cregit-Linux how code gets into the kernel

Release 4.14 drivers/connector/cn_proc.c

/*
 * cn_proc.c - process events connector
 *
 * Copyright (C) Matt Helsley, IBM Corp. 2005
 * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
 * Original copyright notice follows:
 * Copyright (C) 2005 BULL SA.
 *
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/init.h>
#include <linux/connector.h>
#include <linux/gfp.h>
#include <linux/ptrace.h>
#include <linux/atomic.h>
#include <linux/pid_namespace.h>

#include <linux/cn_proc.h>

/*
 * Size of a cn_msg followed by a proc_event structure.  Since the
 * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
 * add one 4-byte word to the size here, and then start the actual
 * cn_msg structure 4 bytes into the stack buffer.  The result is that
 * the immediately following proc_event structure is aligned to 8 bytes.
 */

#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)

/* See comment above; we test our assumption about sizeof struct cn_msg here. */

static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer) { BUILD_BUG_ON(sizeof(struct cn_msg) != 20); return (struct cn_msg *)(buffer + 4); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf36100.00%1100.00%
Total36100.00%1100.00%

static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; /* proc_event_counts is used as the sequence number of the netlink message */ static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
static inline void send_msg(struct cn_msg *msg) { preempt_disable(); msg->seq = __this_cpu_inc_return(proc_event_counts) - 1; ((struct proc_event *)msg->data)->cpu = smp_processor_id(); /* * Preemption remains disabled during send to ensure the messages are * ordered according to their sequence numbers. * * If cn_netlink_send() fails, the data is not sent. */ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT); preempt_enable(); }

Contributors

PersonTokensPropCommitsCommitProp
Aaron Campbell2950.88%133.33%
Matt Helsley2035.09%133.33%
Christoph Lameter814.04%133.33%
Total57100.00%3100.00%


void proc_fork_connector(struct task_struct *task) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); struct task_struct *parent; if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_FORK; rcu_read_lock(); parent = rcu_dereference(task->real_parent); ev->event_data.fork.parent_pid = parent->pid; ev->event_data.fork.parent_tgid = parent->tgid; rcu_read_unlock(); ev->event_data.fork.child_pid = task->pid; ev->event_data.fork.child_tgid = task->tgid; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley14470.59%225.00%
Mathias Krause2411.76%112.50%
Oleg Nesterov2110.29%112.50%
Chris Metcalf115.39%112.50%
Thomas Gleixner20.98%112.50%
Chandra Seetharaman10.49%112.50%
Aaron Campbell10.49%112.50%
Total204100.00%8100.00%


void proc_exec_connector(struct task_struct *task) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_EXEC; ev->event_data.exec.process_pid = task->pid; ev->event_data.exec.process_tgid = task->tgid; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley12276.25%233.33%
Mathias Krause2415.00%116.67%
Chris Metcalf116.88%116.67%
Thomas Gleixner21.25%116.67%
Aaron Campbell10.62%116.67%
Total160100.00%6100.00%


void proc_id_connector(struct task_struct *task, int which_id) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); const struct cred *cred; if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->what = which_id; ev->event_data.id.process_pid = task->pid; ev->event_data.id.process_tgid = task->tgid; rcu_read_lock(); cred = __task_cred(task); if (which_id == PROC_EVENT_UID) { ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid); ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid); } else if (which_id == PROC_EVENT_GID) { ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid); ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid); } else { rcu_read_unlock(); return; } rcu_read_unlock(); ev->timestamp_ns = ktime_get_ns(); memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley19267.13%222.22%
David Howells3211.19%222.22%
Eric W. Biedermann248.39%111.11%
Mathias Krause248.39%111.11%
Chris Metcalf113.85%111.11%
Thomas Gleixner20.70%111.11%
Aaron Campbell10.35%111.11%
Total286100.00%9100.00%


void proc_sid_connector(struct task_struct *task) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_SID; ev->event_data.sid.process_pid = task->pid; ev->event_data.sid.process_tgid = task->tgid; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Scott James Remnant12276.25%120.00%
Mathias Krause2415.00%120.00%
Chris Metcalf116.88%120.00%
Thomas Gleixner21.25%120.00%
Aaron Campbell10.62%120.00%
Total160100.00%5100.00%


void proc_ptrace_connector(struct task_struct *task, int ptrace_id) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_PTRACE; ev->event_data.ptrace.process_pid = task->pid; ev->event_data.ptrace.process_tgid = task->tgid; if (ptrace_id == PTRACE_ATTACH) { ev->event_data.ptrace.tracer_pid = current->pid; ev->event_data.ptrace.tracer_tgid = current->tgid; } else if (ptrace_id == PTRACE_DETACH) { ev->event_data.ptrace.tracer_pid = 0; ev->event_data.ptrace.tracer_tgid = 0; } else return; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Vladimir Zapolskiy18883.19%120.00%
Mathias Krause2410.62%120.00%
Chris Metcalf114.87%120.00%
Thomas Gleixner20.88%120.00%
Aaron Campbell10.44%120.00%
Total226100.00%5100.00%


