From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f67.google.com (mail-pj1-f67.google.com [209.85.216.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 169643164A0 for ; Mon, 17 Nov 2025 03:49:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.67 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763351389; cv=none; b=B4/ApxgcgirzDk1EXbNKGAQQG0rxSh1haGK383+hYC+SbqZbSwTAJijv6HiU89wjiHJH7pwdUpyPtaSWMQoNfBISfTsPlZic0O+CH1yp6b+XeCgETynRHwrUe1kJwp6Yk1+zVVzPszCUSH4Jg7Lfs6GAwj2wqZt27bQAXvStZMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763351389; c=relaxed/simple; bh=u5Rb2C9pYXvckE5T/TpOMjPCug8T6f4VewyBgd5lbhg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Cd7cwNaxv9rQQa96VovIBD74dZ1p+2sHiHEHKTRrCcJXo5HOxiyWT0K1sMD36OsSxrfIGFIvOgQQQtfgQVUGG8xRcSQrz1GBfCbyMJxHk7mA5xqgCye9p/DAen/dD/AxtVIOLlDVVcwgTZlmvDm67S2wShk2aAw90x/vTwc05v4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=W4AvlxL3; arc=none smtp.client-ip=209.85.216.67 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="W4AvlxL3" Received: by mail-pj1-f67.google.com with SMTP id 98e67ed59e1d1-34101107cc8so3433822a91.0 for ; Sun, 16 Nov 2025 19:49:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1763351387; x=1763956187; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=tgOfihzSf2PbQKCPVjj6xpRGhPLmu6v43Rdyu3AIJZY=; b=W4AvlxL3Btg4V4jXhlninNiMhlK51RpIz5bUKtSb5vaa+hIr+j5nU/rTf+H2bdHjJJ miSQrV9FqHwuT8Su7+RKefFQwnrh2RH4xxTQvDQgd+uWUBiMj/HdNqhk8AZv5BmUaAzw zGZ9JVp0HkPfJrEcfyXXW72H+3nwEq/XEwK/9Brg9ikmOMMTmgkxyJ2AMQguqR5mEi4d wCPLn/gEOp+7G0YKn0/esgUs/B6h+pkaPujsLmntNPDSvkgtVWHtAcOmNXQ+qO3S/Mf9 6MU0nXhmLgceOTcUckUsNLCIEk18QhTUGn57tKCilDPhI0j05DpEY58yJy8sIxi+0bpP 9wew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763351387; x=1763956187; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=tgOfihzSf2PbQKCPVjj6xpRGhPLmu6v43Rdyu3AIJZY=; b=G+0o/VbAbzoLD/dewz4ba0FwPyloE0/MrarBDvr8GxanIBtktVb7oQ33QfFg7xjsZk AS4UICHhkEK1FXPvy5hr31DnNV+ZKMURDruFkelA4HY64J+i7BTcDg3+zVXK+kA9LZft EcGTW7vvXElZKE+lrKgM79exYrTK4GMYCxoqvdKpo5CiAfoFzFpy0Ql1H58XWONpWzMg Gmz/6UlMccaYuT6Ai/JUJZt9hzpYS6IFL3qK/2AgygYOG7jUD9FlpDD7JKNFgwfP9WLu UDO/e8byt01eeBigbjuZfP/dRfTqnhAwGub8pYyIPmPcgnAlBE7uecsHIBkCePrh7aA4 UsSg== X-Forwarded-Encrypted: i=1; AJvYcCVdwbPyzpPQPN5JU1l87oCbU6onhHr9RyOKvkYCGoGs/5SYj2dQa8h3+AeRjSQr6/nLdYOKu8SGTxS2fHA=@vger.kernel.org X-Gm-Message-State: AOJu0YyYtUiwWLAw0X+TvdL+Mxp/2YEygPbb4au84A/HcxQoQWnRo75B rGuxxOHGJn7Rh59CYLRCQC/OoMA0y8KehpRqPKKxRnDn/txCHm5YFAFa X-Gm-Gg: ASbGncsevB+XcezVfKb9dOAb0gIY3pWv+eljJ5VXH+i6Ny/7tiJiF/fLFz25uBqmEfw LlJtUnQVrs5jrpKvJdqPkAFkMhVTMibRFjK3uvbr7BlxHhLY2HhbjuKm9T6CB9zVFG3XdKzuYAF WvcQrHRA8LmaSpFx2HxZ3oaJ4NAYWlG6OmVtga6kW/uPVYZpIF+a5RkEJNh6UnHwUNuvZKfCEBc h59dUDs8yalXhKw/xaAfUOuMrkr9q3im/UqrxVXZfg4nSxjsvekr/i49l7MIkVWQ83mhQNV30aa wRvyUKfOxWOuuH50mzq3IVKnk8SzBAZXvtE8Pwm7Kwg1eaqgAYD60Bm7yNyLWDdo5H+22dCOz5x M8NpWye1NqDATe2nopf+qxXzRwM5Qag5wIenj381WzowvWEzMmOSUKvGF9sJVw6BffPvAGSsog6 BC X-Google-Smtp-Source: AGHT+IHagUEA3uPZ5gtcQdccIe+pzAvPra/VZ3Ntx70iEi1QOdM9Ilv7D22FAgxKJInZwTAya3ne4A== X-Received: by 2002:a17:90b:2f83:b0:33f:eca0:47ae with SMTP id 98e67ed59e1d1-343fa7327fdmr11744548a91.28.1763351387393; Sun, 16 Nov 2025 19:49:47 -0800 (PST) Received: from 7950hx ([43.129.244.20]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-bc37703a0d9sm10348179a12.31.2025.11.16.19.49.