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 650AFC87FCE for ; Fri, 25 Jul 2025 16:56:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 095E56B008A; Fri, 25 Jul 2025 12:56:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 046D16B0096; Fri, 25 Jul 2025 12:56:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E77B66B0099; Fri, 25 Jul 2025 12:56:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id D681E6B008A for ; Fri, 25 Jul 2025 12:56:29 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 805201340AB for ; Fri, 25 Jul 2025 16:56:29 +0000 (UTC) X-FDA: 83703390498.12.770A7E0 Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) by imf24.hostedemail.com (Postfix) with ESMTP id 87675180004 for ; Fri, 25 Jul 2025 16:56:27 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=W0zRL7aU; spf=pass (imf24.hostedemail.com: domain of debug@rivosinc.com designates 209.85.210.181 as permitted sender) smtp.mailfrom=debug@rivosinc.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1753462587; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=WtgAXG2zxYUZH6Gw9dzWRKSuSkjlPnsCAnmjzmjgcv8=; b=dlDEW6hK6Ue/huekKp1Au+cl1eXJE3euD159fN7RlBBJJEJIt2UD62YW7U5tKvd1KMQADH JSrQevqySdT1st3L0eJ3gpGOwxKv4b5/nLXsq1l2P1JLQPeGr5R26roQjdw7mWZc/+XCFT 3S++IRvYBvWYH3f74Ach5FGjeBJxIhE= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1753462587; a=rsa-sha256; cv=none; b=6/MTMd5idWe9EjT9oLf5uJqAx09i8Rnh8uNvOxNh1ZzpMrdOQ5ZpNyXp06ncvXZgK00wxL tslB/trIpiDjgOQdFODmDbJB8ckWgYDI/KzHwB40Ui9Y4x+TPIFMgdlzbqm4yOqnJoZ9gd 9N8HfzD00JIroyaHXi1W5HvDNJaPgF0= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=W0zRL7aU; spf=pass (imf24.hostedemail.com: domain of debug@rivosinc.com designates 209.85.210.181 as permitted sender) smtp.mailfrom=debug@rivosinc.com; dmarc=none Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-748f5a4a423so1738322b3a.1 for ; Fri, 25 Jul 2025 09:56:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1753462586; x=1754067386; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=WtgAXG2zxYUZH6Gw9dzWRKSuSkjlPnsCAnmjzmjgcv8=; b=W0zRL7aUuIuAskE46pPtab9y7KoCp9AosDwsngRkYVLdkOPzkCWkzh3A6ibFXBUcQ7 Uab1d6M+uTbc77RBx0iGMCVdynXQcx2XTnAzIbHve9LIY3EXe5IZlnYg1VPns6Bejs0I G+ucmfV4PVM5GCAzoNAyv5rcTdIjOvIzyjCHNIw8f7tIk3yYdspWn3aLZynH3AEuGdvQ jzQHOF8JngVlsYvBB9/iF7cjQBxalFiEhjZeRocrPWb/Kgie47P1vajDRP4S7fbd0Fpm h2Uh0Lr+SgSPTdDeGhXKbEMF52+XG6MHDAo4/mJ2YrdyN3s/jgTYXXWCsQWSFHvYZVQC fPkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753462586; x=1754067386; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=WtgAXG2zxYUZH6Gw9dzWRKSuSkjlPnsCAnmjzmjgcv8=; b=tCmlw23sShsfiK+NQPHOjMmrsWc1bbUeoGk5w04TOZM92DeWR+m2jmlFdOP/z+euAu Vr366k17bh9LXVVyL2WtwNyDRLw7ARKhEJF9PVS8Js3rG8LGD3M1oHSxZS8Q0QHjZiOk 4hAe32pc0znC2AxfsnpIr8A2hbBiRkorbzoG8n5NoQwscaDjRAfAaVe1jyFzLF1SGxFC Cxqwf2DOfBme96MqhJyw1jHj/YEZ3OWCOU/qkA21ElY2yCnbu3UmKayRIxTl5ERkyhLG MR5Gjg1LDOyb0m+KKDB00Sb4sEDW3wUwAqRkA9iBKCDfYGl/J2/mD8pdmbJTeHETqpb6 0fIw== X-Forwarded-Encrypted: i=1; AJvYcCXg79DOdGF7U4Q7/wyyKac2tjov5OcWwfHoZbe9ztvPuNbbcvn9ihT9KTGbNOF6LQ7tJjIphfDO4w==@kvack.org X-Gm-Message-State: AOJu0Yy7Sta9ouwsnWqT1uv5bFGXbW/rYf8qeArbBjXsI2TkEzp59SWS hRVDOgv7k1ER/66vWDl3OGeCDChmyjMGwIn9TepTskuGi2JQdH8SPcf7Bz/ZXIr86v4= X-Gm-Gg: ASbGnct5pr7YeXS1L+EY+E9OZWrw6doqAa5cWLo4CMuUDcBSt0WMqAoP6AQZ5zP7CnR xqpRTz/DBQeLyQbkw7IXLWWpLzevLV/ae33VUinUezyTU5CTW9U2cbHRUwLG6RLGBtKaRbc3lYu