void proc_comm_connector(struct task_struct *task) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_COMM; ev->event_data.comm.process_pid = task->pid; ev->event_data.comm.process_tgid = task->tgid; get_task_comm(ev->event_data.comm.comm, task); memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Vladimir Zapolskiy12672.83%116.67%
Mathias Krause2413.87%116.67%
Chris Metcalf116.36%116.67%
Jesper Derehag95.20%116.67%
Thomas Gleixner21.16%116.67%
Aaron Campbell10.58%116.67%
Total173100.00%6100.00%


void proc_coredump_connector(struct task_struct *task) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_COREDUMP; ev->event_data.coredump.process_pid = task->pid; ev->event_data.coredump.process_tgid = task->tgid; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Derehag11370.62%116.67%
Mathias Krause2415.00%116.67%
Chris Metcalf116.88%116.67%
Vladimir Zapolskiy95.62%116.67%
Thomas Gleixner21.25%116.67%
Aaron Campbell10.62%116.67%
Total160100.00%6100.00%


void proc_exit_connector(struct task_struct *task) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); ev->timestamp_ns = ktime_get_ns(); ev->what = PROC_EVENT_EXIT; ev->event_data.exit.process_pid = task->pid; ev->event_data.exit.process_tgid = task->tgid; ev->event_data.exit.exit_code = task->exit_code; ev->event_data.exit.exit_signal = task->exit_signal; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley14679.35%233.33%
Mathias Krause2413.04%116.67%
Chris Metcalf115.98%116.67%
Thomas Gleixner21.09%116.67%
Aaron Campbell10.54%116.67%
Total184100.00%6100.00%

/* * Send an acknowledgement message to userspace * * Use 0 for success, EFOO otherwise. * Note: this is the negative of conventional kernel error * values because it's not being returned via syscall return * mechanisms. */
static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) { struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); if (atomic_read(&proc_event_num_listeners) < 1) return; msg = buffer_to_cn_msg(buffer); ev = (struct proc_event *)msg->data; memset(&ev->event_data, 0, sizeof(ev->event_data)); msg->seq = rcvd_seq; ev->timestamp_ns = ktime_get_ns(); ev->cpu = -1; ev->what = PROC_EVENT_NONE; ev->event_data.ack.err = err; memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = rcvd_ack + 1; msg->len = sizeof(*ev); msg->flags = 0; /* not used */ send_msg(msg); }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley12776.97%233.33%
Mathias Krause2414.55%116.67%
Chris Metcalf116.67%116.67%
Thomas Gleixner21.21%116.67%
Aaron Campbell10.61%116.67%
Total165100.00%6100.00%

/** * cn_proc_mcast_ctl * @data: message sent from userspace via the connector */
static void cn_proc_mcast_ctl(struct cn_msg *msg, struct netlink_skb_parms *nsp) { enum proc_cn_mcast_op *mc_op = NULL; int err = 0; if (msg->len != sizeof(*mc_op)) return; /* * Events are reported with respect to the initial pid * and user namespaces so ignore requestors from * other namespaces. */ if ((current_user_ns() != &init_user_ns) || (task_active_pid_ns(current) != &init_pid_ns)) return; /* Can only change if privileged. */ if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) { err = EPERM; goto out; } mc_op = (enum proc_cn_mcast_op *)msg->data; switch (*mc_op) { case PROC_CN_MCAST_LISTEN: atomic_inc(&proc_event_num_listeners); break; case PROC_CN_MCAST_IGNORE: atomic_dec(&proc_event_num_listeners); break; default: err = EINVAL; break; } out: cn_proc_ack(err, msg->seq, msg->ack); }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley9162.76%116.67%
Eric W. Biedermann2819.31%233.33%
Kees Cook1913.10%116.67%
Stephen Boyd53.45%116.67%
Mike Frysinger21.38%116.67%
Total145100.00%6100.00%

/* * cn_proc_init - initialization entry point * * Adds the connector callback to the connector driver. */
static int __init cn_proc_init(void) { int err = cn_add_callback(&cn_proc_event_id, "cn_proc", &cn_proc_mcast_ctl); if (err) { pr_warn("cn_proc failed to register\n"); return err; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley3485.00%150.00%
Valentin Ilie615.00%150.00%
Total40100.00%2100.00%

device_initcall(cn_proc_init);

Overall Contributors

PersonTokensPropCommitsCommitProp
Matt Helsley93645.20%414.81%
Vladimir Zapolskiy32615.74%27.41%
Mathias Krause21610.43%13.70%
Chris Metcalf1386.66%13.70%
Scott James Remnant1225.89%13.70%
Jesper Derehag1225.89%13.70%
Eric W. Biedermann552.66%27.41%
Aaron Campbell381.83%13.70%
David Howells321.55%27.41%
Oleg Nesterov211.01%13.70%
Kees Cook190.92%13.70%
Thomas Gleixner180.87%13.70%
Christoph Lameter80.39%13.70%
Valentin Ilie60.29%13.70%
Stephen Boyd50.24%13.70%
Tejun Heo30.14%13.70%
Mike Frysinger20.10%13.70%
Paul Gortmaker10.05%13.70%
David S. Miller10.05%13.70%
Chandra Seetharaman10.05%13.70%
Arun Sharma10.05%13.70%
Total2071100.00%27100.00%
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