Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2)  * Copyright (c) 2006 Oracle.  All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * This software is available to you under a choice of one of two
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * licenses.  You may choose to be licensed under the terms of the GNU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * General Public License (GPL) Version 2, available from the file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * COPYING in the main directory of this source tree, or the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * OpenIB.org BSD license below:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *     Redistribution and use in source and binary forms, with or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  *     without modification, are permitted provided that the following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  *     conditions are met:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  *      - Redistributions of source code must retain the above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *        copyright notice, this list of conditions and the following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  *        disclaimer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *      - Redistributions in binary form must reproduce the above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  *        copyright notice, this list of conditions and the following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  *        disclaimer in the documentation and/or other materials
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  *        provided with the distribution.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  * SOFTWARE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) #include <linux/seq_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) #include <linux/proc_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) #include "rds.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42)  * This file implements a getsockopt() call which copies a set of fixed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43)  * sized structs into a user-specified buffer as a means of providing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44)  * read-only information about RDS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46)  * For a given information source there are a given number of fixed sized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47)  * structs at a given time.  The structs are only copied if the user-specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48)  * buffer is big enough.  The destination pages that make up the buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)  * are pinned for the duration of the copy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)  * This gives us the following benefits:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53)  * - simple implementation, no copy "position" across multiple calls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54)  * - consistent snapshot of an info source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55)  * - atomic copy works well with whatever locking info source has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56)  * - one portable tool to get rds info across implementations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57)  * - long-lived tool can get info without allocating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59)  * at the following costs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61)  * - info source copy must be pinned, may be "large"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) struct rds_info_iterator {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	struct page **pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	void *addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) static DEFINE_SPINLOCK(rds_info_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) static rds_info_func rds_info_funcs[RDS_INFO_LAST - RDS_INFO_FIRST + 1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) void rds_info_register_func(int optname, rds_info_func func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	int offset = optname - RDS_INFO_FIRST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	spin_lock(&rds_info_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	BUG_ON(rds_info_funcs[offset]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	rds_info_funcs[offset] = func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	spin_unlock(&rds_info_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) EXPORT_SYMBOL_GPL(rds_info_register_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) void rds_info_deregister_func(int optname, rds_info_func func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	int offset = optname - RDS_INFO_FIRST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	spin_lock(&rds_info_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	BUG_ON(rds_info_funcs[offset] != func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	rds_info_funcs[offset] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	spin_unlock(&rds_info_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) EXPORT_SYMBOL_GPL(rds_info_deregister_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)  * Typically we hold an atomic kmap across multiple rds_info_copy() calls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)  * because the kmap is so expensive.  This must be called before using blocking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)  * operations while holding the mapping and as the iterator is torn down.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) void rds_info_iter_unmap(struct rds_info_iterator *iter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	if (iter->addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		kunmap_atomic(iter->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		iter->addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)  * get_user_pages() called flush_dcache_page() on the pages for us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) void rds_info_copy(struct rds_info_iterator *iter, void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 		   unsigned long bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	unsigned long this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	while (bytes) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		if (!iter->addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 			iter->addr = kmap_atomic(*iter->pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 		this = min(bytes, PAGE_SIZE - iter->offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		rdsdebug("page %p addr %p offset %lu this %lu data %p "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 			  "bytes %lu\n", *iter->pages, iter->addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 			  iter->offset, this, data, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		memcpy(iter->addr + iter->offset, data, this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		data += this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		bytes -= this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 		iter->offset += this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		if (iter->offset == PAGE_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 			kunmap_atomic(iter->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 			iter->addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 			iter->offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 			iter->pages++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) EXPORT_SYMBOL_GPL(rds_info_copy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)  * @optval points to the userspace buffer that the information snapshot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)  * will be copied into.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)  * @optlen on input is the size of the buffer in userspace.  @optlen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)  * on output is the size of the requested snapshot in bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)  * This function returns -errno if there is a failure, particularly -ENOSPC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)  * if the given userspace buffer was not large enough to fit the snapshot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)  * On success it returns the positive number of bytes of each array element
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)  * in the snapshot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 			int __user *optlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	struct rds_info_iterator iter;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	struct rds_info_lengths lens;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	unsigned long nr_pages = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	unsigned long start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	rds_info_func func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	struct page **pages = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	int total;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	if (get_user(len, optlen)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		ret = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	/* check for all kinds of wrapping and the like */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	start = (unsigned long)optval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	if (len < 0 || len > INT_MAX - PAGE_SIZE + 1 || start + len < start) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	/* a 0 len call is just trying to probe its length */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	if (len == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		goto call_func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	nr_pages = (PAGE_ALIGN(start + len) - (start & PAGE_MASK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 			>> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	if (!pages) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	ret = pin_user_pages_fast(start, nr_pages, FOLL_WRITE, pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	if (ret != nr_pages) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		if (ret > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 			nr_pages = ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 			nr_pages = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		ret = -EAGAIN; /* XXX ? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	rdsdebug("len %d nr_pages %lu\n", len, nr_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) call_func:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	func = rds_info_funcs[optname - RDS_INFO_FIRST];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	if (!func) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		ret = -ENOPROTOOPT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	iter.pages = pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	iter.addr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	iter.offset = start & (PAGE_SIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	func(sock, len, &iter, &lens);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	BUG_ON(lens.each == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	total = lens.nr * lens.each;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	rds_info_iter_unmap(&iter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	if (total > len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		len = total;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		ret = -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		len = total;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		ret = lens.each;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	if (put_user(len, optlen))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		ret = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	if (pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		unpin_user_pages(pages, nr_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	kfree(pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) }