![Greg Kroah-Hartman](/assets/img/avatar_default.png)
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1692 lines
41 KiB
C
1692 lines
41 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* /proc/sys support
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*/
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#include <linux/init.h>
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#include <linux/sysctl.h>
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#include <linux/poll.h>
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#include <linux/proc_fs.h>
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#include <linux/printk.h>
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#include <linux/security.h>
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#include <linux/sched.h>
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#include <linux/cred.h>
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#include <linux/namei.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include "internal.h"
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static const struct dentry_operations proc_sys_dentry_operations;
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static const struct file_operations proc_sys_file_operations;
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static const struct inode_operations proc_sys_inode_operations;
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static const struct file_operations proc_sys_dir_file_operations;
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static const struct inode_operations proc_sys_dir_operations;
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/* Support for permanently empty directories */
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struct ctl_table sysctl_mount_point[] = {
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{ }
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};
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static bool is_empty_dir(struct ctl_table_header *head)
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{
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return head->ctl_table[0].child == sysctl_mount_point;
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}
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static void set_empty_dir(struct ctl_dir *dir)
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{
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dir->header.ctl_table[0].child = sysctl_mount_point;
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}
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static void clear_empty_dir(struct ctl_dir *dir)
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{
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dir->header.ctl_table[0].child = NULL;
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}
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void proc_sys_poll_notify(struct ctl_table_poll *poll)
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{
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if (!poll)
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return;
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atomic_inc(&poll->event);
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wake_up_interruptible(&poll->wait);
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}
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static struct ctl_table root_table[] = {
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{
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.procname = "",
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.mode = S_IFDIR|S_IRUGO|S_IXUGO,
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},
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{ }
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};
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static struct ctl_table_root sysctl_table_root = {
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.default_set.dir.header = {
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{{.count = 1,
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.nreg = 1,
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.ctl_table = root_table }},
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.ctl_table_arg = root_table,
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.root = &sysctl_table_root,
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.set = &sysctl_table_root.default_set,
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},
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};
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static DEFINE_SPINLOCK(sysctl_lock);
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static void drop_sysctl_table(struct ctl_table_header *header);
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static int sysctl_follow_link(struct ctl_table_header **phead,
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struct ctl_table **pentry);
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static int insert_links(struct ctl_table_header *head);
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static void put_links(struct ctl_table_header *header);
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static void sysctl_print_dir(struct ctl_dir *dir)
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{
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if (dir->header.parent)
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sysctl_print_dir(dir->header.parent);
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pr_cont("%s/", dir->header.ctl_table[0].procname);
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}
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static int namecmp(const char *name1, int len1, const char *name2, int len2)
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{
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int minlen;
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int cmp;
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minlen = len1;
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if (minlen > len2)
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minlen = len2;
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cmp = memcmp(name1, name2, minlen);
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if (cmp == 0)
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cmp = len1 - len2;
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return cmp;
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}
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/* Called under sysctl_lock */
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static struct ctl_table *find_entry(struct ctl_table_header **phead,
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struct ctl_dir *dir, const char *name, int namelen)
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{
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struct ctl_table_header *head;
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struct ctl_table *entry;
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struct rb_node *node = dir->root.rb_node;
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while (node)
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{
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struct ctl_node *ctl_node;
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const char *procname;
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int cmp;
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ctl_node = rb_entry(node, struct ctl_node, node);
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head = ctl_node->header;
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entry = &head->ctl_table[ctl_node - head->node];
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procname = entry->procname;
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cmp = namecmp(name, namelen, procname, strlen(procname));
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if (cmp < 0)
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node = node->rb_left;
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else if (cmp > 0)
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node = node->rb_right;
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else {
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*phead = head;
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return entry;
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}
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}
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return NULL;
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}
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static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
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{
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struct rb_node *node = &head->node[entry - head->ctl_table].node;
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struct rb_node **p = &head->parent->root.rb_node;
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struct rb_node *parent = NULL;
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const char *name = entry->procname;
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int namelen = strlen(name);
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while (*p) {
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struct ctl_table_header *parent_head;
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struct ctl_table *parent_entry;
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struct ctl_node *parent_node;
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const char *parent_name;
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int cmp;
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parent = *p;
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parent_node = rb_entry(parent, struct ctl_node, node);
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parent_head = parent_node->header;
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parent_entry = &parent_head->ctl_table[parent_node - parent_head->node];
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parent_name = parent_entry->procname;
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cmp = namecmp(name, namelen, parent_name, strlen(parent_name));
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if (cmp < 0)
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p = &(*p)->rb_left;
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else if (cmp > 0)
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p = &(*p)->rb_right;
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else {
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pr_err("sysctl duplicate entry: ");
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sysctl_print_dir(head->parent);
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pr_cont("/%s\n", entry->procname);
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return -EEXIST;
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}
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, &head->parent->root);
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return 0;
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}
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static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)
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{
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struct rb_node *node = &head->node[entry - head->ctl_table].node;
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rb_erase(node, &head->parent->root);
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}
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static void init_header(struct ctl_table_header *head,
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struct ctl_table_root *root, struct ctl_table_set *set,
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struct ctl_node *node, struct ctl_table *table)
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{
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head->ctl_table = table;
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head->ctl_table_arg = table;
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head->used = 0;
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head->count = 1;
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head->nreg = 1;
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head->unregistering = NULL;
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head->root = root;
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head->set = set;
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head->parent = NULL;
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head->node = node;
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INIT_HLIST_HEAD(&head->inodes);
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if (node) {
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struct ctl_table *entry;
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for (entry = table; entry->procname; entry++, node++)
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node->header = head;
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}
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}
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static void erase_header(struct ctl_table_header *head)
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{
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struct ctl_table *entry;
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for (entry = head->ctl_table; entry->procname; entry++)
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erase_entry(head, entry);
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}
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static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
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{
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struct ctl_table *entry;
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int err;
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/* Is this a permanently empty directory? */
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if (is_empty_dir(&dir->header))
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return -EROFS;
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/* Am I creating a permanently empty directory? */
