From 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 2 Sep 2026 15:31:14 -0700 Subject: treewide: refresh kmalloc_obj() conversions This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook --- net/rds/info.c | 267 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 267 insertions(+) create mode 100644 net/rds/info.c (limited to 'net/rds/info.c') diff --git a/net/rds/info.c b/net/rds/info.c new file mode 100644 index 000000000..a57f81a05 --- /dev/null +++ b/net/rds/info.c @@ -0,0 +1,267 @@ +/* + * Copyright (c) 2006 Oracle. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include +#include +#include +#include +#include +#include +#include + +#include "rds.h" + +/* + * This file implements a getsockopt() call which copies a set of fixed + * sized structs into a user-specified buffer as a means of providing + * read-only information about RDS. + * + * For a given information source there are a given number of fixed sized + * structs at a given time. The structs are only copied if the user-specified + * buffer is big enough. The destination pages that make up the buffer + * are pinned for the duration of the copy. + * + * This gives us the following benefits: + * + * - simple implementation, no copy "position" across multiple calls + * - consistent snapshot of an info source + * - atomic copy works well with whatever locking info source has + * - one portable tool to get rds info across implementations + * - long-lived tool can get info without allocating + * + * at the following costs: + * + * - info source copy must be pinned, may be "large" + */ + +struct rds_info_iterator { + struct page **pages; + void *addr; + unsigned long offset; +}; + +DEFINE_STATIC_SRCU(rds_info_srcu); +static DEFINE_SPINLOCK(rds_info_lock); +static rds_info_func rds_info_funcs[RDS_INFO_LAST - RDS_INFO_FIRST + 1]; + +void rds_info_register_func(int optname, rds_info_func func) +{ + int offset = optname - RDS_INFO_FIRST; + + BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST); + + spin_lock(&rds_info_lock); + if (WARN_ON_ONCE(rds_info_funcs[offset])) { + spin_unlock(&rds_info_lock); + return; + } + WRITE_ONCE(rds_info_funcs[offset], func); + spin_unlock(&rds_info_lock); +} +EXPORT_SYMBOL_GPL(rds_info_register_func); + +void rds_info_deregister_func(int optname, rds_info_func func) +{ + int offset = optname - RDS_INFO_FIRST; + + BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST); + + spin_lock(&rds_info_lock); + if (WARN_ON_ONCE(rds_info_funcs[offset] != func)) { + spin_unlock(&rds_info_lock); + return; + } + WRITE_ONCE(rds_info_funcs[offset], NULL); + spin_unlock(&rds_info_lock); + synchronize_srcu(&rds_info_srcu); +} +EXPORT_SYMBOL_GPL(rds_info_deregister_func); + +/* + * Typically we hold an atomic kmap across multiple rds_info_copy() calls + * because the kmap is so expensive. This must be called before using blocking + * operations while holding the mapping and as the iterator is torn down. + */ +void rds_info_iter_unmap(struct rds_info_iterator *iter) +{ + if (iter->addr) { + kunmap_atomic(iter->addr); + iter->addr = NULL; + } +} + +/* + * get_user_pages() called flush_dcache_page() on the pages for us. + */ +void rds_info_copy(struct rds_info_iterator *iter, void *data, + unsigned long bytes) +{ + unsigned long this; + + while (bytes) { + if (!iter->addr) + iter->addr = kmap_atomic(*iter->pages); + + this = min(bytes, PAGE_SIZE - iter->offset); + + rdsdebug("page %p addr %p offset %lu this %lu data %p " + "bytes %lu\n", *iter->pages, iter->addr, + iter->offset, this, data, bytes); + + memcpy(iter->addr + iter->offset, data, this); + + data += this; + bytes -= this; + iter->offset += this; + + if (iter->offset == PAGE_SIZE) { + kunmap_atomic(iter->addr); + iter->addr = NULL; + iter->offset = 0; + iter->pages++; + } + } +} +EXPORT_SYMBOL_GPL(rds_info_copy); + +/* + * @opt->iter_out describes the buffer that the information snapshot will be + * copied into, and @opt->optlen is the size of that buffer on input. On + * output @opt->optlen is set to the size of the requested snapshot in bytes. + * + * This function returns -errno if there is a failure, particularly -ENOSPC + * if the given buffer was not large enough to fit the snapshot. On success + * it returns the positive number of bytes of each array element in the + * snapshot. + */ +int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt) +{ + struct rds_info_iterator iter; + struct rds_info_lengths lens; + unsigned long nr_pages = 0; + rds_info_func func; + struct page **pages = NULL; + size_t offset0 = 0; + int srcu_idx; + int npages = 0; + int ret; + int len; + int total; + + len = opt->optlen; + + /* check for all kinds of wrapping and the like */ + if (len < 0 || len > INT_MAX - PAGE_SIZE + 1) { + ret = -EINVAL; + goto out; + } + + /* The info producers write into the pages with kmap_atomic() while + * holding a spinlock, so they need a genuine page-backed user buffer. + */ + if (!user_backed_iter(&opt->iter_out)) { + ret = -EOPNOTSUPP; + goto out; + } + + /* a 0 len call is just trying to probe its length */ + if (len == 0) + goto call_func; + + /* + * Preallocate the page array and pass it in so that + * iov_iter_extract_pages() fills it in place rather than allocating + * one for us. Handing it a non-NULL array keeps ownership of the + * array with us on every return path, instead of depending on the + * iterator code to allocate and hand it back. + */ + npages = iov_iter_npages(&opt->iter_out, INT_MAX); + pages = kvmalloc_objs(*pages, npages); + if (!pages) { + ret = -ENOMEM; + goto out; + } + + ret = iov_iter_extract_pages(&opt->iter_out, &pages, len, npages, + 0, &offset0); + if (ret < 0) + goto out; + nr_pages = DIV_ROUND_UP(offset0 + ret, PAGE_SIZE); + if (ret != len) { + ret = -EAGAIN; /* XXX ? */ + goto out; + } + + rdsdebug("len %d nr_pages %lu\n", len, nr_pages); + +call_func: + srcu_idx = srcu_read_lock(&rds_info_srcu); + func = READ_ONCE(rds_info_funcs[optname - RDS_INFO_FIRST]); + if (!func) { + srcu_read_unlock(&rds_info_srcu, srcu_idx); + ret = -ENOPROTOOPT; + goto out; + } + + iter.pages = pages; + iter.addr = NULL; + iter.offset = offset0; + + func(sock, len, &iter, &lens); + srcu_read_unlock(&rds_info_srcu, srcu_idx); + BUG_ON(lens.each == 0); + + total = lens.nr * lens.each; + + rds_info_iter_unmap(&iter); + + if (total > len) { + len = total; + ret = -ENOSPC; + } else { + len = total; + ret = lens.each; + } + + opt->optlen = len; + +out: + /* + * iov_iter_extract_pages() pins only user-backed (ubuf) iters; + * iov_iter_extract_will_pin() reports whether an unpin is owed here. + */ + if (pages && iov_iter_extract_will_pin(&opt->iter_out)) + unpin_user_pages_dirty_lock(pages, nr_pages, true); + kvfree(pages); + + return ret; +} -- cgit v1.3.1