busybox/coreutils/nice.c
Denys Vlasenko 5c527dc57e make 17 state-changing execing applets (ex: "nice PROG ARGS") noexec
The applets with "<applet> [opts] PROG ARGS" API very quickly exec
another program, noexec is okay for them:

 chpst/envdir/envuidgid/softlimit/setuidgid
 chroot
 chrt
 ionice
 nice
 nohup
 setarch/linux32/linux64
 taskset
 cttyhack

"reset" and "sulogin" applets don't have this form, but also exec
another program at once, thus made noexec too.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-04 19:55:01 +02:00

67 lines
1.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* nice implementation for busybox
*
* Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config NICE
//config: bool "nice (1.8 kb)"
//config: default y
//config: help
//config: nice runs a program with modified scheduling priority.
//applet:IF_NICE(APPLET_NOEXEC(nice, nice, BB_DIR_BIN, BB_SUID_DROP, nice))
//kbuild:lib-$(CONFIG_NICE) += nice.o
//usage:#define nice_trivial_usage
//usage: "[-n ADJUST] [PROG ARGS]"
//usage:#define nice_full_usage "\n\n"
//usage: "Change scheduling priority, run PROG\n"
//usage: "\n -n ADJUST Adjust priority by ADJUST"
#include <sys/resource.h>
#include "libbb.h"
int nice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int nice_main(int argc, char **argv)
{
int old_priority, adjustment;
old_priority = getpriority(PRIO_PROCESS, 0);
if (!*++argv) { /* No args, so (GNU) output current nice value. */
printf("%d\n", old_priority);
fflush_stdout_and_exit(EXIT_SUCCESS);
}
adjustment = 10; /* Set default adjustment. */
if (argv[0][0] == '-') {
if (argv[0][1] == 'n') { /* -n */
if (argv[0][2]) { /* -nNNNN (w/o space) */
argv[0] += 2; argv--; argc++;
}
} else { /* -NNN (NNN may be negative) == -n NNN */
argv[0] += 1; argv--; argc++;
}
if (argc < 4) { /* Missing priority and/or utility! */
bb_show_usage();
}
adjustment = xatoi_range(argv[1], INT_MIN/2, INT_MAX/2);
argv += 2;
}
{ /* Set our priority. */
int prio = old_priority + adjustment;
if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
bb_perror_msg_and_die("setpriority(%d)", prio);
}
}
BB_EXECVP_or_die(argv);
}