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if (header->ctl_table == sysctl_mount_point) {
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if (!RB_EMPTY_ROOT(&dir->root))
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return -EINVAL;
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set_empty_dir(dir);
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}
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dir->header.nreg++;
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header->parent = dir;
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err = insert_links(header);
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if (err)
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goto fail_links;
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for (entry = header->ctl_table; entry->procname; entry++) {
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err = insert_entry(header, entry);
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if (err)
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goto fail;
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}
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return 0;
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fail:
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erase_header(header);
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put_links(header);
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fail_links:
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if (header->ctl_table == sysctl_mount_point)
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clear_empty_dir(dir);
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header->parent = NULL;
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drop_sysctl_table(&dir->header);
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return err;
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}
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/* called under sysctl_lock */
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static int use_table(struct ctl_table_header *p)
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{
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if (unlikely(p->unregistering))
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return 0;
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p->used++;
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return 1;
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}
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/* called under sysctl_lock */
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static void unuse_table(struct ctl_table_header *p)
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{
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if (!--p->used)
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if (unlikely(p->unregistering))
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complete(p->unregistering);
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}
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static void proc_sys_prune_dcache(struct ctl_table_header *head)
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{
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struct inode *inode;
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struct proc_inode *ei;
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struct hlist_node *node;
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struct super_block *sb;
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rcu_read_lock();
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for (;;) {
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node = hlist_first_rcu(&head->inodes);
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if (!node)
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break;
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ei = hlist_entry(node, struct proc_inode, sysctl_inodes);
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spin_lock(&sysctl_lock);
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hlist_del_init_rcu(&ei->sysctl_inodes);
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spin_unlock(&sysctl_lock);
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inode = &ei->vfs_inode;
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sb = inode->i_sb;
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if (!atomic_inc_not_zero(&sb->s_active))
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continue;
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inode = igrab(inode);
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rcu_read_unlock();
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if (unlikely(!inode)) {
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deactivate_super(sb);
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rcu_read_lock();
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continue;
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}
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d_prune_aliases(inode);
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iput(inode);
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deactivate_super(sb);
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rcu_read_lock();
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}
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rcu_read_unlock();
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}
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/* called under sysctl_lock, will reacquire if has to wait */
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static void start_unregistering(struct ctl_table_header *p)
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{
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/*
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* if p->used is 0, nobody will ever touch that entry again;
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* we'll eliminate all paths to it before dropping sysctl_lock
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*/
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if (unlikely(p->used)) {
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struct completion wait;
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init_completion(&wait);
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p->unregistering = &wait;
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spin_unlock(&sysctl_lock);
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wait_for_completion(&wait);
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} else {
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/* anything non-NULL; we'll never dereference it */
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p->unregistering = ERR_PTR(-EINVAL);
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spin_unlock(&sysctl_lock);
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}
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/*
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* Prune dentries for unregistered sysctls: namespaced sysctls
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* can have duplicate names and contaminate dcache very badly.
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*/
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proc_sys_prune_dcache(p);
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/*
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* do not remove from the list until nobody holds it; walking the
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* list in do_sysctl() relies on that.
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*/
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spin_lock(&sysctl_lock);
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erase_header(p);
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}
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static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
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{
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BUG_ON(!head);
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spin_lock(&sysctl_lock);
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if (!use_table(head))
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head = ERR_PTR(-ENOENT);
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spin_unlock(&sysctl_lock);
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return head;
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}
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static void sysctl_head_finish(struct ctl_table_header *head)
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{
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if (!head)
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return;
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spin_lock(&sysctl_lock);
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unuse_table(head);
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spin_unlock(&sysctl_lock);
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}
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static struct ctl_table_set *
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lookup_header_set(struct ctl_table_root *root)
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{
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struct ctl_table_set *set = &root->default_set;
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if (root->lookup)
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set = root->lookup(root);
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return set;
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}
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static struct ctl_table *lookup_entry(struct ctl_table_header **phead,
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struct ctl_dir *dir,
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const char *name, int namelen)
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{
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struct ctl_table_header *head;
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struct ctl_table *entry;
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spin_lock(&sysctl_lock);
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entry = find_entry(&head, dir, name, namelen);
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if (entry && use_table(head))
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*phead = head;
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else
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entry = NULL;
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spin_unlock(&sysctl_lock);
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return entry;
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}
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static struct ctl_node *first_usable_entry(struct rb_node *node)
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{
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struct ctl_node *ctl_node;
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for (;node; node = rb_next(node)) {
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ctl_node = rb_entry(node, struct ctl_node, node);
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if (use_table(ctl_node->header))
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return ctl_node;
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}
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return NULL;
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}
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static void first_entry(struct ctl_dir *dir,
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struct ctl_table_header **phead, struct ctl_table **pentry)
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{
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struct ctl_table_header *head = NULL;
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struct ctl_table *entry = NULL;
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struct ctl_node *ctl_node;
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spin_lock(&sysctl_lock);
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ctl_node = first_usable_entry(rb_first(&dir->root));
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spin_unlock(&sysctl_lock);
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if (ctl_node) {
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head = ctl_node->header;
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entry = &head->ctl_table[ctl_node - head->node];
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}
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*phead = head;
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*pentry = entry;
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}
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static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry)
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{
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struct ctl_table_header *head = *phead;
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struct ctl_table *entry = *pentry;
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struct ctl_node *ctl_node = &head->node[entry - head->ctl_table];
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spin_lock(&sysctl_lock);
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unuse_table(head);
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ctl_node = first_usable_entry(rb_next(&ctl_node->node));
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spin_unlock(&sysctl_lock);
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head = NULL;
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if (ctl_node) {
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head = ctl_node->header;
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entry = &head->ctl_table[ctl_node - head->node];
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}
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*phead = head;
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*pentry = entry;
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}
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/*
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* sysctl_perm does NOT grant the superuser all rights automatically, because
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* some sysctl variables are readonly even to root.
