source: trunk/kernel/syscalls/sys_kill.c

Last change on this file was 683, checked in by alain, 11 months ago

All modifications required to support the <tcp_chat> application
including error recovery in case of packet loss.A

File size: 8.1 KB
Line 
1/*
2 * sys_kill.c - Kernel function implementing the "kill" system call.
3 *
4 * Author    Alain Greiner     (2016,2017,2018,2019,2020)
5 *
6 * Copyright (c)  UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <kernel_config.h>
25#include <hal_kernel_types.h>
26#include <hal_irqmask.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <process.h>
31#include <shared_syscalls.h>
32#include <cluster.h>
33#include <rpc.h>
34
35#include <syscalls.h>
36
37
38#if DEBUG_SYS_KILL
39////////////////////////////////////////////
40static char* sig_type_str( uint32_t sig_id )
41{
42    switch( sig_id )
43    {
44        case SIGKILL: return "SIGKILL";
45        case SIGSTOP: return "SIGSTOP";
46        case SIGCONT: return "SIGCONT";
47        default:      return "undefined";
48    }
49}
50#endif
51
52
53///////////////////////////
54int sys_kill( pid_t    pid,
55              uint32_t sig_id )
56{
57    xptr_t      owner_xp;          // extended pointer on process in owner cluster
58    cxy_t       owner_cxy;         // process owner cluster
59    process_t * owner_ptr;         // local pointer on process in owner cluster
60    xptr_t      parent_xp;         // extended pointer on parent process
61    cxy_t       parent_cxy;        // parent process cluster
62    process_t * parent_ptr;        // local pointer on parent process
63    thread_t  * parent_main_ptr;   // local pointer on parent main thread
64    xptr_t      parent_main_xp;    // extended pointer on parent main thread
65
66    thread_t  * this    = CURRENT_THREAD;
67    process_t * process = this->process;
68
69#if DEBUG_SYS_KILL || DEBUG_SYSCALLS_ERROR || CONFIG_INSTRUMENTATION_SYSCALLS
70uint64_t     tm_start = hal_get_cycles();
71#endif
72
73#if DEBUG_SYS_KILL
74if( DEBUG_SYS_KILL < tm_start )
75printk("\n[%s] thread[%x,%x] enter : %s to process %x / cycle %d\n",
76__FUNCTION__, this->process->pid, this->trdid,
77sig_type_str(sig_id), pid, (uint32_t)tm_start );
78#endif
79
80    // get pointers on process descriptor in owner cluster
81    owner_xp  = cluster_get_owner_process_from_pid( pid );
82    owner_cxy = GET_CXY( owner_xp );
83    owner_ptr = GET_PTR( owner_xp );
84   
85#if (DEBUG_SYS_KILL & 1)
86if( DEBUG_SYS_KILL < tm_start )
87printk("\n[%s] thread[%x,%x] get target process descriptor %x in owner cluster %x\n",
88__FUNCTION__ , this->process->pid, this->trdid, owner_ptr, owner_cxy );
89#endif
90
91    // check process found
92    if( owner_xp == XPTR_NULL)
93    {
94
95#if DEBUG_SYSCALLS_ERROR
96if( DEBUG_SYSCALLS_ERROR < tm_start )
97printk("\n[ERROR] in %s : thread[%x,%x] / process %x not found\n",
98__FUNCTION__, process->pid, this->trdid, pid );
99#endif
100        this->errno = EINVAL;
101        return -1;
102    }
103
104    // get parent process descriptor pointers
105    parent_xp  = (xptr_t)hal_remote_l64( XPTR( owner_cxy , &owner_ptr->parent_xp ) );
106    parent_cxy = GET_CXY( parent_xp );
107    parent_ptr = GET_PTR( parent_xp );
108
109#if (DEBUG_SYS_KILL & 1)
110if( DEBUG_SYS_KILL < tm_start )
111printk("\n[%s] thread[%x,%x] get parent process descriptor %x in cluster %x\n",
112__FUNCTION__ , this->process->pid, this->trdid, parent_ptr, parent_cxy );
113#endif
114
115    // get pointers on the parent process main thread
116    parent_main_ptr = hal_remote_lpt( XPTR( parent_cxy , &parent_ptr->th_tbl[0] ) ); 
117    parent_main_xp  = XPTR( parent_cxy , parent_main_ptr );
118
119    // analyse signal type / supported values are : 0, SIGSTOP, SIGCONT, SIGKILL
120    switch( sig_id )
121    {
122        case 0 :          // does nothing
123        {
124            break;
125        }
126        case SIGSTOP:     // block all target process threads
127        {
128            // block all threads in all clusters
129            process_sigaction( pid , BLOCK_ALL_THREADS );
130
131#if (DEBUG_SYS_KILL & 1)
132if( DEBUG_SYS_KILL < tm_start )
133printk("\n[%s] thread[%x,%x] blocked all threads of process %x\n",
134__FUNCTION__ , this->process->pid, this->trdid, pid );
