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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F811C433E1 for ; Wed, 19 Aug 2020 11:56:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 076322072D for ; Wed, 19 Aug 2020 11:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597838201; bh=nB9SuwtUizzYREhBl09f96wwqfl+6v1Nki9XxEYxFmg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=I/F0ePKjDMRPCRMNJMZdFm+/TuCJFGow9GXIEUrqiUTKJDcs6rj386CTY3Y0KpwPz wvU6Vdxve3bRd5aes487FU+rrOJ2BD6xEtpV5Xou1YEZRk85f5Yb0ypgStwtyIVqgM ui99xFlDwixcV/QHyao/+6Ft6XqH8Rn3imMAdf1M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728079AbgHSL4E (ORCPT ); Wed, 19 Aug 2020 07:56:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:56344 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728259AbgHSLzJ (ORCPT ); Wed, 19 Aug 2020 07:55:09 -0400 Received: from kernel.org (unknown [87.70.91.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7FB6322CB2; Wed, 19 Aug 2020 11:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597838028; bh=nB9SuwtUizzYREhBl09f96wwqfl+6v1Nki9XxEYxFmg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XzrjsD+88ReKpEKVPxcwBs0sO7/deF5YmgL8LgJvrSN6vKteBo3UksVlQ439kYefA pqi62Er1Ztem1X6xeUf0PcjYSye7F9ZeTEP4gsLHxxhVLZS4GHJvJhgTJYf67ZgHza yH2N2HWN3WZDusoyvsFWvEe6drqcLGHPLKWZz18o= Date: Wed, 19 Aug 2020 14:53:35 +0300 From: Mike Rapoport To: David Hildenbrand Cc: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , Elena Reshetova , "H. Peter Anvin" , Idan Yaniv , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org Subject: Re: [PATCH v4 6/6] mm: secretmem: add ability to reserve memory at boot Message-ID: <20200819115335.GU752365@kernel.org> References: <20200818141554.13945-1-rppt@kernel.org> <20200818141554.13945-7-rppt@kernel.org> <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Wed, Aug 19, 2020 at 12:49:05PM +0200, David Hildenbrand wrote: > On 18.08.20 16:15, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Taking pages out from the direct map and bringing them back may create > > undesired fragmentation and usage of the smaller pages in the direct > > mapping of the physical memory. > > > > This can be avoided if a significantly large area of the physical memory > > would be reserved for secretmem purposes at boot time. > > > > Add ability to reserve physical memory for secretmem at boot time using > > "secretmem" kernel parameter and then use that reserved memory as a global > > pool for secret memory needs. > > Wouldn't something like CMA be the better fit? Just wondering. Then, the > memory can actually be reused for something else while not needed. The memory allocated as secret is removed from the direct map and the boot time reservation is intended to reduce direct map fragmentatioan and to avoid splitting 1G pages there. So with CMA I'd still need to allocate 1G chunks for this and once 1G page is dropped from the direct map it still cannot be reused for anything else until it is freed. I could use CMA to do the boot time reservation, but doing the reservesion directly seemed simpler and more explicit to me. > > Signed-off-by: Mike Rapoport > > --- > > mm/secretmem.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 126 insertions(+), 8 deletions(-) > > > > diff --git a/mm/secretmem.c b/mm/secretmem.c > > index 333eb18fb483..54067ea62b2d 100644 > > --- a/mm/secretmem.c > > +++ b/mm/secretmem.c > > @@ -14,6 +14,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -45,6 +46,39 @@ struct secretmem_ctx { > > unsigned int mode; > > }; > > > > +struct secretmem_pool { > > + struct gen_pool *pool; > > + unsigned long reserved_size; > > + void *reserved; > > +}; > > + > > +static struct secretmem_pool secretmem_pool; > > + > > +static struct page *secretmem_alloc_huge_page(gfp_t gfp) > > +{ > > + struct gen_pool *pool = secretmem_pool.pool; > > + unsigned long addr = 0; > > + struct page *page = NULL; > > + > > + if (pool) { > > + if (gen_pool_avail(pool) < PMD_SIZE) > > + return NULL; > > + > > + addr = gen_pool_alloc(pool, PMD_SIZE); > > + if (!addr) > > + return NULL; > > + > > + page = virt_to_page(addr); > > + } else { > > + page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + > > + if (page) > > + split_page(page, PMD_PAGE_ORDER); > > + } > > + > > + return page; > > +} > > + > > static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > { > > unsigned long nr_pages = (1 << PMD_PAGE_ORDER); > > @@ -53,12 +87,11 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > struct page *page; > > int err; > > > > - page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + page = secretmem_alloc_huge_page(gfp); > > if (!page) > > return -ENOMEM; > > > > addr = (unsigned long)page_address(page); > > - split_page(page, PMD_PAGE_ORDER); > > > > err = gen_pool_add(pool, addr, PMD_SIZE, NUMA_NO_NODE); > > if (err) { > > @@ -267,11 +300,13 @@ SYSCALL_DEFINE1(memfd_secret, unsigned long, flags) > > return err; > > } > > > > -static void secretmem_cleanup_chunk(struct gen_pool *pool, > > - struct gen_pool_chunk *chunk, void *data) > > +static void secretmem_recycle_range(unsigned long start, unsigned long end) > > +{ > > + gen_pool_free(secretmem_pool.pool, start, PMD_SIZE); > > +} > > + > > +static void secretmem_release_range(unsigned long start, unsigned long end) > > { > > - unsigned long start = chunk->start_addr; > > - unsigned long end = chunk->end_addr; > > unsigned long nr_pages, addr; > > > > nr_pages = (end - start + 1) / PAGE_SIZE; > > @@ -281,6 +316,18 @@ static void secretmem_cleanup_chunk(struct gen_pool *pool, > > put_page(virt_to_page(addr)); > > } > > > > +static void secretmem_cleanup_chunk(struct gen_pool *pool, > > + struct gen_pool_chunk *chunk, void *data) > > +{ > > + unsigned long start = chunk->start_addr; > > + unsigned long end = chunk->end_addr; > > + > > + if (secretmem_pool.pool) > > + secretmem_recycle_range(start, end); > > + else > > + secretmem_release_range(start, end); > > +} > > + > > static void secretmem_cleanup_pool(struct secretmem_ctx *ctx) > > { > > struct gen_pool *pool = ctx->pool; > > @@ -320,14 +367,85 @@ static struct file_system_type secretmem_fs = { > > .kill_sb = kill_anon_super, > > }; > > > > +static int secretmem_reserved_mem_init(void) > > +{ > > + struct gen_pool *pool; > > + struct page *page; > > + void *addr; > > + int err; > > + > > + if (!secretmem_pool.reserved) > > + return 0; > > + > > + pool = gen_pool_create(PMD_SHIFT, NUMA_NO_NODE); > > + if (!pool) > > + return -ENOMEM; > > + > > + err = gen_pool_add(pool, (unsigned long)secretmem_pool.reserved, > > + secretmem_pool.reserved_size, NUMA_NO_NODE); > > + if (err) > > + goto err_destroy_pool; > > + > > + for (addr = secretmem_pool.reserved; > > + addr < secretmem_pool.reserved + secretmem_pool.reserved_size; > > + addr += PAGE_SIZE) { > > + page = virt_to_page(addr); > > + __ClearPageReserved(page); > > + set_page_count(page, 1); > > + } > > + > > + secretmem_pool.pool = pool; > > + page = virt_to_page(secretmem_pool.reserved); > > + __kernel_map_pages(page, secretmem_pool.reserved_size / PAGE_SIZE, 0); > > + return 0; > > + > > +err_destroy_pool: > > + gen_pool_destroy(pool); > > + return err; > > +} > > + > > static int secretmem_init(void) > > { > > - int ret = 0; > > + int ret; > > + > > + ret = secretmem_reserved_mem_init(); > > + if (ret) > > + return ret; > > > > secretmem_mnt = kern_mount(&secretmem_fs); > > - if (IS_ERR(secretmem_mnt)) > > + if (IS_ERR(secretmem_mnt)) { > > + gen_pool_destroy(secretmem_pool.pool); > > ret = PTR_ERR(secretmem_mnt); > > + } > > > > return ret; > > } > > fs_initcall(secretmem_init); > > + > > +static int __init secretmem_setup(char *str) > > +{ > > + phys_addr_t align = PMD_SIZE; > > + unsigned long reserved_size; > > + void *reserved; > > + > > + reserved_size = memparse(str, NULL); > > + if (!reserved_size) > > + return 0; > > + > > + if (reserved_size * 2 > PUD_SIZE) > > + align = PUD_SIZE; > > + > > + reserved = memblock_alloc(reserved_size, align); > > + if (!reserved) { > > + pr_err("failed to reserve %lu bytes\n", secretmem_pool.reserved_size); > > + return 0; > > + } > > + > > + secretmem_pool.reserved_size = reserved_size; > > + secretmem_pool.reserved = reserved; > > + > > + pr_info("reserved %luM\n", reserved_size >> 20); > > + > > + return 1; > > +} > > +__setup("secretmem=", secretmem_setup); > > > > > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. 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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11D94C433E1 for ; Wed, 19 Aug 2020 11:53:51 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D7D3A2224D for ; Wed, 19 Aug 2020 11:53:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="XzrjsD+8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D7D3A2224D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 8CA17135003B2; Wed, 19 Aug 2020 04:53:50 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=rppt@kernel.org; receiver= Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id B0AB8130990C9 for ; Wed, 19 Aug 2020 04:53:48 -0700 (PDT) Received: from kernel.org (unknown [87.70.91.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7FB6322CB2; Wed, 19 Aug 2020 11:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597838028; bh=nB9SuwtUizzYREhBl09f96wwqfl+6v1Nki9XxEYxFmg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XzrjsD+88ReKpEKVPxcwBs0sO7/deF5YmgL8LgJvrSN6vKteBo3UksVlQ439kYefA pqi62Er1Ztem1X6xeUf0PcjYSye7F9ZeTEP4gsLHxxhVLZS4GHJvJhgTJYf67ZgHza yH2N2HWN3WZDusoyvsFWvEe6drqcLGHPLKWZz18o= Date: Wed, 19 Aug 2020 14:53:35 +0300 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH v4 6/6] mm: secretmem: add ability to reserve memory at boot Message-ID: <20200819115335.GU752365@kernel.org> References: <20200818141554.13945-1-rppt@kernel.org> <20200818141554.13945-7-rppt@kernel.org> <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> Message-ID-Hash: GQLIJYS6TIAOAS2NR5HD7FUL66TTI2WO X-Message-ID-Hash: GQLIJYS6TIAOAS2NR5HD7FUL66TTI2WO X-MailFrom: rppt@kernel.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dave Hansen , Elena Reshetova , "H. Peter Anvin" , Idan Yaniv , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.o rg, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, Aug 19, 2020 at 12:49:05PM +0200, David Hildenbrand wrote: > On 18.08.20 16:15, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Taking pages out from the direct map and bringing them back may create > > undesired fragmentation and usage of the smaller pages in the direct > > mapping of the physical memory. > > > > This can be avoided if a significantly large area of the physical memory > > would be reserved for secretmem purposes at boot time. > > > > Add ability to reserve physical memory for secretmem at boot time using > > "secretmem" kernel parameter and then use that reserved memory as a global > > pool for secret memory needs. > > Wouldn't something like CMA be the better fit? Just wondering. Then, the > memory can actually be reused for something else while not needed. The memory allocated as secret is removed from the direct map and the boot time reservation is intended to reduce direct map fragmentatioan and to avoid splitting 1G pages there. So with CMA I'd still need to allocate 1G chunks for this and once 1G page is dropped from the direct map it still cannot be reused for anything else until it is freed. I could use CMA to do the boot time reservation, but doing the reservesion directly seemed simpler and more explicit to me. > > Signed-off-by: Mike Rapoport > > --- > > mm/secretmem.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 126 insertions(+), 8 deletions(-) > > > > diff --git a/mm/secretmem.c b/mm/secretmem.c > > index 333eb18fb483..54067ea62b2d 100644 > > --- a/mm/secretmem.c > > +++ b/mm/secretmem.c > > @@ -14,6 +14,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -45,6 +46,39 @@ struct secretmem_ctx { > > unsigned int mode; > > }; > > > > +struct secretmem_pool { > > + struct gen_pool *pool; > > + unsigned long reserved_size; > > + void *reserved; > > +}; > > + > > +static struct secretmem_pool secretmem_pool; > > + > > +static struct page *secretmem_alloc_huge_page(gfp_t gfp) > > +{ > > + struct gen_pool *pool = secretmem_pool.pool; > > + unsigned long addr = 0; > > + struct page *page = NULL; > > + > > + if (pool) { > > + if (gen_pool_avail(pool) < PMD_SIZE) > > + return NULL; > > + > > + addr = gen_pool_alloc(pool, PMD_SIZE); > > + if (!addr) > > + return