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*/
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static int test_perm(int mode, int op)
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{
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if (uid_eq(current_euid(), GLOBAL_ROOT_UID))
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mode >>= 6;
|
|
else if (in_egroup_p(GLOBAL_ROOT_GID))
|
|
mode >>= 3;
|
|
if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
|
|
return 0;
|
|
return -EACCES;
|
|
}
|
|
|
|
static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op)
|
|
{
|
|
struct ctl_table_root *root = head->root;
|
|
int mode;
|
|
|
|
if (root->permissions)
|
|
mode = root->permissions(head, table);
|
|
else
|
|
mode = table->mode;
|
|
|
|
return test_perm(mode, op);
|
|
}
|
|
|
|
static struct inode *proc_sys_make_inode(struct super_block *sb,
|
|
struct ctl_table_header *head, struct ctl_table *table)
|
|
{
|
|
struct ctl_table_root *root = head->root;
|
|
struct inode *inode;
|
|
struct proc_inode *ei;
|
|
|
|
inode = new_inode(sb);
|
|
if (!inode)
|
|
goto out;
|
|
|
|
inode->i_ino = get_next_ino();
|
|
|
|
ei = PROC_I(inode);
|
|
|
|
spin_lock(&sysctl_lock);
|
|
if (unlikely(head->unregistering)) {
|
|
spin_unlock(&sysctl_lock);
|
|
iput(inode);
|
|
inode = NULL;
|
|
goto out;
|
|
}
|
|
ei->sysctl = head;
|
|
ei->sysctl_entry = table;
|
|
hlist_add_head_rcu(&ei->sysctl_inodes, &head->inodes);
|
|
head->count++;
|
|
spin_unlock(&sysctl_lock);
|
|
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
|
|
inode->i_mode = table->mode;
|
|
if (!S_ISDIR(table->mode)) {
|
|
inode->i_mode |= S_IFREG;
|
|
inode->i_op = &proc_sys_inode_operations;
|
|
inode->i_fop = &proc_sys_file_operations;
|
|
} else {
|
|
inode->i_mode |= S_IFDIR;
|
|
inode->i_op = &proc_sys_dir_operations;
|
|
inode->i_fop = &proc_sys_dir_file_operations;
|
|
if (is_empty_dir(head))
|
|
make_empty_dir_inode(inode);
|
|
}
|
|
|
|
if (root->set_ownership)
|
|
root->set_ownership(head, table, &inode->i_uid, &inode->i_gid);
|
|
|
|
out:
|
|
return inode;
|
|
}
|
|
|
|
void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head)
|
|
{
|
|
spin_lock(&sysctl_lock);
|
|
hlist_del_init_rcu(&PROC_I(inode)->sysctl_inodes);
|
|
if (!--head->count)
|
|
kfree_rcu(head, rcu);
|
|
spin_unlock(&sysctl_lock);
|
|
}
|
|
|
|
static struct ctl_table_header *grab_header(struct inode *inode)
|
|
{
|
|
struct ctl_table_header *head = PROC_I(inode)->sysctl;
|
|
if (!head)
|
|
head = &sysctl_table_root.default_set.dir.header;
|
|
return sysctl_head_grab(head);
|
|
}
|
|
|
|
static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
struct ctl_table_header *head = grab_header(dir);
|
|
struct ctl_table_header *h = NULL;
|
|
const struct qstr *name = &dentry->d_name;
|
|
struct ctl_table *p;
|
|
struct inode *inode;
|
|
struct dentry *err = ERR_PTR(-ENOENT);
|
|
struct ctl_dir *ctl_dir;
|
|
int ret;
|
|
|
|
if (IS_ERR(head))
|
|
return ERR_CAST(head);
|
|
|
|
ctl_dir = container_of(head, struct ctl_dir, header);
|
|
|
|
p = lookup_entry(&h, ctl_dir, name->name, name->len);
|
|
if (!p)
|
|
goto out;
|
|
|
|
if (S_ISLNK(p->mode)) {
|
|
ret = sysctl_follow_link(&h, &p);
|
|
err = ERR_PTR(ret);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
err = ERR_PTR(-ENOMEM);
|
|
inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);
|
|
if (!inode)
|
|
goto out;
|
|
|
|
err = NULL;
|
|
d_set_d_op(dentry, &proc_sys_dentry_operations);
|
|
d_add(dentry, inode);
|
|
|
|
out:
|
|
if (h)
|
|
sysctl_head_finish(h);
|
|
sysctl_head_finish(head);
|
|
return err;
|
|
}
|
|
|
|
static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
|
|
size_t count, loff_t *ppos, int write)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
struct ctl_table_header *head = grab_header(inode);
|
|
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
|
|
ssize_t error;
|
|
size_t res;
|
|
|
|
if (IS_ERR(head))
|
|
return PTR_ERR(head);
|
|
|
|
/*
|
|
* At this point we know that the sysctl was not unregistered
|
|
* and won't be until we finish.
|
|
*/
|
|
error = -EPERM;
|
|
if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ))
|
|
goto out;
|
|
|
|
/* if that can happen at all, it should be -EINVAL, not -EISDIR */
|
|
error = -EINVAL;
|
|
if (!table->proc_handler)
|
|
goto out;
|
|
|
|
/* careful: calling conventions are nasty here */
|
|
res = count;
|
|
error = table->proc_handler(table, write, buf, &res, ppos);
|
|
if (!error)
|
|
error = res;
|
|
out:
|
|
sysctl_head_finish(head);
|
|
|
|
return error;
|
|
}
|
|
|
|
static ssize_t proc_sys_read(struct file *filp, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
|
|
}
|
|
|
|
static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
|
|
}
|
|
|
|
static int proc_sys_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ctl_table_header *head = grab_header(inode);
|
|
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
|
|
|
|
/* sysctl was unregistered */
|
|
if (IS_ERR(head))
|
|
return PTR_ERR(head);
|
|
|
|
if (table->poll)
|
|
filp->private_data = proc_sys_poll_event(table->poll);
|
|
|
|
sysctl_head_finish(head);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int proc_sys_poll(struct file *filp, poll_table *wait)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
struct ctl_table_header *head = grab_header(inode);
|
|
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
|
|
unsigned int ret = DEFAULT_POLLMASK;
|
|
unsigned long event;
|
|
|
|
/* sysctl was unregistered */
|
|
if (IS_ERR(head))
|
|
return POLLERR | POLLHUP;
|
|
|
|
if (!table->proc_handler)
|
|
goto out;
|
|
|
|
if (!table->poll)
|
|
goto out;
|
|
|
|
event = (unsigned long)filp->private_data;
|
|
poll_wait(filp, &table->poll->wait, wait);
|
|
|
|
if (event != atomic_read(&table->poll->event)) {
|
|
filp->private_data = proc_sys_poll_event(table->poll);
|
|
ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI;
|
|
}
|
|
|
|
out:
|
|
sysctl_head_finish(head);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool proc_sys_fill_cache(struct file *file,
|
|
struct dir_context *ctx,
|
|
struct ctl_table_header *head,
|
|
struct ctl_table *table)
|
|
{
|
|
struct dentry *child, *dir = file->f_path.dentry;
|
|
struct inode *inode;
|
|
struct qstr qname;
|
|
ino_t ino = 0;
|
|
unsigned type = DT_UNKNOWN;
|
|
|
|
qname.name = table->procname;
|
|
qname.len = strlen(table->procname);
|
|
qname.hash = full_name_hash(dir, qname.name, qname.len);
|
|
|
|
child = d_lookup(dir, &qname);
|
|
if (!child) {
|
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
|
|
child = d_alloc_parallel(dir, &qname, &wq);
|
|
if (IS_ERR(child))
|
|
return false;
|
|
if (d_in_lookup(child)) {
|
|
inode = proc_sys_make_inode(dir->d_sb, head, table);
|
|
if (!inode) {
|
|
d_lookup_done(child);
|
|
dput(child);
|
|
return false;
|
|
}
|
|
d_set_d_op(child, &proc_sys_dentry_operations);
|
|
d_add(child, inode);
|
|
}
|
|
}
|
|
inode = d_inode(child);
