1/* ulimit.c - Modify resource limits 2 * 3 * Copyright 2015 Rob Landley <rob@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 19USE_ULIMIT(NEWTOY(ulimit, ">1P#<1SHavutsrRqpnmlifedc[-SH][!apvutsrRqnmlifedc]", TOYFLAG_USR|TOYFLAG_BIN)) 20USE_ULIMIT(OLDTOY(prlimit, ulimit, TOYFLAG_USR|TOYFLAG_BIN)) 21 22config ULIMIT 23 bool "ulimit" 24 default y 25 depends on TOYBOX_PRLIMIT 26 help 27 usage: ulimit [-P PID] [-SHRacdefilmnpqrstuv] [LIMIT] 28 29 Print or set resource limits for process number PID. If no LIMIT specified 30 (or read-only -ap selected) display current value (sizes in bytes). 31 Default is ulimit -P $PPID -Sf" (show soft filesize of your shell). 32 33 -S Set/show soft limit -H Set/show hard (maximum) limit 34 -a Show all limits -c Core file size 35 -d Process data segment -e Max scheduling priority 36 -f Output file size -i Pending signal count 37 -l Locked memory -m Resident Set Size 38 -n Number of open files -p Pipe buffer 39 -q Posix message queue -r Max Real-time priority 40 -R Realtime latency (usec) -s Stack size 41 -t Total CPU time (in seconds) -u Maximum processes (under this UID) 42 -v Virtual memory size -P PID to affect (default $PPID) 43*/ 44 45#define FOR_ulimit 46#include "toys.h" 47 48GLOBALS( 49 long P; 50) 51 52// This is a linux kernel syscall added in 2.6.36 (git c022a0acad53) which 53// glibc only exports a wrapper prototype for if you #define _FSF_HURD_RULZE. 54int prlimit(pid_t pid, int resource, const struct rlimit *new_limit, 55 struct rlimit *old_limit); 56 57// I'd like to sort the RLIMIT values 0-15, but mips, alpha and sparc 58// override the asm-generic values for 5-9. Also, the kernel implementation 59// of RLIMIT_LOCKS (-x) was removed from Linux in 2003. 60void ulimit_main(void) 61{ 62 struct rlimit rr; 63 int i; 64 // Order is cdefilmnqRrstuv 65 char map[] = {RLIMIT_CORE, RLIMIT_DATA, RLIMIT_NICE, RLIMIT_FSIZE, 66 RLIMIT_SIGPENDING, RLIMIT_MEMLOCK, RLIMIT_RSS, RLIMIT_NOFILE, 0, 67 RLIMIT_MSGQUEUE, RLIMIT_RTTIME, RLIMIT_RTPRIO, RLIMIT_STACK, 68 RLIMIT_CPU, RLIMIT_NPROC, RLIMIT_AS}; 69 70 if (!(toys.optflags&(FLAG_H-1))) toys.optflags |= FLAG_f; 71 if ((FLAG(a)||FLAG(p)) && toys.optc) error_exit("can't set -ap"); 72 73 // Fetch data 74 if (!FLAG(P)) TT.P = getppid(); 75 76 for (i=0; i<sizeof(map); i++) { 77 char *flags="cdefilmnpqRrstuv"; 78 79 int get = toys.optflags&(FLAG_a|(1<<i)); 80 81 if (get && prlimit(TT.P, map[i], 0, &rr)) perror_exit("-%c", flags[i]); 82 if (!toys.optc) { 83 if (FLAG(a)) printf("-%c: ", flags[i]); 84 if (get) { 85 if ((1<<i)&FLAG_p) { 86 if (FLAG(H)) 87 xreadfile("/proc/sys/fs/pipe-max-size", toybuf, sizeof(toybuf)); 88 else { 89 int pp[2]; 90 91 xpipe(pp); 92 sprintf(toybuf, "%d\n", fcntl(*pp, F_GETPIPE_SZ)); 93 } 94 printf("%s", toybuf); 95 } else { 96 rlim_t rl = FLAG(H) ? rr.rlim_max : rr.rlim_cur; 97 98 if (rl == RLIM_INFINITY) printf("unlimited\n"); 99 else printf("%ld\n", (long)rl); 100 } 101 } 102 } 103 if (toys.optflags&(1<<i)) break; 104 } 105 106 if (FLAG(a)||FLAG(p)) return; 107 108 if (toys.optc) { 109 rlim_t val; 110 111 if (tolower(**toys.optargs) == 'u') val = RLIM_INFINITY; 112 else val = atolx_range(*toys.optargs, 0, LONG_MAX); 113 114 if (FLAG(H)) rr.rlim_max = val; 115 else rr.rlim_cur = val; 116 if (prlimit(TT.P, map[i], &rr, 0)) perror_exit(0); 117 } 118} 119