From owner-freebsd-hackers@freebsd.org Wed Oct 24 17:26:36 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id EBF28FFE092 for ; Wed, 24 Oct 2018 17:26:35 +0000 (UTC) (envelope-from lev@FreeBSD.org) Received: from onlyone.not-for.work (onlyone.not-for.work [148.251.9.81]) by mx1.freebsd.org (Postfix) with ESMTP id 4865E6FE8C; Wed, 24 Oct 2018 17:26:35 +0000 (UTC) (envelope-from lev@FreeBSD.org) Received: from [192.168.23.186] (unknown [89.113.128.32]) (Authenticated sender: lev@serebryakov.spb.ru) by onlyone.not-for.work (Postfix) with ESMTPSA id E3748E35; Wed, 24 Oct 2018 20:26:33 +0300 (MSK) Reply-To: lev@FreeBSD.org Subject: Re: What is wrong with dtrace's stack()? To: Ryan Stone Cc: freebsd-hackers@freebsd.org, Conrad Meyer , Alan Somers References: <170994671.20181021201021@serebryakov.spb.ru> <475670271.20181022003734@serebryakov.spb.ru> <234d745d-37a9-9610-15b9-0f5cd5af21bf@FreeBSD.org> <168122586.20181024003412@serebryakov.spb.ru> From: Lev Serebryakov Openpgp: preference=signencrypt Autocrypt: addr=lev@FreeBSD.org; prefer-encrypt=mutual; keydata= xsFNBFKbGksBEADeguVs+XyJc3mL3iiOBqDd16wSk97YTJYOi4VsHsINzJr09oFvNDiaDBIi fLn2p8XcJvehcsF2GSgrfXfw+uK4O1jyNIKJmiYA0EtE+ZbRtvDrrE0w6Q8+SDeKA21SWh3Y vSQ0DJUontbgW55ER2CbEiIUTIn34uQ0kmESAaw/v5p/9ue8yPTmURvv130FqPFz8VPzltqL NxyGt54TxPfKAzAHEIwxlEZ63JOwzloKh1UDBExcsf9nJO08/TAVgR5UZ5njFBPzaaquhRoP qPJLEQQDqxPIlvMNtHKf7iIebE4BHeqgCdJA0BoiR6gpa0wlsZtdrTPK3n4wYSphLvGbhfOZ YW/hbcu7HYS/FImkVxB3iY17kcC1UTnx4ZaYeASPBGOOPbXky1lLfmDGWIFT//70yx+G17qD OZzF1SvJJhGvh6ilFYaWMX7T+nIp6Mcafc4D7AakXM+XdubNXOMlCJhzPcZ0skgAEnYV587w V7em5fDVwQccwvtfezzqKeJAU5TGiywBHSR5Svzk2FwRNf6M//hWkpq0SRR63iOhkHGOAEBi 69GfEIwH2/w24rLxP0E+Hqq8n+EWNkPatw1Mhcl5PKkdvGCjJUaGNMkpBffjyYo254JXRscR eEnwdIkJt4ErDvjb2/UrOFq31wWMOiLzJeVchAgvTHBMRfP9aQARAQABzShMZXYgU2VyZWJy eWFrb3YgPGxldkBzZXJlYnJ5YWtvdi5zcGIucnU+wsGCBBMBCAAsAhsDBwsJCAcDAgEGFQgC CQoLBBYCAwECHgECF4ACGQEFAlKbP8wFCQlmJwEACgkQ6rA8WL/cR4/6VBAAjRMyyX3PBFx/ HxyiIZ698EfwlWUua8Ft4crtrdK52m0qNkbBB9BH8xQgBHG32A1CwyzQnzxHgZuoOWMjh+Qq WJv7dmpM/q/c1GCJHhlPgewXrciTwpAamZILN071u+1GCPWwGRPzfQ/U+k63KJWx9ozf4doM WTTom6Cqcssi4J1u5kkt52a5ZRhsCK9pEVGilk36XTP9BakGrnMSIxF/NK4xeZVX2q+Nuqvf RchyofKXVgLEDLwb1cd/baLtBpDzy0PTN2Zl2lX4kOA6jwTKsqRya9A1Vui1KXwPh2XViTQ1 