|
|
ino = inode->i_ino;
|
|
type = inode->i_mode >> 12;
|
|
dput(child);
|
|
return dir_emit(ctx, qname.name, qname.len, ino, type);
|
|
}
|
|
|
|
static bool proc_sys_link_fill_cache(struct file *file,
|
|
struct dir_context *ctx,
|
|
struct ctl_table_header *head,
|
|
struct ctl_table *table)
|
|
{
|
|
bool ret = true;
|
|
head = sysctl_head_grab(head);
|
|
|
|
if (S_ISLNK(table->mode)) {
|
|
/* It is not an error if we can not follow the link ignore it */
|
|
int err = sysctl_follow_link(&head, &table);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
ret = proc_sys_fill_cache(file, ctx, head, table);
|
|
out:
|
|
sysctl_head_finish(head);
|
|
return ret;
|
|
}
|
|
|
|
static int scan(struct ctl_table_header *head, struct ctl_table *table,
|
|
unsigned long *pos, struct file *file,
|
|
struct dir_context *ctx)
|
|
{
|
|
bool res;
|
|
|
|
if ((*pos)++ < ctx->pos)
|
|
return true;
|
|
|
|
if (unlikely(S_ISLNK(table->mode)))
|
|
res = proc_sys_link_fill_cache(file, ctx, head, table);
|
|
else
|
|
res = proc_sys_fill_cache(file, ctx, head, table);
|
|
|
|
if (res)
|
|
ctx->pos = *pos;
|
|
|
|
return res;
|
|
}
|
|
|
|
static int proc_sys_readdir(struct file *file, struct dir_context *ctx)
|
|
{
|
|
struct ctl_table_header *head = grab_header(file_inode(file));
|
|
struct ctl_table_header *h = NULL;
|
|
struct ctl_table *entry;
|
|
struct ctl_dir *ctl_dir;
|
|
unsigned long pos;
|
|
|
|
if (IS_ERR(head))
|
|
return PTR_ERR(head);
|
|
|
|
ctl_dir = container_of(head, struct ctl_dir, header);
|
|
|
|
if (!dir_emit_dots(file, ctx))
|
|
goto out;
|
|
|
|
pos = 2;
|
|
|
|
for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) {
|
|
if (!scan(h, entry, &pos, file, ctx)) {
|
|
sysctl_head_finish(h);
|
|
break;
|
|
}
|
|
}
|
|
out:
|
|
sysctl_head_finish(head);
|
|
return 0;
|
|
}
|
|
|
|
static int proc_sys_permission(struct inode *inode, int mask)
|
|
{
|
|
/*
|
|
* sysctl entries that are not writeable,
|
|
* are _NOT_ writeable, capabilities or not.
|
|
*/
|
|
struct ctl_table_header *head;
|
|
struct ctl_table *table;
|
|
int error;
|
|
|
|
/* Executable files are not allowed under /proc/sys/ */
|
|
if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))
|
|
return -EACCES;
|
|
|
|
head = grab_header(inode);
|
|
if (IS_ERR(head))
|
|
return PTR_ERR(head);
|
|
|
|
table = PROC_I(inode)->sysctl_entry;
|
|
if (!table) /* global root - r-xr-xr-x */
|
|
error = mask & MAY_WRITE ? -EACCES : 0;
|
|
else /* Use the permissions on the sysctl table entry */
|
|
error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK);
|
|
|
|
sysctl_head_finish(head);
|
|
return error;
|
|
}
|
|
|
|
static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
int error;
|
|
|
|
if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))
|
|
return -EPERM;
|
|
|
|
error = setattr_prepare(dentry, attr);
|
|
if (error)
|
|
return error;
|
|
|
|
setattr_copy(inode, attr);
|
|
mark_inode_dirty(inode);
|
|
return 0;
|
|
}
|
|
|
|
static int proc_sys_getattr(const struct path *path, struct kstat *stat,
|
|
u32 request_mask, unsigned int query_flags)
|
|
{
|
|
struct inode *inode = d_inode(path->dentry);
|
|
struct ctl_table_header *head = grab_header(inode);
|
|
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
|
|
|
|
if (IS_ERR(head))
|
|
return PTR_ERR(head);
|
|
|
|
generic_fillattr(inode, stat);
|
|
if (table)
|
|
stat->mode = (stat->mode & S_IFMT) | table->mode;
|
|
|
|
sysctl_head_finish(head);
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations proc_sys_file_operations = {
|
|
.open = proc_sys_open,
|
|
.poll = proc_sys_poll,
|
|
.read = proc_sys_read,
|
|
.write = proc_sys_write,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
static const struct file_operations proc_sys_dir_file_operations = {
|
|
.read = generic_read_dir,
|
|
.iterate_shared = proc_sys_readdir,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct inode_operations proc_sys_inode_operations = {
|
|
.permission = proc_sys_permission,
|
|
.setattr = proc_sys_setattr,
|
|
.getattr = proc_sys_getattr,
|
|
};
|
|
|
|
static const struct inode_operations proc_sys_dir_operations = {
|
|
.lookup = proc_sys_lookup,
|
|
.permission = proc_sys_permission,
|
|
.setattr = proc_sys_setattr,
|
|
.getattr = proc_sys_getattr,
|
|
};
|
|
|
|
static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags)
|
|
{
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
return !PROC_I(d_inode(dentry))->sysctl->unregistering;
|
|
}
|
|
|
|
static int proc_sys_delete(const struct dentry *dentry)
|
|
{
|
|
return !!PROC_I(d_inode(dentry))->sysctl->unregistering;
|
|
}
|
|
|
|
static int sysctl_is_seen(struct ctl_table_header *p)
|
|
{
|
|
struct ctl_table_set *set = p->set;
|
|
int res;
|
|
spin_lock(&sysctl_lock);
|
|
if (p->unregistering)
|
|
res = 0;
|
|
else if (!set->is_seen)
|
|
res = 1;
|
|
else
|
|
res = set->is_seen(set);
|
|
spin_unlock(&sysctl_lock);
|
|
return res;
|
|
}
|
|
|
|
static int proc_sys_compare(const struct dentry *dentry,
|
|
unsigned int len, const char *str, const struct qstr *name)
|
|
{
|
|
struct ctl_table_header *head;
|
|
struct inode *inode;
|
|
|
|
/* Although proc doesn't have negative dentries, rcu-walk means
|
|
* that inode here can be NULL */
|
|
/* AV: can it, indeed? */
|
|
inode = d_inode_rcu(dentry);
|
|
if (!inode)
|
|
return 1;
|
|
if (name->len != len)
|
|
return 1;
|
|
if (memcmp(name->name, str, len))
|
|
return 1;
|
|
head = rcu_dereference(PROC_I(inode)->sysctl);
|
|
return !head || !sysctl_is_seen(head);
|
|
}
|
|
|
|
static const struct dentry_operations proc_sys_dentry_operations = {
|
|
.d_revalidate = proc_sys_revalidate,
|
|
.d_delete = proc_sys_delete,
|
|
.d_compare = proc_sys_compare,
|
|
};
|
|
|
|
static struct ctl_dir *find_subdir(struct ctl_dir *dir,
|
|
const char *name, int namelen)
|
|
{
|
|
struct ctl_table_header *head;
|
|
struct ctl_table *entry;
|
|
|
|
entry = find_entry(&head, dir, name, namelen);
|
|
if (!entry)
|
|
return ERR_PTR(-ENOENT);
|
|
if (!S_ISDIR(entry->mode))
|
|
return ERR_PTR(-ENOTDIR);
|
|
return container_of(head, struct ctl_dir, header);
|
|
}
|
|
|
|
static struct ctl_dir *new_dir(struct ctl_table_set *set,
|
|
const char *name, int namelen)
|
|
{
|
|
struct ctl_table *table;
|
|
struct ctl_dir *new;
|
|
struct ctl_node *node;
|
|
char *new_name;
|
|
|
|
new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) +
|
|
sizeof(struct ctl_table)*2 + namelen + 1,
|
|
GFP_KERNEL);
|
|
if (!new)
|
|
return NULL;
|
|
|
|
node = (struct ctl_node *)(new + 1);
|
|
table = (struct ctl_table *)(node + 1);
|
|
new_name = (char *)(table + 2);
|
|
memcpy(new_name, name, namelen);
|
|
new_name[namelen] = '\0';
|
|
table[0].procname = new_name;
|
|
table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO;
|
|
init_header(&new->header, set->dir.header.root, set, node, table);
|
|
|
|
return new;
|
|
}
|
|
|
|
/**
|
|
* get_subdir - find or create a subdir with the specified name.
