From patchwork Fri Jan 10 18:40:43 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Jackman X-Patchwork-Id: 13935357 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9403D216E02 for ; Fri, 10 Jan 2025 18:41:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736534510; cv=none; b=Z0L8C/x5asgupevIbyiXB5kEhEahskAdoJoENR89i+sn5EX0OSmSZT04moLFiJvsmWo9RjjJ+joPuM4/0iXBaRh/i1GRph7fZgQ4FtHpbBEE/7BT37aijXrm3wt1CJamBYzPkKLjguNl88lNoLmyQIf5fw9OmDo25SOk2v0jUIY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736534510; c=relaxed/simple; bh=qC2aC8eAp33KA8O+Z6LlsHyIL/uhbg4PRbpKGbN5hWc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=fv4mGp9s4SXZxwO1db8mitW7WNd9YYLsPftr0JEgJ9YjtDnYPo2MX73gy295DVFZBZoq4r5TPvj54iHu9qgVcky/25StMqXRwMC0ZdefCPYjgrV8ymfc26dnT0Z1z/Sq/3UciV/K4YUky0pvwRmmVKiAueNZqCUmrcXQA5mEi9Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=E0ek2zTG; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="E0ek2zTG" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-43621907030so19341145e9.1 for ; Fri, 10 Jan 2025 10:41:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1736534484; x=1737139284; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=HFKS9He99X0lK3xnnbI99ZyULyVP6qmX2/a79HHV3Mw=; b=E0ek2zTG7RebbpLy1ud9IqdpKB+S/lUlq8VpwddP0/BcCU99Lrx63wjurhuegtUV/9 4vw7MHLpK/2P78qLxCwzHnV0jgswt6RtNizyiOvHYTQybNoxxyVGsX63h3W+U45uBIjf E65QJUPR3waUNOu30Tgu2L04sYsTBzfCf66QwOZ8hV4/iOrtZEMYOZKgrAxtX6Y4kw8s ew3Tufd33HyB0Z345QUqOSOXsYC2JnUr7StCQBomz/XaAV8X9WyXdTnVVhjPwhBguB5S MHhhYWr9Ixc2U647WKeCKTKDH84ACy/m39Qm+jid0LFOAgB7Ze+n2I2i6b/dG2GAYQBp BEzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736534484; x=1737139284; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=HFKS9He99X0lK3xnnbI99ZyULyVP6qmX2/a79HHV3Mw=; b=t/2irYU8SSHAuIoCXxWHzB1Qp54HOaugDDMmvreKgJkPeQQsbdP65gmmAScGhgxnEA RZgCI+enesZWyfgx22+gJVnN6O8vx82sBeyMWI/GP2l7WqRX7qyqRFScl0yinEyKeSUX ZmwX1pIJYsJrsypX62sS1o7YnApjrnfjo1AvyubzHff385UEQEGEs9dEPzx6pn3YZds9 ymDJQloMZPrnbUyOoPbzu+IMQ7xQEEUpMbPGsG/Pyog58KV1kD5MI/9ElcI+w/fh3Er/ 26SqU0bolB/vp+EyT0FVfnPxayou2FZw/uKwVW07aKVubOVxeS+A6i5LO95XdTjLayEk TW5w== X-Forwarded-Encrypted: i=1; AJvYcCXBA+fOGutceEwUEH7zXTD+s1sXJme6Tr1LPvikDt1TmDwRhacsTM7BxrGKGQXmDnlvBEY=@vger.kernel.org X-Gm-Message-State: AOJu0Ywn3Iy+2Bylt83bRAYb5u1s9QsHZ5XONy7XdGCwGARXRhYVa8dx 4l/4Jh01F433Iay0uuiB0m6orbUMPktzpO9RD+k2NNui17PtvT2Lvymjt0idVBox7xqLPgS7YqO i59ZGYgq/dQ== X-Google-Smtp-Source: AGHT+IHb2tLJeEj/nhEIcvCueP11HP0tzz903p60s9RvGJF27LFwQlQKr5YD0ey6aPDR1IvAD0AJ740K8RZlJQ== X-Received: from wmbbh20.prod.google.com ([2002:a05:600c:3d14:b0:434:fd4d:ffad]) (user=jackmanb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3c85:b0:436:18d0:aa6e with SMTP id 5b1f17b1804b1-436e2679a7cmr125832515e9.5.1736534484149; Fri, 10 Jan 2025 10:41:24 -0800 (PST) Date: Fri, 10 Jan 2025 18:40:43 +0000 In-Reply-To: <20250110-asi-rfc-v2-v2-0-8419288bc805@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250110-asi-rfc-v2-v2-0-8419288bc805@google.com> X-Mailer: b4 0.15-dev Message-ID: <20250110-asi-rfc-v2-v2-17-8419288bc805@google.com> Subject: [PATCH RFC v2 17/29] mm: asi: Map vmalloc/vmap data as nonsensitive From: Brendan Jackman To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Richard Henderson , Matt Turner , Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Guo Ren , Brian Cain , Huacai Chen , WANG Xuerui , Geert Uytterhoeven , Michal Simek , Thomas Bogendoerfer , Dinh Nguyen , Jonas Bonn , Stefan Kristiansson , Stafford Horne , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Chris Zankel , Max Filippov , Arnd Bergmann , Andrew Morton , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Uladzislau