@ -882,17 +857,64 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, } else { tr->progs_cnt[kind]++; } - err = bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data); - if (err) { - hlist_del_init(&link->tramp_hlist); - if (kind == BPF_TRAMP_FSESSION) { - tr->progs_cnt[BPF_TRAMP_FENTRY]--; - hlist_del_init(&fslink->fexit.tramp_hlist); - tr->progs_cnt[BPF_TRAMP_FEXIT]--; - } else { - tr->progs_cnt[kind]--; - } + return 0; +} + +static void bpf_trampoline_remove_prog(struct bpf_trampoline *tr, + struct bpf_tramp_link *link) +{ + struct bpf_fsession_link *fslink; + enum bpf_tramp_prog_type kind; + + kind = bpf_attach_type_to_tramp(link->link.prog); + if (kind == BPF_TRAMP_FSESSION) { + fslink = container_of(link, struct bpf_fsession_link, link.link); + hlist_del_init(&fslink->fexit.tramp_hlist); + tr->progs_cnt[BPF_TRAMP_FEXIT]--; + kind = BPF_TRAMP_FENTRY; + } + hlist_del_init(&link->tramp_hlist); + tr->progs_cnt[kind]--; +} + +static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog, + const struct bpf_trampoline_ops *ops, + void *data) +{ + enum bpf_tramp_prog_type kind; + int err = 0; + int cnt = 0, i; + + kind = bpf_attach_type_to_tramp(link->link.prog); + if (tr->extension_prog) + /* cannot attach fentry/fexit if extension prog is attached. + * cannot overwrite extension prog either. + */ + return -EBUSY; + + for (i = 0; i < BPF_TRAMP_MAX; i++) + cnt += tr->progs_cnt[i]; + + if (kind == BPF_TRAMP_REPLACE) { + /* Cannot attach extension if fentry/fexit are in use. */ + if (cnt) + return -EBUSY; + err = bpf_freplace_check_tgt_prog(tgt_prog); + if (err) + return err; + tr->extension_prog = link->link.prog; + return bpf_arch_text_poke(tr->func.addr, BPF_MOD_NOP, + BPF_MOD_JUMP, NULL, + link->link.prog->bpf_func); } + err = bpf_trampoline_add_prog(tr, link, cnt); + if (err) + return err; + err = bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data); + if (err) + bpf_trampoline_remove_prog(tr, link); return err; } @@ -927,16 +949,8 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, guard(mutex)(&tgt_prog->aux->ext_mutex); tgt_prog->aux->is_extended = false; return err; - } else if (kind == BPF_TRAMP_FSESSION) { - struct bpf_fsession_link *fslink = - container_of(link, struct bpf_fsession_link, link.link); - - hlist_del_init(&fslink->fexit.tramp_hlist); - tr->progs_cnt[BPF_TRAMP_FEXIT]--; - kind = BPF_TRAMP_FENTRY; } - hlist_del_init(&link->tramp_hlist); - tr->progs_cnt[kind]--; + bpf_trampoline_remove_prog(tr, link); return bpf_trampoline_update(tr, true /* lock_direct_mutex */, ops, data); } -- 2.54.0