|
|
* @dir: Directory to create the subdirectory in
|
|
* @name: The name of the subdirectory to find or create
|
|
* @namelen: The length of name
|
|
*
|
|
* Takes a directory with an elevated reference count so we know that
|
|
* if we drop the lock the directory will not go away. Upon success
|
|
* the reference is moved from @dir to the returned subdirectory.
|
|
* Upon error an error code is returned and the reference on @dir is
|
|
* simply dropped.
|
|
*/
|
|
static struct ctl_dir *get_subdir(struct ctl_dir *dir,
|
|
const char *name, int namelen)
|
|
{
|
|
struct ctl_table_set *set = dir->header.set;
|
|
struct ctl_dir *subdir, *new = NULL;
|
|
int err;
|
|
|
|
spin_lock(&sysctl_lock);
|
|
subdir = find_subdir(dir, name, namelen);
|
|
if (!IS_ERR(subdir))
|
|
goto found;
|
|
if (PTR_ERR(subdir) != -ENOENT)
|
|
goto failed;
|
|
|
|
spin_unlock(&sysctl_lock);
|
|
new = new_dir(set, name, namelen);
|
|
spin_lock(&sysctl_lock);
|
|
subdir = ERR_PTR(-ENOMEM);
|
|
if (!new)
|
|
goto failed;
|
|
|
|
/* Was the subdir added while we dropped the lock? */
|
|
subdir = find_subdir(dir, name, namelen);
|
|
if (!IS_ERR(subdir))
|
|
goto found;
|
|
if (PTR_ERR(subdir) != -ENOENT)
|
|
goto failed;
|
|
|
|
/* Nope. Use the our freshly made directory entry. */
|
|
err = insert_header(dir, &new->header);
|
|
subdir = ERR_PTR(err);
|
|
if (err)
|
|
goto failed;
|
|
subdir = new;
|
|
found:
|
|
subdir->header.nreg++;
|
|
failed:
|
|
if (IS_ERR(subdir)) {
|
|
pr_err("sysctl could not get directory: ");
|
|
sysctl_print_dir(dir);
|
|
pr_cont("/%*.*s %ld\n",
|
|
namelen, namelen, name, PTR_ERR(subdir));
|
|
}
|
|
drop_sysctl_table(&dir->header);
|
|
if (new)
|
|
drop_sysctl_table(&new->header);
|
|
spin_unlock(&sysctl_lock);
|
|
return subdir;
|
|
}
|
|
|
|
static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir)
|
|
{
|
|
struct ctl_dir *parent;
|
|
const char *procname;
|
|
if (!dir->header.parent)
|
|
return &set->dir;
|
|
parent = xlate_dir(set, dir->header.parent);
|
|
if (IS_ERR(parent))
|
|
return parent;
|
|
procname = dir->header.ctl_table[0].procname;
|
|
return find_subdir(parent, procname, strlen(procname));
|
|
}
|
|
|
|
static int sysctl_follow_link(struct ctl_table_header **phead,
|
|
struct ctl_table **pentry)
|
|
{
|
|
struct ctl_table_header *head;
|
|
struct ctl_table_root *root;
|
|
struct ctl_table_set *set;
|
|
struct ctl_table *entry;
|
|
struct ctl_dir *dir;
|
|
int ret;
|
|
|
|
ret = 0;
|
|
spin_lock(&sysctl_lock);
|
|
root = (*pentry)->data;
|
|
set = lookup_header_set(root);
|
|
dir = xlate_dir(set, (*phead)->parent);
|
|
if (IS_ERR(dir))
|
|
ret = PTR_ERR(dir);
|
|
else {
|
|
const char *procname = (*pentry)->procname;
|
|
head = NULL;
|
|
entry = find_entry(&head, dir, procname, strlen(procname));
|
|
ret = -ENOENT;
|
|
if (entry && use_table(head)) {
|
|
unuse_table(*phead);
|
|
*phead = head;
|
|
*pentry = entry;
|
|
ret = 0;
|
|
}
|
|
}
|
|
|
|
spin_unlock(&sysctl_lock);
|
|
return ret;
|
|
}
|
|
|
|
static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
pr_err("sysctl table check failed: %s/%s %pV\n",
|
|
path, table->procname, &vaf);
|
|
|
|
va_end(args);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int sysctl_check_table_array(const char *path, struct ctl_table *table)
|
|
{
|
|
int err = 0;
|
|
|
|
if ((table->proc_handler == proc_douintvec) ||
|
|
(table->proc_handler == proc_douintvec_minmax)) {
|
|
if (table->maxlen != sizeof(unsigned int))
|
|
err |= sysctl_err(path, table, "array now allowed");
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int sysctl_check_table(const char *path, struct ctl_table *table)
|
|
{
|
|
int err = 0;
|
|
for (; table->procname; table++) {
|
|
if (table->child)
|
|
err |= sysctl_err(path, table, "Not a file");
|
|
|
|
if ((table->proc_handler == proc_dostring) ||
|
|
(table->proc_handler == proc_dointvec) ||
|
|
(table->proc_handler == proc_douintvec) ||
|
|
(table->proc_handler == proc_douintvec_minmax) ||
|
|
(table->proc_handler == proc_dointvec_minmax) ||
|
|
(table->proc_handler == proc_dointvec_jiffies) ||
|
|
(table->proc_handler == proc_dointvec_userhz_jiffies) ||
|
|
(table->proc_handler == proc_dointvec_ms_jiffies) ||
|
|
(table->proc_handler == proc_doulongvec_minmax) ||
|
|
(table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
|
|
if (!table->data)
|
|
err |= sysctl_err(path, table, "No data");
|
|
if (!table->maxlen)
|
|
err |= sysctl_err(path, table, "No maxlen");
|
|
else
|
|
err |= sysctl_check_table_array(path, table);
|
|
}
|
|
if (!table->proc_handler)
|
|
err |= sysctl_err(path, table, "No proc_handler");
|
|
|
|
if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode)
|
|
err |= sysctl_err(path, table, "bogus .mode 0%o",
|
|
