1 /* ulimit.c - Modify resource limits 2 * 3 * Copyright 2015 Rob Landley <rob (at) landley.net> 4 * 5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ulimit.html 6 * And man prlimit(2). 7 * 8 * Deviations from posix: The units on -f are supposed to be 512 byte 9 * "blocks" (no other options are specified, and even hard drives don't 10 * do that anymore). Bash uses 1024 byte blocks, so they don't care either. 11 * We consistently use bytes everywhere we can. 12 * 13 * Deviations from bash: Sizes are in bytes (instead of -p 512 and -f 1024). 14 * Bash's -p value has been wrong since 2010 (git 35f3d14dbbc5). 15 * The kernel implementation of RLIMIT_LOCKS (-x) was removed from Linux in 16 * 2003. Bash never implemented -b (it's in the help but unrecognized at 17 * runtime). We support -P to affect processes other than us. 18 19 USE_ULIMIT(NEWTOY(ulimit, ">1P#<1SHavutsrRqpnmlifedc[-SH][!apvutsrRqnmlifedc]", TOYFLAG_USR|TOYFLAG_BIN)) 20 21 config ULIMIT 22 bool "ulimit" 23 default y 24 depends on TOYBOX_PRLIMIT 25 help 26 usage: ulimit [-P PID] [-SHRacdefilmnpqrstuv] [LIMIT] 27 28 Print or set resource limits for process number PID. If no LIMIT specified 29 (or read-only -ap selected) display current value (sizes in bytes). 30 Default is ulimit -P $PPID -Sf" (show soft filesize of your shell). 31 32 -S Set/show soft limit -H Set/show hard (maximum) limit 33 -a Show all limits -c Core file size 34 -d Process data segment -e Max scheduling priority 35 -f Output file size -i Pending signal count 36 -l Locked memory -m Resident Set Size 37 -n Number of open files -p Pipe buffer 38 -q Posix message queue -r Max Real-time priority 39 -R Realtime latency (usec) -s Stack size 40 -t Total CPU time (in seconds) -u Maximum processes (under this UID) 41 -v Virtual memory size -P PID to affect (default $PPID) 42 */ 43 44 #define FOR_ulimit 45 #include "toys.h" 46 47 GLOBALS( 48 long pid; 49 ) 50 51 // This is a linux kernel syscall added in 2.6.36 (git c022a0acad53) which 52 // glibc only exports a wrapper prototype for if you #define _FSF_HURD_RULZE. 53 int prlimit(pid_t pid, int resource, const struct rlimit *new_limit, 54 struct rlimit *old_limit); 55 56 // I'd like to sort the RLIMIT values 0-15, but mips, alpha and sparc 57 // override the asm-generic values for 5-9. Also, the kernel implementation 58 // of RLIMIT_LOCKS (-x) was removed from Linux in 2003. 59 void ulimit_main(void) 60 { 61 struct rlimit rr; 62 int i; 63 // Order is cdefilmnqRrstuv 64 char map[] = {RLIMIT_CORE, RLIMIT_DATA, RLIMIT_NICE, RLIMIT_FSIZE, 65 RLIMIT_SIGPENDING, RLIMIT_MEMLOCK, RLIMIT_RSS, RLIMIT_NOFILE, 0, 66 RLIMIT_MSGQUEUE, RLIMIT_RTTIME, RLIMIT_RTPRIO, RLIMIT_STACK, 67 RLIMIT_CPU, RLIMIT_NPROC, RLIMIT_AS}; 68 69 if (!(toys.optflags&(FLAG_H-1))) toys.optflags |= FLAG_f; 70 if ((toys.optflags&(FLAG_a|FLAG_p)) && toys.optc) error_exit("can't set -ap"); 71 72 // Fetch data 73 if (!(toys.optflags&FLAG_P)) TT.pid = getppid(); 74 75 for (i=0; i<sizeof(map); i++) { 76 char *flags="cdefilmnpqRrstuv"; 77 78 int get = toys.optflags&(FLAG_a|(1<<i)); 79 80 if (get && prlimit(TT.pid, map[i], 0, &rr)) perror_exit("-%c", flags[i]); 81 if (!toys.optc) { 82 if (toys.optflags&FLAG_a) printf("-%c: ", flags[i]); 83 if (get) { 84 if ((1<<i)&FLAG_p) { 85 if (toys.optflags&FLAG_H) 86 xreadfile("/proc/sys/fs/pipe-max-size", toybuf, sizeof(toybuf)); 87 else { 88 int pp[2]; 89 90 xpipe(pp); 91 sprintf(toybuf, "%d\n", fcntl(*pp, F_GETPIPE_SZ)); 92 } 93 printf("%s", toybuf); 94 } else { 95 rlim_t rl = (toys.optflags&FLAG_H) ? rr.rlim_max : rr.rlim_cur; 96 97 if (rl == RLIM_INFINITY) printf("unlimited\n"); 98 else printf("%ld\n", (long)rl); 99 } 100 } 101 } 102 if (toys.optflags&(1<<i)) break; 103 } 104 105 if (toys.optflags&(FLAG_a|FLAG_p)) return; 106 107 if (toys.optc) { 108 rlim_t val; 109 110 if (tolower(**toys.optargs) == 'u') val = RLIM_INFINITY; 111 else val = atolx_range(*toys.optargs, 0, LONG_MAX); 112 113 if (toys.optflags&FLAG_H) rr.rlim_max = val; 114 else rr.rlim_cur = val; 115 if (prlimit(TT.pid, map[i], &rr, 0)) perror_exit(0); 116 } 117 } 118