XsgyUlqD08M54jwxxtAx2UumM0Gyet0AVYHoAPE7U0R44ApURdZMx0QzM+T4EqXp2NbyrVS+oZ9 SlhC/MbP7FmxjEC68Z571iZkpUXCByCCLxdKsPIAX5K0cFxk/3yWLUY7lBvxzcu/QcjIFes2FUS CXEbCe0c9N55pTV2SVwgNaijF2POZZbCynpGW7AQ7gbhYlMcv6x5hA9MarqpK+89EQy7dx63/ad KwZwazbWeJX2X4TvKUSzNjegiPq3jA6Mr19zUodZcykY= X-Google-Smtp-Source: AGHT+IETBPZe8HlkltWjZZmkG8X/wqZoM335inOFOubYlGpOP3IUTPKQOC96UsFlPqNZzJonrdrGDQ== X-Received: by 2002:a05:6a00:b50:b0:740:a023:5d60 with SMTP id d2e1a72fcca58-76335b7ef36mr4059760b3a.19.1753462586198; Fri, 25 Jul 2025 09:56:26 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-b3f7f6d6312sm231084a12.62.2025.07.25.09.56.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Jul 2025 09:56:25 -0700 (PDT) Date: Fri, 25 Jul 2025 09:56:22 -0700 From: Deepak Gupta To: Sami Tolvanen Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Nick Desaulniers , Bill Wendling , Monk Chiang , Kito Cheng , Justin Stitt , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, rick.p.edgecombe@intel.com, broonie@kernel.org, cleger@rivosinc.com, apatel@ventanamicro.com, ajones@ventanamicro.com, conor.dooley@microchip.com, charlie@rivosinc.com, samuel.holland@sifive.com, bjorn@rivosinc.com, fweimer@redhat.com, jeffreyalaw@gmail.com, heinrich.schuchardt@canonical.com, andrew@sifive.com, ved@rivosinc.com Subject: Re: [PATCH 02/11] riscv: update asm call site in `call_on_irq_stack` to setup correct label Message-ID: References: <20250724-riscv_kcfi-v1-0-04b8fa44c98c@rivosinc.com> <20250724-riscv_kcfi-v1-2-04b8fa44c98c@rivosinc.com> <20250725153351.GB1724026@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20250725153351.GB1724026@google.com> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 87675180004 X-Stat-Signature: ptwoq8bb1mo8wupfo91mfxtrf3n7yhsu X-Rspam-User: X-HE-Tag: 1753462587-229023 X-HE-Meta: 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 OOU8VYlm 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Fri, Jul 25, 2025 at 03:33:51PM +0000, Sami Tolvanen wrote: >On Thu, Jul 24, 2025 at 04:36:55PM -0700, Deepak Gupta wrote: >> Call sites written in asm performing indirect call, they need to setup >> label register (t2/x7) with correct label. >> >> Currently first kernel was compiled with `-save-temps` option and >> normalized function signature string is captured and then placed at the >> asm callsite. >> >> TODO: to write a macro wrapper with toolchain support. >> >> Signed-off-by: Deepak Gupta >> --- >> arch/riscv/kernel/entry.S | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S >> index 2660faf52232..598e17e800ae 100644 >> --- a/arch/riscv/kernel/entry.S >> +++ b/arch/riscv/kernel/entry.S >> @@ -389,6 +389,7 @@ SYM_FUNC_START(call_on_irq_stack) >> load_per_cpu t0, irq_stack_ptr, t1 >> li t1, IRQ_STACK_SIZE >> add sp, t0, t1 >> + lui t2, %lpad_hash("FvP7pt_regsE") > >Ah, I see. The plan is to hardcode the signatures in assembly code and >keep them manually in sync with C code. When we implemented KCFI, we >thought this would become extremely tedious to maintain after a while. This is extremely tedious and not maintainable and primary reason (among other secondary ones) to keep this patch series as RFC. >Do you have any plans to add KCFI-style __kcfi_typeid_ symbols >that would allow labels to be determined from C type signatures instead? Yes something on similar lines. I have asked toolchain folks (Monk and Kito) on how best to support this. > >Sami