table->mode);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table,
|
|
struct ctl_table_root *link_root)
|
|
{
|
|
struct ctl_table *link_table, *entry, *link;
|
|
struct ctl_table_header *links;
|
|
struct ctl_node *node;
|
|
char *link_name;
|
|
int nr_entries, name_bytes;
|
|
|
|
name_bytes = 0;
|
|
nr_entries = 0;
|
|
for (entry = table; entry->procname; entry++) {
|
|
nr_entries++;
|
|
name_bytes += strlen(entry->procname) + 1;
|
|
}
|
|
|
|
links = kzalloc(sizeof(struct ctl_table_header) +
|
|
sizeof(struct ctl_node)*nr_entries +
|
|
sizeof(struct ctl_table)*(nr_entries + 1) +
|
|
name_bytes,
|
|
GFP_KERNEL);
|
|
|
|
if (!links)
|
|
return NULL;
|
|
|
|
node = (struct ctl_node *)(links + 1);
|
|
link_table = (struct ctl_table *)(node + nr_entries);
|
|
link_name = (char *)&link_table[nr_entries + 1];
|
|
|
|
for (link = link_table, entry = table; entry->procname; link++, entry++) {
|
|
int len = strlen(entry->procname) + 1;
|
|
memcpy(link_name, entry->procname, len);
|
|
link->procname = link_name;
|
|
link->mode = S_IFLNK|S_IRWXUGO;
|
|
link->data = link_root;
|
|
link_name += len;
|
|
}
|
|
init_header(links, dir->header.root, dir->header.set, node, link_table);
|
|
links->nreg = nr_entries;
|
|
|
|
return links;
|
|
}
|
|
|
|
static bool get_links(struct ctl_dir *dir,
|
|
struct ctl_table *table, struct ctl_table_root *link_root)
|
|
{
|
|
struct ctl_table_header *head;
|
|
struct ctl_table *entry, *link;
|
|
|
|
/* Are there links available for every entry in table? */
|
|
for (entry = table; entry->procname; entry++) {
|
|
const char *procname = entry->procname;
|
|
link = find_entry(&head, dir, procname, strlen(procname));
|
|
if (!link)
|
|
return false;
|
|
if (S_ISDIR(link->mode) && S_ISDIR(entry->mode))
|
|
continue;
|
|
if (S_ISLNK(link->mode) && (link->data == link_root))
|
|
continue;
|
|
return false;
|
|
}
|
|
|
|
/* The checks passed. Increase the registration count on the links */
|
|
for (entry = table; entry->procname; entry++) {
|
|
const char *procname = entry->procname;
|
|
link = find_entry(&head, dir, procname, strlen(procname));
|
|
head->nreg++;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static int insert_links(struct ctl_table_header *head)
|
|
{
|
|
struct ctl_table_set *root_set = &sysctl_table_root.default_set;
|
|
struct ctl_dir *core_parent = NULL;
|
|
struct ctl_table_header *links;
|
|
int err;
|
|
|
|
if (head->set == root_set)
|
|
return 0;
|
|
|
|
core_parent = xlate_dir(root_set, head->parent);
|
|
if (IS_ERR(core_parent))
|
|
return 0;
|
|
|
|
if (get_links(core_parent, head->ctl_table, head->root))
|
|
return 0;
|
|
|
|
core_parent->header.nreg++;
|
|
spin_unlock(&sysctl_lock);
|
|
|
|
links = new_links(core_parent, head->ctl_table, head->root);
|
|
|
|
spin_lock(&sysctl_lock);
|
|
err = -ENOMEM;
|
|
if (!links)
|
|
goto out;
|
|
|
|
err = 0;
|
|
if (get_links(core_parent, head->ctl_table, head->root)) {
|
|
kfree(links);
|
|
goto out;
|
|
}
|
|
|
|
err = insert_header(core_parent, links);
|
|
if (err)
|
|
kfree(links);
|
|
out:
|
|
drop_sysctl_table(&core_parent->header);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* __register_sysctl_table - register a leaf sysctl table
|
|
* @set: Sysctl tree to register on
|
|
* @path: The path to the directory the sysctl table is in.
|
|
* @table: the top-level table structure
|
|
*
|
|
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
|
|
* array. A completely 0 filled entry terminates the table.
|
|
*
|
|
* The members of the &struct ctl_table structure are used as follows:
|
|
*
|
|
* procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
|
|
* enter a sysctl file
|
|
*
|
|
* data - a pointer to data for use by proc_handler
|
|
*
|
|
* maxlen - the maximum size in bytes of the data
|
|
*
|
|
* mode - the file permissions for the /proc/sys file
|
|
*
|
|
* child - must be %NULL.
|
|
*
|
|
* proc_handler - the text handler routine (described below)
|
|
*
|
|
* extra1, extra2 - extra pointers usable by the proc handler routines
|
|
*
|
|
* Leaf nodes in the sysctl tree will be represented by a single file
|
|
* under /proc; non-leaf nodes will be represented by directories.
|
|
*
|
|
* There must be a proc_handler routine for any terminal nodes.
|
|
* Several default handlers are available to cover common cases -
|
|
*
|
|
* proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
|
|
* proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
|
|
* proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
|
|
*
|
|
* It is the handler's job to read the input buffer from user memory
|
|
* and process it. The handler should return 0 on success.
|
|
*
|
|
* This routine returns %NULL on a failure to register, and a pointer
|
|
* to the table header on success.
