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 54F06CE7A90 for ; Sat, 23 Sep 2023 16:28:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BC0546B027A; Sat, 23 Sep 2023 12:28:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B6FF16B027F; Sat, 23 Sep 2023 12:28:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A37D76B0281; Sat, 23 Sep 2023 12:28:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 95D016B027A for ; Sat, 23 Sep 2023 12:28:43 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 6BCF6140180 for ; Sat, 23 Sep 2023 16:28:43 +0000 (UTC) X-FDA: 81268395726.24.9B4C646 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf05.hostedemail.com (Postfix) with ESMTP id 8FE04100002 for ; Sat, 23 Sep 2023 16:28:41 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=kdX7uAUn; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf05.hostedemail.com: domain of rppt@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695486521; 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=LVhzKv59o4GVMxVkdtW171K/F7Liht7V34XZBgcW2M4=; b=X1o6icaqEDk3GlOn5P9/HEm4HZxx19AoOgIiKZuYIAgjeFOzTQKS3XAOtaOPOOm3t9b4Vc o9NzLRHV88PNh4+HigK2+261I2c1Lub72Qeiv5zLyCtgT60id2uDS5NPaDJPZBKdXV8j+A uOTrvT7QR+TXgBTzoGrUxDEjlPA64AA= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=kdX7uAUn; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf05.hostedemail.com: domain of rppt@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695486521; a=rsa-sha256; cv=none; b=VRPvwO4RKp1d4Q/Rm2R47B6czAsFA9aFFFyB4iTDF/xaL8kPxEZLQtVXCnhUyW+JkYFT/Q cf2LzvQAjPyd4mXizIZSbsz1m3cjqcTS0wUItmwq9LLW2hI/lEQ6ERRmNsJWGnjRooEeFT cg5TWicZqVwufMz5ouwZFT3KH35GNBg= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 99BF6B80092; Sat, 23 Sep 2023 16:28:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98403C433C7; Sat, 23 Sep 2023 16:28:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695486519; bh=RqAizeoAgpyrjTuWTc3EPt+00fz0GKOYt3wgiu3ilxI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kdX7uAUn5A/nOh6b98KyxWdk9fFgHiJgriB/fwuK77YQxwt85ckYKTY9t3fBf62wY OdfH5+weEeIpqZEmVKOTk/M6qPAq6DbFmu80HRazp/dQJOGu5Fdotg7Z2IUrfIcHFK CzwEzww+QWurkfb1eX0LPowGymg+QANEOY5nujQK9DRlmOgfq/CMbzYwknq+dY7tnp PeA7IOMb8Twk1q2cqZZhCdVsAByDQXH6HWv6/P0+r3F48yu28WNKT0AH75egCCxIj0 rSO4bYh3+oBADB8dkFnn9uQPpZxQXif883hCwsCk2af3dw5oO2O8+odTCE6fZmVuyX JCGFYC8Rtz+ZQ== Date: Sat, 23 Sep 2023 19:27:42 +0300 From: Mike Rapoport To: Christophe Leroy Cc: "linux-kernel@vger.kernel.org" , Andrew Morton , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Catalin Marinas , "David S. Miller" , Dinh Nguyen , Heiko Carstens , Helge Deller , Huacai Chen , Kent Overstreet , Luis Chamberlain , Mark Rutland , Michael Ellerman , Nadav Amit , "Naveen N. Rao" , Palmer Dabbelt , Puranjay Mohan , Rick Edgecombe , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , "bpf@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mips@vger.kernel.org" , "linux-mm@kvack.org" , "linux-modules@vger.kernel.org" , "linux-parisc@vger.kernel.org" , "linux-riscv@lists.infradead.org" , "linux-s390@vger.kernel.org" , "linux-trace-kernel@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "loongarch@lists.linux.dev" , "netdev@vger.kernel.org" , "sparclinux@vger.kernel.org" , "x86@kernel.org" Subject: Re: [PATCH v3 09/13] powerpc: extend execmem_params for kprobes allocations Message-ID: <20230923162742.GO3303@kernel.org> References: <20230918072955.2507221-1-rppt@kernel.org> <20230918072955.2507221-10-rppt@kernel.org> <1cb41761-29d0-5d33-b7c1-0ca3acaa810d@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1cb41761-29d0-5d33-b7c1-0ca3acaa810d@csgroup.eu> X-Rspam-User: X-Stat-Signature: 118ehaixb3qkcno9irgjmr6mpx7ckfrw X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 8FE04100002 X-HE-Tag: 1695486521-127407 X-HE-Meta: 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 aK5GQqYd QZpYSTrRsCEDQYEQqPzkJUnGngYMnTFeJeTohJj1kAV1jn5v/s62DVqsDcnTu6GUiRBKnWL0flxy+KTEmcS32Ttij3an51vfrweMQb2VXH0YXosPP1jDeOlqy7sxYLdBhi6xABws1qIc5ef5xX5QxFOp3mUOYmm7YKllYNl8EbvyLmGSnBgtlW4sr9+oDxjA41RMYcrUtqX9D9P/RnTpt6S8Aa3IWgTfzfOQsSyPpK6WiYf2EQOoMMiEhoSbKObUHJRTPepQ7aDVOOJpIUh1m/u7vjyaaGIxDOjJBogpu9dvaa55RkEPuonDplrmQVul2+RP4vYeVAoetPvEb+VHo7si3XiQEBKJIqhWAbbCt9yxC+6T8NyqjjoYPvoFiQwIF9aIkej1LRcoXUsP9HtFiCQNl/EV0pSB8GcAg 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: Hi Christophe, On Fri, Sep 22, 2023 at 10:32:46AM +0000, Christophe Leroy wrote: > Hi Mike, > > Le 18/09/2023 à 09:29, Mike Rapoport a écrit : > > From: "Mike Rapoport (IBM)" > > > > powerpc overrides kprobes::alloc_insn_page() to remove writable > > permissions when STRICT_MODULE_RWX is on. > > > > Add definition of EXECMEM_KRPOBES to execmem_params to allow using the > > generic kprobes::alloc_insn_page() with the desired permissions. > > > > As powerpc uses breakpoint instructions to inject kprobes, it does not > > need to constrain kprobe allocations to the modules area and can use the > > entire vmalloc address space. > > I don't understand what you mean here. Does it mean kprobe allocation > doesn't need to be executable ? I don't think so based on the pgprot you > set. > > On powerpc book3s/32, vmalloc space is not executable. Only modules > space is executable. X/NX cannot be set on a per page basis, it can only > be set on a 256 Mbytes segment basis. > > See commit c49643319715 ("powerpc/32s: Only leave NX unset on segments > used for modules") and 6ca055322da8 ("powerpc/32s: Use dedicated segment > for modules with STRICT_KERNEL_RWX") and 7bee31ad8e2f ("powerpc/32s: Fix > is_module_segment() when MODULES_VADDR is defined"). > > So if your intention is still to have an executable kprobes, then you > can't use vmalloc address space. Right, and I've fixed the KPROBES range to uses the same range as MODULES. The commit message is stale and I need to update it. > Christophe > > > > > Signed-off-by: Mike Rapoport (IBM) > > --- > > arch/powerpc/kernel/kprobes.c | 14 -------------- > > arch/powerpc/kernel/module.c | 11 +++++++++++ > > 2 files changed, 11 insertions(+), 14 deletions(-) > > > > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c > > index 62228c7072a2..14c5ddec3056 100644 > > --- a/arch/powerpc/kernel/kprobes.c > > +++ b/arch/powerpc/kernel/kprobes.c > > @@ -126,20 +126,6 @@ kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offse > > return (kprobe_opcode_t *)(addr + offset); > > } > > > > -void *alloc_insn_page(void) > > -{ > > - void *page; > > - > > - page = execmem_text_alloc(EXECMEM_KPROBES, PAGE_SIZE); > > - if (!page) > > - return NULL; > > - > > - if (strict_module_rwx_enabled()) > > - set_memory_rox((unsigned long)page, 1); > > - > > - return page; > > -} > > - > > int arch_prepare_kprobe(struct kprobe *p) > > { > > int ret = 0; > > diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c > > index 824d9541a310..bf2c62aef628 100644 > > --- a/arch/powerpc/kernel/module.c > > +++ b/arch/powerpc/kernel/module.c > > @@ -95,6 +95,9 @@ static struct execmem_params execmem_params __ro_after_init = { > > [EXECMEM_DEFAULT] = { > > .alignment = 1, > > }, > > + [EXECMEM_KPROBES] = { > > + .alignment = 1, > > + }, > > [EXECMEM_MODULE_DATA] = { > > .alignment = 1, > > }, > > @@ -135,5 +138,13 @@ struct execmem_params __init *execmem_arch_params(void) > > > > range->pgprot = prot; > > > > + execmem_params.ranges[EXECMEM_KPROBES].start = VMALLOC_START; > > + execmem_params.ranges[EXECMEM_KPROBES].start = VMALLOC_END; > > + > > + if (strict_module_rwx_enabled()) > > + execmem_params.ranges[EXECMEM_KPROBES].pgprot = PAGE_KERNEL_ROX; > > + else > > + execmem_params.ranges[EXECMEM_KPROBES].pgprot = PAGE_KERNEL_EXEC; > > + > > return &execmem_params; > > } -- Sincerely yours, Mike.