135#endif
136            // atomically update owner process termination state
137            hal_remote_atomic_or( XPTR( owner_cxy , &owner_ptr->term_state ) ,
138                                  PROCESS_TERM_STOP );
139
140            // unblock the parent process main thread
141            thread_unblock( parent_main_xp , THREAD_BLOCKED_WAIT );
142
143            // calling thread deschedules when it is itself a target thread
144            if( this->process->pid == pid )
145            {
146
147#if (DEBUG_SYS_KILL & 1)
148if( DEBUG_SYS_KILL < tm_start )
149printk("\n[%s] thread[%x,%x] is a target thread => deschedule\n",
150__FUNCTION__ , this->process->pid, this->trdid );
151#endif
152                sched_yield("block itself");
153            }
154
155            break;
156        }
157        case SIGCONT:     // unblock all target process threads
158        {
159            // unblock all threads in all clusters
160            process_sigaction( pid , UNBLOCK_ALL_THREADS );
161
162            // atomically update owner process termination state
163            hal_remote_atomic_and( XPTR( owner_cxy , &owner_ptr->term_state ) ,
164                                   ~PROCESS_TERM_STOP );
165
166            // unblock the parent process main thread
167            thread_unblock( parent_main_xp , THREAD_BLOCKED_WAIT );
168
169            break;
170        }
171        case SIGKILL:
172        {
173            // a process cannot kill itself
174            if( (pid == process->pid) ) 
175            {
176
177#if DEBUG_SYSCALLS_ERROR
178if( DEBUG_SYSCALLS_ERROR < tm_start )
179printk("\n[ERROR] in %s : thread[%x,%x] / process %x cannot kill itself\n",
180__FUNCTION__, process->pid, this->trdid, pid );
181#endif
182                this->errno = EINVAL;
183                return -1;
184            }
185
186            // processe INIT cannot be killed
187            if( pid == 1 )
188            {
189
190#if DEBUG_SYSCALLS_ERROR
191if( DEBUG_SYSCALLS_ERROR < tm_start )
192printk("\n[ERROR] in %s : thread[%x,%x] / process_init cannot be killed\n",
193 __FUNCTION__, process->pid, this->trdid);
194#endif
195                        this->errno = EINVAL;
196                return -1;
197            }
198
199            // remove process from TXT list
200            process_txt_detach( owner_xp );
201
202            // close all open files
203            process_fd_clean_all( owner_xp );
204
205            // mark for delete all threads in all clusters, but the main
206            process_sigaction( pid , DELETE_ALL_THREADS );
207
208            // block main thread
209            xptr_t main_xp = XPTR( owner_cxy , &owner_ptr->th_tbl[0] );
210            thread_block( main_xp , THREAD_BLOCKED_GLOBAL );
211
212            // atomically update owner process descriptor term_state to ask
213            // the parent process sys_wait() function to delete this main thread
214            hal_remote_atomic_or( XPTR( owner_cxy , &owner_ptr->term_state ) ,
215                                  PROCESS_TERM_KILL );
216
217            // unblock the parent process main thread
218            thread_unblock( parent_main_xp , THREAD_BLOCKED_WAIT );
219
220            break;
221        }
222        default:
223        {
224
225#if DEBUG_SYSCALLS_ERROR
226if( DEBUG_SYSCALLS_ERROR < tm_start )
227printk("\n[ERROR] in %s : thread[%x,%x] / illegal signal %d\n",
228__FUNCTION__, process->pid, this->trdid, sig_id );
229#endif
230            this->errno = EINVAL;
231            return -1;
232        }
233    }
234   
235    hal_fence();
236
237#if (DEBUG_SYS_KILL || CONFIG_INSTRUMENTATION_SYSCALLS)
238uint64_t     tm_end = hal_get_cycles();
239#endif
240
241#if DEBUG_SYS_KILL
242if( DEBUG_SYS_KILL < tm_end )
243printk("\n[%s] thread[%x,%x] exit / process %x / %s / cycle %d\n",
244__FUNCTION__ , this->process->pid, this->trdid, pid,
245sig_type_str(sig_id), (uint32_t)tm_end );
246#endif
247
248#if CONFIG_INSTRUMENTATION_SYSCALLS
249hal_atomic_add( &syscalls_cumul_cost[SYS_KILL] , tm_end - tm_start );
250hal_atomic_add( &syscalls_occurences[SYS_KILL] , 1 );
251#endif
252
253        return 0;
254
255}  // end sys_kill()
256
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