|
|
*/
|
|
struct ctl_table_header *__register_sysctl_table(
|
|
struct ctl_table_set *set,
|
|
const char *path, struct ctl_table *table)
|
|
{
|
|
struct ctl_table_root *root = set->dir.header.root;
|
|
struct ctl_table_header *header;
|
|
const char *name, *nextname;
|
|
struct ctl_dir *dir;
|
|
struct ctl_table *entry;
|
|
struct ctl_node *node;
|
|
int nr_entries = 0;
|
|
|
|
for (entry = table; entry->procname; entry++)
|
|
nr_entries++;
|
|
|
|
header = kzalloc(sizeof(struct ctl_table_header) +
|
|
sizeof(struct ctl_node)*nr_entries, GFP_KERNEL);
|
|
if (!header)
|
|
return NULL;
|
|
|
|
node = (struct ctl_node *)(header + 1);
|
|
init_header(header, root, set, node, table);
|
|
if (sysctl_check_table(path, table))
|
|
goto fail;
|
|
|
|
spin_lock(&sysctl_lock);
|
|
dir = &set->dir;
|
|
/* Reference moved down the diretory tree get_subdir */
|
|
dir->header.nreg++;
|
|
spin_unlock(&sysctl_lock);
|
|
|
|
/* Find the directory for the ctl_table */
|
|
for (name = path; name; name = nextname) {
|
|
int namelen;
|
|
nextname = strchr(name, '/');
|
|
if (nextname) {
|
|
namelen = nextname - name;
|
|
nextname++;
|
|
} else {
|
|
namelen = strlen(name);
|
|
}
|
|
if (namelen == 0)
|
|
continue;
|
|
|
|
dir = get_subdir(dir, name, namelen);
|
|
if (IS_ERR(dir))
|
|
goto fail;
|
|
}
|
|
|
|
spin_lock(&sysctl_lock);
|
|
if (insert_header(dir, header))
|
|
goto fail_put_dir_locked;
|
|
|
|
drop_sysctl_table(&dir->header);
|
|
spin_unlock(&sysctl_lock);
|
|
|
|
return header;
|
|
|
|
fail_put_dir_locked:
|
|
drop_sysctl_table(&dir->header);
|
|
spin_unlock(&sysctl_lock);
|
|
fail:
|
|
kfree(header);
|
|
dump_stack();
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* register_sysctl - register a sysctl table
|
|
* @path: The path to the directory the sysctl table is in.
|
|
* @table: the table structure
|
|
*
|
|
* Register a sysctl table. @table should be a filled in ctl_table
|
|
* array. A completely 0 filled entry terminates the table.
|
|
*
|
|
* See __register_sysctl_table for more details.
|
|
*/
|
|
struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
|
|
{
|
|
return __register_sysctl_table(&sysctl_table_root.default_set,
|
|
path, table);
|
|
}
|
|
EXPORT_SYMBOL(register_sysctl);
|
|
|
|
static char *append_path(const char *path, char *pos, const char *name)
|
|
{
|
|
int namelen;
|
|
namelen = strlen(name);
|
|
if (((pos - path) + namelen + 2) >= PATH_MAX)
|
|
return NULL;
|
|
memcpy(pos, name, namelen);
|
|
pos[namelen] = '/';
|
|
pos[namelen + 1] = '\0';
|
|
pos += namelen + 1;
|
|
return pos;
|
|
}
|
|
|
|
static int count_subheaders(struct ctl_table *table)
|
|
{
|
|
int has_files = 0;
|
|
int nr_subheaders = 0;
|
|
struct ctl_table *entry;
|
|
|
|
/* special case: no directory and empty directory */
|
|
if (!table || !table->procname)
|
|
return 1;
|
|
|
|
for (entry = table; entry->procname; entry++) {
|
|
if (entry->child)
|
|
nr_subheaders += count_subheaders(entry->child);
|
|
else
|
|
has_files = 1;
|
|
}
|
|
return nr_subheaders + has_files;
|
|
}
|
|
|
|
static int register_leaf_sysctl_tables(const char *path, char *pos,
|
|
struct ctl_table_header ***subheader, struct ctl_table_set *set,
|
|
struct ctl_table *table)
|
|
{
|
|
struct ctl_table *ctl_table_arg = NULL;
|
|
struct ctl_table *entry, *files;
|
|
int nr_files = 0;
|
|
int nr_dirs = 0;
|
|
int err = -ENOMEM;
|
|
|
|
for (entry = table; entry->procname; entry++) {
|
|
if (entry->child)
|
|
nr_dirs++;
|
|
else
|
|
nr_files++;
|
|
}
|
|
|
|
files = table;
|
|
/* If there are mixed files and directories we need a new table */
|
|
if (nr_dirs && nr_files) {
|
|
struct ctl_table *new;
|
|
files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1),
|
|
GFP_KERNEL);
|
|
if (!files)
|
|
goto out;
|
|
|
|
ctl_table_arg = files;
|
|
for (new = files, entry = table; entry->procname; entry++) {
|
|
if (entry->child)
|
|
continue;
|
|
*new = *entry;
|
|
new++;
|
|
}
|
|
}
|
|
|
|
/* Register everything except a directory full of subdirectories */
|
|
if (nr_files || !nr_dirs) {
|
|
struct ctl_table_header *header;
|
|
header = __register_sysctl_table(set, path, files);
|
|
if (!header) {
|
|
kfree(ctl_table_arg);
|
|
goto out;
|
|
}
|
|
|
|
/* Remember if we need to free the file table */
|
|
header->ctl_table_arg = ctl_table_arg;
|
|
**subheader = header;
|
|
(*subheader)++;
|
|
}
|
|
|
|
/* Recurse into the subdirectories. */
|
|
for (entry = table; entry->procname; entry++) {
|
|
char *child_pos;
|
|
|
|
if (!entry->child)
|
|
continue;
|
|
|
|
err = -ENAMETOOLONG;
|
|
child_pos = append_path(path, pos, entry->procname);
|
|
if (!child_pos)
|
|
goto out;
|
|
|
|
err = register_leaf_sysctl_tables(path, child_pos, subheader,
|
|
set, entry->child);
|
|
pos[0] = '\0';
|
|
if (err)
|
|
goto out;
|
|
}
|
|
err = 0;
|
|
out:
|
|
/* On failure our caller will unregister all registered subheaders */
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* __register_sysctl_paths - register a sysctl table hierarchy
|
|
* @set: Sysctl tree to register on
|
|
* @path: The path to the directory the sysctl table is in.
|
|
* @table: the top-level table structure
|
|
*
|
|
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
|
|
* array. A completely 0 filled entry terminates the table.
|
|
*
|
|
* See __register_sysctl_table for more details.
