/* * Copyright (c) 2013 * Phillip Lougher * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include #include #include #include "page_actor.h" /* * This file contains implementations of page_actor for decompressing into * an intermediate buffer, and for decompressing directly into the * page cache. * * Calling code should avoid sleeping between calls to squashfs_first_page() * and squashfs_finish_page(). */ /* Implementation of page_actor for decompressing into intermediate buffer */ static void *cache_first_page(struct squashfs_page_actor *actor) { actor->next_page = 1; return actor->buffer[0]; } static void *cache_next_page(struct squashfs_page_actor *actor) { if (actor->next_page == actor->pages) return NULL; return actor->buffer[actor->next_page++]; } static void cache_finish_page(struct squashfs_page_actor *actor) { /* empty */ } struct squashfs_page_actor *squashfs_page_actor_init(void **buffer, int pages, int length) { struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL); if (actor == NULL) return NULL; actor->length = length ? : pages * PAGE_SIZE; actor->buffer = buffer; actor->pages = pages; actor->next_page = 0; actor->squashfs_first_page = cache_first_page; actor->squashfs_next_page = cache_next_page; actor->squashfs_finish_page = cache_finish_page; return actor; } /* Implementation of page_actor for decompressing directly into page cache. */ static void *direct_first_page(struct squashfs_page_actor *actor) { actor->next_page = 1; return actor->pageaddr = kmap_atomic(actor->page[0]); } static void *direct_next_page(struct squashfs_page_actor *actor) { if (actor->pageaddr) kunmap_atomic(actor->pageaddr); return actor->pageaddr = actor->next_page == actor->pages ? NULL : kmap_atomic(actor->page[actor->next_page++]); } static void direct_finish_page(struct squashfs_page_actor *actor) { if (actor->pageaddr) kunmap_atomic(actor->pageaddr); } struct squashfs_page_actor *squashfs_page_actor_init_special(struct page **page, int pages, int length) { struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL); if (actor == NULL) return NULL; actor->length = length ? : pages * PAGE_SIZE; actor->page = page; actor->pages = pages; actor->next_page = 0; actor->pageaddr = NULL; actor->squashfs_first_page = direct_first_page; actor->squashfs_next_page = direct_next_page; actor->squashfs_finish_page = direct_finish_page; return actor; } 'qt'>
path: root/include/trace/events/skb.h
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authorzhong jiang <zhongjiang@huawei.com>2017-01-24 15:18:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-24 16:26:14 -0800
commit3277953de2f31dd03c6375e9a9f680ac37fc9d27 (patch)
tree6ba22924faa1b82ef2f0277db10a3f5abdc44157 /include/trace/events/skb.h
parent3705ccfdd1e8b539225ce20e3925a945cc788d67 (diff)
mm: do not export ioremap_page_range symbol for external module
Recently, I've found cases in which ioremap_page_range was used incorrectly, in external modules, leading to crashes. This can be partly attributed to the fact that ioremap_page_range is lower-level, with fewer protections, as compared to the other functions that an external module would typically call. Those include: ioremap_cache ioremap_nocache ioremap_prot ioremap_uc ioremap_wc ioremap_wt ...each of which wraps __ioremap_caller, which in turn provides a safer way to achieve the mapping. Therefore, stop EXPORT-ing ioremap_page_range. Link: http://lkml.kernel.org/r/1485173220-29010-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Suggested-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/trace/events/skb.h')