cregit-Linux how code gets into the kernel

Release 4.15 kernel/utsname.c

Directory: kernel
/*
 *  Copyright (C) 2004 IBM Corporation
 *
 *  Author: Serge Hallyn <serue@us.ibm.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2 of the
 *  License.
 */

#include <linux/export.h>
#include <linux/uts.h>
#include <linux/utsname.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/cred.h>
#include <linux/user_namespace.h>
#include <linux/proc_ns.h>
#include <linux/sched/task.h>


static struct ucounts *inc_uts_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_UTS_NAMESPACES); }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann24100.00%1100.00%
Total24100.00%1100.00%


static void dec_uts_namespaces(struct ucounts *ucounts) { dec_ucount(ucounts, UCOUNT_UTS_NAMESPACES); }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann18100.00%1100.00%
Total18100.00%1100.00%


static struct uts_namespace *create_uts_ns(void) { struct uts_namespace *uts_ns; uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL); if (uts_ns) kref_init(&uts_ns->kref); return uts_ns; }

Contributors

PersonTokensPropCommitsCommitProp
Alexey Dobriyan43100.00%1100.00%
Total43100.00%1100.00%

/* * Clone a new ns copying an original utsname, setting refcount to 1 * @old_ns: namespace to clone * Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise */
static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, struct uts_namespace *old_ns) { struct uts_namespace *ns; struct ucounts *ucounts; int err; err = -ENOSPC; ucounts = inc_uts_namespaces(user_ns); if (!ucounts) goto fail; err = -ENOMEM; ns = create_uts_ns(); if (!ns) goto fail_dec; err = ns_alloc_inum(&ns->ns); if (err) goto fail_free; ns->ucounts = ucounts; ns->ns.ops = &utsns_operations; down_read(&uts_sem); memcpy(&ns->name, &old_ns->name, sizeof(ns->name)); ns->user_ns = get_user_ns(user_ns); up_read(&uts_sem); return ns; fail_free: kfree(ns); fail_dec: dec_uts_namespaces(ucounts); fail: return ERR_PTR(err); }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann8148.50%430.77%
Serge E. Hallyn6035.93%323.08%
Alexey Dobriyan148.38%215.38%
Al Viro116.59%323.08%
Cédric Le Goater10.60%17.69%
Total167100.00%13100.00%

/* * Copy task tsk's utsname namespace, or clone it if flags * specifies CLONE_NEWUTS. In latter case, changes to the * utsname of this process won't be seen by parent, and vice * versa. */
struct uts_namespace *copy_utsname(unsigned long flags, struct user_namespace *user_ns, struct uts_namespace *old_ns) { struct uts_namespace *new_ns; BUG_ON(!old_ns); get_uts_ns(old_ns); if (!(flags & CLONE_NEWUTS)) return old_ns; new_ns = clone_uts_ns(user_ns, old_ns); put_uts_ns(old_ns); return new_ns; }

Contributors

PersonTokensPropCommitsCommitProp
Serge E. Hallyn5278.79%350.00%
Eric W. Biedermann812.12%233.33%
Badari Pulavarty69.09%116.67%
Total66100.00%6100.00%


void free_uts_ns(struct kref *kref) { struct uts_namespace *ns; ns = container_of(kref, struct uts_namespace, kref); dec_uts_namespaces(ns->ucounts); put_user_ns(ns->user_ns); ns_free_inum(&ns->ns); kfree(ns); }

Contributors

PersonTokensPropCommitsCommitProp
Serge E. Hallyn3972.22%233.33%
Eric W. Biedermann1222.22%233.33%
Al Viro35.56%233.33%
Total54100.00%6100.00%


static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) { return container_of(ns, struct uts_namespace, ns); }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro25100.00%1100.00%
Total25100.00%1100.00%


static struct ns_common *utsns_get(struct task_struct *task) { struct uts_namespace *ns = NULL; struct nsproxy *nsproxy; task_lock(task); nsproxy = task->nsproxy; if (nsproxy) { ns = nsproxy->uts_ns; get_uts_ns(ns); } task_unlock(task); return ns ? &ns->ns : NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann5986.76%250.00%
Al Viro913.24%250.00%
Total68100.00%4100.00%


static void utsns_put(struct ns_common *ns) { put_uts_ns(to_uts_ns(ns)); }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann1473.68%133.33%
Al Viro526.32%266.67%
Total19100.00%3100.00%


static int utsns_install(struct nsproxy *nsproxy, struct ns_common *new) { struct uts_namespace *ns = to_uts_ns(new); if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) return -EPERM; get_uts_ns(ns); put_uts_ns(nsproxy->uts_ns); nsproxy->uts_ns = ns; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann6793.06%466.67%
Al Viro56.94%233.33%
Total72100.00%6100.00%


static struct user_namespace *utsns_owner(struct ns_common *ns) { return to_uts_ns(ns)->user_ns; }

Contributors

PersonTokensPropCommitsCommitProp
Andrey Vagin21100.00%1100.00%
Total21100.00%1100.00%

const struct proc_ns_operations utsns_operations = { .name = "uts", .type = CLONE_NEWUTS, .get = utsns_get, .put = utsns_put, .install = utsns_install, .owner = utsns_owner, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann31749.22%1033.33%
Serge E. Hallyn16325.31%413.33%
Al Viro589.01%516.67%
Alexey Dobriyan578.85%26.67%
Andrey Vagin264.04%13.33%
Badari Pulavarty71.09%13.33%
Ingo Molnar60.93%26.67%
Cédric Le Goater40.62%13.33%
Robert P. J. Day30.47%13.33%
David Howells10.16%13.33%
Paul Gortmaker10.16%13.33%
Yuanhan Liu10.16%13.33%
Total644100.00%30100.00%
Directory: kernel
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