1 /* $NetBSD: procfs_cmdline.c,v 1.32 2019/09/27 14:36:18 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1999 Jaromir Dolecek <dolecek@ics.muni.cz> 5 * Copyright (c) 1999 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Jaromir Dolecek. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: procfs_cmdline.c,v 1.32 2019/09/27 14:36:18 christos Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/syslimits.h> 39 #include <sys/proc.h> 40 #include <sys/vnode.h> 41 #include <sys/exec.h> 42 #include <sys/malloc.h> 43 #include <sys/sysctl.h> 44 #include <miscfs/procfs/procfs.h> 45 46 #include <uvm/uvm_extern.h> 47 48 static int 49 procfs_doprocargs_helper(void *cookie, const void *src, size_t off, size_t len) 50 { 51 struct uio *uio = cookie; 52 char *buf = __UNCONST(src); 53 54 buf += uio->uio_offset - off; 55 if (off + len <= (uintmax_t)uio->uio_offset) 56 return 0; 57 return uiomove(buf, off + len - uio->uio_offset, cookie); 58 } 59 60 /* 61 * code for returning process's command line arguments/environment 62 */ 63 int 64 procfs_doprocargs( 65 struct lwp *curl, 66 struct proc *p, 67 struct pfsnode *pfs, 68 struct uio *uio, 69 int oid 70 ) 71 { 72 size_t len, start; 73 int error; 74 75 /* Don't allow writing. */ 76 if (uio->uio_rw != UIO_READ) 77 return EOPNOTSUPP; 78 79 /* 80 * Zombies don't have a stack, so we can't read their psstrings. 81 * System processes also don't have a user stack. This is what 82 * ps(1) would display. 83 */ 84 if (P_ZOMBIE(p) || (p->p_flag & PK_SYSTEM) != 0) { 85 static char msg[] = "()"; 86 error = 0; 87 if (0 == uio->uio_offset) { 88 error = uiomove(msg, 1, uio); 89 if (error) 90 return error; 91 } 92 len = strlen(p->p_comm); 93 if (len >= (uintmax_t)uio->uio_offset) { 94 start = uio->uio_offset - 1; 95 error = uiomove(p->p_comm + start, len - start, uio); 96 if (error) 97 return error; 98 } 99 if (len + 2 >= (uintmax_t)uio->uio_offset) { 100 start = uio->uio_offset - 1 - len; 101 error = uiomove(msg + 1 + start, 2 - start, uio); 102 } 103 return error; 104 } 105 106 len = uio->uio_offset + uio->uio_resid; 107 return copy_procargs(p, oid, &len, procfs_doprocargs_helper, uio); 108 } 109