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 16 Nov 2025 19:49:47 -0800 (PST) From: Menglong Dong X-Google-Original-From: Menglong Dong To: ast@kernel.org, rostedt@goodmis.org Cc: daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, mhiramat@kernel.org, mark.rutland@arm.com, mathieu.desnoyers@efficios.com, jiang.biao@linux.dev, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH bpf-next v2 6/6] bpf: implement "jmp" mode for trampoline Date: Mon, 17 Nov 2025 11:49:06 +0800 Message-ID: <20251117034906.32036-7-dongml2@chinatelecom.cn> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251117034906.32036-1-dongml2@chinatelecom.cn> References: <20251117034906.32036-1-dongml2@chinatelecom.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Implement the "jmp" mode for the bpf trampoline. For the ftrace_managed case, we need only to set the FTRACE_OPS_FL_JMP on the tr->fops if "jmp" is needed. For the bpf poke case, we will check the origin poke type with the "origin_flags", and current poke type with "tr->flags". The function bpf_trampoline_update_fentry() is introduced to do the job. The "jmp" mode will only be enabled with CONFIG_DYNAMIC_FTRACE_WITH_JMP enabled and BPF_TRAMP_F_SHARE_IPMODIFY is not set. With BPF_TRAMP_F_SHARE_IPMODIFY, we need to get the origin call ip from the stack, so we can't use the "jmp" mode. Signed-off-by: Menglong Dong --- v2: - rename bpf_text_poke to bpf_trampoline_update_fentry - remove the BPF_TRAMP_F_JMPED and check the current mode with the origin flags instead. --- kernel/bpf/trampoline.c | 68 ++++++++++++++++++++++++++++++----------- 1 file changed, 51 insertions(+), 17 deletions(-) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 2dcc999a411f..80ab435d6e00 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -175,24 +175,42 @@ static struct bpf_trampoline *bpf_trampoline_lookup(u64 key) return tr; } -static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr) +static int bpf_trampoline_update_fentry(struct bpf_trampoline *tr, u32 orig_flags, + void *old_addr, void *new_addr) { + enum bpf_text_poke_type new_t = BPF_MOD_CALL, old_t = BPF_MOD_CALL; void *ip = tr->func.addr; + + if (!new_addr) + new_t = BPF_MOD_NOP; + else if (bpf_trampoline_use_jmp(tr->flags)) + new_t = BPF_MOD_JUMP; + + if (!old_addr) + old_t = BPF_MOD_NOP; + else if (bpf_trampoline_use_jmp(orig_flags)) + old_t = BPF_MOD_JUMP; + + return bpf_arch_text_poke(ip, old_t, new_t, old_addr, new_addr); +} + +static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags, + void *old_addr) +{ int ret; if (tr->func.ftrace_managed) ret = unregister_ftrace_direct(tr->fops, (long)old_addr, false); else - ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, BPF_MOD_NOP, - old_addr, NULL); + ret = bpf_trampoline_update_fentry(tr, orig_flags, old_addr, NULL); return ret; } -static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr, +static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags, + void *old_addr, void *new_addr, bool lock_direct_mutex) { - void *ip = tr->func.addr; int ret; if (tr->func.ftrace_managed) { @@ -201,10 +219,8 @@ static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_ad else ret = modify_ftrace_direct_nolock(tr->fops, (long)new_addr); } else { - ret = bpf_arch_text_poke(ip, - old_addr ? BPF_MOD_CALL : BPF_MOD_NOP, - new_addr ? BPF_MOD_CALL : BPF_MOD_NOP, - old_addr, new_addr); + ret = bpf_trampoline_update_fentry(tr, orig_flags, old_addr, + new_addr); } return ret; } @@ -229,8 +245,7 @@ static int register_fentry(struct bpf_trampoline *tr, void *new_addr) return ret; ret = register_ftrace_direct(tr->fops, (long)new_addr); } else { - ret = bpf_arch_text_poke(ip, BPF_MOD_NOP, BPF_MOD_CALL, - NULL, new_addr); + ret = bpf_trampoline_update_fentry(tr, 0, NULL, new_addr); } return ret; @@ -416,7 +431,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut return PTR_ERR(tlinks); if (total == 0) { - err = unregister_fentry(tr, tr->cur_image->image); + err = unregister_fentry(tr, orig_flags, tr->cur_image->image); bpf_tramp_image_put(tr->cur_image); tr->cur_image = NULL; goto out; @@ -440,9 +455,17 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS again: - if ((tr->flags & BPF_TRAMP_F_SHARE_IPMODIFY) && - (tr->flags & BPF_TRAMP_F_CALL_ORIG)) - tr->flags |= BPF_TRAMP_F_ORIG_STACK; + if (tr->flags & BPF_TRAMP_F_CALL_ORIG) { + if (tr->flags & BPF_TRAMP_F_SHARE_IPMODIFY) { + tr->flags |= BPF_TRAMP_F_ORIG_STACK; + } else if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_JMP)) { + /* Use "jmp" instead of "call" for the trampoline + * in the origin call case, and we don't need to + * skip the frame. + */ + tr->flags &= ~BPF_TRAMP_F_SKIP_FRAME; + } + } #endif size = arch_bpf_trampoline_size(&tr->func.model, tr->flags, @@ -473,10 +496,16 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut if (err) goto out_free; + if (bpf_trampoline_use_jmp(tr->flags)) + tr->fops->flags |= FTRACE_OPS_FL_JMP; + else + tr->fops->flags &= ~FTRACE_OPS_FL_JMP; + WARN_ON(tr->cur_image && total == 0); if (tr->cur_image) /* progs already running at this address */ - err = modify_fentry(tr, tr->cur_image->image, im->image, lock_direct_mutex); + err = modify_fentry(tr, orig_flags, tr->cur_image->image, + im->image, lock_direct_mutex); else /* first time registering */ err = register_fentry(tr, im->image); @@ -499,8 +528,13 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut tr->cur_image = im; out: /* If any error happens, restore previous flags */ - if (err) + if (err) { tr->flags = orig_flags; + if (bpf_trampoline_use_jmp(tr->flags)) + tr->fops->flags |= FTRACE_OPS_FL_JMP; + else + tr->fops->flags &= ~FTRACE_OPS_FL_JMP; + } kfree(tlinks); return err; -- 2.51.2