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/*
* Copyright (C) 2014-2022 Firejail Authors
*
* This file is part of firejail project
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sys/wait.h>
void oom_set(const char *oom_string) {
int oom = atoi(oom_string);
uid_t uid = getuid();
if (uid == 0) {
if (oom < -1000 || oom > 1000) {
fprintf(stderr, "Error: invalid oom value (-1000 to 1000)\n");
exit(1);
}
}
else {
if (oom < 0 || oom > 1000) {
fprintf(stderr, "Error: invalid oom value (0 to 1000)\n");
exit(1);
}
}
pid_t parent = getpid();
pid_t child = fork();
if (child == -1)
errExit("fork");
if (child == 0) {
EUID_ROOT();
// elevate privileges
if (setreuid(0, 0))
errExit("setreuid");
if (setregid(0, 0))
errExit("setregid");
char *fname;
if (asprintf(&fname, "/proc/%d/oom_score_adj", parent) == -1)
errExit("asprintf");
FILE *fp = fopen(fname, "w");
if (!fp) {
fprintf(stderr, "Error: cannot open %s\n", fname);
exit(1);
}
fprintf(fp, "%d", oom);
fclose(fp);
free(fname);
if (asprintf(&fname, "/proc/%d/oom_score", parent) == -1)
errExit("asprintf");
fp = fopen(fname, "r");
if (!fp) {
fprintf(stderr, "Error: cannot open %s\n", fname);
exit(1);
}
int newoom;
if (1 != fscanf(fp, "%d", &newoom)) {
fprintf(stderr, "Error: cannot read from %s\n", fname);
exit(1);
}
fclose(fp);
free(fname);
if (!arg_quiet)
printf("Out-Of-Memory score adjusted, new value %d\n", newoom);
exit(0);
}
int status;
if (waitpid(child, &status, 0) == -1 )
errExit("waitpid");
}
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