From mboxrd@z Thu Jan 1 00:00:00 1970 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 89CE31CDFD5; Wed, 8 Jan 2025 20:14:53 +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=1736367293; cv=none; b=QNNVt7gAx0nnXJ3WLbjpiw1d+Km2zZz1I6DpZfvjzV7ABKBJyaD0Fz/nq96tGWKglnqJDAz44+cEBnTu9NLVrnXn1ksg1cYSIbImmzViraHZtjpbQZizYuuwKWIHcMsL5ArDMO/nSXQ64PtxDH0Q49AJ6m1FtVgseVGgYBL/gN0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736367293; c=relaxed/simple; bh=+k8VSgg2WNZLayqdbQDDh8INehLekajaO7o4aXfvkpA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LWImct6xtt/W4KrfVX8mGvdYlQNphEolVqh6zOa9YEg+HtKoogq9GXrw4XdmJ5Q32o6Erfbf+zmYMDYi2IwRBkBSaIn8yogxnqaQu/rak/YB09NnJMwz6FP6HVz0DF65UOHYT6GVD9LJjnVTH+VvIGSzwGlil8GAnx53LYW+MJc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=el/bqvOE; 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="el/bqvOE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAEA1C4CED3; Wed, 8 Jan 2025 20:14:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736367293; bh=+k8VSgg2WNZLayqdbQDDh8INehLekajaO7o4aXfvkpA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=el/bqvOEmDTzHp5fiNlPZyX8I/jbI79LrxZhOyFlRE2mlN2YQJPBX8XoFMH8+/zhz QOxms9We+e8b6bF0okRur4OeFWM60a1IZraBU5+v6Hrdt/fnSSPnWLucPXLeE///HU wH3zvmmHhIeMSXlTIEjLz4r5AWMFKS1You4/PdNpxnBpf946W3JUIp19drATxrpyiP 2SSGRy32UJYi4zcfGz6QrGh54TsXYIknlpZYooz7Sk9GWn9Y2SnavOKuSpusWVphuE 28/1a+ITi0dKmQmKW9fuCRnGnJ56k1jjGEdgF8AQmHWooUdrah2a1XzlAiL7Eh6STU zNseIIk+8fhvw== Date: Wed, 8 Jan 2025 17:14:50 -0300 From: Arnaldo Carvalho de Melo To: Christophe Leroy Cc: Peter Zijlstra , Ingo Molnar , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Song Liu , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH] perf machine: Don't ignore _etext when not a text symbol Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jan 08, 2025 at 10:15:24AM +0100, Christophe Leroy wrote: > Depending on how vmlinux.lds is written, _etext might be the very > first data symbol instead of the very last text symbol. > > Don't require it to be a text symbol, accept any symbol type. I'm adding a Link: Link: https://lore.kernel.org/all/752a31b0-4370-4f52-b7cc-45f0078c1d6c@csgroup.eu To give more context as where this has been observed, and also add a snippet of your explanation there, this: ---- # grep -e _stext -e _etext -e _edata /proc/kallsyms c0000000 T _stext c08b8000 D _etext So there is no _edata and _etext is not text $ ppc-linux-objdump -x vmlinux | grep -e _stext -e _etext -e _edata c0000000 g .head.text 00000000 _stext c08b8000 g .rodata 00000000 _etext c1378000 g .sbss 00000000 _edata ---- Thanks, - Arnaldo > Fixes: ed9adb2035b5 ("perf machine: Read also the end of the kernel") > Signed-off-by: Christophe Leroy > --- > tools/perf/util/machine.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 27d5345d2b30..9be2f4479f52 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -1003,7 +1003,7 @@ static int machine__get_running_kernel_start(struct machine *machine, > > err = kallsyms__get_symbol_start(filename, "_edata", &addr); > if (err) > - err = kallsyms__get_function_start(filename, "_etext", &addr); > + err = kallsyms__get_symbol_start(filename, "_etext", &addr); > if (!err) > *end = addr; > > -- > 2.47.0