NULL; > > + > > + page = virt_to_page(addr); > > + } else { > > + page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + > > + if (page) > > + split_page(page, PMD_PAGE_ORDER); > > + } > > + > > + return page; > > +} > > + > > static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > { > > unsigned long nr_pages = (1 << PMD_PAGE_ORDER); > > @@ -53,12 +87,11 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > struct page *page; > > int err; > > > > - page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + page = secretmem_alloc_huge_page(gfp); > > if (!page) > > return -ENOMEM; > > > > addr = (unsigned long)page_address(page); > > - split_page(page, PMD_PAGE_ORDER); > > > > err = gen_pool_add(pool, addr, PMD_SIZE, NUMA_NO_NODE); > > if (err) { > > @@ -267,11 +300,13 @@ SYSCALL_DEFINE1(memfd_secret, unsigned long, flags) > > return err; > > } > > > > -static void secretmem_cleanup_chunk(struct gen_pool *pool, > > - struct gen_pool_chunk *chunk, void *data) > > +static void secretmem_recycle_range(unsigned long start, unsigned long end) > > +{ > > + gen_pool_free(secretmem_pool.pool, start, PMD_SIZE); > > +} > > + > > +static void secretmem_release_range(unsigned long start, unsigned long end) > > { > > - unsigned long start = chunk->start_addr; > > - unsigned long end = chunk->end_addr; > > unsigned long nr_pages, addr; > > > > nr_pages = (end - start + 1) / PAGE_SIZE; > > @@ -281,6 +316,18 @@ static void secretmem_cleanup_chunk(struct gen_pool *pool, > > put_page(virt_to_page(addr)); > > } > > > > +static void secretmem_cleanup_chunk(struct gen_pool *pool, > > + struct gen_pool_chunk *chunk, void *data) > > +{ > > + unsigned long start = chunk->start_addr; > > + unsigned long end = chunk->end_addr; > > + > > + if (secretmem_pool.pool) > > + secretmem_recycle_range(start, end); > > + else > > + secretmem_release_range(start, end); > > +} > > + > > static void secretmem_cleanup_pool(struct secretmem_ctx *ctx) > > { > > struct gen_pool *pool = ctx->pool; > > @@ -320,14 +367,85 @@ static struct file_system_type secretmem_fs = { > > .kill_sb = kill_anon_super, > > }; > > > > +static int secretmem_reserved_mem_init(void) > > +{ > > + struct gen_pool *pool; > > + struct page *page; > > + void *addr; > > + int err; > > + > > + if (!secretmem_pool.reserved) > > + return 0; > > + > > + pool = gen_pool_create(PMD_SHIFT, NUMA_NO_NODE); > > + if (!pool) > > + return -ENOMEM; > > + > > + err = gen_pool_add(pool, (unsigned long)secretmem_pool.reserved, > > + secretmem_pool.reserved_size, NUMA_NO_NODE); > > + if (err) > > + goto err_destroy_pool; > > + > > + for (addr = secretmem_pool.reserved; > > + addr < secretmem_pool.reserved + secretmem_pool.reserved_size; > > + addr += PAGE_SIZE) { > > + page = virt_to_page(addr); > > + __ClearPageReserved(page); > > + set_page_count(page, 1); > > + } > > + > > + secretmem_pool.pool = pool; > > + page = virt_to_page(secretmem_pool.reserved); > > + __kernel_map_pages(page, secretmem_pool.reserved_size / PAGE_SIZE, 0); > > + return 0; > > + > > +err_destroy_pool: > > + gen_pool_destroy(pool); > > + return err; > > +} > > + > > static int secretmem_init(void) > > { > > - int ret = 0; > > + int ret; > > + > > + ret = secretmem_reserved_mem_init(); > > + if (ret) > > + return ret; > > > > secretmem_mnt = kern_mount(&secretmem_fs); > > - if (IS_ERR(secretmem_mnt)) > > + if (IS_ERR(secretmem_mnt)) { > > + gen_pool_destroy(secretmem_pool.pool); > > ret = PTR_ERR(secretmem_mnt); > > + } > > > > return ret; > > } > > fs_initcall(secretmem_init); > > + > > +static int __init secretmem_setup(char *str) > > +{ > > + phys_addr_t align = PMD_SIZE; > > + unsigned long reserved_size; > > + void *reserved; > > + > > + reserved_size = memparse(str, NULL); > > + if (!reserved_size) > > + return 0; > > + > > + if (reserved_size * 2 > PUD_SIZE) > > + align = PUD_SIZE; > > + > > + reserved = memblock_alloc(reserved_size, align); > > + if (!reserved) { > > + pr_err("failed to reserve %lu bytes\n", secretmem_pool.reserved_size); > > + return 0; > > + } > > + > > + secretmem_pool.reserved_size = reserved_size; > > + secretmem_pool.reserved = reserved; > > + > > + pr_info("reserved %luM\n", reserved_size >> 20); > > + > > + return 1; > > +} > > +__setup("secretmem=", secretmem_setup); > > > > > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org 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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6F9AC433DF for ; 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bh=0rbZlGLF4uErw05TSYhS6ztAcg3s7SPltt3nv7PVebo=; b=UjBpt+Ar1VGS+8lOCwL/WsS2P MdC1WArYxDlJ7LNu/qBVZUhw/V1TFUx1qa4wkg25olBKIUkHqvghagn07m38IaTpg5fF3sxnYq4JP zrk0XZ1nWqxTiEaFtdSUUjycSE/tkeOhAaviyxi42SmPy+MMVGfox52IKAMogqzMuFEfUW2PHbRk5 W4YrCmZ2H6TVg5w92wh7FCFnKPRl7PoNl7WCPN0+Xm+q6KDUdiYTqLUe2EWW/0RuiBrWl+p89s4F1 POiujkysApqO1KU5gXZwK2eJFcILT993GgiSBt3ibK5oRrs8HSy2K1nRzu42wk7QuM+gOLFlZDPyf SqTlqmsYw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8MfP-000786-RE; Wed, 19 Aug 2020 11:54:07 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8Mf7-0006yW-Py; Wed, 19 Aug 2020 11:53:55 +0000 Received: from kernel.org (unknown [87.70.91.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7FB6322CB2; Wed, 19 Aug 2020 11:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597838028; bh=nB9SuwtUizzYREhBl09f96wwqfl+6v1Nki9XxEYxFmg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XzrjsD+88ReKpEKVPxcwBs0sO7/deF5YmgL8LgJvrSN6vKteBo3UksVlQ439kYefA pqi62Er1Ztem1X6xeUf0PcjYSye7F9ZeTEP4gsLHxxhVLZS4GHJvJhgTJYf67ZgHza yH2N2HWN3WZDusoyvsFWvEe6drqcLGHPLKWZz18o= Date: Wed, 19 Aug 2020 14:53:35 +0300 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH v4 6/6] mm: secretmem: add ability to reserve memory at boot Message-ID: <20200819115335.GU752365@kernel.org> References: <20200818141554.13945-1-rppt@kernel.org> <20200818141554.13945-7-rppt@kernel.org> <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200819_075350_077351_9FDB00D9 X-CRM114-Status: GOOD ( 38.58 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, "H. Peter Anvin" , Christopher Lameter , Idan Yaniv , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, Matthew Wilcox , Mike Rapoport , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Andrew Morton Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Wed, Aug 19, 2020 at 12:49:05PM +0200, David Hildenbrand wrote: > On 18.08.20 16:15, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Taking pages out from the direct map and bringing them back may create > > undesired fragmentation and usage of the smaller pages in the direct > > mapping of the physical memory. > > > > This can be avoided if a significantly large area of the physical memory > > would be reserved for secretmem purposes at boot time. > > > > Add ability to reserve physical memory for secretmem at boot time using > > "secretmem" kernel parameter and then use that reserved memory as a global > > pool for secret memory needs. > > Wouldn't something like CMA be the better fit? Just wondering. Then, the > memory can actually be reused for something else while not needed. The memory allocated as secret is removed from the direct map and the boot time reservation is intended to reduce direct map fragmentatioan and to avoid splitting 1G pages there. So with CMA I'd still need to allocate 1G chunks for this and once 1G page is dropped from the direct map it still cannot be reused for anything else until it is freed. I could use CMA to do the boot time reservation, but doing the reservesion directly seemed simpler and more explicit to me. > > Signed-off-by: Mike Rapoport > > --- > > mm/secretmem.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 126 insertions(+), 8 deletions(-) > > > > diff --git a/mm/secretmem.c b/mm/secretmem.c > > index 333eb18fb483..54067ea62b2d 100644 > > --- a/mm/secretmem.c > > +++ b/mm/secretmem.c > > @@ -14,6 +14,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -45,6 +46,39 @@ struct secretmem_ctx { > > unsigned int mode; > > }; > > > > +struct secretmem_pool { > > + struct gen_pool *pool; > > + unsigned long reserved_size; > > + void *reserved; > > +}; > > + > > +static struct secretmem_pool secretmem_pool; > > + > > +static struct page *secretmem_alloc_huge_page(gfp_t gfp) > > +{ > > + struct gen_pool *pool = secretmem_pool.pool; > > + unsigned long addr = 0; > > + struct page *page = NULL; > > + > > + if (pool) { > > + if (gen_pool_avail(pool) < PMD_SIZE) > > + return NULL; > > + > > + addr = gen_pool_alloc(pool, PMD_SIZE); > > + if (!addr) > > + return NULL; > > + > > + page = virt_to_page(addr); > > + } else { > > + page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + > > + if (page) > > + split_page(page, PMD_PAGE_ORDER); > > + } > > + > > + return page; > > +} > > + > > static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > { > > unsigned long nr_pages = (1 << PMD_PAGE_ORDER); > > @@ -53,12 +87,11 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > struct page *page; > > int err; > > > > - page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + page = secretmem_alloc_huge_page(gfp); > > if (!page) > > return -ENOMEM; > > > > addr = (unsigned long)page_address(page); > > - split_page(page, PMD_PAGE_ORDER); > > > > err = gen_pool_add(pool, addr, PMD_SIZE, NUMA_NO_NODE); > > if (err) { > > @@ -267,11 +300,13 @@ SYSCALL_DEFINE1(memfd_secret, unsigned long, flags) > > return err; > > } > > > > -static void secretmem_cleanup_chunk(struct gen_pool *pool, > > - struct gen_pool_chunk *chunk, void *data) > > +static void secretmem_recycle_range(unsigned long start, unsigned long end) > > +{ > > + gen_pool_free(secretmem_pool.pool, start, PMD_SIZE); > > +} > > + > > +static void secretmem_release_range(unsigned long start, unsigned long end) > > { > > - unsigned long start = chunk->start_addr; > > - unsigned long end = chunk->end_addr; > > unsigned long nr_pages, addr; > > > > nr_pages = (end - start + 1) / PAGE_SIZE; > > @@ -281,6 +316,18 @@ static void secretmem_cleanup_chunk(struct gen_pool *pool, > > put_page(virt_to_page(addr)); > > } > > > > +static void secretmem_cleanup_chunk(struct gen_pool *pool, > > + struct gen_pool_chunk *chunk, void *data) > > +{ > > + unsigned long start = chunk->start_addr; > > + unsigned long end = chunk->end_addr; > > + > > + if (secretmem_pool.pool) > > + secretmem_recycle_range(start, end); > > + else > > + secretmem_release_range(start, end); > > +} > > + > > static void secretmem_cleanup_pool(struct secretmem_ctx *ctx) > > { > > struct gen_pool *pool = ctx->pool; > > @@ -320,14 +367,85 @@ static struct file_system_type secretmem_fs = { > > .kill_sb = kill_anon_super, > > }; > > > > +static int secretmem_reserved_mem_init(void) > > +{ > > + struct gen_pool *pool; > > + struct page *page; > > + void *addr; > > + int err; > > + > > + if (!secretmem_pool.reserved) > > + return 0; > > + > > + pool = gen_pool_create(PMD_SHIFT, NUMA_NO_NODE); > > + if (!pool) > > + return -ENOMEM; > > + > > + err = gen_pool_add(pool, (unsigned long)secretmem_pool.reserved, > > + secretmem_pool.reserved_size, NUMA_NO_NODE); > > + if (err) > > + goto err_destroy_pool; > > + > > + for (addr = secretmem_pool.reserved; > > + addr < secretmem_pool.reserved + secretmem_pool.reserved_size; > > + addr += PAGE_SIZE) { > > + page = virt_to_page(addr); > > + __ClearPageReserved(page); > > + set_page_count(page, 1); > > + } > > + > > + secretmem_pool.pool = pool; > > + page = virt_to_page(secretmem_pool.reserved); > > + __kernel_map_pages(page, secretmem_pool.reserved_size / PAGE_SIZE, 0); > > + return 0; > > + > > +err_destroy_pool: > > + gen_pool_destroy(pool); > > + return err; > > +} > > + > > static int secretmem_init(void) > > { > > - int ret = 0; > > + int ret; > > + > > + ret = secretmem_reserved_mem_init(); > > + if (ret) > > + return ret; > > > > secretmem_mnt = kern_mount(&secretmem_fs); > > - if (IS_ERR(secretmem_mnt)) > > + if (IS_ERR(secretmem_mnt)) { > > + gen_pool_destroy(secretmem_pool.pool); > > ret = PTR_ERR(secretmem_mnt); > > + } > > > > return ret; > > } > > fs_initcall(secretmem_init); > > + > > +static int __init secretmem_setup(char *str) > > +{ > > + phys_addr_t align = PMD_SIZE; > > + unsigned long reserved_size; > > + void *reserved; > > + > > + reserved_size = memparse(str, NULL); > > + if (!reserved_size) > > + return 0; > > + > > + if (reserved_size * 2 > PUD_SIZE) > > + align = PUD_SIZE; > > + > > + reserved = memblock_alloc(reserved_size, align); > > + if (!reserved) { > > + pr_err("failed to reserve %lu bytes\n", secretmem_pool.reserved_size); > > + return 0; > > + } > > + > > + secretmem_pool.reserved_size = reserved_size; > > + secretmem_pool.reserved = reserved; > > + > > + pr_info("reserved %luM\n", reserved_size >> 20); > > + > > + return 1; > > +} > > +__setup("secretmem=", secretmem_setup); > > > > > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1156BC433DF for ; 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Wed, 19 Aug 2020 11:53:55 +0000 Received: from kernel.org (unknown [87.70.91.