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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F0431C71135 for ; Sun, 15 Jun 2025 03:21:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KmeIBIrovCZu0zm7zk1FJ57d7hjR3UrOOt26bU7uTfU=; b=Z57cAr1NGMvyfzadMxtdbQh7qX uKwD4bRtRMpkFLbN62sZ/Y2hZx/N9JcHo0IEsAusyLQs0ttNMas/uGqRfZ6HSwi+qXQ3Y+vP6Lijd VxYMJM+NTXWmzlpvplMjI4S7S1lLa4gCJGByVpDtcHF8LRr4F3EuhXJGpz3K8t7+mRS5phTIgJ6lX ZDmM6dmvW6jcuYLBpfmiZVehQL0F3ic+c6b40eP6LCbHjwaPPNgW5RjvHDqL3f9Z280W+Cwo6jd+f zVREwJeoTXbSkIpL/jeLlqdFBVkxmcdZ0FvfxLJj4JtMSxl5Nf9I0RmRTGLECwdEab6VvCIEnLPQw yT82wjfA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uQdvW-00000002AUh-0Sax; Sun, 15 Jun 2025 03:20:58 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uQdtE-00000002AMx-0Kjp; Sun, 15 Jun 2025 03:18:37 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id B6CD044A48; Sun, 15 Jun 2025 03:18:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34907C4CEED; Sun, 15 Jun 2025 03:18:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749957514; bh=QyNmeeqe/QCejIB1o+4hWQjoOtCd19AfCElA8Pxgmf4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MPYTBuCd7X45YU//pkrHZijODUDPe4eBXgOI24hNeaiz4dbjbb/3k5BQs1Xc6Fr2G 1SUuS34Vh6YlA3y4WIOmnc4WfVDp48/8YLKBe6aqQhXOnefPSHjIKv2Q/Z3IVnq3Hb /sbJrNGZlRTYza+Mt9gtQEwDcX0tW6FwYwQK3fWqyZEOw58reqeyiqce64xdk3csvB T1sYLtQc6KtNQoM975rjkVarhrrjsKE/VcsUDyELJ/EoeWCL4NAn8Q+rcrYDoz6k3b pZWCNS2I90e08jz9scf576cleOvu8Rx8hgtaV7hycc5/OzK21YtwWT4NF2/+EHEREh UnZExOsX46Q9A== Date: Sat, 14 Jun 2025 20:18:07 -0700 From: Eric Biggers To: Herbert Xu Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, ardb@kernel.org, Jason@zx2c4.com, torvalds@linux-foundation.org Subject: Re: [PATCH] crypto: ahash - Stop legacy tfms from using the set_virt fallback path Message-ID: <20250615031807.GA81869@sol> References: <20250611020923.1482701-8-ebiggers@kernel.org> <20250611033957.GA1484147@sol> <20250611035842.GB1484147@sol> <20250613053624.GA163131@sol> <20250613055439.GB163131@sol> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250614_201836_160613_C20075F9 X-CRM114-Status: GOOD ( 20.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jun 13, 2025 at 04:51:38PM +0800, Herbert Xu wrote: > On Thu, Jun 12, 2025 at 10:54:39PM -0700, Eric Biggers wrote: > > > > Actually, crypto_ahash::base::fb is initialized if CRYPTO_ALG_NEED_FALLBACK, > > which many of the drivers already set. Then crypto_ahash_update() calls > > ahash_do_req_chain() if the algorithm does *not* have > > CRYPTO_AHASH_ALG_BLOCK_ONLY set. Which then exports the driver's custom state > > and tries to import it into the fallback. > > > > As far as I can tell, it's just broken for most of the existing drivers. > > This fallback path is only meant to be used for drivers that have > been converted. But you're right there is a check missing in there. > > Thanks, > > ---8<--- > Ensure that drivers that have not been converted to the ahash API > do not use the ahash_request_set_virt fallback path as they cannot > use the software fallback. > > Reported-by: Eric Biggers > Fixes: 9d7a0ab1c753 ("crypto: ahash - Handle partial blocks in API") > Signed-off-by: Herbert Xu Okay. Out of curiosity I decided to actually test the Qualcomm Crypto Engine driver on a development board that has a Qualcomm SoC, using latest mainline. Even with your patch applied, it overflows the stack when running the crypto self-tests, apparently due to crypto/ahash.c calling into itself recursively: [ 9.230887] Insufficient stack space to handle exception! [ 9.230889] ESR: 0x0000000096000047 -- DABT (current EL) [ 9.230891] FAR: 0xffff800084927fe0 [ 9.230891] Task stack: [0xffff800084928000..0xffff80008492c000] [ 9.230893] IRQ stack: [0xffff800080030000..0xffff800080034000] [ 9.230894] Overflow stack: [0xffff000a72dd2100..0xffff000a72dd3100] [ 9.230896] CPU: 6 UID: 0 PID: 747 Comm: cryptomgr_test Tainted: G S 6.16.0-rc1-00237-g84ffcd88616f #7 PREEMPT [ 9.230900] Tainted: [S]=CPU_OUT_OF_SPEC [ 9.230901] Hardware name: Qualcomm Technologies, Inc. SM8650 HDK (DT) [ 9.230901] pstate: 01400005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 9.230903] pc : qce_ahash_update+0x4/0x1f4 [ 9.230910] lr : ahash_do_req_chain+0xb4/0x19c [ 9.230915] sp : ffff800084928030 [ 9.230915] x29: ffff8000849281a0 x28: 0000000000000003 x27: 0000000000000001 [ 9.230918] x26: ffff0008022d8060 x25: ffff000800a33500 x24: ffff80008492b8d8 [ 9.230920] x23: ffff80008492b918 x22: 0000000000000400 x21: ffff000800a33510 [ 9.230922] x20: ffff000800b62030 x19: ffff00080122d400 x18: 00000000ffffffff [ 9.230923] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 9.230925] x14: 0000000000000001 x13: 0000000000000000 x12: 0000000000000000 [ 9.230927] x11: eee1c132902c61e2 x10: 0000000000000063 x9 : 0000000000000000 [ 9.230928] x8 : 0000000000000062 x7 : a54ff53a3c6ef372 x6 : 0000000000000400 [ 9.230930] x5 : fefefefefefefefe x4 : ffff000800a33510 x3 : 0000000000000000 [ 9.230931] x2 : ffff000805d76900 x1 : ffffcea2349738cc x0 : ffff00080122d400 [ 9.230933] Kernel panic - not syncing: kernel stack overflow [ 9.230934] CPU: 6 UID: 0 PID: 747 Comm: cryptomgr_test Tainted: G S 6.16.0-rc1-00237-g84ffcd88616f #7 PREEMPT [ 9.230936] Tainted: [S]=CPU_OUT_OF_SPEC [ 9.230937] Hardware name: Qualcomm Technologies, Inc. SM8650 HDK (DT) [ 9.230938] Call trace: [ 9.230939] show_stack+0x18/0x24 (C) [ 9.230943] dump_stack_lvl+0x60/0x80 [ 9.230947] dump_stack+0x18/0x24 [ 9.230949] panic+0x168/0x360 [ 9.230952] add_taint+0x0/0xbc [ 9.230955] panic_bad_stack+0x108/0x120 [ 9.230958] handle_bad_stack+0x34/0x40 [ 9.230962] __bad_stack+0x80/0x84 [ 9.230963] qce_ahash_update+0x4/0x1f4 (P) [ 9.230965] crypto_ahash_update+0x17c/0x18c [ 9.230967] crypto_ahash_finup+0x184/0x1e4 [ 9.230969] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230970] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230972] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230973] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230974] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230976] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230977] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230979] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230980] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230981] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230983] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230984] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230986] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230988] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230989] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230991] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230993] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230995] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230996] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230998] crypto_ahash_finup+0x1ac/0x1e4 [ 9.230999] crypto_ahash_finup+0x1ac/0x1e4 [ 9.231001] crypto_ahash_finup+0x1ac/0x1e4 [ 9.231002] crypto_ahash_finup+0x1ac/0x1e4 [ 9.231004] crypto_ahash_finup+0x1ac/0x1e4 [ 9.231005] crypto_ahash_finup+0x1ac/0x1e4 [the above line repeated a few hundred times more...] [ 9.231571] test_ahash_vec_cfg+0x508/0x8f8 [ 9.231573] test_hash_vec+0xb8/0x21c [ 9.231575] __alg_test_hash+0x144/0x2e0 [ 9.231577] alg_test_hash+0xc0/0x178 [ 9.231578] alg_test+0x148/0x5ec [ 9.231579] cryptomgr_test+0x24/0x40 [ 9.231581] kthread+0x12c/0x204 [ 9.231583] ret_from_fork+0x10/0x20 [ 9.231587] SMP: stopping secondary CPUs [ 9.240072] Kernel Offset: 0x4ea1b2a80000 from 0xffff800080000000 [ 9.240073] PHYS_OFFSET: 0xfff1000080000000 [ 9.240074] CPU features: 0x6000,000001c0,62130cb1,357e7667 [ 9.240075] Memory Limit: none [ 11.373410] ---[ end Kernel panic - not syncing: kernel stack overflow ]--- After disabling the crypto self-tests, I was then able to run a benchmark of SHA-256 hashing 4096-byte messages, which fortunately didn't encounter the recursion bug. I got the following results: ARMv8 crypto extensions: 1864 MB/s Generic C code: 358 MB/s Qualcomm Crypto Engine: 55 MB/s So just to clarify, you believe that asynchronous hash drivers like the Qualcomm Crypto Engine one are useful, and the changes that you're requiring to the CPU-based code are to support these drivers? - Eric