From patchwork Mon Jan 24 18:05:00 2022 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: 12722809 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4EE0CC433F5 for ; Mon, 24 Jan 2022 19:00:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0s0zdjK4/A2zGfh6YpagJTxa7ydzPB0HqIUIsQW042g=; b=fz19Ns3iqUhVLR wkHDoTOvPIhZTO08teLKTwU0aAgtyTj4pkZ26e6tHgrnyMjwcpiQbo5BYrTCSfZ+D9OMialXgJ/6V gJ9R7Nda2L2UFU//06IoKvWZJAQfEv6ER+aaVjQ11utlVfLGe9yVUNvd0PXKOBZv8Uk+TQs+gjW1I aL035zkbmrtDB1E4gb2bJFgVXNPhz7zn6LMH6hO/EugfVyjhPikxa1vgdc2VpSyoDunkiMiLKowKy kx7GroWyLMfbrFS1at8qjlrD6c2qFwQyeHlnq7nYjtamNI6FvHYdnhuthfXPIuXTDzssloBQ09JQP 42dNv77kBsL4vVQn672A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC4Ya-004gz4-Ue; Mon, 24 Jan 2022 18:59:14 +0000 Received: from out0.migadu.com ([94.23.1.103]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC3jU-004NES-Pk for linux-arm-kernel@lists.infradead.org; Mon, 24 Jan 2022 18:06:26 +0000 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=1643047583; 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=4/y0HjGmlj8gRZl7sKKC15OiIQ+URUy4QXcXfGAQLsE=; b=cEt2JHsQwrkLVfMoZK13nWffMlEiwZaIGbGyF4gC8cAeDpRvqj1bkguYhGcbPfveiE3JA2 +1sTkZavlWgOjB5XJNxkdXXXbmh7xEABFORykbamGRFegBc2vbxDSqj+Mw7AZ4f8QGXi31 /c/hBakatNfmGBIuDYr5ea0bqnV1CIo= 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 v6 26/39] kasan, vmalloc: unpoison VM_ALLOC pages after mapping Date: Mon, 24 Jan 2022 19:05:00 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220124_100625_033449_EDEECFB5 X-CRM114-Status: GOOD ( 18.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 92e635b7490c..b65adac1cd80 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; } @@ -3055,7 +3063,7 @@ 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; @@ -3117,10 +3125,13 @@ 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. @@ -3132,7 +3143,7 @@ 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) { @@ -3816,7 +3827,10 @@ 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);