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7FB6322CB2; Wed, 19 Aug 2020 11:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597838028; bh=nB9SuwtUizzYREhBl09f96wwqfl+6v1Nki9XxEYxFmg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XzrjsD+88ReKpEKVPxcwBs0sO7/deF5YmgL8LgJvrSN6vKteBo3UksVlQ439kYefA pqi62Er1Ztem1X6xeUf0PcjYSye7F9ZeTEP4gsLHxxhVLZS4GHJvJhgTJYf67ZgHza yH2N2HWN3WZDusoyvsFWvEe6drqcLGHPLKWZz18o= Date: Wed, 19 Aug 2020 14:53:35 +0300 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH v4 6/6] mm: secretmem: add ability to reserve memory at boot Message-ID: <20200819115335.GU752365@kernel.org> References: <20200818141554.13945-1-rppt@kernel.org> <20200818141554.13945-7-rppt@kernel.org> <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <03ec586d-c00c-c57e-3118-7186acb7b823@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200819_075350_077351_9FDB00D9 X-CRM114-Status: GOOD ( 38.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, "H. Peter Anvin" , Christopher Lameter , Idan Yaniv , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, Matthew Wilcox , Mike Rapoport , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Andrew Morton Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Aug 19, 2020 at 12:49:05PM +0200, David Hildenbrand wrote: > On 18.08.20 16:15, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Taking pages out from the direct map and bringing them back may create > > undesired fragmentation and usage of the smaller pages in the direct > > mapping of the physical memory. > > > > This can be avoided if a significantly large area of the physical memory > > would be reserved for secretmem purposes at boot time. > > > > Add ability to reserve physical memory for secretmem at boot time using > > "secretmem" kernel parameter and then use that reserved memory as a global > > pool for secret memory needs. > > Wouldn't something like CMA be the better fit? Just wondering. Then, the > memory can actually be reused for something else while not needed. The memory allocated as secret is removed from the direct map and the boot time reservation is intended to reduce direct map fragmentatioan and to avoid splitting 1G pages there. So with CMA I'd still need to allocate 1G chunks for this and once 1G page is dropped from the direct map it still cannot be reused for anything else until it is freed. I could use CMA to do the boot time reservation, but doing the reservesion directly seemed simpler and more explicit to me. > > Signed-off-by: Mike Rapoport > > --- > > mm/secretmem.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 126 insertions(+), 8 deletions(-) > > > > diff --git a/mm/secretmem.c b/mm/secretmem.c > > index 333eb18fb483..54067ea62b2d 100644 > > --- a/mm/secretmem.c > > +++ b/mm/secretmem.c > > @@ -14,6 +14,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -45,6 +46,39 @@ struct secretmem_ctx { > > unsigned int mode; > > }; > > > > +struct secretmem_pool { > > + struct gen_pool *pool; > > + unsigned long reserved_size; > > + void *reserved; > > +}; > > + > > +static struct secretmem_pool secretmem_pool; > > + > > +static struct page *secretmem_alloc_huge_page(gfp_t gfp) > > +{ > > + struct gen_pool *pool = secretmem_pool.pool; > > + unsigned long addr = 0; > > + struct page *page = NULL; > > + > > + if (pool) { > > + if (gen_pool_avail(pool) < PMD_SIZE) > > + return NULL; > > + > > + addr = gen_pool_alloc(pool, PMD_SIZE); > > + if (!addr) > > + return NULL; > > + > > + page = virt_to_page(addr); > > + } else { > > + page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + > > + if (page) > > + split_page(page, PMD_PAGE_ORDER); > > + } > > + > > + return page; > > +} > > + > > static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > { > > unsigned long nr_pages = (1 << PMD_PAGE_ORDER); > > @@ -53,12 +87,11 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) > > struct page *page; > > int err; > > > > - page = alloc_pages(gfp, PMD_PAGE_ORDER); > > + page = secretmem_alloc_huge_page(gfp); > > if (!page) > > return -ENOMEM; > > > > addr = (unsigned long)page_address(page); > > - split_page(page, PMD_PAGE_ORDER); > > > > err = gen_pool_add(pool, addr, PMD_SIZE, NUMA_NO_NODE); > > if (err) { > > @@ -267,11 +300,13 @@ SYSCALL_DEFINE1(memfd_secret, unsigned long, flags) > > return err; > > } > > > > -static void secretmem_cleanup_chunk(struct gen_pool *pool, > > - struct gen_pool_chunk *chunk, void *data) > > +static void secretmem_recycle_range(unsigned long start, unsigned long end) > > +{ > > + gen_pool_free(secretmem_pool.pool, start, PMD_SIZE); > > +} > > + > > +static void secretmem_release_range(unsigned long start, unsigned long end) > > { > > - unsigned long start = chunk->start_addr; > > - unsigned long end = chunk->end_addr; > > unsigned long nr_pages, addr; > > > > nr_pages = (end - start + 1) / PAGE_SIZE; > > @@ -281,6 +316,18 @@ static void secretmem_cleanup_chunk(struct gen_pool *pool, > > put_page(virt_to_page(addr)); > > } > > > > +static void secretmem_cleanup_chunk(struct gen_pool *pool, > > + struct gen_pool_chunk *chunk, void *data) > > +{ > > + unsigned long start = chunk->start_addr; > > + unsigned long end = chunk->end_addr; > > + > > + if (secretmem_pool.pool) > > + secretmem_recycle_range(start, end); > > + else > > + secretmem_release_range(start, end); > > +} > > + > > static void secretmem_cleanup_pool(struct secretmem_ctx *ctx) > > { > > struct gen_pool *pool = ctx->pool; > > @@ -320,14 +367,85 @@ static struct file_system_type secretmem_fs = { > > .kill_sb = kill_anon_super, > > }; > > > > +static int secretmem_reserved_mem_init(void) > > +{ > > + struct gen_pool *pool; > > + struct page *page; > > + void *addr; > > + int err; > > + > > + if (!secretmem_pool.reserved) > > + return 0; > > + > > + pool = gen_pool_create(PMD_SHIFT, NUMA_NO_NODE); > > + if (!pool) > > + return -ENOMEM; > > + > > + err = gen_pool_add(pool, (unsigned long)secretmem_pool.reserved, > > + secretmem_pool.reserved_size, NUMA_NO_NODE); > > + if (err) > > + goto err_destroy_pool; > > + > > + for (addr = secretmem_pool.reserved; > > + addr < secretmem_pool.reserved + secretmem_pool.reserved_size; > > + addr += PAGE_SIZE) { > > + page = virt_to_page(addr); > > + __ClearPageReserved(page); > > + set_page_count(page, 1); > > + } > > + > > + secretmem_pool.pool = pool; > > + page = virt_to_page(secretmem_pool.reserved); > > + __kernel_map_pages(page, secretmem_pool.reserved_size / PAGE_SIZE, 0); > > + return 0; > > + > > +err_destroy_pool: > > + gen_pool_destroy(pool); > > + return err; > > +} > > + > > static int secretmem_init(void) > > { > > - int ret = 0; > > + int ret; > > + > > + ret = secretmem_reserved_mem_init(); > > + if (ret) > > + return ret; > > > > secretmem_mnt = kern_mount(&secretmem_fs); > > - if (IS_ERR(secretmem_mnt)) > > + if (IS_ERR(secretmem_mnt)) { > > + gen_pool_destroy(secretmem_pool.pool); > > ret = PTR_ERR(secretmem_mnt); > > + } > > > > return ret; > > } > > fs_initcall(secretmem_init); > > + > > +static int __init secretmem_setup(char *str) > > +{ > > + phys_addr_t align = PMD_SIZE; > > + unsigned long reserved_size; > > + void *reserved; > > + > > + reserved_size = memparse(str, NULL); > > + if (!reserved_size) > > + return 0; > > + > > + if (reserved_size * 2 > PUD_SIZE) > > + align = PUD_SIZE; > > + > > + reserved = memblock_alloc(reserved_size, align); > > + if (!reserved) { > > + pr_err("failed to reserve %lu bytes\n", secretmem_pool.reserved_size); > > + return 0; > > + } > > + > > + secretmem_pool.reserved_size = reserved_size; > > + secretmem_pool.reserved = reserved; > > + > > + pr_info("reserved %luM\n", reserved_size >> 20); > > + > > + return 1; > > +} > > +__setup("secretmem=", secretmem_setup); > > > > > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel