From patchwork Mon Aug 26 12:04:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: yukaixiong X-Patchwork-Id: 13777691 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9149171E76; Mon, 26 Aug 2024 12:05:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724673940; cv=none; b=R53BL8moHkqVGXC5YGfjE+QzZQvaP4dWp9uQMYdSupliyCxOmNiQMS/Yyfw9AiIycgABnGKCSAxGhaKVabH/dTqU9uf6y9RBwKunnUz1ONUuJ9z53EWMeZ8O86NO1yPbTx0F4Pljci8+DVO4Wt+eg/AYQclr5mYcSZYDN/+hE5Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724673940; c=relaxed/simple; bh=iC+NEcThU7d/U6VYyZvq1sKDNfpWMYDZgg/hLa8DA+U=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tFcHIkfpON3VQPpi4niyRcvntK/vhmq5T1OezNaTMnHszb1J/2wn3aS8ydi9Td5KHaXTYcKxAnZHjzfCMcxRsx+4f8BMpwxZs3OAcMXXvcHFTL4cEfn8IogDpaEe8yKqh4nOL2iOIzi870iktj2Q/EzfiEp7TLY2z765p9ExlpQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Wsq4v1T1SzQqgW; Mon, 26 Aug 2024 20:00:47 +0800 (CST) Received: from kwepemh100016.china.huawei.com (unknown [7.202.181.102]) by mail.maildlp.com (Postfix) with ESMTPS id C95D01800A5; Mon, 26 Aug 2024 20:05:34 +0800 (CST) Received: from huawei.com (10.175.113.32) by kwepemh100016.china.huawei.com (7.202.181.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 26 Aug 2024 20:05:32 +0800 From: Kaixiong Yu To: , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH -next 06/15] mm: mmap: move sysctl into its own file Date: Mon, 26 Aug 2024 20:04:40 +0800 Message-ID: <20240826120449.1666461-7-yukaixiong@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240826120449.1666461-1-yukaixiong@huawei.com> References: <20240826120449.1666461-1-yukaixiong@huawei.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemh100016.china.huawei.com (7.202.181.102) This moves all mmap related sysctls to its own file, as part of the kernel/sysctl.c cleaning, also move the variable declaration from kernel/sysctl.c into mm/mmap.c. Besides, move MAPCOUNT_ELF_CORE_MARGIN and DEFAULT_MAX_MAP_COUNT into mmap.c from mm.h. Signed-off-by: Kaixiong Yu --- include/linux/mm.h | 19 ------------ kernel/sysctl.c | 50 +------------------------------ mm/mmap.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++ mm/util.c | 1 - 4 files changed, 76 insertions(+), 69 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index a04543984a46..9400c92b4522 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -176,25 +176,6 @@ static inline void __mm_zero_struct_page(struct page *page) #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) #endif -/* - * Default maximum number of active map areas, this limits the number of vmas - * per mm struct. Users can overwrite this number by sysctl but there is a - * problem. - * - * When a program's coredump is generated as ELF format, a section is created - * per a vma. In ELF, the number of sections is represented in unsigned short. - * This means the number of sections should be smaller than 65535 at coredump. - * Because the kernel adds some informative sections to a image of program at - * generating coredump, we need some margin. The number of extra sections is - * 1-3 now and depends on arch. We use "5" as safe margin, here. - * - * ELF extended numbering allows more than 65535 sections, so 16-bit bound is - * not a hard limit any more. Although some userspace tools can be surprised by - * that. - */ -#define MAPCOUNT_ELF_CORE_MARGIN (5) -#define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN) - extern int sysctl_max_map_count; extern unsigned long sysctl_user_reserve_kbytes; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index ad3ac6f6c808..41d4afc978e6 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -127,12 +127,6 @@ enum sysctl_writes_mode { static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT; #endif /* CONFIG_PROC_SYSCTL */ - -#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ - defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) -int sysctl_legacy_va_layout; -#endif - #endif /* CONFIG_SYSCTL */ /* @@ -2047,16 +2041,7 @@ static struct ctl_table vm_table[] = { .extra1 = SYSCTL_ONE, .extra2 = SYSCTL_FOUR, }, -#ifdef CONFIG_MMU - { - .procname = "max_map_count", - .data = &sysctl_max_map_count, - .maxlen = sizeof(sysctl_max_map_count), - .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = SYSCTL_ZERO, - }, -#else +#ifndef CONFIG_MMU { .procname = "nr_trim_pages", .data = &sysctl_nr_trim_pages, @@ -2074,17 +2059,6 @@ static struct ctl_table vm_table[] = { .