|
|
*/
|
|
struct ctl_table_header *__register_sysctl_paths(
|
|
struct ctl_table_set *set,
|
|
const struct ctl_path *path, struct ctl_table *table)
|
|
{
|
|
struct ctl_table *ctl_table_arg = table;
|
|
int nr_subheaders = count_subheaders(table);
|
|
struct ctl_table_header *header = NULL, **subheaders, **subheader;
|
|
const struct ctl_path *component;
|
|
char *new_path, *pos;
|
|
|
|
pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL);
|
|
if (!new_path)
|
|
return NULL;
|
|
|
|
pos[0] = '\0';
|
|
for (component = path; component->procname; component++) {
|
|
pos = append_path(new_path, pos, component->procname);
|
|
if (!pos)
|
|
goto out;
|
|
}
|
|
while (table->procname && table->child && !table[1].procname) {
|
|
pos = append_path(new_path, pos, table->procname);
|
|
if (!pos)
|
|
goto out;
|
|
table = table->child;
|
|
}
|
|
if (nr_subheaders == 1) {
|
|
header = __register_sysctl_table(set, new_path, table);
|
|
if (header)
|
|
header->ctl_table_arg = ctl_table_arg;
|
|
} else {
|
|
header = kzalloc(sizeof(*header) +
|
|
sizeof(*subheaders)*nr_subheaders, GFP_KERNEL);
|
|
if (!header)
|
|
goto out;
|
|
|
|
subheaders = (struct ctl_table_header **) (header + 1);
|
|
subheader = subheaders;
|
|
header->ctl_table_arg = ctl_table_arg;
|
|
|
|
if (register_leaf_sysctl_tables(new_path, pos, &subheader,
|
|
set, table))
|
|
goto err_register_leaves;
|
|
}
|
|
|
|
out:
|
|
kfree(new_path);
|
|
return header;
|
|
|
|
err_register_leaves:
|
|
while (subheader > subheaders) {
|
|
struct ctl_table_header *subh = *(--subheader);
|
|
struct ctl_table *table = subh->ctl_table_arg;
|
|
unregister_sysctl_table(subh);
|
|
kfree(table);
|
|
}
|
|
kfree(header);
|
|
header = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/**
|
|
* register_sysctl_table_path - register a sysctl table hierarchy
|
|
* @path: The path to the directory the sysctl table is in.
|
|
* @table: the top-level table structure
|
|
*
|
|
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
|
|
* array. A completely 0 filled entry terminates the table.
|
|
*
|
|
* See __register_sysctl_paths for more details.
|
|
*/
|
|
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
|
|
struct ctl_table *table)
|
|
{
|
|
return __register_sysctl_paths(&sysctl_table_root.default_set,
|
|
path, table);
|
|
}
|
|
EXPORT_SYMBOL(register_sysctl_paths);
|
|
|
|
/**
|
|
* register_sysctl_table - register a sysctl table hierarchy
|
|
* @table: the top-level table structure
|
|
*
|
|
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
|
|
* array. A completely 0 filled entry terminates the table.
|
|
*
|
|
* See register_sysctl_paths for more details.
|
|
*/
|
|
struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
|
|
{
|
|
static const struct ctl_path null_path[] = { {} };
|
|
|
|
return register_sysctl_paths(null_path, table);
|
|
}
|
|
EXPORT_SYMBOL(register_sysctl_table);
|
|
|
|
static void put_links(struct ctl_table_header *header)
|
|
{
|
|
struct ctl_table_set *root_set = &sysctl_table_root.default_set;
|
|
struct ctl_table_root *root = header->root;
|
|
struct ctl_dir *parent = header->parent;
|
|
struct ctl_dir *core_parent;
|
|
struct ctl_table *entry;
|
|
|
|
if (header->set == root_set)
|
|
return;
|
|
|
|
core_parent = xlate_dir(root_set, parent);
|
|
if (IS_ERR(core_parent))
|
|
return;
|
|
|
|
for (entry = header->ctl_table; entry->procname; entry++) {
|
|
struct ctl_table_header *link_head;
|
|
struct ctl_table *link;
|
|
const char *name = entry->procname;
|
|
|
|
link = find_entry(&link_head, core_parent, name, strlen(name));
|
|
if (link &&
|
|
((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) ||
|
|
(S_ISLNK(link->mode) && (link->data == root)))) {
|
|
drop_sysctl_table(link_head);
|
|
}
|
|
else {
|
|
pr_err("sysctl link missing during unregister: ");
|
|
sysctl_print_dir(parent);
|
|
pr_cont("/%s\n", name);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void drop_sysctl_table(struct ctl_table_header *header)
|
|
{
|
|
struct ctl_dir *parent = header->parent;
|
|
|
|
if (--header->nreg)
|
|
return;
|
|
|
|
put_links(header);
|
|
start_unregistering(header);
|
|
if (!--header->count)
|
|
kfree_rcu(header, rcu);
|
|
|
|
if (parent)
|
|
drop_sysctl_table(&parent->header);
|
|
}
|
|
|
|
/**
|
|
* unregister_sysctl_table - unregister a sysctl table hierarchy
|
|
* @header: the header returned from register_sysctl_table
|
|
*
|
|
* Unregisters the sysctl table and all children. proc entries may not
|
|
* actually be removed until they are no longer used by anyone.
|
|
*/
|
|
void unregister_sysctl_table(struct ctl_table_header * header)
|
|
{
|
|
int nr_subheaders;
|
|
might_sleep();
|
|
|
|
if (header == NULL)
|
|
return;
|
|
|
|
nr_subheaders = count_subheaders(header->ctl_table_arg);
|
|
if (unlikely(nr_subheaders > 1)) {
|
|
struct ctl_table_header **subheaders;
|
|
int i;
|
|
|
|
subheaders = (struct ctl_table_header **)(header + 1);
|
|
for (i = nr_subheaders -1; i >= 0; i--) {
|
|
struct ctl_table_header *subh = subheaders[i];
|
|
struct ctl_table *table = subh->ctl_table_arg;
|
|
unregister_sysctl_table(subh);
|
|
kfree(table);
|
|
}
|
|
kfree(header);
|
|
return;
|
|
}
|
|
|
|
spin_lock(&sysctl_lock);
|
|
drop_sysctl_table(header);
|
|
spin_unlock(&sysctl_lock);
|
|
}
|
|
EXPORT_SYMBOL(unregister_sysctl_table);
|
|
|
|
void setup_sysctl_set(struct ctl_table_set *set,
|
|
struct ctl_table_root *root,
|
|
int (*is_seen)(struct ctl_table_set *))
|
|
{
|
|
memset(set, 0, sizeof(*set));
|
|
set->is_seen = is_seen;
|
|
init_header(&set->dir.header, root, set, NULL, root_table);
|
|
}
|
|
|
|
void retire_sysctl_set(struct ctl_table_set *set)
|
|
{
|
|
WARN_ON(!RB_EMPTY_ROOT(&set->dir.root));
|
|
}
|
|
|
|
int __init proc_sys_init(void)
|
|
{
|
|
struct proc_dir_entry *proc_sys_root;
|
|
|
|
proc_sys_root = proc_mkdir("sys", NULL);
|
|
proc_sys_root->proc_iops = &proc_sys_dir_operations;
|
|
proc_sys_root->proc_fops = &proc_sys_dir_file_operations;
|
|
proc_sys_root->nlink = 0;
|
|
|
|
return sysctl_init();
|
|
}
|