From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvMpWze1v15tMpZ0LuMJiEzrVnqlcAxrcQm5ocfYd/MOf6U/mFXGHFZiDXAunVfS6XYP0td ARC-Seal: i=1; a=rsa-sha256; t=1519676577; cv=none; d=google.com; s=arc-20160816; b=iXOSltPe/eZMKCjx4D6CmzfQ6EhXjZY+rgUxpUrSjW6c++8Fj+mJ4EeKbMUrtZ2qDe HOtmoBnFeKifFPqwpR2ARymYzXCkMKxfsNT7rLIjzg2XleLwON5fir8x/PxUrE2MXnXn t0v53kP7NqavEC3ah+Vn2R+/WDuDStmFVcQNVYAerARXm/4fXBEW/5taBmJ0QUhLxXKb SU1jLqSYDE8fChZG2wxjahZKXZRFgSrb4Uyr/rvz/ec1vZX1cgfoYZPW6P9hKXrkVSPu 2K7NQuN7ZNpy+eleN/9CZTEQZs8kV9uzGXtvZ+0wsBHcOHoiRFSVBKwtHr8t+4DdwHTO s9+Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=tIZhhCboYYS+rnbDlp3dn5iRKVO1yAR1PI7YIpVe9mc=; b=OPRqf2PQa+fnJbvJdNUMQ06hu0zKUV3QBi5yvsIhJhUhKhwcHm4RZ7xDMTVkm8U7Yt KYonOGzKHY9J2GQe8iGycAFHCB368rJDA8EvpkdNDc3HZBJjewkDK1iQstLWkGVCId7+ IzMv99pNioa43o9ikFUG7WEo8Op6p54TSKSe9tpU0bisLCyoUCMwRwQ2JM5fkH064bFy kFlSxONa4Ip/j6bikiXrxEoYkLHFzaCU1Et6bXVojVodrfrSVcr+0SKGzNDKSUSyR0G7 9Ovf3QfG7hfuaAD/oI1e5TTkI8UVa2CoQ8pRORNZT0sUj3jFNDh0Y3mNlk3EQpGdFTY2 Yveg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 83.175.124.243 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 83.175.124.243 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "=?UTF-8?q?Jan=20H . =20Sch=C3=B6nherr?=" , Dan Williams Subject: [PATCH 4.9 37/39] mm: Fix devm_memremap_pages() collision handling Date: Mon, 26 Feb 2018 21:20:58 +0100 Message-Id: <20180226201645.292220747@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180226201643.660109883@linuxfoundation.org> References: <20180226201643.660109883@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593231662350727514?= X-GMAIL-MSGID: =?utf-8?q?1593496387556325036?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan H. Schönherr commit 77dd66a3c67c93ab401ccc15efff25578be281fd upstream. If devm_memremap_pages() detects a collision while adding entries to the radix-tree, we call pgmap_radix_release(). Unfortunately, the function removes *all* entries for the range -- including the entries that caused the collision in the first place. Modify pgmap_radix_release() to take an additional argument to indicate where to stop, so that only newly added entries are removed from the tree. Cc: Fixes: 9476df7d80df ("mm: introduce find_dev_pagemap()") Signed-off-by: Jan H. Schönherr Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- kernel/memremap.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -194,7 +194,7 @@ void put_zone_device_page(struct page *p } EXPORT_SYMBOL(put_zone_device_page); -static void pgmap_radix_release(struct resource *res) +static void pgmap_radix_release(struct resource *res, resource_size_t end_key) { resource_size_t key, align_start, align_size, align_end; @@ -203,8 +203,11 @@ static void pgmap_radix_release(struct r align_end = align_start + align_size - 1; mutex_lock(&pgmap_lock); - for (key = res->start; key <= res->end; key += SECTION_SIZE) + for (key = res->start; key <= res->end; key += SECTION_SIZE) { + if (key >= end_key) + break; radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT); + } mutex_unlock(&pgmap_lock); } @@ -255,7 +258,7 @@ static void devm_memremap_pages_release( unlock_device_hotplug(); untrack_pfn(NULL, PHYS_PFN(align_start), align_size); - pgmap_radix_release(res); + pgmap_radix_release(res, -1); dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, "%s: failed to free all reserved pages\n", __func__); } @@ -289,7 +292,7 @@ struct dev_pagemap *find_dev_pagemap(res void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap) { - resource_size_t key, align_start, align_size, align_end; + resource_size_t key = 0, align_start, align_size, align_end; pgprot_t pgprot = PAGE_KERNEL; struct dev_pagemap *pgmap; struct page_map *page_map; @@ -392,7 +395,7 @@ void *devm_memremap_pages(struct device untrack_pfn(NULL, PHYS_PFN(align_start), align_size); err_pfn_remap: err_radix: - pgmap_radix_release(res); + pgmap_radix_release(res, key); devres_free(page_map); return ERR_PTR(error); }