From patchwork Tue Mar 5 03:05:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 13581566 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-oi1-f175.google.com (mail-oi1-f175.google.com [209.85.167.175]) (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 689BE28E23 for ; Tue, 5 Mar 2024 03:05:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709607926; cv=none; b=bt0gCZ+dYAiRyyiLQQoZqasB5VHy5WiwujhpXv4vBfjDaChwEA6GGwaiKpSWs97fdIqKgZ6sZM5RyKIzxI3YIOrxWx9GhIVR4zsIpXnDo8bxhdF9hkY1vqOhl8qITzwGVyqvSWO/nyeZS3RkpDTuKF53dQ7L/73HXW6MoPi+iJ4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709607926; c=relaxed/simple; bh=lgfINaiLdOBQ4e4ik4QRTuWaoLgUUvuFaltC5V5ewrI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=l2PZLouM3HJZHoug9uGiJBbX/s/HM+JrsLFdFD0kg92PDc1fBPs9XM/2L/pqnln/iPgkIRqBt8IdXcnq93OYvDQn1HcCiifTkK7GTja4UQlmxLqe/wqjtuCrf+uLcVSl1DaVuvDxlBUy+NSlq0UF5aQKWu/lvC6HK+uoooHpY28= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=NT5APoc9; arc=none smtp.client-ip=209.85.167.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NT5APoc9" Received: by mail-oi1-f175.google.com with SMTP id 5614622812f47-3c19e18470aso3417827b6e.1 for ; Mon, 04 Mar 2024 19:05:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1709607924; x=1710212724; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Lvs1TetY/ywxZOqb7cu6/qS8FYbgNwju0ZDKmLnC7pk=; b=NT5APoc96Dviubg/QNLXZi9InEUbwVkFqfi7kwpXoGAEHO7GIJnkJCS8yq0hrNoRMW Z5dPMjU36IWXZYvnsBct5fJiAogDEVNAsdY+sZxMmTZ/NYF6HhuszGsyA4b4LiBNLA6Y DctfF6056mOmtIX8XV17OXr5aFHWPBb8MQnJTDAsFAe6Fb7B2GtYc4bEf6cBy4bPsf/4 ZiGtgaRDlFUK2pAHccUc5c0aLLgpEqfV7KPxf6mHyN523g4bAd4teqppLoyoXlFT9YOQ kKJbwOKU6bMRqC4D2XYwbF/B6k95JwLUTCNplr2z6lS12nsaqHJAayisf5gXl0XZC37A l+DA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709607924; x=1710212724; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Lvs1TetY/ywxZOqb7cu6/qS8FYbgNwju0ZDKmLnC7pk=; b=S3uRr7+Wc7cNBg4YCkuh+RpUg94bUoc7KFJxNtJ/nC/py+NZnJQwkHKOB9HYPRHv3G 1eSCW8nHIK38Jekb7cneWrDcnd9yF/szSb6CPyXeIQ4ZNajSoNDKu0OBqVaQn0TBa8v9 eBuyLmtKufiiT2qqjbRx23J3EC2i8J8wCjvminvlPaSOtg0AsJELXXcqAtuj2qR7aeGf pZkwVp/CSS6OQRHo0dDC022WwKNfXByZZGxRyJPft1b4G+xpRmU8QD2n8ilVtOt8SFuA Bm1vK0mW0Hk6vrsezVhhm2p+75fB6ouJ6z2VcbsNPD0UScup4D/WlUDGOqg3zZBG+XVV rYbQ== X-Gm-Message-State: AOJu0YxP8Xb6uG9cJBXzDA61WwoO9fS0MicOWC83+Zzvy8qr+j11JmE3 6E3buM9Tdb5HRVl3fMbE3Pltm3pCj7kri7nQF0mMTQaD3wv8AdHVMeMXcoio X-Google-Smtp-Source: AGHT+IFYfdb0wzVKskM65cSKwSSitCWQ5HIwpxCM5POpmVMYG5/Wx6Ndr8UyOlbODBpKZ1uFvI0VUw== X-Received: by 2002:a05:6808:4c3:b0:3c2:c13:978c with SMTP id a3-20020a05680804c300b003c20c13978cmr597466oie.5.1709607923728; Mon, 04 Mar 2024 19:05:23 -0800 (PST) Received: from localhost.localdomain ([2620:10d:c090:400::5:9426]) by smtp.gmail.com with ESMTPSA id i37-20020a635865000000b005dc5289c4edsm7941060pgm.64.2024.03.04.19.05.22 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Mon, 04 Mar 2024 19:05:23 -0800 (PST) From: Alexei Starovoitov To: bpf@vger.kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, torvalds@linux-foundation.org, brho@google.com, hannes@cmpxchg.org, lstoakes@gmail.com, akpm@linux-foundation.org, urezki@gmail.com, hch@infradead.org, rppt@kernel.org, boris.ostrovsky@oracle.com, sstabellini@kernel.org, jgross@suse.com, linux-mm@kvack.org, xen-devel@lists.xenproject.org, kernel-team@fb.com Subject: [PATCH v4 bpf-next 1/2] mm: Enforce VM_IOREMAP flag and range in ioremap_page_range. Date: Mon, 4 Mar 2024 19:05:15 -0800 Message-Id: <20240305030516.41519-2-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.39.3 (Apple Git-145) In-Reply-To: <20240305030516.41519-1-alexei.starovoitov@gmail.com> References: <20240305030516.41519-1-alexei.starovoitov@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net From: Alexei Starovoitov There are various users of get_vm_area() + ioremap_page_range() APIs. Enforce that get_vm_area() was requested as VM_IOREMAP type and range passed to ioremap_page_range() matches created vm_area to avoid accidentally ioremap-ing into wrong address range. Reviewed-by: Christoph Hellwig Signed-off-by: Alexei Starovoitov --- mm/vmalloc.