1 | /* Copyright (C) 1991-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <sys/types.h> |
20 | #include <signal.h> |
21 | #include <hurd.h> |
22 | #include <hurd/port.h> |
23 | #include <hurd/signal.h> |
24 | #include <hurd/msg.h> |
25 | |
26 | /* Send signal SIG to process number PID. If PID is zero, |
27 | send SIG to all processes in the current process's process group. |
28 | If PID is < -1, send SIG to all processes in process group - PID. */ |
29 | int |
30 | __kill (pid_t pid, int sig) |
31 | { |
32 | int delivered = 0; /* Set when we deliver any signal. */ |
33 | error_t err; |
34 | mach_port_t proc; |
35 | struct hurd_userlink ulink; |
36 | |
37 | void kill_pid (pid_t pid) /* Kill one PID. */ |
38 | { |
39 | /* SIGKILL is not delivered as a normal signal. |
40 | Sending SIGKILL to a process means to terminate its task. */ |
41 | if (sig == SIGKILL) |
42 | /* Fetch the process's task port and terminate the task. We |
43 | loop in case the process execs and changes its task port. |
44 | If the old task port dies after we fetch it but before we |
45 | send the RPC, we get MACH_SEND_INVALID_DEST; if it dies |
46 | after we send the RPC request but before it is serviced, we |
47 | get MIG_SERVER_DIED. */ |
48 | do |
49 | { |
50 | task_t refport; |
51 | err = __proc_pid2task (proc, pid, &refport); |
52 | /* Ignore zombies. */ |
53 | if (!err && refport != MACH_PORT_NULL) |
54 | { |
55 | err = __task_terminate (refport); |
56 | __mach_port_deallocate (__mach_task_self (), refport); |
57 | } |
58 | } while (err == MACH_SEND_INVALID_DEST |
59 | || err == MIG_SERVER_DIED); |
60 | else |
61 | { |
62 | error_t taskerr; |
63 | error_t kill_port (mach_port_t msgport, mach_port_t refport) |
64 | { |
65 | if (msgport != MACH_PORT_NULL) |
66 | /* Send a signal message to his message port. */ |
67 | return __msg_sig_post (msgport, sig, SI_USER, refport); |
68 | |
69 | /* The process has no message port. Perhaps try direct |
70 | frobnication of the task. */ |
71 | |
72 | if (taskerr) |
73 | /* If we could not get the task port, we can do nothing. */ |
74 | return taskerr; |
75 | |
76 | if (refport == MACH_PORT_NULL) |
77 | /* proc_pid2task returned success with a null task port. |
78 | That means the process is a zombie. Signals |
79 | to zombies should return success and do nothing. */ |
80 | return 0; |
81 | |
82 | /* For user convenience in the case of a task that has |
83 | not registered any message port with the proc server, |
84 | translate a few signals to direct task operations. */ |
85 | switch (sig) |
86 | { |
87 | /* The only signals that really make sense for an |
88 | unregistered task are kill, suspend, and continue. */ |
89 | case SIGSTOP: |
90 | case SIGTSTP: |
91 | return __task_suspend (refport); |
92 | case SIGCONT: |
93 | return __task_resume (refport); |
94 | case SIGTERM: |
95 | case SIGQUIT: |
96 | case SIGINT: |
97 | return __task_terminate (refport); |
98 | default: |
99 | /* We have full permission to send signals, but there is |
100 | no meaningful way to express this signal. */ |
101 | return EPERM; |
102 | } |
103 | } |
104 | err = HURD_MSGPORT_RPC (__proc_getmsgport (proc, pid, &msgport), |
105 | (taskerr = __proc_pid2task (proc, pid, |
106 | &refport)) |
107 | ? __proc_getsidport (proc, &refport) : 0, 1, |
108 | kill_port (msgport, refport)); |
109 | } |
110 | if (! err) |
111 | delivered = 1; |
112 | } |
113 | |
114 | proc = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink); |
115 | |
116 | if (pid <= 0) |
117 | { |
118 | /* Send SIG to each process in pgrp (- PID). */ |
119 | pid_t pidbuf[10], *pids = pidbuf; |
120 | mach_msg_type_number_t i, npids = sizeof (pidbuf) / sizeof (pidbuf[0]); |
121 | |
122 | err = __proc_getpgrppids (proc, - pid, &pids, &npids); |
123 | if (!err) |
124 | { |
125 | for (i = 0; i < npids; ++i) |
126 | { |
127 | kill_pid (pids[i]); |
128 | if (err == ESRCH) |
129 | /* The process died already. Ignore it. */ |
130 | err = 0; |
131 | } |
132 | if (pids != pidbuf) |
133 | __vm_deallocate (__mach_task_self (), |
134 | (vm_address_t) pids, npids * sizeof (pids[0])); |
135 | } |
136 | } |
137 | else |
138 | kill_pid (pid); |
139 | |
140 | _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, proc); |
141 | |
142 | /* If we delivered no signals, but ERR is clear, this must mean that |
143 | every kill_pid call failed with ESRCH, meaning all the processes in |
144 | the pgrp died between proc_getpgrppids and kill_pid; in that case we |
145 | fail with ESRCH. */ |
146 | return delivered ? 0 : __hurd_fail (err ?: ESRCH); |
147 | } |
148 | |
149 | libc_hidden_def (__kill) |
150 | weak_alias (__kill, kill) |
151 | |