Rezki , Christoph Hellwig , Masami Hiramatsu , Mathieu Desnoyers , Mike Rapoport , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Dennis Zhou , Tejun Heo , Christoph Lameter , Sean Christopherson , Paolo Bonzini , Ard Biesheuvel , Josh Poimboeuf , Pawan Gupta Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, Brendan Jackman We add new VM flags for sensitive and global-nonsensitive, parallel to the corresponding GFP flags. __get_vm_area_node and friends will default to creating global-nonsensitive VM areas, and vmap then calls asi_map as necessary. __vmalloc_node_range has additional logic to check and set defaults for the sensitivity of the underlying page allocation. It does this via an initial __set_asi_flags call - note that it then calls __get_vm_area_node which also calls __set_asi_flags. This second call is a NOP. By default, we mark the underlying page allocation as sensitive, even if the VM area is global-nonsensitive. This is just an optimization to avoid unnecessary asi_map etc, since presumably most code has no reason to access vmalloc'd data through the direct map. There are some details of the GFP-flag/VM-flag interaction that are not really obvious, for example: what should happen when callers of __vmalloc explicitly set GFP sensitivity flags? (That function has no VM flags argument). For the moment let's just not block on that and focus on adding the infrastructure, though. At the moment, the high-level vmalloc APIs doesn't actually provide a way to configure sensitivity, this commit just adds the infrastructure. We'll have to decide how to expose this to allocation sites as we implement more denylist logic. vmap does already allow configuring vm flags. Signed-off-by: Brendan Jackman --- mm/vmalloc.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 8d260f2174fe664b54dcda054cb9759ae282bf03..00745edf0b2c5f4c769a46bdcf0872223de5299d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3210,6 +3210,7 @@ struct vm_struct *remove_vm_area(const void *addr) { struct vmap_area *va; struct vm_struct *vm; + unsigned long vm_addr; might_sleep(); @@ -3221,6 +3222,7 @@ struct vm_struct *remove_vm_area(const void *addr) if (!va || !va->vm) return NULL; vm = va->vm; + vm_addr = (unsigned long) READ_ONCE(vm->addr); debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm)); debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm)); @@ -3352,6 +3354,7 @@ void vfree(const void *addr) addr); return; } + asi_unmap(ASI_GLOBAL_NONSENSITIVE, vm->addr, get_vm_area_size(vm)); if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS)) vm_reset_perms(vm); @@ -3397,6 +3400,7 @@ void vunmap(const void *addr) addr); return; } + asi_unmap(ASI_GLOBAL_NONSENSITIVE, vm->addr, get_vm_area_size(vm)); kfree(vm); } EXPORT_SYMBOL(vunmap); @@ -3445,16 +3449,21 @@ void *vmap(struct page **pages, unsigned int count, addr = (unsigned long)area->addr; if (vmap_pages_range(addr, addr + size, pgprot_nx(prot), - pages, PAGE_SHIFT) < 0) { - vunmap(area->addr); - return NULL; - } + pages, PAGE_SHIFT) < 0) + goto err; + + if (asi_map(ASI_GLOBAL_NONSENSITIVE, area->addr, + get_vm_area_size(area))) + goto err; /* The necessary asi_unmap() is in vunmap. */ if (flags & VM_MAP_PUT_PAGES) { area->pages = pages; area->nr_pages = count; } return area->addr; +err: + vunmap(area->addr); + return NULL; } EXPORT_SYMBOL(vmap); @@ -3711,6 +3720,10 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, goto fail; } + if (asi_map(ASI_GLOBAL_NONSENSITIVE, area->addr, + get_vm_area_size(area))) + goto fail; /* The necessary asi_unmap() is in vfree. */ + return area->addr; fail: