From patchwork Thu Dec 30 19:14:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12701622 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 36F06C433F5 for ; Thu, 30 Dec 2021 19:15:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A9CA46B00A9; Thu, 30 Dec 2021 14:15:46 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D42F6B00AB; Thu, 30 Dec 2021 14:15:46 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 89C256B00AC; Thu, 30 Dec 2021 14:15:46 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0170.hostedemail.com [216.40.44.170]) by kanga.kvack.org (Postfix) with ESMTP id 5BCA56B00A9 for ; Thu, 30 Dec 2021 14:15:46 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 181428249980 for ; Thu, 30 Dec 2021 19:15:46 +0000 (UTC) X-FDA: 78975415092.28.DCD57E4 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by imf29.hostedemail.com (Postfix) with ESMTP id CB9C4120009 for ; Thu, 30 Dec 2021 19:15:39 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1640891744; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FABrWA5761iiZUkXnIazPnhUDwA8MsEm5+WPei3KGi8=; b=J9RmHsI724Wyz2OZ3fhPnYnVKm0959DLfvaYXHBpdTS5m0zqSZbW4B7U6rxzuFmV1QmKvD aHLpQkjOWPCTipkenXm4679cUEgEoqjz4tFE73XwRqBc3np4Iqfi6TZhKZ0qaF8o7ljYlQ 60I8ogDgKnMUkj8eT7NoH+YfUdXKISY= From: andrey.konovalov@linux.dev To: Andrew Morton Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Peter Collingbourne , Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm v5 26/39] kasan, vmalloc: unpoison VM_ALLOC pages after mapping Date: Thu, 30 Dec 2021 20:14:51 +0100 Message-Id: <2aec888039eb8e7f9bd8c1f8bb289081f0136e60.1640891329.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Stat-Signature: ufkfn4hk1gzbccbbwhq59aowbnzejs6w X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: CB9C4120009 Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=J9RmHsI7; spf=pass (imf29.hostedemail.com: domain of andrey.konovalov@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-HE-Tag: 1640891739-762977 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: From: Andrey Konovalov Make KASAN unpoison vmalloc mappings after they have been mapped in when it's possible: for vmalloc() (indentified via VM_ALLOC) and vm_map_ram(). The reasons for this are: - For vmalloc() and vm_map_ram(): pages don't get unpoisoned in case mapping them fails. - For vmalloc(): HW_TAGS KASAN needs pages to be mapped to set tags via kasan_unpoison_vmalloc(). As a part of these changes, the return value of __vmalloc_node_range() is changed to area->addr. This is a non-functional change, as __vmalloc_area_node() returns area->addr anyway. Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko --- Changes v3->v4: - Don't forget to save tagged addr to vm_struct->addr for VM_ALLOC so that find_vm_area(addr)->addr == addr for vmalloc(). - Reword comments. - Update patch description. Changes v2->v3: - Update patch description. --- mm/vmalloc.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 598bb65263c7..bcf973a54737 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2210,14 +2210,15 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node) mem = (void *)addr; } - mem = kasan_unpoison_vmalloc(mem, size); - if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, pages, PAGE_SHIFT) < 0) { vm_unmap_ram(mem, count); return NULL; } + /* Mark the pages as accessible, now that they are mapped. */ + mem = kasan_unpoison_vmalloc(mem, size); + return mem; } EXPORT_SYMBOL(vm_map_ram); @@ -2445,7 +2446,14 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, setup_vmalloc_vm(area, va, flags, caller); - area->addr = kasan_unpoison_vmalloc(area->addr, requested_size); + /* + * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a + * best-effort approach, as they can be mapped outside of vmalloc code. + * For VM_ALLOC mappings, the pages are marked as accessible after + * getting mapped in __vmalloc_node_range(). + */ + if (!(flags & VM_ALLOC)) + area->addr = kasan_unpoison_vmalloc(area->addr, requested_size); return area; } @@ -3054,7 +3062,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, const void *caller) { struct vm_struct *area; - void *addr; + void *ret; unsigned long real_size = size; unsigned long real_align = align; unsigned int shift = PAGE_SHIFT; @@ -3116,10 +3124,13 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, prot = arch_vmap_pgprot_tagged(prot); /* Allocate physical pages and map them into vmalloc space. */ - addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node); - if (!addr) + ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node); + if (!ret) goto fail; + /* Mark the pages as accessible, now that they are mapped. */ + area->addr = kasan_unpoison_vmalloc(area->addr, real_size); + /* * In this function, newly allocated vm_struct has VM_UNINITIALIZED * flag. It means that vm_struct is not fully initialized. @@ -3131,7 +3142,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, if (!(vm_flags & VM_DEFER_KMEMLEAK)) kmemleak_vmalloc(area, size, gfp_mask); - return addr; + return area->addr; fail: if (shift > PAGE_SHIFT) { @@ -3823,7 +3834,10 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, } spin_unlock(&vmap_area_lock); - /* mark allocated areas as accessible */ + /* + * Mark allocated areas as accessible. Do it now as a best-effort + * approach, as they can be mapped outside of vmalloc code. + */ for (area = 0; area < nr_vms; area++) vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, vms[area]->size);