From patchwork Wed Mar 9 17:44:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12775383 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 624DAC433FE for ; Wed, 9 Mar 2022 17:45:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ECF718D0010; Wed, 9 Mar 2022 12:45:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E571A8D0001; Wed, 9 Mar 2022 12:45:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D1EB28D0010; Wed, 9 Mar 2022 12:45:47 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id C3F618D0001 for ; Wed, 9 Mar 2022 12:45:47 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 9B19C218AE for ; Wed, 9 Mar 2022 17:45:47 +0000 (UTC) X-FDA: 79225575534.10.66760AF Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by imf27.hostedemail.com (Postfix) with ESMTP id F2B084001A for ; Wed, 9 Mar 2022 17:45:46 +0000 (UTC) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4KDKNC0sf9z9sTQ; Wed, 9 Mar 2022 18:45:15 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RSGCSf_gVQVT; Wed, 9 Mar 2022 18:45:15 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4KDKN02jYkz9sTS; Wed, 9 Mar 2022 18:45:04 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 424F28B786; Wed, 9 Mar 2022 18:45:04 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id yTn6sHsrOdJ4; Wed, 9 Mar 2022 18:45:04 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.202.27]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 07D998B792; Wed, 9 Mar 2022 18:45:02 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 229Hj0Q53619072 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 9 Mar 2022 18:45:00 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 229Hj0Lt3619071; Wed, 9 Mar 2022 18:45:00 +0100 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , alex@ghiti.fr Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, akpm@linux-foundation.org, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v8 14/14] powerpc: Simplify and move arch_randomize_brk() Date: Wed, 9 Mar 2022 18:44:48 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1646847883; l=3535; s=20211009; h=from:subject:message-id; bh=m8/bRotc0cgZPMEveh9v8pqEIJxpWDsSnOKuKTObI2Q=; b=YGBpwgh4PoZQFhFaREAeLU/2Vhlwbby/NZsYDjaE6th2MphGJoPw0aF6+aAWNSYurzkF7QrtlNvS yasMMlnjD0sP+jG0tmQ40RaCpJeQW7cFN154xroL4Qr1GPCSR0Nx X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: 3siyxyd1z7xz4hoongnxfn4mhqhqnr4o Authentication-Results: imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of christophe.leroy@csgroup.eu designates 93.17.235.10 as permitted sender) smtp.mailfrom=christophe.leroy@csgroup.eu; dmarc=none X-Rspamd-Queue-Id: F2B084001A X-HE-Tag: 1646847946-785916 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: arch_randomize_brk() is only needed for hash on book3s/64, for other platforms the one provided by the default mmap layout is good enough. Move it to hash_utils.c and use randomize_page() like the generic one. And properly opt out the radix case instead of making an assumption on mmu_highuser_ssize. Also change to a 32M range like most other architectures instead of 8M. Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/process.c | 41 --------------------------- arch/powerpc/mm/book3s64/hash_utils.c | 19 +++++++++++++ 2 files changed, 19 insertions(+), 41 deletions(-) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 984813a4d5dc..e7f809bdd433 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -34,10 +34,8 @@ #include #include #include -#include #include #include -#include #include #include @@ -2313,42 +2311,3 @@ unsigned long arch_align_stack(unsigned long sp) sp -= get_random_int() & ~PAGE_MASK; return sp & ~0xf; } - -static inline unsigned long brk_rnd(void) -{ - unsigned long rnd = 0; - - /* 8MB for 32bit, 1GB for 64bit */ - if (is_32bit_task()) - rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT))); - else - rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT))); - - return rnd << PAGE_SHIFT; -} - -unsigned long arch_randomize_brk(struct mm_struct *mm) -{ - unsigned long base = mm->brk; - unsigned long ret; - -#ifdef CONFIG_PPC_BOOK3S_64 - /* - * If we are using 1TB segments and we are allowed to randomise - * the heap, we can put it above 1TB so it is backed by a 1TB - * segment. Otherwise the heap will be in the bottom 1TB - * which always uses 256MB segments and this may result in a - * performance penalty. - */ - if (!radix_enabled() && !is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T)) - base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T); -#endif - - ret = PAGE_ALIGN(base + brk_rnd()); - - if (ret < mm->brk) - return mm->brk; - - return ret; -} - diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 43ecad8f9564..72a3eca02449 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -37,6 +37,8 @@ #include #include #include +#include +#include #include #include @@ -2133,3 +2135,20 @@ void __init print_system_hash_info(void) if (htab_hash_mask) pr_info("htab_hash_mask = 0x%lx\n", htab_hash_mask); } + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + /* + * If we are using 1TB segments and we are allowed to randomise + * the heap, we can put it above 1TB so it is backed by a 1TB + * segment. Otherwise the heap will be in the bottom 1TB + * which always uses 256MB segments and this may result in a + * performance penalty. + */ + if (is_32bit_task()) + return randomize_page(mm->brk, SZ_32M); + else if (!radix_enabled() && mmu_highuser_ssize == MMU_SEGSIZE_1T) + return randomize_page(max_t(unsigned long, mm->brk, SZ_1T), SZ_1G); + else + return randomize_page(mm->brk, SZ_1G); +}