1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License version 2. 4 * 5 * This program is distributed in the hope that it will be useful, 6 * but WITHOUT ANY WARRANTY; without even the implied warranty of 7 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 8 * GNU General Public License for more details. 9 * 10 * 11 * Test that the policy and scheduling parameters remain unchanged when the 12 * requesting process does not have permission to set the scheduling parameters 13 * for the specified process, or does not have the appropriate privilege to 14 * invoke sched_setscheduler(). 15 * 16 * Atempt to change the policy of the process whose ID is 1 which is generally 17 * belongs to root. This test can not be run by root. 18 * Steps: 19 * 1. Get the old policy and priority. 20 * 2. Call sched_setscheduler with pid arg == 1. 21 * 3. Check that the policy and priority have not changed. 22 */ 23 #include <sched.h> 24 #include <stdio.h> 25 #include <errno.h> 26 #include <unistd.h> 27 #include <pwd.h> 28 #include <string.h> 29 #include "posixtest.h" 30 31 /** Set the euid of this process to a non-root uid */ 32 int set_nonroot() 33 { 34 struct passwd *pw; 35 setpwent(); 36 /* search for the first user which is non root */ 37 while ((pw = getpwent()) != NULL) 38 if (strcmp(pw->pw_name, "root")) 39 break; 40 endpwent(); 41 if (pw == NULL) { 42 printf("There is no other user than current and root.\n"); 43 return 1; 44 } 45 46 if (seteuid(pw->pw_uid) != 0) { 47 if (errno == EPERM) { 48 printf 49 ("You don't have permission to change your UID.\n"); 50 return 1; 51 } 52 perror("An error occurs when calling seteuid()"); 53 return 1; 54 } 55 56 printf("Testing with user '%s' (uid: %d)\n", 57 pw->pw_name, (int)geteuid()); 58 return 0; 59 } 60 61 int main(void) 62 { 63 int max_priority, old_priority, old_policy, new_policy, policy; 64 struct sched_param param; 65 66 /* We assume process Number 1 is created by root */ 67 /* and can only be accessed by root */ 68 /* This test should be run under standard user permissions */ 69 if (getuid() == 0) { 70 if (set_nonroot() != 0) { 71 printf("Cannot run this test as non-root user\n"); 72 return PTS_UNTESTED; 73 } 74 } 75 76 if (sched_getparam(getpid(), ¶m) == -1) { 77 perror("An error occurs when calling sched_getparam()"); 78 return PTS_UNRESOLVED; 79 } 80 old_priority = param.sched_priority; 81 82 old_policy = sched_getscheduler(getpid()); 83 if (old_policy == -1) { 84 perror("An error occurs when calling sched_getscheduler()"); 85 return PTS_UNRESOLVED; 86 } 87 88 /* Make sure that policy != old_policy */ 89 policy = old_policy == SCHED_FIFO ? SCHED_RR : SCHED_FIFO; 90 91 /* Make sure that param.sched_priority != old_priority */ 92 max_priority = sched_get_priority_max(policy); 93 param.sched_priority = (old_priority == max_priority) ? 94 sched_get_priority_min(policy) : max_priority; 95 96 sched_setscheduler(1, policy, ¶m); 97 98 if (sched_getparam(getpid(), ¶m) != 0) { 99 perror("An error occurs when calling sched_getparam()"); 100 return PTS_UNRESOLVED; 101 } 102 103 new_policy = sched_getscheduler(getpid()); 104 if (new_policy == -1) { 105 perror("An error occurs when calling sched_getscheduler()"); 106 return PTS_UNRESOLVED; 107 } 108 109 if (old_policy == new_policy && old_priority == param.sched_priority) { 110 printf("Test PASSED\n"); 111 return PTS_PASS; 112 } 113 114 if (param.sched_priority != old_priority) { 115 printf("The param has changed\n"); 116 } 117 if (new_policy != old_policy) { 118 printf("The policy has changed\n"); 119 } 120 return PTS_FAIL; 121 } 122