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d12a17fc0c17..f42f98a127d5 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -307,8 +307,21 @@ static int vmap_range_noflush(unsigned long addr, unsigned long end, int ioremap_page_range(unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { + struct vm_struct *area; int err; + area = find_vm_area((void *)addr); + if (!area || !(area->flags & VM_IOREMAP)) { + WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr); + return -EINVAL; + } + if (addr != (unsigned long)area->addr || + (void *)end != area->addr + get_vm_area_size(area)) { + WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n", + addr, end, (long)area->addr, + (long)area->addr + get_vm_area_size(area)); + return -ERANGE; + } err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), ioremap_max_page_shift); 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Mon, 04 Mar 2024 19:05:27 -0800 (PST) Received: from localhost.localdomain ([2620:10d:c090:400::5:9426]) by smtp.gmail.com with ESMTPSA id ep2-20020a17090ae64200b0029932d175c3sm62083pjb.0.2024.03.04.19.05.25 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Mon, 04 Mar 2024 19:05:27 -0800 (PST) From: Alexei Starovoitov To: bpf@vger.kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, torvalds@linux-foundation.org, brho@google.com, hannes@cmpxchg.org, lstoakes@gmail.com, akpm@linux-foundation.org, urezki@gmail.com, hch@infradead.org, rppt@kernel.org, boris.ostrovsky@oracle.com, sstabellini@kernel.org, jgross@suse.com, linux-mm@kvack.org, xen-devel@lists.xenproject.org, kernel-team@fb.com Subject: [PATCH v4 bpf-next 2/2] mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages(). Date: Mon, 4 Mar 2024 19:05:16 -0800 Message-Id: <20240305030516.41519-3-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.39.3 (Apple Git-145) In-Reply-To: <20240305030516.41519-1-alexei.starovoitov@gmail.com> References: <20240305030516.41519-1-alexei.starovoitov@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net From: Alexei Starovoitov vmap/vmalloc APIs are used to map a set of pages into contiguous kernel virtual space. get_vm_area() with appropriate flag is used to request an area of kernel address range. It's used for vmalloc, vmap, ioremap, xen use cases. - vmalloc use case dominates the usage. Such vm areas have VM_ALLOC flag. - the areas created by vmap() function should be tagged with VM_MAP. - ioremap areas are tagged with VM_IOREMAP. BPF would like to extend the vmap API to implement a lazily-populated sparse, yet contiguous kernel virtual space. Introduce VM_SPARSE flag and vm_area_map_pages(area, start_addr, count, pages) API to map a set of pages within a given area. It has the same sanity checks as vmap() does. It also checks that get_vm_area() was created with VM_SPARSE flag which identifies such areas in /proc/vmallocinfo and returns zero pages on read through /proc/kcore. The next commits will introduce bpf_arena which is a sparsely populated shared memory region between bpf program and user space process. It will map privately-managed pages into a sparse vm area with the following steps: // request