From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EAEFC48297 for ; Sat, 10 Feb 2024 01:15:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CD2D76B0074; Fri, 9 Feb 2024 20:15:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C826D6B0075; Fri, 9 Feb 2024 20:15:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B71336B0078; Fri, 9 Feb 2024 20:15:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id A67B06B0074 for ; Fri, 9 Feb 2024 20:15:39 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 780AE801DC for ; Sat, 10 Feb 2024 01:15:39 +0000 (UTC) X-FDA: 81774126798.19.4A96596 Received: from mail-ej1-f50.google.com (mail-ej1-f50.google.com [209.85.218.50]) by imf25.hostedemail.com (Postfix) with ESMTP id 852F3A0008 for ; Sat, 10 Feb 2024 01:15:37 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=i20Bm5jf; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf25.hostedemail.com: domain of eddyz87@gmail.com designates 209.85.218.50 as permitted sender) smtp.mailfrom=eddyz87@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1707527737; a=rsa-sha256; cv=none; b=An8ZPx9OnlKcIEkwETDtodvCR4nqkmXrX1uGpTUnOn0bHntv+/9c8OkI6uFVm+ePPT5S03 1OAY2qYYX7bLCndW9L37Z69qDCEcNEhT5NFWjiotiJaQ+FvLfzEanmPv0c9yaebicrogGi 2/Dk9vAARHokw3awCOqlFtzqrUog7IQ= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=i20Bm5jf; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf25.hostedemail.com: domain of eddyz87@gmail.com designates 209.85.218.50 as permitted sender) smtp.mailfrom=eddyz87@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1707527737; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gFZnYmzeHMAt6iMfxJAYwJ9Dx55YZqUDFu5cZtAPcOk=; b=DIO+J9bS0pRS0uiW06SRI+4Ov4mCBgCkHTWc2JoCzceEi5x5bGnVV9TPEOEa+tN32k8KQ5 4uw0QedYgc1Hc5y0kVIQhcvDovTCAmx99VmUI/k/50dD9q0BX00cr43fj9aPIAQN8rz1/T kWt/EatUugWcMk5uXPhnMpwi1eMdNZ0= Received: by mail-ej1-f50.google.com with SMTP id a640c23a62f3a-a3122b70439so183020666b.3 for ; Fri, 09 Feb 2024 17:15:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1707527736; x=1708132536; darn=kvack.org; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id:from:to :cc:subject:date:message-id:reply-to; bh=gFZnYmzeHMAt6iMfxJAYwJ9Dx55YZqUDFu5cZtAPcOk=; b=i20Bm5jfdj9nFc270XDGa/tLgL5klAAW3t9TdK02OROkzzXD9NRIGWbtiJ4baREU/P yy9JT8QniKZkbcfqFjeg1VORZ5ApuTsPIreweCa7SK3jd8iUiyZ/hln9tk1p6qPpCjnu 0TDkzFyUJ8tsZrE3rezu+Lzoihuxsvb8nNBoZMEz/aefLYC7qvNNsmND0ZFjx/LqQZSW B9tYlXiYKNO9pYIxs1JDQJtNp5jybRgE2W+r9W7LE2kMmNCgOdCQliwmpYEW1zoTnicn tFciNz6qza9iTW+bsVAUWD6zjp7usysBsiHHbXcBANmfwPZfbZkZF7lKuTGNXmieNpA0 BHUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707527736; x=1708132536; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=gFZnYmzeHMAt6iMfxJAYwJ9Dx55YZqUDFu5cZtAPcOk=; b=ixG5b2E1eaUNYDY+E/xgkHR6bfzUtfx6GJSSP8xXD9tY6tnHEDjuBu3mLRvOGpGdtk jamN2cEKofLz3OGgz8XCCqe6Jd5w/G7sEZcVrULFW0GSikkSb1Lsb8HC1MWsX+HqomzS t2ebiqNt+i1GWCM89LIAMC+1kG/X2oTthYEYN1dF4j4huejFGvyAwMNTWxaGsD9+zBXC GdZBd/871s76TCIBJTt+EmUa4jtL0wb2gqP+O0SBftO2D2gMoQ40Erkvj75XdyolTdPJ pIZAfsMcoffVKEIUHewEICyETZfeIB5QveUFMPWtMQMKIZi9emvEaTgQk51C3niHTcIZ 2Jdw== X-Gm-Message-State: AOJu0Yy0dpAgB3cdfxcYAtMYe45h5tTpeaM+VeG7j8vFDMWxrRtFzksH o2hptSJSPbS6r6o7+jCUjw2dPc5WxV5T7PCQIM2v4xdLXhPcWZOf X-Google-Smtp-Source: AGHT+IEMnuyEIt3pscQg52niFTAKyozNBJ3/4waNRyaCnq3XJR0JUqsqyp9kTYL0LcghUUabZXWwPQ== X-Received: by 2002:a17:906:c7c3:b0:a37:78f1:12f6 with SMTP id dc3-20020a170906c7c300b00a3778f112f6mr416787ejb.67.1707527735986; Fri, 09 Feb 2024 17:15:35 