From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) (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 C27AF1F9409; Fri, 11 Oct 2024 06:33:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728628437; cv=none; b=SNMHWTdPPFvhXNPia2uWymZulYkjvHkPzM87JxRYAAOHl8Fv6E4Qjyv/UQatVpGPXcZeKJWW+0UaIg9DIR9Ynj0FPGOvL3lAs8no16Yqocm7YgeiQbMQpy9pfbd1fFKIW4X+eVw5GmEa1am3zJlK9SrQSzDy5Y/tviLn3qM5LOw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728628437; c=relaxed/simple; bh=ArjalxxQ+s6rtUD5kzrvbWQPdJuCy05+qv3EO41cnzw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UUZmkUKQZC6B9ABULwTdu0XOz5tZ8UNUD9/MTpUJySDYkwNkafkon1MESkTMm1tM0IRAyDhyJoLFQwdzX/nNpYTtQLT3/q3sNNuHmvbvabzE4sreAgdxqVbJ8p+kfZr360HKTSsi+y7Nyq4gpXsFUhH+Mg+3JZ5qai9hYWA9ER4= 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=WhWZoY6f; arc=none smtp.client-ip=209.85.214.178 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="WhWZoY6f" Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-20c805a0753so14710185ad.0; Thu, 10 Oct 2024 23:33:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1728628435; x=1729233235; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=3WnRI6VJW3LMJo7XyXYei3wi8KKKDu4i1MPedhJrbTs=; b=WhWZoY6fKlkmkHhr+XdkKXaP67O6mRMqzorx0TjpL+peeBTK7hP1k4Tl5FGZ1Xqhz4 lwMJQY8L2xcg+3Y4PTveVs9Dbrxha22+ANB4iVxkC0O8NnoiDgQ5ypj1esF/rLUo4tmq fheVDQLz+tpt2vLUq9k5Fklv7DJnv/WKnA21qPFovAXj6DaXSzHwWAuEhmH4f02wxoiR ZfVHglnqzZv71wgFHWBvFIPdKboVxm/NmvSYQCbLhNCAt3yi60u3NYQgECoR6trCCCE7 0+28WQ2wU24fQkqLAxnwhM0quiQ1yjhhz/N/087LmYSG4NSqhHOURcXCSAxaMn8KTAP5 1P5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728628435; x=1729233235; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3WnRI6VJW3LMJo7XyXYei3wi8KKKDu4i1MPedhJrbTs=; b=vN32zBD+He80SeNGB1LuBk5Ol7/mL90eIUhdEkOeXNHoParYQSRvH11oPDGi5ZOA0c keigWg8wM2/fH9ECetGh0Wust0Jd8Vrivt2wJTwYnqGgmwwU0Je8fk84BbPaNbmyUFLk /B8+Wg6ykq5nrD4RQVzPqGg36Qp0ENoLMRIzCqhF0ig5erix0AttABQp0MUw5zffamdS PIPA7LYtOdBz4DcJ/pE/63vGuds/Fkp9kRM0/Vf0wMWjlW1UnwcudveVdeLGUKT25IUt Sxb5aZHi6MCpKZrn4vCjtNbxkj2/QNJJBF1gu9xN0zvce+Wkz2qhC+AkdjZ5WFcHMEj9 s5Hg== X-Forwarded-Encrypted: i=1; AJvYcCV6mwPNk/aeHObKoq6vRsGqlL3uIzYlakMS3w0809Emote5nBhcP9tnqj7MnJNxbZg+6VRQFIIrWfjGrTI=@vger.kernel.org, AJvYcCXicqqKOXnxziQYUzbv8SJZRhv4O2Sr4ptJhBG8oe4ErkbbzD3mrYWMDOUFn0qX2C90iF91AplYJOFkB4+KPa4ynT/6@vger.kernel.org X-Gm-Message-State: AOJu0YxobvbFt7vSVNG2UmvuVHtyRUKzP/zA0iGNb8VIVE3l5k34Yaxg cVwJSReLBMNPV/AfI1OXanF7kiUUgx6V7FWmuE+TWIb3hn1JLEdBlAOXqgOa X-Google-Smtp-Source: AGHT+IGuBokSOGFJjSMAWGi7G5B5xEW5Hzvq7E3ESeZXv9hQ8ngmO1CJIkB5s1U2pM5S8nH44z3Zag== X-Received: by 2002:a17:903:2b10:b0:20b:8bf5:cd72 with SMTP id d9443c01a7336-20ca16dd70dmr24748315ad.49.1728628434968; Thu, 10 Oct 2024 23:33:54 -0700 (PDT) Received: from ?IPV6:240d:1a:13a:f00:4b94:68e0:2d8b:3983? ([240d:1a:13a:f00:4b94:68e0:2d8b:3983]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-20c8c33ffe2sm18189905ad.270.2024.10.10.23.33.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Oct 2024 23:33:54 -0700 (PDT) Message-ID: Date: Fri, 11 Oct 2024 15:34:07 +0900 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ftrace: Fix function name for trampoline To: "Masami Hiramatsu (Google)" Cc: Steven Rostedt , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20241010130300.2083-1-tatsuya.s2862@gmail.com> <20241011000347.4b16dc96221873388475cb40@kernel.org> Content-Language: en-US From: Tatsuya S In-Reply-To: <20241011000347.4b16dc96221873388475cb40@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/11/24 12:03 AM, Masami Hiramatsu (Google) wrote: > On Thu, 10 Oct 2024 22:02:59 +0900 > Tatsuya S wrote: > >> The issue that unrelated function name is shown on stack trace like >> following even though it should be trampoline code address is caused by >> the creation of trampoline code in the area where .init.text section >> of module was freed after module is loaded. >> >> bash-1344 [002] ..... 43.644608: >> => (MODULE INIT FUNCTION) >> => vfs_write >> => ksys_write >> => do_syscall_64 >> => entry_SYSCALL_64_after_hwframe >> >> To resolve this, when function address of stack trace entry is in >> trampoline, output without looking up symbol name. >> >> Signed-off-by: Tatsuya S >> --- >> kernel/trace/trace_output.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c >> index 868f2f912f28..32a0858373e2 100644 >> --- a/kernel/trace/trace_output.c >> +++ b/kernel/trace/trace_output.c >> @@ -1246,6 +1246,11 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter, >> break; >> >> trace_seq_puts(s, " => "); >> + if (is_ftrace_trampoline((*p) + delta)) { >> + trace_seq_printf(s, "0x%08lx", (*p) + delta); > > If we know that address is the ftrace trampoline, we'd better show something > like "[FTRACE TRAMPOLINE]" > >> + trace_seq_putc(s, '\n'); > > And this is not needed. So for example, > > trace_seq_puts(s, "[FTRACE TRAMPOLINE]\n"); > > is enough. Thanks for review. OK. > >> + continue; >> + } >> seq_print_ip_sym(s, (*p) + delta, flags); >> trace_seq_putc(s, '\n'); >> } > > Thank you, > >> -- >> 2.46.2 >> > >