7Y3l5qg/M+sR73DohezP6bO6huOnLhty17jAqHPNlD6RonDo+j8uIlEg4iMSTN3MhzkBAu0Q pe3ucQ0o1767JiXN3fsNvRzSFhLVNDqPLce4uKlMogsbreXWvdgHGTN1ybOHGbybZnP77yHz uNBacbmG3vL/OLXMqwLdL2JXoiec4DmXjjCdhTBl5xLV9Hz/6VWKqElteg8QFVvHB3tHWzJ4 /rpiVEixytCIII6DS33BXZ0h2EOkK/6AYA2SJxy1vgOH4SZBtDBHoezmHV2nFnq5O0c7AuAB 7WPWgQG0sEwHQPZmg/baRGitRJnaxf/Gvf1DeD1x1VrcoVke2vwBcgDM3kugP8L9hsqic2D3 dI+gP76haeuvNNZr3y9L9zvOwU0EUpsaSwEQALRr3B+OjY/cnJPstz5CVsVWyEZtJtrNviZr tBgbkhlkPm98sEWR4+gbpyeufdYJengDjeGzMDKcLB7h5fICS/j6A8XdlJ40TlbPfNgb6OHa ebaIYKTJpXKR9sD7ZyGivYMofm0em40wGUX7BIkdkomaWj+wUiS0CdXU0FWDj9wv73+Eim+X zZyXeFgIPv97v+pET7DfwKkADOfrkW9s4OfvGVjd+wm35wc8EngQEz0qdPBxx74X7vZFAxlA SXu8gDBJGYt2Bkc3QwULnfeXrZJWgqNPR5o44gGu96yaiOFaN/C6CJtev5ZEX+0ZxbvsHHB7 Z5AtsRURKpZ4w5HFHGhzHtDtoAKgeZ/gbhTVXPHvNQR818eN+Nl5BV8BRF/8yhR6VlJb8GYw h8oKDeVGVYC34+raHZQAM9WoBnN7jlt4T9zzPwtmw5mIahGFgvw1KDr7OItN2ZgtZ20UYC5m Go602nmHq0aPbU6SwGi1xohrliNsKaaciYiMaVIGRQq8iGr9Fe2HlvaA3BpB275i/gCVlUdG y5XLAv+yQMUvn5Z7XVsMroxDk/O+ae1ElyBvKiKyfWGJXTg5XUukkkyQmfWPxWUGoNA1P/P4 GMHSu7/Rqe/7m4uPu/RyTTqsSjjKJdP9kBwEzvqPtXsVoZuShtrptRQJDYflhgE4qmKSMKen ABEBAAHCwWUEGAECAA8FAlKbGksCGwwFCRLMAwAACgkQ6rA8WL/cR48RkA//SNzeW3CI8KHx rA0aeHW6Nb5ieoqVRBGLyjBM06RX6vHB9v4dJL6Z+yV2jGN2s+XZX2HILbuTOwcTxGkI3xTT e0cDXVaF5K8R/liigUjtwuC2v/sWgoWyUmK1Cy9CPYdcXmFq6nESfkUe8DYiGOUULdHq5w63 F53yOZ72iXRBQBZgkhPtRFu4lPYIzOsMag9DIJ9CthR1r0ziqU/keb94Qt3l+aXK7CwGdY7X T4zUIMHNYsuAuyX+NJIXfsN68TT6m7QmlUwxPs13nxmoVQzm4ruV+hlQKh1MtbsjWRkNgPxF IPiqoAEhy8QoddlSvRTwL5Z7zFQiwMdiXU7toL8pfzj/zJR1jELXKMipijrt5MLrV8XX3OPN yZZvh95VIl8mv+iAqwSZUufd2EJnvj5TObB0eH+a+34NWf/XqA3fPjE6KHzmdnw9PZjPEjlx JCPECSs+6gse1+GaEfKYuXzB/ENe2ctlcfx5iQJXFc+/+zG/uU/JX/pXJHA12CUfB5g7lH6X BZIHvRo3VTCDjXgbF5xxDAe5V4exf8d4oSNjQIFLYxxN7zkvH89EN6RPfRgsWN7bYArCwfS9 MOgs9pFeCOewR6qieK150aoqNENGfKFXJup+5VVl6I0mU+j0rgVDZDht2/QgP/Tb4lGBe+ai pOGaK/GYNR+Ad6bUmokKsx4= Organization: FreeBSD Message-ID: Date: Wed, 24 Oct 2018 20:26:21 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="7BrRdxDYahHwCnPlh3S6ZYNNhCexDf7a6" X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Oct 2018 17:26:36 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --7BrRdxDYahHwCnPlh3S6ZYNNhCexDf7a6 Content-Type: multipart/mixed; boundary="U3JEUfUuyBAemrdoU3tZDIQLpBBTsohOn"; protected-headers="v1" From: Lev Serebryakov Reply-To: lev@FreeBSD.org To: Ryan Stone Cc: freebsd-hackers@freebsd.org, Conrad Meyer , Alan Somers Message-ID: Subject: Re: What is wrong with dtrace's stack()? References: <170994671.20181021201021@serebryakov.spb.ru> <475670271.20181022003734@serebryakov.spb.ru> <234d745d-37a9-9610-15b9-0f5cd5af21bf@FreeBSD.org> <168122586.20181024003412@serebryakov.spb.ru> In-Reply-To: --U3JEUfUuyBAemrdoU3tZDIQLpBBTsohOn Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 24.10.2018 20:14, Ryan Stone wrote: > ia32_pause() is an inline function. How does dtrace map instruction > pointers to symbol names? Is it getting that mapping from some CTF > data, and is that CTF data aware of inline functions? It looks like plausable explanation, but why sometimes it pick-up "middle layer" like this: kernel`ia32_pause+0x6 kernel`tcp_usr_send+0x131 kernel`sosend_generic+0xf61 And sometimes doesn't: kernel`ia32_pause+0x7 kernel`sosend_generic+0xf61 As I said, these stacks are equivalent, I've proved it (ok, it is not mathematical proof, of course) with custom SDT probes around this "`tcp_usr_send+0x131" place. --=20 // Lev Serebryakov --U3JEUfUuyBAemrdoU3tZDIQLpBBTsohOn-- --7BrRdxDYahHwCnPlh3S6ZYNNhCexDf7a6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE+W0coLX0MYtnSzMK6rA8WL/cR48FAlvQqz1fFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEY5 NkQxQ0EwQjVGNDMxOEI2NzRCMzMwQUVBQjAzQzU4QkZEQzQ3OEYACgkQ6rA8WL/c R4+sbBAAoNs2RjYO8mnrJbqfH18OsvJ7U/dwnxnlaC/gYWZ6BAdfvQV0P0mDFNxS 2lD4K8k7SWQTJIesaVwqk13kTg1ICvBs/WxUlSSEZTeFUwnBxkQRYlqPT6hnvaeX olXt/S0PPrpTY0vMywP7OnkAbWziYq0r3d3lnKkj15kgcMkAPNubK2JdlF4/J1Fg Sz8kwJ5BjMbemiDGL5PpX7bYfthsFpFkjvlrius6hhEiSvdvQ1l6TED5gGqP6660 qZ8DG0/NUeX42WIlMhgYVRBEkNooALlUqdq+LVdT/tM/x2VI3pfICgWt6iy/sYgl 5dG55w8DW4kTfzU9yXpcGshM3sSKToykzKbbF6yoQgoBz+J9i/Z4N+mOfb0Brfr7 bs3QKs34oZs0hv76VbIzujClnlQScW18sWvAudfFwV1dUPMa1GZkzEqZt4CYO4OQ 0Vpz/BbhrZpdrz7qp1WMaau+5UJ6bo8wFxJSgzZJoXzSMZ8PFmntP8zMVKsnQVLg HylYELI3iD3nCSWba4nFE18735J2lLe9f0qCxTqIkHCZqdTQKvzY0gXoZ3v/UKmp Nwnx5d4w2U66mXER8cTfeX8gp5k4IJernXbTae6A2Nhgj94oKfEs2D/vg+l0lK1+ Ekd8X1ICe/lrfE9niBFxDXwHIfq4SeePZB/ktnxg0LUjaGGw1kE= =kTcY -----END PGP SIGNATURE----- --7BrRdxDYahHwCnPlh3S6ZYNNhCexDf7a6--