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCVFlkoL3XEVAOUHqOOoFLFNx1RLHdAsi8W/8wN4cpjKHyfvlM8WECNdMndRzswx5/RO+iTmNQ7sIEFo+z3I60vw7g9A2bugRoK+da/BZrhTj7TMBkTigMLNzHMLzvybs9/DX4sTaslM3kWStOV92HWZ/OkafXgEkE2f187PFUHOZEsT8kyiyI1KcemtAF97oF0ddUHlRKX2E8C8ab05qDq14UZfDDsa0F1/qzgo5EqSoXfWZShDDW9RiDmJ5JnmDbC59PyXtqCUIBXSsJ1yQUizg+3kTAGF3/U0C6aMfoGe1NT28T0WDBXO7L4/1+yydfxfJnwGEsqX3a9BjKb+H5Edtv8wd96eNe5mJP/QoqItE3oLsq3+Vvr2 Received: from [192.168.1.94] (host-176-36-0-241.b024.la.net.ua. [176.36.0.241]) by smtp.gmail.com with ESMTPSA id h12-20020a170906718c00b00a3890e2389bsm1284802ejk.51.2024.02.09.17.15.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Feb 2024 17:15:35 -0800 (PST) Message-ID: <25ae80439abad5722719dba1f9951e69e8d01375.camel@gmail.com> Subject: Re: [PATCH v2 bpf-next 08/20] bpf: Add x86-64 JIT support for bpf_cast_user instruction. From: Eduard Zingerman To: Alexei Starovoitov , bpf@vger.kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, memxor@gmail.com, tj@kernel.org, brho@google.com, hannes@cmpxchg.org, lstoakes@gmail.com, akpm@linux-foundation.org, urezki@gmail.com, hch@infradead.org, linux-mm@kvack.org, kernel-team@fb.com Date: Sat, 10 Feb 2024 03:15:34 +0200 In-Reply-To: <20240209040608.98927-9-alexei.starovoitov@gmail.com> References: <20240209040608.98927-1-alexei.starovoitov@gmail.com> <20240209040608.98927-9-alexei.starovoitov@gmail.com> Autocrypt: addr=eddyz87@gmail.com; prefer-encrypt=mutual; keydata=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 A+T7mluw nYzhLWGcczc6J71q1Dje0l5vIPaSFOgwmWD4DA+WvuxM/shH4rtWeodbv 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 IYKvsh7s t1iq+gsfnXbPz5AnS598ScZI1oP7OrPSFJkt/z4acEbOQDQs8aUqrd46PV jsdqGvKnXZxzylux29UTNby4jTlz9pNJM+wPrDRmGfchLDUmf6CffaUYCbu4FiId+9+dcTCDvxbABRy1C3OJ8QY7cxfJ+pEZW18fRJ0XCl/fiV/ecAOfB3HsqgTzAn555h0rkFgay0hAvMU/mAW/CFNSIxV397zm749ZNLA0L2dMy1AKuOqH+/B+/ImBfJMDjmdyJQ8WU/OFRuGLdqOd2oZrA1iuPIa+yUYyZkaZfz/emQwpIL1+Q4p1R/OplA4yc301AqruXXUcVDbEB+joHW3hy5FwK5t5OwTKatrSJBkydSF9zdXy98fYzGniRyRA65P0Ix/8J3BYB4edY2/w0Ip/mdYsYQljBY0A== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.3 MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 852F3A0008 X-Stat-Signature: 96xo4ij57jte5o8dnewx5iyse3cmxqkg X-HE-Tag: 1707527737-873545 X-HE-Meta: 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 8TdCQ3YB 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 2024-02-08 at 20:05 -0800, Alexei Starovoitov wrote: > From: Alexei Starovoitov >=20 > LLVM generates bpf_cast_kern and bpf_cast_user instructions while transla= ting > pointers with __attribute__((address_space(1))). >=20 > rX =3D cast_kern(rY) is processed by the verifier and converted to > normal 32-bit move: wX =3D wY >=20 > bpf_cast_user has to be converted by JIT. >=20 > rX =3D cast_user(rY) is >=20 > aux_reg =3D upper_32_bits of arena->user_vm_start > aux_reg <<=3D 32 > wX =3D wY // clear upper 32 bits of dst register > if (wX) // if not zero add upper bits of user_vm_start > wX |=3D aux_reg >=20 > JIT can do it more efficiently: >=20 > mov dst_reg32, src_reg32 // 32-bit move > shl dst_reg, 32 > or dst_reg, user_vm_start > rol dst_reg, 32 > xor r11, r11 > test dst_reg32, dst_reg32 // check if lower 32-bit are zero > cmove r11, dst_reg // if so, set dst_reg to zero > // Intel swapped src/dst register encoding in CMOVcc >=20 > Signed-off-by: Alexei Starovoitov Checked generated x86 code for all reg combinations, works as expected. Acked-by: Eduard Zingerman