virtual memory region during bpf prog verification area = get_vm_area(area_size, VM_SPARSE); // on demand vm_area_map_pages(area, kaddr, kend, pages); vm_area_unmap_pages(area, kaddr, kend); // after bpf program is detached and unloaded free_vm_area(area); Signed-off-by: Alexei Starovoitov Reviewed-by: Christoph Hellwig Reviewed-by: Pasha Tatashin --- include/linux/vmalloc.h | 5 ++++ mm/vmalloc.c | 59 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 62 insertions(+), 2 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index c720be70c8dd..0f72c85a377b 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -35,6 +35,7 @@ struct iov_iter; /* in uio.h */ #else #define VM_DEFER_KMEMLEAK 0 #endif +#define VM_SPARSE 0x00001000 /* sparse vm_area. not all pages are present. */ /* bits [20..32] reserved for arch specific ioremap internals */ @@ -232,6 +233,10 @@ static inline bool is_vm_area_hugepages(const void *addr) } #ifdef CONFIG_MMU +int vm_area_map_pages(struct vm_struct *area, unsigned long start, + unsigned long end, struct page **pages); +void vm_area_unmap_pages(struct vm_struct *area, unsigned long start, + unsigned long end); void vunmap_range(unsigned long addr, unsigned long end); static inline void set_vm_flush_reset_perms(void *addr) { diff --git a/mm/vmalloc.c b/mm/vmalloc.c index f42f98a127d5..e5b8c70950bc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -648,6 +648,58 @@ static int vmap_pages_range(unsigned long addr, unsigned long end, return err; } +static int check_sparse_vm_area(struct vm_struct *area, unsigned long start, + unsigned long end) +{ + might_sleep(); + if (WARN_ON_ONCE(area->flags & VM_FLUSH_RESET_PERMS)) + return -EINVAL; + if (WARN_ON_ONCE(area->flags & VM_NO_GUARD)) + return -EINVAL; + if (WARN_ON_ONCE(!(area->flags & VM_SPARSE))) + return -EINVAL; + if ((end - start) >> PAGE_SHIFT > totalram_pages()) + return -E2BIG; + if (start < (unsigned long)area->addr || + (void *)end > area->addr + get_vm_area_size(area)) + return -ERANGE; + return 0; +} + +/** + * vm_area_map_pages - map pages inside given sparse vm_area + * @area: vm_area + * @start: start address inside vm_area + * @end: end address inside vm_area + * @pages: pages to map (always PAGE_SIZE pages) + */ +int vm_area_map_pages(struct vm_struct *area, unsigned long start, + unsigned long end, struct page **pages) +{ + int err; + + err = check_sparse_vm_area(area, start, end); + if (err) + return err; + + return vmap_pages_range(start, end, PAGE_KERNEL, pages, PAGE_SHIFT); +} + +/** + * vm_area_unmap_pages - unmap pages inside given sparse vm_area + * @area: vm_area + * @start: start address inside vm_area + * @end: end address inside vm_area + */ +void vm_area_unmap_pages(struct vm_struct *area, unsigned long start, + unsigned long end) +{ + if (check_sparse_vm_area(area, start, end)) + return; + + vunmap_range(start, end); +} + int is_vmalloc_or_module_addr(const void *x) { /* @@ -3822,9 +3874,9 @@ long vread_iter(struct iov_iter *iter, const char *addr, size_t count) if (flags & VMAP_RAM) copied = vmap_ram_vread_iter(iter, addr, n, flags); - else if (!(vm && (vm->flags & VM_IOREMAP))) + else if (!(vm && (vm->flags & (VM_IOREMAP | VM_SPARSE)))) copied = aligned_vread_iter(iter, addr, n); - else /* IOREMAP area is treated as memory hole */ + else /* IOREMAP | SPARSE area is treated as memory hole */ copied = zero_iter(iter, n); addr += copied; @@ -4415,6 +4467,9 @@ static int s_show(struct seq_file *m, void *p) if (v->flags & VM_IOREMAP) seq_puts(m, " ioremap"); + if (v->flags & VM_SPARSE) + seq_puts(m, " sparse"); + if (v->flags & VM_ALLOC) seq_puts(m, " vmalloc");