#include #include #include #include #include #include #include #include /* * build a vector of user pages */ struct page **ceph_get_direct_page_vector(const void __user *data, int num_pages, bool write_page) { struct page **pages; int got = 0; int rc = 0; pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS); if (!pages) return ERR_PTR(-ENOMEM); while (got < num_pages) { rc = get_user_pages_unlocked( (unsigned long)data + ((unsigned long)got * PAGE_SIZE), num_pages - got, pages + got, write_page ? FOLL_WRITE : 0); if (rc < 0) break; BUG_ON(rc == 0); got += rc; } if (rc < 0) goto fail; return pages; fail: ceph_put_page_vector(pages, got, false); return ERR_PTR(rc); } EXPORT_SYMBOL(ceph_get_direct_page_vector); void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty) { int i; for (i = 0; i < num_pages; i++) { if (dirty) set_page_dirty_lock(pages[i]); put_page(pages[i]); } kvfree(pages); } EXPORT_SYMBOL(ceph_put_page_vector); void ceph_release_page_vector(struct page **pages, int num_pages) { int i; for (i = 0; i < num_pages; i++) __free_pages(pages[i], 0); kfree(pages); } EXPORT_SYMBOL(ceph_release_page_vector); /* * allocate a vector new pages */ struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags) { struct page **pages; int i; pages = kmalloc(sizeof(*pages) * num_pages, flags); if (!pages) return ERR_PTR(-ENOMEM); for (i = 0; i < num_pages; i++) { pages[i] = __page_cache_alloc(flags); if (pages[i] == NULL) { ceph_release_page_vector(pages, i); return ERR_PTR(-ENOMEM); } } return pages; } EXPORT_SYMBOL(ceph_alloc_page_vector); /* * copy user data into a page vector */ int ceph_copy_user_to_page_vector(struct page **pages, const void __user *data, loff_t off, size_t len) { int i = 0; int po = off & ~PAGE_MASK; int left = len; int l, bad; while (left > 0) { l = min_t(int, PAGE_SIZE-po, left); bad = copy_from_user(page_address(pages[i]) + po, data, l); if (bad == l) return -EFAULT; data += l - bad; left -= l - bad; po += l - bad; if (po == PAGE_SIZE) { po = 0; i++; } } return len; } EXPORT_SYMBOL(ceph_copy_user_to_page_vector); void ceph_copy_to_page_vector(struct page **pages, const void *data, loff_t off, size_t len) { int i = 0; size_t po = off & ~PAGE_MASK; size_t left = len; while (left > 0) { size_t l = min_t(size_t, PAGE_SIZE-po, left); memcpy(page_address(pages[i]) + po, data, l); data += l; left -= l; po += l; if (po == PAGE_SIZE) { po = 0; i++; } } } EXPORT_SYMBOL(ceph_copy_to_page_vector); void ceph_copy_from_page_vector(struct page **pages, void *data, loff_t off, size_t len) { int i = 0; size_t po = off & ~PAGE_MASK; size_t left = len; while (left > 0) { size_t l = min_t(size_t, PAGE_SIZE-po, left); memcpy(data, page_address(pages[i]) + po, l); data += l; left -= l; po += l; if (po == PAGE_SIZE) { po = 0; i++; } } } EXPORT_SYMBOL(ceph_copy_from_page_vector); /* * Zero an extent within a page vector. Offset is relative to the * start of the first page. */ void ceph_zero_page_vector_range(int off, int len, struct page **pages) { int i = off >> PAGE_SHIFT; off &= ~PAGE_MASK; dout("zero_page_vector_page %u~%u\n", off, len); /* leading partial page? */ if (off) { int end = min((int)PAGE_SIZE, off + len); dout("zeroing %d %p head from %d\n", i, pages[i], (int)off); zero_user_segment(pages[i], off, end); len -= (end - off); i++; } while (len >= PAGE_SIZE) { dout("zeroing %d %p len=%d\n", i, pages[i], len); zero_user_segment(pages[i], 0, PAGE_SIZE); len -= PAGE_SIZE; i++; } /* trailing partial page? */ if (len) { dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len); zero_user_segment(pages[i], 0, len); } } EXPORT_SYMBOL(ceph_zero_page_vector_range); '>ignoremode:
authorTejun Heo <tj@kernel.org>2017-01-26 16:47:28 -0500
committerTejun Heo <tj@kernel.org>2017-01-26 16:47:28 -0500
commit07cd12945551b63ecb1a349d50a6d69d1d6feb4a (patch)
tree75f65eba7eac9277971082a2d5a4cf1370562c0c /net/x25/Makefile
parent7ce7d89f48834cefece7804d38fc5d85382edf77 (diff)
cgroup: don't online subsystems before cgroup_name/path() are operational
While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems before the new cgroup is associated with it kernfs_node. This is fine for cgroup proper but cgroup_name/path() depend on the associated kernfs_node and if a subsystem makes the new cgroup_subsys_state visible, which they're allowed to after onlining, it can lead to NULL dereference. The current code performs cgroup creation and subsystem onlining in cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems visible afterwards. There's no reason to online the subsystems early and we can simply drop cgroup_apply_control_enable() call from cgroup_create() so that the subsystems are onlined and made visible at the same time. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") Cc: stable@vger.kernel.org # v4.6+
Diffstat (limited to 'net/x25/Makefile')