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ZERO, }, -#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ - defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) - { - .procname = "legacy_va_layout", - .data = &sysctl_legacy_va_layout, - .maxlen = sizeof(sysctl_legacy_va_layout), - .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = SYSCTL_ZERO, - }, -#endif #ifdef CONFIG_MMU { .procname = "mmap_min_addr", @@ -2110,28 +2084,6 @@ static struct ctl_table vm_table[] = { .extra1 = SYSCTL_ZERO, }, #endif -#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS - { - .procname = "mmap_rnd_bits", - .data = &mmap_rnd_bits, - .maxlen = sizeof(mmap_rnd_bits), - .mode = 0600, - .proc_handler = proc_dointvec_minmax, - .extra1 = (void *)&mmap_rnd_bits_min, - .extra2 = (void *)&mmap_rnd_bits_max, - }, -#endif -#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS - { - .procname = "mmap_rnd_compat_bits", - .data = &mmap_rnd_compat_bits, - .maxlen = sizeof(mmap_rnd_compat_bits), - .mode = 0600, - .proc_handler = proc_dointvec_minmax, - .extra1 = (void *)&mmap_rnd_compat_bits_min, - .extra2 = (void *)&mmap_rnd_compat_bits_max, - }, -#endif }; int __init sysctl_init_bases(void) diff --git a/mm/mmap.c b/mm/mmap.c index 88524a3768f6..2b37d8fb997f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -62,6 +62,27 @@ #define arch_mmap_check(addr, len, flags) (0) #endif +/* + * Default maximum number of active map areas, this limits the number of vmas + * per mm struct. Users can overwrite this number by sysctl but there is a + * problem. + * + * When a program's coredump is generated as ELF format, a section is created + * per a vma. In ELF, the number of sections is represented in unsigned short. + * This means the number of sections should be smaller than 65535 at coredump. + * Because the kernel adds some informative sections to a image of program at + * generating coredump, we need some margin. The number of extra sections is + * 1-3 now and depends on arch. We use "5" as safe margin, here. + * + * ELF extended numbering allows more than 65535 sections, so 16-bit bound is + * not a hard limit any more. Although some userspace tools can be surprised by + * that. + */ +#define MAPCOUNT_ELF_CORE_MARGIN (5) +#define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN) + +int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; + #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS const int mmap_rnd_bits_min = CONFIG_ARCH_MMAP_RND_BITS_MIN; int mmap_rnd_bits_max __ro_after_init = CONFIG_ARCH_MMAP_RND_BITS_MAX; @@ -2171,6 +2192,57 @@ struct vm_area_struct *_install_special_mapping( &special_mapping_vmops); } +#ifdef CONFIG_SYSCTL +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ + defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) +int sysctl_legacy_va_layout; +#endif + +static struct ctl_table mmap_table[] = { + { + .procname = "max_map_count", + .data = &sysctl_max_map_count, + .maxlen = sizeof(sysctl_max_map_count), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + }, +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ + defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) + { + .procname = "legacy_va_layout", + .data = &sysctl_legacy_va_layout, + .maxlen = sizeof(sysctl_legacy_va_layout), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + }, +#endif +#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS + { + .procname = "mmap_rnd_bits", + .data = &mmap_rnd_bits, + .maxlen = sizeof(mmap_rnd_bits), + .mode = 0600, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&mmap_rnd_bits_min, + .extra2 = (void *)&mmap_rnd_bits_max, + }, +#endif +#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS + { + .procname = "mmap_rnd_compat_bits", + .data = &mmap_rnd_compat_bits, + .maxlen = sizeof(mmap_rnd_compat_bits), + .mode = 0600, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&mmap_rnd_compat_bits_min, + .extra2 = (void *)&mmap_rnd_compat_bits_max, + }, +#endif +}; +#endif /* CONFIG_SYSCTL */ + /* * initialise the percpu counter for VM */ @@ -2180,6 +2252,9 @@ void __init mmap_init(void) ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); VM_BUG_ON(ret); +#ifdef CONFIG_SYSCTL + register_sysctl_init("vm", mmap_table); +#endif } /* diff --git a/mm/util.c b/mm/util.c index 04a677f04ca9..7f687563b8c7 100644 --- a/mm/util.c +++ b/mm/util.c @@ -906,7 +906,6 @@ EXPORT_SYMBOL(folio_mc_copy); int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; static int sysctl_overcommit_ratio __read_mostly = 50; static unsigned long sysctl_overcommit_kbytes __read_mostly; -int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */ unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */