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/*
* Copyright (c) 2000-2011 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
* Mach Operating System
* Copyright (c) 1987 Carnegie-Mellon University
* All rights reserved. The CMU software License Agreement specifies
* the terms and conditions for use and redistribution.
*/
/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)kern_exec.c 8.1 (Berkeley) 6/10/93
*/
/*
* NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
#include <machine/reg.h>
#include <machine/cpu_capabilities.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/user.h>
#include <sys/socketvar.h>
#include <sys/malloc.h>
#include <sys/namei.h>
#include <sys/mount_internal.h>
#include <sys/vnode_internal.h>
#include <sys/file_internal.h>
#include <sys/stat.h>
#include <sys/uio_internal.h>
#include <sys/acct.h>
#include <sys/exec.h>
#include <sys/kdebug.h>
#include <sys/signal.h>
#include <sys/aio_kern.h>
#include <sys/sysproto.h>
#if SYSV_SHM
#include <sys/shm_internal.h> /* shmexec() */
#endif
#include <sys/ubc_internal.h> /* ubc_map() */
#include <sys/spawn.h>
#include <sys/spawn_internal.h>
#include <sys/process_policy.h>
#include <sys/codesign.h>
#include <crypto/sha1.h>
#include <libkern/libkern.h>
#include <security/audit/audit.h>
#include <ipc/ipc_types.h>
#include <mach/mach_types.h>
#include <mach/port.h>
#include <mach/task.h>
#include <mach/task_access.h>
#include <mach/thread_act.h>
#include <mach/vm_map.h>
#include <mach/mach_vm.h>
#include <mach/vm_param.h>
#include <kern/sched_prim.h> /* thread_wakeup() */
#include <kern/affinity.h>
#include <kern/assert.h>
#include <kern/task.h>
#include <kern/coalition.h>
#if CONFIG_MACF
#include <security/mac.h>
#include <security/mac_mach_internal.h>
#endif
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_protos.h>
#include <vm/vm_kern.h>
#include <vm/vm_fault.h>
#include <vm/vm_pageout.h>
#include <kdp/kdp_dyld.h>
#include <machine/pal_routines.h>
#include <pexpert/pexpert.h>
#if CONFIG_MEMORYSTATUS
#include <sys/kern_memorystatus.h>
#endif
#if CONFIG_DTRACE
/* Do not include dtrace.h, it redefines kmem_[alloc/free] */
extern void (*dtrace_fasttrap_exec_ptr)(proc_t);
extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
extern void (*dtrace_helpers_cleanup)(proc_t);
extern void dtrace_lazy_dofs_destroy(proc_t);
/*
* Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
* we will store its value before actually calling it.
*/
static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
#include <sys/dtrace_ptss.h>
#endif
/* support for child creation in exec after vfork */
thread_t fork_create_child(task_t parent_task, coalition_t parent_coalition, proc_t child_proc, int inherit_memory, int is64bit);
void vfork_exit(proc_t p, int rv);
int setsigvec(proc_t, thread_t, int, struct __kern_sigaction *, boolean_t in_sigstart);
extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
/*
* Mach things for which prototypes are unavailable from Mach headers
*/
void ipc_task_reset(
task_t task);
void ipc_thread_reset(
thread_t thread);
kern_return_t ipc_object_copyin(
ipc_space_t space,
mach_port_name_t name,
mach_msg_type_name_t msgt_name,
ipc_object_t *objectp);
void ipc_port_release_send(ipc_port_t);
#if DEVELOPMENT || DEBUG
void task_importance_update_owner_info(task_t);
#endif
extern struct savearea *get_user_regs(thread_t);
__attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
#include <kern/thread.h>
#include <kern/task.h>
#include <kern/ast.h>
#include <kern/mach_loader.h>
#include <kern/mach_fat.h>
#include <mach-o/fat.h>
#include <mach-o/loader.h>
#include <machine/vmparam.h>
#include <sys/imgact.h>
#include <sys/sdt.h>
/*
* EAI_ITERLIMIT The maximum number of times to iterate an image
* activator in exec_activate_image() before treating
* it as malformed/corrupt.
*/
#define EAI_ITERLIMIT 10
/*
* For #! interpreter parsing
*/
#define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
#define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
extern vm_map_t bsd_pageable_map;
extern const struct fileops vnops;
#define ROUND_PTR(type, addr) \
(type *)( ( (uintptr_t)(addr) + 16 - 1) \
& ~(16 - 1) )
struct image_params; /* Forward */
static int exec_activate_image(struct image_params *imgp);
static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
static int load_return_to_errno(load_return_t lrtn);
static int execargs_alloc(struct image_params *imgp);
static int execargs_free(struct image_params *imgp);
static int exec_check_permissions(struct image_params *imgp);
static int exec_extract_strings(struct image_params *imgp);
static int exec_add_apple_strings(struct image_params *imgp);
static int exec_handle_sugid(struct image_params *imgp);
static int sugid_scripts = 0;
SYSCTL_INT (_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
static void exec_resettextvp(proc_t, struct image_params *);
static int check_for_signature(proc_t, struct image_params *);
static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
static errno_t exec_handle_port_actions(struct image_params *imgp, short psa_flags, boolean_t * portwatch_present, ipc_port_t * portwatch_ports);
static errno_t exec_handle_spawnattr_policy(proc_t p, int psa_apptype, uint64_t psa_qos_clamp,
ipc_port_t * portwatch_ports, int portwatch_count);
/*
* exec_add_user_string
*
* Add the requested string to the string space area.
*
* Parameters; struct image_params * image parameter block
* user_addr_t string to add to strings area
* int segment from which string comes
* boolean_t TRUE if string contributes to NCARGS
*
* Returns: 0 Success
* !0 Failure errno from copyinstr()
*
* Implicit returns:
* (imgp->ip_strendp) updated location of next add, if any
* (imgp->ip_strspace) updated byte count of space remaining
* (imgp->ip_argspace) updated byte count of space in NCARGS
*/
static int
exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
{
int error = 0;
do {
size_t len = 0;
int space;
if (is_ncargs)
space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
else
space = imgp->ip_strspace;
if (space <= 0) {
error = E2BIG;
break;
}
if (!UIO_SEG_IS_USER_SPACE(seg)) {
char *kstr = CAST_DOWN(char *,str); /* SAFE */
error = copystr(kstr, imgp->ip_strendp, space, &len);
} else {
error = copyinstr(str, imgp->ip_strendp, space, &len);
}
imgp->ip_strendp += len;
imgp->ip_strspace -= len;
if (is_ncargs)
imgp->ip_argspace -= len;
} while (error == ENAMETOOLONG);
return error;
}
/*
* exec_save_path
*
* To support new app package launching for Mac OS X, the dyld needs the
* first argument to execve() stored on the user stack.
*
* Save the executable path name at the bottom of the strings area and set
* the argument vector pointer to the location following that to indicate
* the start of the argument and environment tuples, setting the remaining
* string space count to the size of the string area minus the path length.
*
* Parameters; struct image_params * image parameter block
* char * path used to invoke program
* int segment from which path comes
*
* Returns: int 0 Success
* EFAULT Bad address
* copy[in]str:EFAULT Bad address
* copy[in]str:ENAMETOOLONG Filename too long
*
* Implicit returns:
* (imgp->ip_strings) saved path
* (imgp->ip_strspace) space remaining in ip_strings
* (imgp->ip_strendp) start of remaining copy area
* (imgp->ip_argspace) space remaining of NCARGS
* (imgp->ip_applec) Initial applev[0]
*
* Note: We have to do this before the initial namei() since in the
* path contains symbolic links, namei() will overwrite the
* original path buffer contents. If the last symbolic link
* resolved was a relative pathname, we would lose the original
* "path", which could be an absolute pathname. This might be
* unacceptable for dyld.
*/
static int
exec_save_path(struct image_params *imgp, user_addr_t path, int seg)
{
int error;
size_t len;
char *kpath;
len = MIN(MAXPATHLEN, imgp->ip_strspace);
switch(seg) {
case UIO_USERSPACE32:
case UIO_USERSPACE64: /* Same for copyin()... */
error = copyinstr(path, imgp->ip_strings, len, &len);
break;
case UIO_SYSSPACE:
kpath = CAST_DOWN(char *,path); /* SAFE */
error = copystr(kpath, imgp->ip_strings, len, &len);
break;
default:
error = EFAULT;
break;
}
if (!error) {
imgp->ip_strendp += len;
imgp->ip_strspace -= len;
}
return(error);
}
/*
* exec_reset_save_path
*
* If we detect a shell script, we need to reset the string area
* state so that the interpreter can be saved onto the stack.
* Parameters; struct image_params * image parameter block
*
* Returns: int 0 Success
*
* Implicit returns:
* (imgp->ip_strings) saved path
* (imgp->ip_strspace) space remaining in ip_strings
* (imgp->ip_strendp) start of remaining copy area
* (imgp->ip_argspace) space remaining of NCARGS
*
*/
static int
exec_reset_save_path(struct image_params *imgp)
{
imgp->ip_strendp = imgp->ip_strings;
imgp->ip_argspace = NCARGS;
imgp->ip_strspace = ( NCARGS + PAGE_SIZE );
return (0);
}
/*
* exec_shell_imgact
*
* Image activator for interpreter scripts. If the image begins with the
* characters "#!", then it is an interpreter script. Verify that we are
* not already executing in PowerPC mode, and that the length of the script
* line indicating the interpreter is not in excess of the maximum allowed
* size. If this is the case, then break out the arguments, if any, which
* are separated by white space, and copy them into the argument save area
* as if they were provided on the command line before all other arguments.
* The line ends when we encounter a comment character ('#') or newline.
*
* Parameters; struct image_params * image parameter block
*
* Returns: -1 not an interpreter (keep looking)
* -3 Success: interpreter: relookup
* >0 Failure: interpreter: error number
*
* A return value other than -1 indicates subsequent image activators should
* not be given the opportunity to attempt to activate the image.
*/
static int
exec_shell_imgact(struct image_params *imgp)
{
char *vdata = imgp->ip_vdata;
char *ihp;
char *line_startp, *line_endp;
char *interp;
proc_t p;
struct fileproc *fp;
int fd;
int error;
/*
* Make sure it's a shell script. If we've already redirected
* from an interpreted file once, don't do it again.
*
* Note: We disallow PowerPC, since the expectation is that we
* may run a PowerPC interpreter, but not an interpret a PowerPC
* image. This is consistent with historical behaviour.
*/
if (vdata[0] != '#' ||
vdata[1] != '!' ||
(imgp->ip_flags & IMGPF_INTERPRET) != 0) {
return (-1);
}
imgp->ip_flags |= IMGPF_INTERPRET;
imgp->ip_interp_sugid_fd = -1;
imgp->ip_interp_buffer[0] = '\0';
/* Check to see if SUGID scripts are permitted. If they aren't then
* clear the SUGID bits.
* imgp->ip_vattr is known to be valid.
*/
if (sugid_scripts == 0) {
imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
}
/* Try to find the first non-whitespace character */
for( ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++ ) {
if (IS_EOL(*ihp)) {
/* Did not find interpreter, "#!\n" */
return (ENOEXEC);
} else if (IS_WHITESPACE(*ihp)) {
/* Whitespace, like "#! /bin/sh\n", keep going. */
} else {
/* Found start of interpreter */
break;
}
}
if (ihp == &vdata[IMG_SHSIZE]) {
/* All whitespace, like "#! " */
return (ENOEXEC);
}
line_startp = ihp;
/* Try to find the end of the interpreter+args string */
for ( ; ihp < &vdata[IMG_SHSIZE]; ihp++ ) {
if (IS_EOL(*ihp)) {
/* Got it */
break;
} else {
/* Still part of interpreter or args */
}
}
if (ihp == &vdata[IMG_SHSIZE]) {
/* A long line, like "#! blah blah blah" without end */
return (ENOEXEC);
}
/* Backtrack until we find the last non-whitespace */
while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
ihp--;
}
/* The character after the last non-whitespace is our logical end of line */
line_endp = ihp + 1;
/*
* Now we have pointers to the usable part of:
*
* "#! /usr/bin/int first second third \n"
* ^ line_startp ^ line_endp
*/
/* copy the interpreter name */
interp = imgp->ip_interp_buffer;
for ( ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++)
*interp++ = *ihp;
*interp = '\0';
exec_reset_save_path(imgp);
exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
UIO_SYSSPACE);
/* Copy the entire interpreter + args for later processing into argv[] */
interp = imgp->ip_interp_buffer;
for ( ihp = line_startp; (ihp < line_endp); ihp++)
*interp++ = *ihp;
*interp = '\0';
/*
* If we have a SUID oder SGID script, create a file descriptor
* from the vnode and pass /dev/fd/%d instead of the actual
* path name so that the script does not get opened twice
*/
if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
p = vfs_context_proc(imgp->ip_vfs_context);
error = falloc(p, &fp, &fd, imgp->ip_vfs_context);
if (error)
return(error);
fp->f_fglob->fg_flag = FREAD;
fp->f_fglob->fg_ops = &vnops;
fp->f_fglob->fg_data = (caddr_t)imgp->ip_vp;
proc_fdlock(p);
procfdtbl_releasefd(p, fd, NULL);
fp_drop(p, fd, fp, 1);
proc_fdunlock(p);
vnode_ref(imgp->ip_vp);
imgp->ip_interp_sugid_fd = fd;
}
return (-3);
}
/*
* exec_fat_imgact
*
* Image activator for fat 1.0 binaries. If the binary is fat, then we
* need to select an image from it internally, and make that the image
* we are going to attempt to execute. At present, this consists of
* reloading the first page for the image with a first page from the
* offset location indicated by the fat header.
*
* Parameters; struct image_params * image parameter block
*
* Returns: -1 not a fat binary (keep looking)
* -2 Success: encapsulated binary: reread
* >0 Failure: error number
*
* Important: This image activator is byte order neutral.
*
* Note: A return value other than -1 indicates subsequent image
* activators should not be given the opportunity to attempt
* to activate the image.
*
* If we find an encapsulated binary, we make no assertions
* about its validity; instead, we leave that up to a rescan
* for an activator to claim it, and, if it is claimed by one,
* that activator is responsible for determining validity.
*/
static int
exec_fat_imgact(struct image_params *imgp)
{
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
kauth_cred_t cred = kauth_cred_proc_ref(p);
struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
struct _posix_spawnattr *psa = NULL;
struct fat_arch fat_arch;
int resid, error;
load_return_t lret;
/* Make sure it's a fat binary */
if ((fat_header->magic != FAT_MAGIC) &&
(fat_header->magic != FAT_CIGAM)) {
error = -1;
goto bad;
}
#if DEVELOPMENT || DEBUG
if (cpu_type() == CPU_TYPE_ARM64) {
uint32_t fat_nfat_arch = OSSwapBigToHostInt32(fat_header->nfat_arch);
struct fat_arch *archs;
int vfexec = (imgp->ip_flags & IMGPF_VFORK_EXEC);
int spawn = (imgp->ip_flags & IMGPF_SPAWN);
archs = (struct fat_arch *)(imgp->ip_vdata + sizeof(struct fat_header));
/* ip_vdata always has PAGE_SIZE of data */
if (PAGE_SIZE >= (sizeof(struct fat_header) + (fat_nfat_arch + 1) * sizeof(struct fat_arch))) {
if (fat_nfat_arch > 0
&& OSSwapBigToHostInt32(archs[fat_nfat_arch].cputype) == CPU_TYPE_ARM64) {
/* rdar://problem/15001727 */
printf("Attempt to execute malformed binary %s\n", imgp->ip_strings);
proc_lock(p);
p->p_csflags |= CS_KILLED;
proc_unlock(p);
/*
* We can't stop the system call, so make sure the child never executes
* For vfork exec, the current implementation has not set up the thread in the
* child process, so we cannot signal it. Return an error code in that case.
*/
if (!vfexec && !spawn) {
psignal(p, SIGKILL);
error = 0;
} else {
error = EBADEXEC;
}
goto bad;
}
}
}
#endif
/* If posix_spawn binprefs exist, respect those prefs. */
psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
if (psa != NULL && psa->psa_binprefs[0] != 0) {
struct fat_arch *arches = (struct fat_arch *) (fat_header + 1);
int nfat_arch = 0, pr = 0, f = 0;
nfat_arch = OSSwapBigToHostInt32(fat_header->nfat_arch);
/* Check each preference listed against all arches in header */
for (pr = 0; pr < NBINPREFS; pr++) {
cpu_type_t pref = psa->psa_binprefs[pr];
if (pref == 0) {
/* No suitable arch in the pref list */
error = EBADARCH;
goto bad;
}
if (pref == CPU_TYPE_ANY) {
/* Fall through to regular grading */
break;
}
for (f = 0; f < nfat_arch; f++) {
cpu_type_t archtype = OSSwapBigToHostInt32(
arches[f].cputype);
cpu_type_t archsubtype = OSSwapBigToHostInt32(
arches[f].cpusubtype) & ~CPU_SUBTYPE_MASK;
if (pref == archtype &&
grade_binary(archtype, archsubtype)) {
/* We have a winner! */
fat_arch.cputype = archtype;
fat_arch.cpusubtype = archsubtype;
fat_arch.offset = OSSwapBigToHostInt32(
arches[f].offset);
fat_arch.size = OSSwapBigToHostInt32(
arches[f].size);
fat_arch.align = OSSwapBigToHostInt32(
arches[f].align);
goto use_arch;
}
}
}
}
/* Look up our preferred architecture in the fat file. */
lret = fatfile_getarch_affinity(imgp->ip_vp,
(vm_offset_t)fat_header,
&fat_arch,
(p->p_flag & P_AFFINITY));
if (lret != LOAD_SUCCESS) {
error = load_return_to_errno(lret);
goto bad;
}
use_arch:
/* Read the Mach-O header out of fat_arch */
error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
PAGE_SIZE, fat_arch.offset,
UIO_SYSSPACE, (IO_UNIT|IO_NODELOCKED),
cred, &resid, p);
if (error) {
goto bad;
}
/* Did we read a complete header? */
if (resid) {
error = EBADEXEC;
goto bad;
}
/* Success. Indicate we have identified an encapsulated binary */
error = -2;
imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
imgp->ip_arch_size = (user_size_t)fat_arch.size;
bad:
kauth_cred_unref(&cred);
return (error);
}
/*
* exec_mach_imgact
*
* Image activator for mach-o 1.0 binaries.
*
* Parameters; struct image_params * image parameter block
*
* Returns: -1 not a fat binary (keep looking)
* -2 Success: encapsulated binary: reread
* >0 Failure: error number
* EBADARCH Mach-o binary, but with an unrecognized
* architecture
* ENOMEM No memory for child process after -
* can only happen after vfork()
*
* Important: This image activator is NOT byte order neutral.
*
* Note: A return value other than -1 indicates subsequent image
* activators should not be given the opportunity to attempt
* to activate the image.
*
* TODO: More gracefully handle failures after vfork
*/
static int
exec_mach_imgact(struct image_params *imgp)
{
struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int error = 0;
task_t task;
task_t new_task = NULL; /* protected by vfexec */
thread_t thread;
struct uthread *uthread;
vm_map_t old_map = VM_MAP_NULL;
vm_map_t map;
load_return_t lret;
load_result_t load_result;
struct _posix_spawnattr *psa = NULL;
int spawn = (imgp->ip_flags & IMGPF_SPAWN);
int vfexec = (imgp->ip_flags & IMGPF_VFORK_EXEC);
/*
* make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
* is a reserved field on the end, so for the most part, we can
* treat them as if they were identical. Reverse-endian Mach-O
* binaries are recognized but not compatible.
*/
if ((mach_header->magic == MH_CIGAM) ||
(mach_header->magic == MH_CIGAM_64)) {
error = EBADARCH;
goto bad;
}
if ((mach_header->magic != MH_MAGIC) &&
(mach_header->magic != MH_MAGIC_64)) {
error = -1;
goto bad;
}
switch (mach_header->filetype) {
case MH_DYLIB:
case MH_BUNDLE:
error = -1;
goto bad;
}
if (!imgp->ip_origcputype) {
imgp->ip_origcputype = mach_header->cputype;
imgp->ip_origcpusubtype = mach_header->cpusubtype;
}
task = current_task();
thread = current_thread();
uthread = get_bsdthread_info(thread);
if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64)
imgp->ip_flags |= IMGPF_IS_64BIT;
/* If posix_spawn binprefs exist, respect those prefs. */
psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
if (psa != NULL && psa->psa_binprefs[0] != 0) {
int pr = 0;
for (pr = 0; pr < NBINPREFS; pr++) {
cpu_type_t pref = psa->psa_binprefs[pr];
if (pref == 0) {
/* No suitable arch in the pref list */
error = EBADARCH;
goto bad;
}
if (pref == CPU_TYPE_ANY) {
/* Jump to regular grading */
goto grade;
}
if (pref == imgp->ip_origcputype) {
/* We have a match! */
goto grade;
}
}
error = EBADARCH;
goto bad;
}
grade:
if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK)) {
error = EBADARCH;
goto bad;
}
/* Copy in arguments/environment from the old process */
error = exec_extract_strings(imgp);
if (error)
goto bad;
error = exec_add_apple_strings(imgp);
if (error)
goto bad;
AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
imgp->ip_endargv - imgp->ip_startargv);
AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
imgp->ip_endenvv - imgp->ip_endargv);
/*
* We are being called to activate an image subsequent to a vfork()
* operation; in this case, we know that our task, thread, and
* uthread are actually those of our parent, and our proc, which we
* obtained indirectly from the image_params vfs_context_t, is the
* new child process.
*/
if (vfexec || spawn) {
if (vfexec) {
imgp->ip_new_thread = fork_create_child(task, COALITION_NULL, p, FALSE, (imgp->ip_flags & IMGPF_IS_64BIT));
if (imgp->ip_new_thread == NULL) {
error = ENOMEM;
goto bad;
}
}
/* reset local idea of thread, uthread, task */
thread = imgp->ip_new_thread;
uthread = get_bsdthread_info(thread);
task = new_task = get_threadtask(thread);
map = get_task_map(task);
} else {
map = VM_MAP_NULL;
}
/*
* We set these flags here; this is OK, since if we fail after
* this point, we have already destroyed the parent process anyway.
*/
task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
if (imgp->ip_flags & IMGPF_IS_64BIT) {
task_set_64bit(task, TRUE);
OSBitOrAtomic(P_LP64, &p->p_flag);
} else {
task_set_64bit(task, FALSE);
OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
}
/*
* Load the Mach-O file.
*
* NOTE: An error after this point indicates we have potentially
* destroyed or overwritten some process state while attempting an
* execve() following a vfork(), which is an unrecoverable condition.
* We send the new process an immediate SIGKILL to avoid it executing
* any instructions in the mutated address space. For true spawns,
* this is not the case, and "too late" is still not too late to
* return an error code to the parent process.
*/
/*
* Actually load the image file we previously decided to load.
*/
lret = load_machfile(imgp, mach_header, thread, map, &load_result);
if (lret != LOAD_SUCCESS) {
error = load_return_to_errno(lret);
goto badtoolate;
}
proc_lock(p);
p->p_cputype = imgp->ip_origcputype;
p->p_cpusubtype = imgp->ip_origcpusubtype;
proc_unlock(p);
vm_map_set_user_wire_limit(get_task_map(task), p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
/*
* Set code-signing flags if this binary is signed, or if parent has
* requested them on exec.
*/
if (load_result.csflags & CS_VALID) {
imgp->ip_csflags |= load_result.csflags &
(CS_VALID|
CS_HARD|CS_KILL|CS_ENFORCEMENT|CS_REQUIRE_LV|CS_DYLD_PLATFORM|
CS_EXEC_SET_HARD|CS_EXEC_SET_KILL|CS_EXEC_SET_ENFORCEMENT);
} else {
imgp->ip_csflags &= ~CS_VALID;
}
if (p->p_csflags & CS_EXEC_SET_HARD)
imgp->ip_csflags |= CS_HARD;
if (p->p_csflags & CS_EXEC_SET_KILL)
imgp->ip_csflags |= CS_KILL;
if (p->p_csflags & CS_EXEC_SET_ENFORCEMENT)
imgp->ip_csflags |= CS_ENFORCEMENT;
if (p->p_csflags & CS_EXEC_SET_INSTALLER)
imgp->ip_csflags |= CS_INSTALLER;
/*
* Set up the system reserved areas in the new address space.
*/
vm_map_exec(get_task_map(task),
task,
(void *) p->p_fd->fd_rdir,
cpu_type());
/*
* Close file descriptors which specify close-on-exec.
*/
fdexec(p, psa != NULL ? psa->psa_flags : 0);
/*
* deal with set[ug]id.
*/
error = exec_handle_sugid(imgp);
if (error) {
goto badtoolate;
}
/*
* deal with voucher on exec-calling thread.
*/
if (imgp->ip_new_thread == NULL)
thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
/* Make sure we won't interrupt ourself signalling a partial process */
if (!vfexec && !spawn && (p->p_lflag & P_LTRACED))
psignal(p, SIGTRAP);
if (load_result.unixproc &&
create_unix_stack(get_task_map(task),
&load_result,
p) != KERN_SUCCESS) {
error = load_return_to_errno(LOAD_NOSPACE);
goto badtoolate;
}
if (vfexec || spawn) {
old_map = vm_map_switch(get_task_map(task));
}
if (load_result.unixproc) {
user_addr_t ap;
/*
* Copy the strings area out into the new process address
* space.
*/
ap = p->user_stack;
error = exec_copyout_strings(imgp, &ap);
if (error) {
if (vfexec || spawn)
vm_map_switch(old_map);
goto badtoolate;
}
/* Set the stack */
thread_setuserstack(thread, ap);
}
if (load_result.dynlinker) {
uint64_t ap;
int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
/* Adjust the stack */
ap = thread_adjuserstack(thread, -new_ptr_size);
error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
if (error) {
if (vfexec || spawn)
vm_map_switch(old_map);
goto badtoolate;
}
task_set_dyld_info(task, load_result.all_image_info_addr,
load_result.all_image_info_size);
}
/* Avoid immediate VM faults back into kernel */
exec_prefault_data(p, imgp, &load_result);
if (vfexec || spawn) {
vm_map_switch(old_map);
}
/* Set the entry point */
thread_setentrypoint(thread, load_result.entry_point);
/* Stop profiling */
stopprofclock(p);
/*
* Reset signal state.
*/
execsigs(p, thread);
/*
* need to cancel async IO requests that can be cancelled and wait for those
* already active. MAY BLOCK!
*/
_aio_exec( p );
#if SYSV_SHM
/* FIXME: Till vmspace inherit is fixed: */
if (!vfexec && p->vm_shm)
shmexec(p);
#endif
#if SYSV_SEM
/* Clean up the semaphores */
semexit(p);
#endif
/*
* Remember file name for accounting.
*/
p->p_acflag &= ~AFORK;
/* If the translated name isn't NULL, then we want to use
* that translated name as the name we show as the "real" name.
* Otherwise, use the name passed into exec.
*/
if (0 != imgp->ip_p_comm[0]) {
bcopy((caddr_t)imgp->ip_p_comm, (caddr_t)p->p_comm,
sizeof(p->p_comm));
} else {
if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN)
imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
(unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
}
pal_dbg_set_task_name( p->task );
#if DEVELOPMENT || DEBUG
/*
* Update the pid an proc name for importance base if any
*/
task_importance_update_owner_info(p->task);
#endif
memcpy(&p->p_uuid[0], &load_result.uuid[0], sizeof(p->p_uuid));
// <rdar://6598155> dtrace code cleanup needed
#if CONFIG_DTRACE
/*
* Invalidate any predicate evaluation already cached for this thread by DTrace.
* That's because we've just stored to p_comm and DTrace refers to that when it
* evaluates the "execname" special variable. uid and gid may have changed as well.
*/
dtrace_set_thread_predcache(current_thread(), 0);
/*
* Free any outstanding lazy dof entries. It is imperative we
* always call dtrace_lazy_dofs_destroy, rather than null check
* and call if !NULL. If we NULL test, during lazy dof faulting
* we can race with the faulting code and proceed from here to
* beyond the helpers cleanup. The lazy dof faulting will then
* install new helpers which no longer belong to this process!
*/
dtrace_lazy_dofs_destroy(p);
/*
* Clean up any DTrace helpers for the process.
*/
if (p->p_dtrace_helpers != NULL && dtrace_helpers_cleanup) {
(*dtrace_helpers_cleanup)(p);
}
/*
* Cleanup the DTrace provider associated with this process.
*/
proc_lock(p);
if (p->p_dtrace_probes && dtrace_fasttrap_exec_ptr) {
(*dtrace_fasttrap_exec_ptr)(p);
}
proc_unlock(p);
#endif
if (kdebug_enable) {
long dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4;
/*
* Collect the pathname for tracing
*/
kdbg_trace_string(p, &dbg_arg1, &dbg_arg2, &dbg_arg3, &dbg_arg4);
if (vfexec || spawn) {
KERNEL_DEBUG_CONSTANT1((TRACEDBG_CODE(DBG_TRACE_DATA, 2)) | DBG_FUNC_NONE,
p->p_pid ,0,0,0, (uintptr_t)thread_tid(thread));
KERNEL_DEBUG_CONSTANT1((TRACEDBG_CODE(DBG_TRACE_STRING, 2)) | DBG_FUNC_NONE,
dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4, (uintptr_t)thread_tid(thread));
} else {
KERNEL_DEBUG_CONSTANT((TRACEDBG_CODE(DBG_TRACE_DATA, 2)) | DBG_FUNC_NONE,
p->p_pid ,0,0,0,0);
KERNEL_DEBUG_CONSTANT((TRACEDBG_CODE(DBG_TRACE_STRING, 2)) | DBG_FUNC_NONE,
dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4, 0);
}
}
/*
* Ensure the 'translated' and 'affinity' flags are cleared, since we
* no longer run PowerPC binaries.
*/
OSBitAndAtomic(~((uint32_t)(P_TRANSLATED | P_AFFINITY)), &p->p_flag);
/*
* If posix_spawned with the START_SUSPENDED flag, stop the
* process before it runs.
*/
if (imgp->ip_px_sa != NULL) {
psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
proc_lock(p);
p->p_stat = SSTOP;
proc_unlock(p);
(void) task_suspend(p->task);
}
}
/*
* mark as execed, wakeup the process that vforked (if any) and tell
* it that it now has its own resources back
*/
OSBitOrAtomic(P_EXEC, &p->p_flag);
proc_resetregister(p);
if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
proc_lock(p);
p->p_lflag &= ~P_LPPWAIT;
proc_unlock(p);
wakeup((caddr_t)p->p_pptr);
}
/*
* Pay for our earlier safety; deliver the delayed signals from
* the incomplete vfexec process now that it's complete.
*/
if (vfexec && (p->p_lflag & P_LTRACED)) {
psignal_vfork(p, new_task, thread, SIGTRAP);
}
goto done;
badtoolate:
/* Don't allow child process to execute any instructions */
if (!spawn) {
if (vfexec) {
psignal_vfork(p, new_task, thread, SIGKILL);
} else {
psignal(p, SIGKILL);
}
/* We can't stop this system call at this point, so just pretend we succeeded */
error = 0;
}
done:
if (!spawn) {
/* notify only if it has not failed due to FP Key error */
if ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)
proc_knote(p, NOTE_EXEC);
}
/* Drop extra references for cases where we don't expect the caller to clean up */
if (vfexec || (spawn && error == 0)) {
task_deallocate(new_task);
thread_deallocate(thread);
}
bad:
return(error);
}
/*
* Our image activator table; this is the table of the image types we are
* capable of loading. We list them in order of preference to ensure the
* fastest image load speed.
*
* XXX hardcoded, for now; should use linker sets
*/
struct execsw {
int (*ex_imgact)(struct image_params *);
const char *ex_name;
} execsw[] = {
{ exec_mach_imgact, "Mach-o Binary" },
{ exec_fat_imgact, "Fat Binary" },
{ exec_shell_imgact, "Interpreter Script" },
{ NULL, NULL}
};
/*
* exec_activate_image
*
* Description: Iterate through the available image activators, and activate
* the image associated with the imgp structure. We start with
* the
*
* Parameters: struct image_params * Image parameter block
*
* Returns: 0 Success
* EBADEXEC The executable is corrupt/unknown
* execargs_alloc:EINVAL Invalid argument
* execargs_alloc:EACCES Permission denied
* execargs_alloc:EINTR Interrupted function
* execargs_alloc:ENOMEM Not enough space
* exec_save_path:EFAULT Bad address
* exec_save_path:ENAMETOOLONG Filename too long
* exec_check_permissions:EACCES Permission denied
* exec_check_permissions:ENOEXEC Executable file format error
* exec_check_permissions:ETXTBSY Text file busy [misuse of error code]
* exec_check_permissions:???
* namei:???
* vn_rdwr:??? [anything vn_rdwr can return]
* <ex_imgact>:??? [anything an imgact can return]
*/
static int
exec_activate_image(struct image_params *imgp)
{
struct nameidata *ndp = NULL;
int error;
int resid;
int once = 1; /* save SGUID-ness for interpreted files */
int i;
int iterlimit = EAI_ITERLIMIT;
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
error = execargs_alloc(imgp);
if (error)
goto bad_notrans;
error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg);
if (error) {
goto bad_notrans;
}
/* Use imgp->ip_strings, which contains the copyin-ed exec path */
DTRACE_PROC1(exec, uintptr_t, imgp->ip_strings);
MALLOC(ndp, struct nameidata *, sizeof(*ndp), M_TEMP, M_WAITOK | M_ZERO);
if (ndp == NULL) {
error = ENOMEM;
goto bad_notrans;
}
NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
UIO_SYSSPACE, CAST_USER_ADDR_T(imgp->ip_strings), imgp->ip_vfs_context);
again:
error = namei(ndp);
if (error)
goto bad_notrans;
imgp->ip_ndp = ndp; /* successful namei(); call nameidone() later */
imgp->ip_vp = ndp->ni_vp; /* if set, need to vnode_put() at some point */
/*
* Before we start the transition from binary A to binary B, make
* sure another thread hasn't started exiting the process. We grab
* the proc lock to check p_lflag initially, and the transition
* mechanism ensures that the value doesn't change after we release
* the lock.
*/
proc_lock(p);
if (p->p_lflag & P_LEXIT) {
proc_unlock(p);
goto bad_notrans;
}
error = proc_transstart(p, 1, 0);
proc_unlock(p);
if (error)
goto bad_notrans;
error = exec_check_permissions(imgp);
if (error)
goto bad;
/* Copy; avoid invocation of an interpreter overwriting the original */
if (once) {
once = 0;
*imgp->ip_origvattr = *imgp->ip_vattr;
}
error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
UIO_SYSSPACE, IO_NODELOCKED,
vfs_context_ucred(imgp->ip_vfs_context),
&resid, vfs_context_proc(imgp->ip_vfs_context));
if (error)
goto bad;
encapsulated_binary:
/* Limit the number of iterations we will attempt on each binary */
if (--iterlimit == 0) {
error = EBADEXEC;
goto bad;
}
error = -1;
for(i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
error = (*execsw[i].ex_imgact)(imgp);
switch (error) {
/* case -1: not claimed: continue */
case -2: /* Encapsulated binary */
goto encapsulated_binary;
case -3: /* Interpreter */
#if CONFIG_MACF
/*
* Copy the script label for later use. Note that
* the label can be different when the script is
* actually read by the interpreter.
*/
if (imgp->ip_scriptlabelp)
mac_vnode_label_free(imgp->ip_scriptlabelp);
imgp->ip_scriptlabelp = mac_vnode_label_alloc();
if (imgp->ip_scriptlabelp == NULL) {
error = ENOMEM;
break;
}
mac_vnode_label_copy(imgp->ip_vp->v_label,
imgp->ip_scriptlabelp);
/*
* Take a ref of the script vnode for later use.
*/
if (imgp->ip_scriptvp)
vnode_put(imgp->ip_scriptvp);
if (vnode_getwithref(imgp->ip_vp) == 0)
imgp->ip_scriptvp = imgp->ip_vp;
#endif
nameidone(ndp);
vnode_put(imgp->ip_vp);
imgp->ip_vp = NULL; /* already put */
imgp->ip_ndp = NULL; /* already nameidone */
/* Use imgp->ip_strings, which exec_shell_imgact reset to the interpreter */
NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
UIO_SYSSPACE, CAST_USER_ADDR_T(imgp->ip_strings), imgp->ip_vfs_context);
proc_transend(p, 0);
goto again;
default:
break;
}
}
/*
* Call out to allow 3rd party notification of exec.
* Ignore result of kauth_authorize_fileop call.
*/
if (error == 0 && kauth_authorize_fileop_has_listeners()) {
kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
KAUTH_FILEOP_EXEC,
(uintptr_t)ndp->ni_vp, 0);
}
bad:
proc_transend(p, 0);
bad_notrans:
if (imgp->ip_strings)
execargs_free(imgp);
if (imgp->ip_ndp)
nameidone(imgp->ip_ndp);
if (ndp)
FREE(ndp, M_TEMP);
return (error);
}
/*
* exec_handle_spawnattr_policy
*
* Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
*
* Parameters: proc_t p process to apply attributes to
* int psa_apptype posix spawn attribute apptype
*
* Returns: 0 Success
*/
static errno_t
exec_handle_spawnattr_policy(proc_t p, int psa_apptype, uint64_t psa_qos_clamp,
ipc_port_t * portwatch_ports, int portwatch_count)
{
int apptype = TASK_APPTYPE_NONE;
int qos_clamp = THREAD_QOS_UNSPECIFIED;
if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
switch(proctype) {
case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
break;
case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
apptype = TASK_APPTYPE_DAEMON_STANDARD;
break;
case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
break;
case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
break;
case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
apptype = TASK_APPTYPE_APP_DEFAULT;
break;
case POSIX_SPAWN_PROC_TYPE_APP_TAL:
apptype = TASK_APPTYPE_APP_TAL;
break;
default:
apptype = TASK_APPTYPE_NONE;
/* TODO: Should an invalid value here fail the spawn? */
break;
}
}
if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
switch (psa_qos_clamp) {
case POSIX_SPAWN_PROC_CLAMP_UTILITY:
qos_clamp = THREAD_QOS_UTILITY;
break;
case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
qos_clamp = THREAD_QOS_BACKGROUND;
break;
case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
qos_clamp = THREAD_QOS_MAINTENANCE;
break;
default:
qos_clamp = THREAD_QOS_UNSPECIFIED;
/* TODO: Should an invalid value here fail the spawn? */
break;
}
}
if (psa_apptype != TASK_APPTYPE_NONE || qos_clamp != THREAD_QOS_UNSPECIFIED) {
proc_set_task_spawnpolicy(p->task, apptype, qos_clamp,
portwatch_ports, portwatch_count);
}
return (0);
}
/*
* exec_handle_port_actions
*
* Description: Go through the _posix_port_actions_t contents,
* calling task_set_special_port, task_set_exception_ports
* and/or audit_session_spawnjoin for the current task.
*
* Parameters: struct image_params * Image parameter block
* short psa_flags posix spawn attribute flags
*
* Returns: 0 Success
* EINVAL Failure
* ENOTSUP Illegal posix_spawn attr flag was set
*/
static errno_t
exec_handle_port_actions(struct image_params *imgp, short psa_flags, boolean_t * portwatch_present, ipc_port_t * portwatch_ports)
{
_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
_ps_port_action_t *act = NULL;
task_t task = p->task;
ipc_port_t port = NULL;
errno_t ret = 0;
int i;
*portwatch_present = FALSE;
for (i = 0; i < pacts->pspa_count; i++) {
act = &pacts->pspa_actions[i];
if (ipc_object_copyin(get_task_ipcspace(current_task()),
act->new_port, MACH_MSG_TYPE_COPY_SEND,
(ipc_object_t *) &port) != KERN_SUCCESS) {
ret = EINVAL;
goto done;
}
switch (act->port_type) {
case PSPA_SPECIAL:
/* Only allowed when not under vfork */
if (!(psa_flags & POSIX_SPAWN_SETEXEC))
ret = ENOTSUP;
else if (task_set_special_port(task,
act->which, port) != KERN_SUCCESS)
ret = EINVAL;
break;
case PSPA_EXCEPTION:
/* Only allowed when not under vfork */
if (!(psa_flags & POSIX_SPAWN_SETEXEC))
ret = ENOTSUP;
else if (task_set_exception_ports(task,
act->mask, port, act->behavior,
act->flavor) != KERN_SUCCESS)
ret = EINVAL;
break;
#if CONFIG_AUDIT
case PSPA_AU_SESSION:
ret = audit_session_spawnjoin(p, port);
break;
#endif
case PSPA_IMP_WATCHPORTS:
if (portwatch_ports != NULL) {
*portwatch_present = TRUE;
/* hold on to this till end of spawn */
portwatch_ports[i] = port;
ret = 0;
} else
ipc_port_release_send(port);
break;
default:
ret = EINVAL;
break;
}
/* action failed, so release port resources */
if (ret) {
ipc_port_release_send(port);
break;
}
}
done:
if (0 != ret)
DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
return (ret);
}
/*
* exec_handle_file_actions
*
* Description: Go through the _posix_file_actions_t contents applying the
* open, close, and dup2 operations to the open file table for
* the current process.
*
* Parameters: struct image_params * Image parameter block
*
* Returns: 0 Success
* ???
*
* Note: Actions are applied in the order specified, with the credential
* of the parent process. This is done to permit the parent
* process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
* the child following operations the child may in fact not be
* normally permitted to perform.
*/
static int
exec_handle_file_actions(struct image_params *imgp, short psa_flags)
{
int error = 0;
int action;
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
int ival[2]; /* dummy retval for system calls) */
for (action = 0; action < px_sfap->psfa_act_count; action++) {
_psfa_action_t *psfa = &px_sfap->psfa_act_acts[ action];
switch(psfa->psfaa_type) {
case PSFA_OPEN: {
/*
* Open is different, in that it requires the use of
* a path argument, which is normally copied in from
* user space; because of this, we have to support an
* open from kernel space that passes an address space
* context of UIO_SYSSPACE, and casts the address
* argument to a user_addr_t.
*/
char *bufp = NULL;
struct vnode_attr *vap;
struct nameidata *ndp;
int mode = psfa->psfaa_openargs.psfao_mode;
struct dup2_args dup2a;
struct close_nocancel_args ca;
int origfd;
MALLOC(bufp, char *, sizeof(*vap) + sizeof(*ndp), M_TEMP, M_WAITOK | M_ZERO);
if (bufp == NULL) {
error = ENOMEM;
break;
}
vap = (struct vnode_attr *) bufp;
ndp = (struct nameidata *) (bufp + sizeof(*vap));
VATTR_INIT(vap);
/* Mask off all but regular access permissions */
mode = ((mode &~ p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT;
VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
imgp->ip_vfs_context);
error = open1(imgp->ip_vfs_context,
ndp,
psfa->psfaa_openargs.psfao_oflag,
vap,
fileproc_alloc_init, NULL,
ival);
FREE(bufp, M_TEMP);
/*
* If there's an error, or we get the right fd by
* accident, then drop out here. This is easier than
* reworking all the open code to preallocate fd
* slots, and internally taking one as an argument.
*/
if (error || ival[0] == psfa->psfaa_filedes)
break;
origfd = ival[0];
/*
* If we didn't fall out from an error, we ended up
* with the wrong fd; so now we've got to try to dup2
* it to the right one.
*/
dup2a.from = origfd;
dup2a.to = psfa->psfaa_filedes;
/*
* The dup2() system call implementation sets
* ival to newfd in the success case, but we
* can ignore that, since if we didn't get the
* fd we wanted, the error will stop us.
*/
error = dup2(p, &dup2a, ival);
if (error)
break;
/*
* Finally, close the original fd.
*/
ca.fd = origfd;
error = close_nocancel(p, &ca, ival);
}
break;
case PSFA_DUP2: {
struct dup2_args dup2a;
dup2a.from = psfa->psfaa_filedes;
dup2a.to = psfa->psfaa_openargs.psfao_oflag;
/*
* The dup2() system call implementation sets
* ival to newfd in the success case, but we
* can ignore that, since if we didn't get the
* fd we wanted, the error will stop us.
*/
error = dup2(p, &dup2a, ival);
}
break;
case PSFA_CLOSE: {
struct close_nocancel_args ca;
ca.fd = psfa->psfaa_filedes;
error = close_nocancel(p, &ca, ival);
}
break;
case PSFA_INHERIT: {
struct fcntl_nocancel_args fcntla;
/*
* Check to see if the descriptor exists, and
* ensure it's -not- marked as close-on-exec.
*
* Attempting to "inherit" a guarded fd will
* result in a error.
*/
fcntla.fd = psfa->psfaa_filedes;
fcntla.cmd = F_GETFD;
if ((error = fcntl_nocancel(p, &fcntla, ival)) != 0)
break;
if ((ival[0] & FD_CLOEXEC) == FD_CLOEXEC) {
fcntla.fd = psfa->psfaa_filedes;
fcntla.cmd = F_SETFD;
fcntla.arg = ival[0] & ~FD_CLOEXEC;
error = fcntl_nocancel(p, &fcntla, ival);
}
}
break;
default:
error = EINVAL;
break;
}
/* All file actions failures are considered fatal, per POSIX */
if (error) {
if (PSFA_OPEN == psfa->psfaa_type) {
DTRACE_PROC1(spawn__open__failure, uintptr_t,
psfa->psfaa_openargs.psfao_path);
} else {
DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
}
break;
}
}
if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0)
return (error);
/*
* If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
* this spawn only) as if "close on exec" is the default
* disposition of all pre-existing file descriptors. In this case,
* the list of file descriptors mentioned in the file actions
* are the only ones that can be inherited, so mark them now.
*
* The actual closing part comes later, in fdexec().
*/
proc_fdlock(p);
for (action = 0; action < px_sfap->psfa_act_count; action++) {
_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
int fd = psfa->psfaa_filedes;
switch (psfa->psfaa_type) {
case PSFA_DUP2:
fd = psfa->psfaa_openargs.psfao_oflag;
/*FALLTHROUGH*/
case PSFA_OPEN:
case PSFA_INHERIT:
*fdflags(p, fd) |= UF_INHERIT;
break;
case PSFA_CLOSE:
break;
}
}
proc_fdunlock(p);
return (0);
}
#if CONFIG_MACF
/*
* exec_spawnattr_getmacpolicyinfo
*/
void *
exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
{
const struct _posix_spawn_mac_policy_extensions *psmx = macextensions;
int i;
if (psmx == NULL)
return NULL;
for (i = 0; i < psmx->psmx_count; i++) {
const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
if (lenp != NULL)
*lenp = extension->datalen;
return extension->datap;
}
}
if (lenp != NULL)
*lenp = 0;
return NULL;
}
static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args, _posix_spawn_mac_policy_extensions_t *psmxp)
{
_posix_spawn_mac_policy_extensions_t psmx = NULL;
int error = 0;
int copycnt = 0;
int i = 0;
*psmxp = NULL;
if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
px_args->mac_extensions_size > PAGE_SIZE) {
error = EINVAL;
goto bad;
}
MALLOC(psmx, _posix_spawn_mac_policy_extensions_t, px_args->mac_extensions_size, M_TEMP, M_WAITOK);
if ((error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size)) != 0)
goto bad;
if (PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count) > px_args->mac_extensions_size) {
error = EINVAL;
goto bad;
}
for (i = 0; i < psmx->psmx_count; i++) {
_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
error = EINVAL;
goto bad;
}
}
for (copycnt = 0; copycnt < psmx->psmx_count; copycnt++) {
_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[copycnt];
void *data = NULL;
MALLOC(data, void *, extension->datalen, M_TEMP, M_WAITOK);
if ((error = copyin(extension->data, data, extension->datalen)) != 0) {
FREE(data, M_TEMP);
goto bad;
}
extension->datap = data;
}
*psmxp = psmx;
return 0;
bad:
if (psmx != NULL) {
for (i = 0; i < copycnt; i++)
FREE(psmx->psmx_extensions[i].datap, M_TEMP);
FREE(psmx, M_TEMP);
}
return error;
}
static void
spawn_free_macpolicyinfo(_posix_spawn_mac_policy_extensions_t psmx)
{
int i;
if (psmx == NULL)
return;
for (i = 0; i < psmx->psmx_count; i++)
FREE(psmx->psmx_extensions[i].datap, M_TEMP);
FREE(psmx, M_TEMP);
}
#endif /* CONFIG_MACF */
/*
* posix_spawn
*
* Parameters: uap->pid Pointer to pid return area
* uap->fname File name to exec
* uap->argp Argument list
* uap->envp Environment list
*
* Returns: 0 Success
* EINVAL Invalid argument
* ENOTSUP Not supported
* ENOEXEC Executable file format error
* exec_activate_image:EINVAL Invalid argument
* exec_activate_image:EACCES Permission denied
* exec_activate_image:EINTR Interrupted function
* exec_activate_image:ENOMEM Not enough space
* exec_activate_image:EFAULT Bad address
* exec_activate_image:ENAMETOOLONG Filename too long
* exec_activate_image:ENOEXEC Executable file format error
* exec_activate_image:ETXTBSY Text file busy [misuse of error code]
* exec_activate_image:EBADEXEC The executable is corrupt/unknown
* exec_activate_image:???
* mac_execve_enter:???
*
* TODO: Expect to need __mac_posix_spawn() at some point...
* Handle posix_spawnattr_t
* Handle posix_spawn_file_actions_t
*/
int
posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
{
proc_t p = ap; /* quiet bogus GCC vfork() warning */
user_addr_t pid = uap->pid;
int ival[2]; /* dummy retval for setpgid() */
char *bufp = NULL;
struct image_params *imgp;
struct vnode_attr *vap;
struct vnode_attr *origvap;
struct uthread *uthread = 0; /* compiler complains if not set to 0*/
int error, sig;
char alt_p_comm[sizeof(p->p_comm)] = {0}; /* for PowerPC */
int is_64 = IS_64BIT_PROCESS(p);
struct vfs_context context;
struct user__posix_spawn_args_desc px_args;
struct _posix_spawnattr px_sa;
_posix_spawn_file_actions_t px_sfap = NULL;
_posix_spawn_port_actions_t px_spap = NULL;
struct __kern_sigaction vec;
boolean_t spawn_no_exec = FALSE;
boolean_t proc_transit_set = TRUE;
boolean_t exec_done = FALSE;
int portwatch_count = 0;
ipc_port_t * portwatch_ports = NULL;
vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
/*
* Allocate a big chunk for locals instead of using stack since these
* structures are pretty big.
*/
MALLOC(bufp, char *, (sizeof(*imgp) + sizeof(*vap) + sizeof(*origvap)), M_TEMP, M_WAITOK | M_ZERO);
imgp = (struct image_params *) bufp;
if (bufp == NULL) {
error = ENOMEM;
goto bad;
}
vap = (struct vnode_attr *) (bufp + sizeof(*imgp));
origvap = (struct vnode_attr *) (bufp + sizeof(*imgp) + sizeof(*vap));
/* Initialize the common data in the image_params structure */
imgp->ip_user_fname = uap->path;
imgp->ip_user_argv = uap->argv;
imgp->ip_user_envv = uap->envp;
imgp->ip_vattr = vap;
imgp->ip_origvattr = origvap;
imgp->ip_vfs_context = &context;
imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT : IMGPF_NONE);
imgp->ip_p_comm = alt_p_comm; /* for PowerPC */
imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
imgp->ip_mac_return = 0;
if (uap->adesc != USER_ADDR_NULL) {
if(is_64) {
error = copyin(uap->adesc, &px_args, sizeof(px_args));
} else {
struct user32__posix_spawn_args_desc px_args32;
error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
/*
* Convert arguments descriptor from external 32 bit
* representation to internal 64 bit representation
*/
px_args.attr_size = px_args32.attr_size;
px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
px_args.file_actions_size = px_args32.file_actions_size;
px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
px_args.port_actions_size = px_args32.port_actions_size;
px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
px_args.mac_extensions_size = px_args32.mac_extensions_size;
px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
}
if (error)
goto bad;
if (px_args.attr_size != 0) {
/*
* We are not copying the port_actions pointer,
* because we already have it from px_args.
* This is a bit fragile: <rdar://problem/16427422>
*/
if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset) != 0))
goto bad;
bzero( (void *)( (unsigned long) &px_sa + px_sa_offset), sizeof(px_sa) - px_sa_offset );
imgp->ip_px_sa = &px_sa;
}
if (px_args.file_actions_size != 0) {
/* Limit file_actions to allowed number of open files */
int maxfa = (p->p_limit ? p->p_rlimit[RLIMIT_NOFILE].rlim_cur : NOFILE);
if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
px_args.file_actions_size > PSF_ACTIONS_SIZE(maxfa)) {
error = EINVAL;
goto bad;
}
MALLOC(px_sfap, _posix_spawn_file_actions_t, px_args.file_actions_size, M_TEMP, M_WAITOK);
if (px_sfap == NULL) {
error = ENOMEM;
goto bad;
}
imgp->ip_px_sfa = px_sfap;
if ((error = copyin(px_args.file_actions, px_sfap,
px_args.file_actions_size)) != 0)
goto bad;
/* Verify that the action count matches the struct size */
if (PSF_ACTIONS_SIZE(px_sfap->psfa_act_count) != px_args.file_actions_size) {
error = EINVAL;
goto bad;
}
}
if (px_args.port_actions_size != 0) {
/* Limit port_actions to one page of data */
if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
px_args.port_actions_size > PAGE_SIZE) {
error = EINVAL;
goto bad;
}
MALLOC(px_spap, _posix_spawn_port_actions_t,
px_args.port_actions_size, M_TEMP, M_WAITOK);
if (px_spap == NULL) {
error = ENOMEM;
goto bad;
}
imgp->ip_px_spa = px_spap;
if ((error = copyin(px_args.port_actions, px_spap,
px_args.port_actions_size)) != 0)
goto bad;
/* Verify that the action count matches the struct size */
if (PS_PORT_ACTIONS_SIZE(px_spap->pspa_count) != px_args.port_actions_size) {
error = EINVAL;
goto bad;
}
}
#if CONFIG_MACF
if (px_args.mac_extensions_size != 0) {
if ((error = spawn_copyin_macpolicyinfo(&px_args, (_posix_spawn_mac_policy_extensions_t *)&imgp->ip_px_smpx)) != 0)
goto bad;
}
#endif /* CONFIG_MACF */
}
/* set uthread to parent */
uthread = get_bsdthread_info(current_thread());
/*
* <rdar://6640530>; this does not result in a behaviour change
* relative to Leopard, so there should not be any existing code
* which depends on it.
*/
if (uthread->uu_flag & UT_VFORK) {
error = EINVAL;
goto bad;
}
/*
* If we don't have the extension flag that turns "posix_spawn()"
* into "execve() with options", then we will be creating a new
* process which does not inherit memory from the parent process,
* which is one of the most expensive things about using fork()
* and execve().
*/
if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)){
/*
* Set the new task's coalition, if it is requested.
* TODO: privilege check - 15365900
*/
coalition_t coal = COALITION_NULL;
#if CONFIG_COALITIONS
if (imgp->ip_px_sa) {
uint64_t cid = px_sa.psa_coalitionid;
if (cid != 0) {
#if COALITION_DEBUG
printf("%s: searching for coalition ID %llu\n", __func__, cid);
#endif
coal = coalition_find_and_activate_by_id(cid);
if (coal == COALITION_NULL) {
#if COALITION_DEBUG
printf("%s: could not find coalition ID %llu (perhaps it has been terminated or reaped)\n", __func__, cid);
#endif
error = ESRCH;
goto bad;
}
}
}
#endif /* CONFIG_COALITIONS */
error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
if (error != 0) {
if (coal != COALITION_NULL) {
#if CONFIG_COALITIONS
coalition_remove_active(coal);
coalition_release(coal);
#endif /* CONFIG_COALITIONS */
}
goto bad;
}
imgp->ip_flags |= IMGPF_SPAWN; /* spawn w/o exec */
spawn_no_exec = TRUE; /* used in later tests */
if (coal != COALITION_NULL) {
#if CONFIG_COALITIONS
coalition_remove_active(coal);
coalition_release(coal);
#endif /* CONFIG_COALITIONS */
}
}
if (spawn_no_exec) {
p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
/*
* We had to wait until this point before firing the
* proc:::create probe, otherwise p would not point to the
* child process.
*/
DTRACE_PROC1(create, proc_t, p);
}
assert(p != NULL);
/* By default, the thread everyone plays with is the parent */
context.vc_thread = current_thread();
context.vc_ucred = p->p_ucred; /* XXX must NOT be kauth_cred_get() */
/*
* However, if we're not in the setexec case, redirect the context
* to the newly created process instead
*/
if (spawn_no_exec)
context.vc_thread = imgp->ip_new_thread;
/*
* Post fdcopy(), pre exec_handle_sugid() - this is where we want
* to handle the file_actions. Since vfork() also ends up setting
* us into the parent process group, and saved off the signal flags,
* this is also where we want to handle the spawn flags.
*/
/* Has spawn file actions? */
if (imgp->ip_px_sfa != NULL) {
/*
* The POSIX_SPAWN_CLOEXEC_DEFAULT flag
* is handled in exec_handle_file_actions().
*/
if ((error = exec_handle_file_actions(imgp,
imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0)) != 0)
goto bad;
}
/* Has spawn port actions? */
if (imgp->ip_px_spa != NULL) {
boolean_t is_adaptive = FALSE;
boolean_t portwatch_present = FALSE;
/* Will this process become adaptive? The apptype isn't ready yet, so we can't look there. */
if (imgp->ip_px_sa != NULL && px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE)
is_adaptive = TRUE;
/*
* portwatch only:
* Allocate a place to store the ports we want to bind to the new task
* We can't bind them until after the apptype is set.
*/
if (px_spap->pspa_count != 0 && is_adaptive) {
portwatch_count = px_spap->pspa_count;
MALLOC(portwatch_ports, ipc_port_t *, (sizeof(ipc_port_t) * portwatch_count), M_TEMP, M_WAITOK | M_ZERO);
} else {
portwatch_ports = NULL;
}
if ((error = exec_handle_port_actions(imgp,
imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0, &portwatch_present, portwatch_ports)) != 0)
goto bad;
if (portwatch_present == FALSE && portwatch_ports != NULL) {
FREE(portwatch_ports, M_TEMP);
portwatch_ports = NULL;
portwatch_count = 0;
}
}
/* Has spawn attr? */
if (imgp->ip_px_sa != NULL) {
/*
* Set the process group ID of the child process; this has
* to happen before the image activation.
*/
if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
struct setpgid_args spga;
spga.pid = p->p_pid;
spga.pgid = px_sa.psa_pgroup;
/*
* Effectively, call setpgid() system call; works
* because there are no pointer arguments.
*/
if((error = setpgid(p, &spga, ival)) != 0)
goto bad;
}
/*
* Reset UID/GID to parent's RUID/RGID; This works only
* because the operation occurs *after* the vfork() and
* before the call to exec_handle_sugid() by the image
* activator called from exec_activate_image(). POSIX
* requires that any setuid/setgid bits on the process
* image will take precedence over the spawn attributes
* (re)setting them.
*
* The use of p_ucred is safe, since we are acting on the
* new process, and it has no threads other than the one
* we are creating for it.
*/
if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
kauth_cred_t my_cred = p->p_ucred;
kauth_cred_t my_new_cred = kauth_cred_setuidgid(my_cred, kauth_cred_getruid(my_cred), kauth_cred_getrgid(my_cred));
if (my_new_cred != my_cred) {
p->p_ucred = my_new_cred;
/* update cred on proc */
PROC_UPDATE_CREDS_ONPROC(p);
}
}
/*
* Disable ASLR for the spawned process.
*/
/*
* But only do so if we are not embedded; embedded allows for a
* boot-arg (-disable_aslr) to deal with this (which itself is
* only honored on DEVELOPMENT or DEBUG builds of xnu).
*/
if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR)
OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
/*
* Forcibly disallow execution from data pages for the spawned process
* even if it would otherwise be permitted by the architecture default.
*/
if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC)
imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
}
/*
* Disable ASLR during image activation. This occurs either if the
* _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
* P_DISABLE_ASLR was inherited from the parent process.
*/
if (p->p_flag & P_DISABLE_ASLR)
imgp->ip_flags |= IMGPF_DISABLE_ASLR;
/*
* Clear transition flag so we won't hang if exec_activate_image() causes
* an automount (and launchd does a proc sysctl to service it).
*
* <rdar://problem/6848672>, <rdar://problem/5959568>.
*/
if (spawn_no_exec) {
proc_transend(p, 0);
proc_transit_set = 0;
}
#if MAC_SPAWN /* XXX */
if (uap->mac_p != USER_ADDR_NULL) {
error = mac_execve_enter(uap->mac_p, imgp);
if (error)
goto bad;
}
#endif
/*
* Activate the image
*/
error = exec_activate_image(imgp);
if (error == 0) {
/* process completed the exec */
exec_done = TRUE;
} else if (error == -1) {
/* Image not claimed by any activator? */
error = ENOEXEC;
}
/*
* If we have a spawn attr, and it contains signal related flags,
* the we need to process them in the "context" of the new child
* process, so we have to process it following image activation,
* prior to making the thread runnable in user space. This is
* necessitated by some signal information being per-thread rather
* than per-process, and we don't have the new allocation in hand
* until after the image is activated.
*/
if (!error && imgp->ip_px_sa != NULL) {
thread_t child_thread = current_thread();
uthread_t child_uthread = uthread;
/*
* If we created a new child thread, then the thread and
* uthread are different than the current ones; otherwise,
* we leave them, since we are in the exec case instead.
*/
if (spawn_no_exec) {
child_thread = imgp->ip_new_thread;
child_uthread = get_bsdthread_info(child_thread);
}
/*
* Mask a list of signals, instead of them being unmasked, if
* they were unmasked in the parent; note that some signals
* are not maskable.
*/
if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK)
child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
/*
* Default a list of signals instead of ignoring them, if
* they were ignored in the parent. Note that we pass
* spawn_no_exec to setsigvec() to indicate that we called
* fork1() and therefore do not need to call proc_signalstart()
* internally.
*/
if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
vec.sa_handler = SIG_DFL;
vec.sa_tramp = 0;
vec.sa_mask = 0;
vec.sa_flags = 0;
for (sig = 0; sig < NSIG; sig++)
if (px_sa.psa_sigdefault & (1 << sig)) {
error = setsigvec(p, child_thread, sig + 1, &vec, spawn_no_exec);
}
}
/*
* Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
* usage limit, which will generate a resource exceeded exception if any one thread exceeds the
* limit.
*
* Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
*/
if (px_sa.psa_cpumonitor_percent != 0) {
/*
* Always treat a CPU monitor activation coming from spawn as entitled. Requiring
* an entitlement to configure the monitor a certain way seems silly, since
* whomever is turning it on could just as easily choose not to do so.
*
* XXX - Ignore the parameters that we get from userland. The spawnattr method of
* activating the monitor always gets the system default parameters. Once we have
* an explicit spawn SPI for configuring the defaults, we can revert this to
* respect the params passed in from userland.
*/
error = proc_set_task_ruse_cpu(p->task,
TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
PROC_POLICY_CPUMON_DEFAULTS, 0,
0, TRUE);
}
}
bad:
if (error == 0) {
/* reset delay idle sleep status if set */
if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP)
OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
/* upon successful spawn, re/set the proc control state */
if (imgp->ip_px_sa != NULL) {
switch (px_sa.psa_pcontrol) {
case POSIX_SPAWN_PCONTROL_THROTTLE:
p->p_pcaction = P_PCTHROTTLE;
break;
case POSIX_SPAWN_PCONTROL_SUSPEND:
p->p_pcaction = P_PCSUSP;
break;
case POSIX_SPAWN_PCONTROL_KILL:
p->p_pcaction = P_PCKILL;
break;
case POSIX_SPAWN_PCONTROL_NONE:
default:
p->p_pcaction = 0;
break;
};
}
exec_resettextvp(p, imgp);
#if CONFIG_MEMORYSTATUS && CONFIG_JETSAM
/* Has jetsam attributes? */
if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
memorystatus_update(p, px_sa.psa_priority, 0, (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
TRUE, px_sa.psa_high_water_mark, (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND),
(px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_FATAL));
}
#endif
}
/*
* If we successfully called fork1(), we always need to do this;
* we identify this case by noting the IMGPF_SPAWN flag. This is
* because we come back from that call with signals blocked in the
* child, and we have to unblock them, but we want to wait until
* after we've performed any spawn actions. This has to happen
* before check_for_signature(), which uses psignal.
*/
if (spawn_no_exec) {
if (proc_transit_set)
proc_transend(p, 0);
/*
* Drop the signal lock on the child which was taken on our
* behalf by forkproc()/cloneproc() to prevent signals being
* received by the child in a partially constructed state.
*/
proc_signalend(p, 0);
/* flag the 'fork' has occurred */
proc_knote(p->p_pptr, NOTE_FORK | p->p_pid);
/* then flag exec has occurred */
/* notify only if it has not failed due to FP Key error */
if ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)
proc_knote(p, NOTE_EXEC);
} else {
/* reset the importance attribute from our previous life */
task_importance_reset(p->task);
/* reset atm context from task */
task_atm_reset(p->task);
}
/*
* Apply the spawnattr policy, apptype (which primes the task for importance donation),
* and bind any portwatch ports to the new task.
* This must be done after the exec so that the child's thread is ready,
* and after the in transit state has been released, because priority is
* dropped here so we need to be prepared for a potentially long preemption interval
*
* TODO: Consider splitting this up into separate phases
*/
if (error == 0 && imgp->ip_px_sa != NULL) {
struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
exec_handle_spawnattr_policy(p, psa->psa_apptype, psa->psa_qos_clamp,
portwatch_ports, portwatch_count);
}
/* Apply the main thread qos */
if (error == 0) {
thread_t main_thread = (imgp->ip_new_thread != NULL) ? imgp->ip_new_thread : current_thread();
task_set_main_thread_qos(p->task, main_thread);
}
/*
* Release any ports we kept around for binding to the new task
* We need to release the rights even if the posix_spawn has failed.
*/
if (portwatch_ports != NULL) {
for (int i = 0; i < portwatch_count; i++) {
ipc_port_t port = NULL;
if ((port = portwatch_ports[i]) != NULL) {
ipc_port_release_send(port);
}
}
FREE(portwatch_ports, M_TEMP);
portwatch_ports = NULL;
portwatch_count = 0;
}
/*
* We have to delay operations which might throw a signal until after
* the signals have been unblocked; however, we want that to happen
* after exec_resettextvp() so that the textvp is correct when they
* fire.
*/
if (error == 0) {
error = check_for_signature(p, imgp);
/*
* Pay for our earlier safety; deliver the delayed signals from
* the incomplete spawn process now that it's complete.
*/
if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
psignal_vfork(p, p->task, imgp->ip_new_thread, SIGTRAP);
}
}
if (imgp != NULL) {
if (imgp->ip_vp)
vnode_put(imgp->ip_vp);
if (imgp->ip_scriptvp)
vnode_put(imgp->ip_scriptvp);
if (imgp->ip_strings)
execargs_free(imgp);
if (imgp->ip_px_sfa != NULL)
FREE(imgp->ip_px_sfa, M_TEMP);
if (imgp->ip_px_spa != NULL)
FREE(imgp->ip_px_spa, M_TEMP);
#if CONFIG_MACF
if (imgp->ip_px_smpx != NULL)
spawn_free_macpolicyinfo(imgp->ip_px_smpx);
if (imgp->ip_execlabelp)
mac_cred_label_free(imgp->ip_execlabelp);
if (imgp->ip_scriptlabelp)
mac_vnode_label_free(imgp->ip_scriptlabelp);
#endif
}
#if CONFIG_DTRACE
if (spawn_no_exec) {
/*
* In the original DTrace reference implementation,
* posix_spawn() was a libc routine that just
* did vfork(2) then exec(2). Thus the proc::: probes
* are very fork/exec oriented. The details of this
* in-kernel implementation of posix_spawn() is different
* (while producing the same process-observable effects)
* particularly w.r.t. errors, and which thread/process
* is constructing what on behalf of whom.
*/
if (error) {
DTRACE_PROC1(spawn__failure, int, error);
} else {
DTRACE_PROC(spawn__success);
/*
* Some DTrace scripts, e.g. newproc.d in
* /usr/bin, rely on the the 'exec-success'
* probe being fired in the child after the
* new process image has been constructed
* in order to determine the associated pid.
*
* So, even though the parent built the image
* here, for compatibility, mark the new thread
* so 'exec-success' fires on it as it leaves
* the kernel.
*/
dtrace_thread_didexec(imgp->ip_new_thread);
}
} else {
if (error) {
DTRACE_PROC1(exec__failure, int, error);
} else {
DTRACE_PROC(exec__success);
}
}
if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL)
(*dtrace_proc_waitfor_hook)(p);
#endif
/* Return to both the parent and the child? */
if (imgp != NULL && spawn_no_exec) {
/*
* If the parent wants the pid, copy it out
*/
if (pid != USER_ADDR_NULL)
(void)suword(pid, p->p_pid);
retval[0] = error;
/*
* If we had an error, perform an internal reap ; this is
* entirely safe, as we have a real process backing us.
*/
if (error) {
proc_list_lock();
p->p_listflag |= P_LIST_DEADPARENT;
proc_list_unlock();
proc_lock(p);
/* make sure no one else has killed it off... */
if (p->p_stat != SZOMB && p->exit_thread == NULL) {
p->exit_thread = current_thread();
proc_unlock(p);
exit1(p, 1, (int *)NULL);
if (exec_done == FALSE) {
task_deallocate(get_threadtask(imgp->ip_new_thread));
thread_deallocate(imgp->ip_new_thread);
}
} else {
/* someone is doing it for us; just skip it */
proc_unlock(p);
}
} else {
/*
* Return to the child
*
* Note: the image activator earlier dropped the
* task/thread references to the newly spawned
* process; this is OK, since we still have suspended
* queue references on them, so we should be fine
* with the delayed resume of the thread here.
*/
(void)thread_resume(imgp->ip_new_thread);
}
}
if (bufp != NULL) {
FREE(bufp, M_TEMP);
}
return(error);
}
/*
* execve
*
* Parameters: uap->fname File name to exec
* uap->argp Argument list
* uap->envp Environment list
*
* Returns: 0 Success
* __mac_execve:EINVAL Invalid argument
* __mac_execve:ENOTSUP Invalid argument
* __mac_execve:EACCES Permission denied
* __mac_execve:EINTR Interrupted function
* __mac_execve:ENOMEM Not enough space
* __mac_execve:EFAULT Bad address
* __mac_execve:ENAMETOOLONG Filename too long
* __mac_execve:ENOEXEC Executable file format error
* __mac_execve:ETXTBSY Text file busy [misuse of error code]
* __mac_execve:???
*
* TODO: Dynamic linker header address on stack is copied via suword()
*/
/* ARGSUSED */
int
execve(proc_t p, struct execve_args *uap, int32_t *retval)
{
struct __mac_execve_args muap;
int err;
memoryshot(VM_EXECVE, DBG_FUNC_NONE);
muap.fname = uap->fname;
muap.argp = uap->argp;
muap.envp = uap->envp;
muap.mac_p = USER_ADDR_NULL;
err = __mac_execve(p, &muap, retval);
return(err);
}
/*
* __mac_execve
*
* Parameters: uap->fname File name to exec
* uap->argp Argument list
* uap->envp Environment list
* uap->mac_p MAC label supplied by caller
*
* Returns: 0 Success
* EINVAL Invalid argument
* ENOTSUP Not supported
* ENOEXEC Executable file format error
* exec_activate_image:EINVAL Invalid argument
* exec_activate_image:EACCES Permission denied
* exec_activate_image:EINTR Interrupted function
* exec_activate_image:ENOMEM Not enough space
* exec_activate_image:EFAULT Bad address
* exec_activate_image:ENAMETOOLONG Filename too long
* exec_activate_image:ENOEXEC Executable file format error
* exec_activate_image:ETXTBSY Text file busy [misuse of error code]
* exec_activate_image:EBADEXEC The executable is corrupt/unknown
* exec_activate_image:???
* mac_execve_enter:???
*
* TODO: Dynamic linker header address on stack is copied via suword()
*/
int
__mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval)
{
char *bufp = NULL;
struct image_params *imgp;
struct vnode_attr *vap;
struct vnode_attr *origvap;
int error;
char alt_p_comm[sizeof(p->p_comm)] = {0}; /* for PowerPC */
int is_64 = IS_64BIT_PROCESS(p);
struct vfs_context context;
struct uthread *uthread;
context.vc_thread = current_thread();
context.vc_ucred = kauth_cred_proc_ref(p); /* XXX must NOT be kauth_cred_get() */
/* Allocate a big chunk for locals instead of using stack since these
* structures a pretty big.
*/
MALLOC(bufp, char *, (sizeof(*imgp) + sizeof(*vap) + sizeof(*origvap)), M_TEMP, M_WAITOK | M_ZERO);
imgp = (struct image_params *) bufp;
if (bufp == NULL) {
error = ENOMEM;
goto exit_with_error;
}
vap = (struct vnode_attr *) (bufp + sizeof(*imgp));
origvap = (struct vnode_attr *) (bufp + sizeof(*imgp) + sizeof(*vap));
/* Initialize the common data in the image_params structure */
imgp->ip_user_fname = uap->fname;
imgp->ip_user_argv = uap->argp;
imgp->ip_user_envv = uap->envp;
imgp->ip_vattr = vap;
imgp->ip_origvattr = origvap;
imgp->ip_vfs_context = &context;
imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
imgp->ip_p_comm = alt_p_comm; /* for PowerPC */
imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
imgp->ip_mac_return = 0;
uthread = get_bsdthread_info(current_thread());
if (uthread->uu_flag & UT_VFORK) {
imgp->ip_flags |= IMGPF_VFORK_EXEC;
}
#if CONFIG_MACF
if (uap->mac_p != USER_ADDR_NULL) {
error = mac_execve_enter(uap->mac_p, imgp);
if (error) {
kauth_cred_unref(&context.vc_ucred);
goto exit_with_error;
}
}
#endif
error = exec_activate_image(imgp);
kauth_cred_unref(&context.vc_ucred);
/* Image not claimed by any activator? */
if (error == -1)
error = ENOEXEC;
if (error == 0) {
exec_resettextvp(p, imgp);
error = check_for_signature(p, imgp);
}
if (imgp->ip_vp != NULLVP)
vnode_put(imgp->ip_vp);
if (imgp->ip_scriptvp != NULLVP)
vnode_put(imgp->ip_scriptvp);
if (imgp->ip_strings)
execargs_free(imgp);
#if CONFIG_MACF
if (imgp->ip_execlabelp)
mac_cred_label_free(imgp->ip_execlabelp);
if (imgp->ip_scriptlabelp)
mac_vnode_label_free(imgp->ip_scriptlabelp);
#endif
if (!error) {
/* Sever any extant thread affinity */
thread_affinity_exec(current_thread());
thread_t main_thread = (imgp->ip_new_thread != NULL) ? imgp->ip_new_thread : current_thread();
task_set_main_thread_qos(p->task, main_thread);
/* reset task importance */
task_importance_reset(p->task);
/* reset atm context from task */
task_atm_reset(p->task);
DTRACE_PROC(exec__success);
#if CONFIG_DTRACE
if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL)
(*dtrace_proc_waitfor_hook)(p);
#endif
if (imgp->ip_flags & IMGPF_VFORK_EXEC) {
vfork_return(p, retval, p->p_pid);
(void)thread_resume(imgp->ip_new_thread);
}
} else {
DTRACE_PROC1(exec__failure, int, error);
}
exit_with_error:
if (bufp != NULL) {
FREE(bufp, M_TEMP);
}
return(error);
}
/*
* copyinptr
*
* Description: Copy a pointer in from user space to a user_addr_t in kernel
* space, based on 32/64 bitness of the user space
*
* Parameters: froma User space address
* toptr Address of kernel space user_addr_t
* ptr_size 4/8, based on 'froma' address space
*
* Returns: 0 Success
* EFAULT Bad 'froma'
*
* Implicit returns:
* *ptr_size Modified
*/
static int
copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
{
int error;
if (ptr_size == 4) {
/* 64 bit value containing 32 bit address */
unsigned int i;
error = copyin(froma, &i, 4);
*toptr = CAST_USER_ADDR_T(i); /* SAFE */
} else {
error = copyin(froma, toptr, 8);
}
return (error);
}
/*
* copyoutptr
*
* Description: Copy a pointer out from a user_addr_t in kernel space to
* user space, based on 32/64 bitness of the user space
*
* Parameters: ua User space address to copy to
* ptr Address of kernel space user_addr_t
* ptr_size 4/8, based on 'ua' address space
*
* Returns: 0 Success
* EFAULT Bad 'ua'
*
*/
static int
copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
{
int error;
if (ptr_size == 4) {
/* 64 bit value containing 32 bit address */
unsigned int i = CAST_DOWN_EXPLICIT(unsigned int,ua); /* SAFE */
error = copyout(&i, ptr, 4);
} else {
error = copyout(&ua, ptr, 8);
}
return (error);
}
/*
* exec_copyout_strings
*
* Copy out the strings segment to user space. The strings segment is put
* on a preinitialized stack frame.
*
* Parameters: struct image_params * the image parameter block
* int * a pointer to the stack offset variable
*
* Returns: 0 Success
* !0 Faiure: errno
*
* Implicit returns:
* (*stackp) The stack offset, modified
*
* Note: The strings segment layout is backward, from the beginning
* of the top of the stack to consume the minimal amount of
* space possible; the returned stack pointer points to the
* end of the area consumed (stacks grow downward).
*
* argc is an int; arg[i] are pointers; env[i] are pointers;
* the 0's are (void *)NULL's
*
* The stack frame layout is:
*
* +-------------+ <- p->user_stack
* | 16b |
* +-------------+
* | STRING AREA |
* | : |
* | : |
* | : |
* +- -- -- -- --+
* | PATH AREA |
* +-------------+
* | 0 |
* +-------------+
* | applev[n] |
* +-------------+
* :
* :
* +-------------+
* | applev[1] |
* +-------------+
* | exec_path / |
* | applev[0] |
* +-------------+
* | 0 |
* +-------------+
* | env[n] |
* +-------------+
* :
* :
* +-------------+
* | env[0] |
* +-------------+
* | 0 |
* +-------------+
* | arg[argc-1] |
* +-------------+
* :
* :
* +-------------+
* | arg[0] |
* +-------------+
* | argc |
* sp-> +-------------+
*
* Although technically a part of the STRING AREA, we treat the PATH AREA as
* a separate entity. This allows us to align the beginning of the PATH AREA
* to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
* which preceed it on the stack are properly aligned.
*/
static int
exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
{
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
int ptr_area_size;
void *ptr_buffer_start, *ptr_buffer;
int string_size;
user_addr_t string_area; /* *argv[], *env[] */
user_addr_t ptr_area; /* argv[], env[], applev[] */
user_addr_t argc_area; /* argc */
user_addr_t stack;
int error;
unsigned i;
struct copyout_desc {
char *start_string;
int count;
#if CONFIG_DTRACE
user_addr_t *dtrace_cookie;
#endif
boolean_t null_term;
} descriptors[] = {
{
.start_string = imgp->ip_startargv,
.count = imgp->ip_argc,
#if CONFIG_DTRACE
.dtrace_cookie = &p->p_dtrace_argv,
#endif
.null_term = TRUE
},
{
.start_string = imgp->ip_endargv,
.count = imgp->ip_envc,
#if CONFIG_DTRACE
.dtrace_cookie = &p->p_dtrace_envp,
#endif
.null_term = TRUE
},
{
.start_string = imgp->ip_strings,
.count = 1,
#if CONFIG_DTRACE
.dtrace_cookie = NULL,
#endif
.null_term = FALSE
},
{
.start_string = imgp->ip_endenvv,
.count = imgp->ip_applec - 1, /* exec_path handled above */
#if CONFIG_DTRACE
.dtrace_cookie = NULL,
#endif
.null_term = TRUE
}
};
stack = *stackp;
/*
* All previous contributors to the string area
* should have aligned their sub-area
*/
if (imgp->ip_strspace % ptr_size != 0) {
error = EINVAL;
goto bad;
}
/* Grow the stack down for the strings we've been building up */
string_size = imgp->ip_strendp - imgp->ip_strings;
stack -= string_size;
string_area = stack;
/*
* Need room for one pointer for each string, plus
* one for the NULLs terminating the argv, envv, and apple areas.
*/
ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) *
ptr_size;
stack -= ptr_area_size;
ptr_area = stack;
/* We'll construct all the pointer arrays in our string buffer,
* which we already know is aligned properly, and ip_argspace
* was used to verify we have enough space.
*/
ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
/*
* Need room for pointer-aligned argc slot.
*/
stack -= ptr_size;
argc_area = stack;
/*
* Record the size of the arguments area so that sysctl_procargs()
* can return the argument area without having to parse the arguments.
*/
proc_lock(p);
p->p_argc = imgp->ip_argc;
p->p_argslen = (int)(*stackp - string_area);
proc_unlock(p);
/* Return the initial stack address: the location of argc */
*stackp = stack;
/*
* Copy out the entire strings area.
*/
error = copyout(imgp->ip_strings, string_area,
string_size);
if (error)
goto bad;
for (i = 0; i < sizeof(descriptors)/sizeof(descriptors[0]); i++) {
char *cur_string = descriptors[i].start_string;
int j;
#if CONFIG_DTRACE
if (descriptors[i].dtrace_cookie) {
proc_lock(p);
*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
proc_unlock(p);
}
#endif /* CONFIG_DTRACE */
/*
* For each segment (argv, envv, applev), copy as many pointers as requested
* to our pointer buffer.
*/
for (j = 0; j < descriptors[i].count; j++) {
user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
/* Copy out the pointer to the current string. Alignment has been verified */
if (ptr_size == 8) {
*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
} else {
*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
}
ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
}
if (descriptors[i].null_term) {
if (ptr_size == 8) {
*(uint64_t *)ptr_buffer = 0ULL;
} else {
*(uint32_t *)ptr_buffer = 0;
}
ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
}
}
/*
* Copy out all our pointer arrays in bulk.
*/
error = copyout(ptr_buffer_start, ptr_area,
ptr_area_size);
if (error)
goto bad;
/* argc (int32, stored in a ptr_size area) */
error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
if (error)
goto bad;
bad:
return(error);
}
/*
* exec_extract_strings
*
* Copy arguments and environment from user space into work area; we may
* have already copied some early arguments into the work area, and if
* so, any arguments opied in are appended to those already there.
* This function is the primary manipulator of ip_argspace, since
* these are the arguments the client of execve(2) knows about. After
* each argv[]/envv[] string is copied, we charge the string length
* and argv[]/envv[] pointer slot to ip_argspace, so that we can
* full preflight the arg list size.
*
* Parameters: struct image_params * the image parameter block
*
* Returns: 0 Success
* !0 Failure: errno
*
* Implicit returns;
* (imgp->ip_argc) Count of arguments, updated
* (imgp->ip_envc) Count of environment strings, updated
* (imgp->ip_argspace) Count of remaining of NCARGS
* (imgp->ip_interp_buffer) Interpreter and args (mutated in place)
*
*
* Note: The argument and environment vectors are user space pointers
* to arrays of user space pointers.
*/
static int
exec_extract_strings(struct image_params *imgp)
{
int error = 0;
int ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT) ? 8 : 4;
int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
user_addr_t argv = imgp->ip_user_argv;
user_addr_t envv = imgp->ip_user_envv;
/*
* Adjust space reserved for the path name by however much padding it
* needs. Doing this here since we didn't know if this would be a 32-
* or 64-bit process back in exec_save_path.
*/
while (imgp->ip_strspace % new_ptr_size != 0) {
*imgp->ip_strendp++ = '\0';
imgp->ip_strspace--;
/* imgp->ip_argspace--; not counted towards exec args total */
}
/*
* From now on, we start attributing string space to ip_argspace
*/
imgp->ip_startargv = imgp->ip_strendp;
imgp->ip_argc = 0;
if((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
user_addr_t arg;
char *argstart, *ch;
/* First, the arguments in the "#!" string are tokenized and extracted. */
argstart = imgp->ip_interp_buffer;
while (argstart) {
ch = argstart;
while (*ch && !IS_WHITESPACE(*ch)) {
ch++;
}
if (*ch == '\0') {
/* last argument, no need to NUL-terminate */
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
argstart = NULL;
} else {
/* NUL-terminate */
*ch = '\0';
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
/*
* Find the next string. We know spaces at the end of the string have already
* been stripped.
*/
argstart = ch + 1;
while (IS_WHITESPACE(*argstart)) {
argstart++;
}
}
/* Error-check, regardless of whether this is the last interpreter arg or not */
if (error)
goto bad;
if (imgp->ip_argspace < new_ptr_size) {
error = E2BIG;
goto bad;
}
imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
imgp->ip_argc++;
}
if (argv != 0LL) {
/*
* If we are running an interpreter, replace the av[0] that was
* passed to execve() with the path name that was
* passed to execve() for interpreters which do not use the PATH
* to locate their script arguments.
*/
error = copyinptr(argv, &arg, ptr_size);
if (error)
goto bad;
if (arg != 0LL) {
argv += ptr_size; /* consume without using */
}
}
if (imgp->ip_interp_sugid_fd != -1) {
char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
} else {
error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
}
if (error)
goto bad;
if (imgp->ip_argspace < new_ptr_size) {
error = E2BIG;
goto bad;
}
imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
imgp->ip_argc++;
}
while (argv != 0LL) {
user_addr_t arg;
error = copyinptr(argv, &arg, ptr_size);
if (error)
goto bad;
if (arg == 0LL) {
break;
}
argv += ptr_size;
/*
* av[n...] = arg[n]
*/
error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
if (error)
goto bad;
if (imgp->ip_argspace < new_ptr_size) {
error = E2BIG;
goto bad;
}
imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
imgp->ip_argc++;
}
/* Save space for argv[] NULL terminator */
if (imgp->ip_argspace < new_ptr_size) {
error = E2BIG;
goto bad;
}
imgp->ip_argspace -= new_ptr_size;
/* Note where the args ends and env begins. */
imgp->ip_endargv = imgp->ip_strendp;
imgp->ip_envc = 0;
/* Now, get the environment */
while (envv != 0LL) {
user_addr_t env;
error = copyinptr(envv, &env, ptr_size);
if (error)
goto bad;
envv += ptr_size;
if (env == 0LL) {
break;
}
/*
* av[n...] = env[n]
*/
error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
if (error)
goto bad;
if (imgp->ip_argspace < new_ptr_size) {
error = E2BIG;
goto bad;
}
imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
imgp->ip_envc++;
}
/* Save space for envv[] NULL terminator */
if (imgp->ip_argspace < new_ptr_size) {
error = E2BIG;
goto bad;
}
imgp->ip_argspace -= new_ptr_size;
/* Align the tail of the combined argv+envv area */
while (imgp->ip_strspace % new_ptr_size != 0) {
if (imgp->ip_argspace < 1) {
error = E2BIG;
goto bad;
}
*imgp->ip_strendp++ = '\0';
imgp->ip_strspace--;
imgp->ip_argspace--;
}
/* Note where the envv ends and applev begins. */
imgp->ip_endenvv = imgp->ip_strendp;
/*
* From now on, we are no longer charging argument
* space to ip_argspace.
*/
bad:
return error;
}
static char *
random_hex_str(char *str, int len, boolean_t embedNUL)
{
uint64_t low, high, value;
int idx;
char digit;
/* A 64-bit value will only take 16 characters, plus '0x' and NULL. */
if (len > 19)
len = 19;
/* We need enough room for at least 1 digit */
if (len < 4)
return (NULL);
low = random();
high = random();
value = high << 32 | low;
if (embedNUL) {
/*
* Zero a byte to protect against C string vulnerabilities
* e.g. for userland __stack_chk_guard.
*/
value &= ~(0xffull << 8);
}
str[0] = '0';
str[1] = 'x';
for (idx = 2; idx < len - 1; idx++) {
digit = value & 0xf;
value = value >> 4;
if (digit < 10)
str[idx] = '0' + digit;
else
str[idx] = 'a' + (digit - 10);
}
str[idx] = '\0';
return (str);
}
/*
* Libc has an 8-element array set up for stack guard values. It only fills
* in one of those entries, and both gcc and llvm seem to use only a single
* 8-byte guard. Until somebody needs more than an 8-byte guard value, don't
* do the work to construct them.
*/
#define GUARD_VALUES 1
#define GUARD_KEY "stack_guard="
/*
* System malloc needs some entropy when it is initialized.
*/
#define ENTROPY_VALUES 2
#define ENTROPY_KEY "malloc_entropy="
/*
* System malloc engages nanozone for UIAPP.
*/
#define NANO_ENGAGE_KEY "MallocNanoZone=1"
#define PFZ_KEY "pfz="
extern user32_addr_t commpage_text32_location;
extern user64_addr_t commpage_text64_location;
/*
* Build up the contents of the apple[] string vector
*/
static int
exec_add_apple_strings(struct image_params *imgp)
{
int i, error;
int new_ptr_size=4;
char guard[19];
char guard_vec[strlen(GUARD_KEY) + 19 * GUARD_VALUES + 1];
char entropy[19];
char entropy_vec[strlen(ENTROPY_KEY) + 19 * ENTROPY_VALUES + 1];
char pfz_string[strlen(PFZ_KEY) + 16 + 4 +1];
if( imgp->ip_flags & IMGPF_IS_64BIT) {
new_ptr_size = 8;
snprintf(pfz_string, sizeof(pfz_string),PFZ_KEY "0x%llx",commpage_text64_location);
} else {
snprintf(pfz_string, sizeof(pfz_string),PFZ_KEY "0x%x",commpage_text32_location);
}
/* exec_save_path stored the first string */
imgp->ip_applec = 1;
/* adding the pfz string */
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string),UIO_SYSSPACE,FALSE);
if(error)
goto bad;
imgp->ip_applec++;
/* adding the NANO_ENGAGE_KEY key */
if (imgp->ip_px_sa) {
int proc_flags = (((struct _posix_spawnattr *) imgp->ip_px_sa)->psa_flags);
if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
char uiapp_string[strlen(NANO_ENGAGE_KEY) + 1];
snprintf(uiapp_string, sizeof(uiapp_string), NANO_ENGAGE_KEY);
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(uiapp_string),UIO_SYSSPACE,FALSE);
if (error)
goto bad;
imgp->ip_applec++;
}
}
/*
* Supply libc with a collection of random values to use when
* implementing -fstack-protector.
*
* (The first random string always contains an embedded NUL so that
* __stack_chk_guard also protects against C string vulnerabilities)
*/
(void)strlcpy(guard_vec, GUARD_KEY, sizeof (guard_vec));
for (i = 0; i < GUARD_VALUES; i++) {
random_hex_str(guard, sizeof (guard), i == 0);
if (i)
(void)strlcat(guard_vec, ",", sizeof (guard_vec));
(void)strlcat(guard_vec, guard, sizeof (guard_vec));
}
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(guard_vec), UIO_SYSSPACE, FALSE);
if (error)
goto bad;
imgp->ip_applec++;
/*
* Supply libc with entropy for system malloc.
*/
(void)strlcpy(entropy_vec, ENTROPY_KEY, sizeof(entropy_vec));
for (i = 0; i < ENTROPY_VALUES; i++) {
random_hex_str(entropy, sizeof (entropy), FALSE);
if (i)
(void)strlcat(entropy_vec, ",", sizeof (entropy_vec));
(void)strlcat(entropy_vec, entropy, sizeof (entropy_vec));
}
error = exec_add_user_string(imgp, CAST_USER_ADDR_T(entropy_vec), UIO_SYSSPACE, FALSE);
if (error)
goto bad;
imgp->ip_applec++;
/* Align the tail of the combined applev area */
while (imgp->ip_strspace % new_ptr_size != 0) {
*imgp->ip_strendp++ = '\0';
imgp->ip_strspace--;
}
bad:
return error;
}
#define unix_stack_size(p) (p->p_rlimit[RLIMIT_STACK].rlim_cur)
/*
* exec_check_permissions
*
* Description: Verify that the file that is being attempted to be executed
* is in fact allowed to be executed based on it POSIX file
* permissions and other access control criteria
*
* Parameters: struct image_params * the image parameter block
*
* Returns: 0 Success
* EACCES Permission denied
* ENOEXEC Executable file format error
* ETXTBSY Text file busy [misuse of error code]
* vnode_getattr:???
* vnode_authorize:???
*/
static int
exec_check_permissions(struct image_params *imgp)
{
struct vnode *vp = imgp->ip_vp;
struct vnode_attr *vap = imgp->ip_vattr;
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int error;
kauth_action_t action;
/* Only allow execution of regular files */
if (!vnode_isreg(vp))
return (EACCES);
/* Get the file attributes that we will be using here and elsewhere */
VATTR_INIT(vap);
VATTR_WANTED(vap, va_uid);
VATTR_WANTED(vap, va_gid);
VATTR_WANTED(vap, va_mode);
VATTR_WANTED(vap, va_fsid);
VATTR_WANTED(vap, va_fileid);
VATTR_WANTED(vap, va_data_size);
if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0)
return (error);
/*
* Ensure that at least one execute bit is on - otherwise root
* will always succeed, and we don't want to happen unless the
* file really is executable.
*/
if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0))
return (EACCES);
/* Disallow zero length files */
if (vap->va_data_size == 0)
return (ENOEXEC);
imgp->ip_arch_offset = (user_size_t)0;
imgp->ip_arch_size = vap->va_data_size;
/* Disable setuid-ness for traced programs or if MNT_NOSUID */
if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED))
vap->va_mode &= ~(VSUID | VSGID);
/*
* Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
* flags for setuid/setgid binaries.
*/
if (vap->va_mode & (VSUID | VSGID))
imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
#if CONFIG_MACF
error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
if (error)
return (error);
#endif
/* Check for execute permission */
action = KAUTH_VNODE_EXECUTE;
/* Traced images must also be readable */
if (p->p_lflag & P_LTRACED)
action |= KAUTH_VNODE_READ_DATA;
if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0)
return (error);
#if 0
/* Don't let it run if anyone had it open for writing */
vnode_lock(vp);
if (vp->v_writecount) {
panic("going to return ETXTBSY %x", vp);
vnode_unlock(vp);
return (ETXTBSY);
}
vnode_unlock(vp);
#endif
/* XXX May want to indicate to underlying FS that vnode is open */
return (error);
}
/*
* exec_handle_sugid
*
* Initially clear the P_SUGID in the process flags; if an SUGID process is
* exec'ing a non-SUGID image, then this is the point of no return.
*
* If the image being activated is SUGID, then replace the credential with a
* copy, disable tracing (unless the tracing process is root), reset the
* mach task port to revoke it, set the P_SUGID bit,
*
* If the saved user and group ID will be changing, then make sure it happens
* to a new credential, rather than a shared one.
*
* Set the security token (this is probably obsolete, given that the token
* should not technically be separate from the credential itself).
*
* Parameters: struct image_params * the image parameter block
*
* Returns: void No failure indication
*
* Implicit returns:
* <process credential> Potentially modified/replaced
* <task port> Potentially revoked
* <process flags> P_SUGID bit potentially modified
* <security token> Potentially modified
*/
static int
exec_handle_sugid(struct image_params *imgp)
{
kauth_cred_t cred = vfs_context_ucred(imgp->ip_vfs_context);
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int i;
int leave_sugid_clear = 0;
int mac_reset_ipc = 0;
int error = 0;
#if CONFIG_MACF
int mac_transition, disjoint_cred = 0;
int label_update_return = 0;
/*
* Determine whether a call to update the MAC label will result in the
* credential changing.
*
* Note: MAC policies which do not actually end up modifying
* the label subsequently are strongly encouraged to
* return 0 for this check, since a non-zero answer will
* slow down the exec fast path for normal binaries.
*/
mac_transition = mac_cred_check_label_update_execve(
imgp->ip_vfs_context,
imgp->ip_vp,
imgp->ip_arch_offset,
imgp->ip_scriptvp,
imgp->ip_scriptlabelp,
imgp->ip_execlabelp,
p,
imgp->ip_px_smpx);
#endif
OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
/*
* Order of the following is important; group checks must go last,
* as we use the success of the 'ismember' check combined with the
* failure of the explicit match to indicate that we will be setting
* the egid of the process even though the new process did not
* require VSUID/VSGID bits in order for it to set the new group as
* its egid.
*
* Note: Technically, by this we are implying a call to
* setegid() in the new process, rather than implying
* it used its VSGID bit to set the effective group,
* even though there is no code in that process to make
* such a call.
*/
if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
(kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
#if CONFIG_MACF
/* label for MAC transition and neither VSUID nor VSGID */
handle_mac_transition:
#endif
/*
* Replace the credential with a copy of itself if euid or
* egid change.
*
* Note: setuid binaries will automatically opt out of
* group resolver participation as a side effect
* of this operation. This is an intentional
* part of the security model, which requires a
* participating credential be established by
* escalating privilege, setting up all other
* aspects of the credential including whether
* or not to participate in external group
* membership resolution, then dropping their
* effective privilege to that of the desired
* final credential state.
*/
if (imgp->ip_origvattr->va_mode & VSUID) {
p->p_ucred = kauth_cred_setresuid(p->p_ucred, KAUTH_UID_NONE, imgp->ip_origvattr->va_uid, imgp->ip_origvattr->va_uid, KAUTH_UID_NONE);
/* update cred on proc */
PROC_UPDATE_CREDS_ONPROC(p);
}
if (imgp->ip_origvattr->va_mode & VSGID) {
p->p_ucred = kauth_cred_setresgid(p->p_ucred, KAUTH_GID_NONE, imgp->ip_origvattr->va_gid, imgp->ip_origvattr->va_gid);
/* update cred on proc */
PROC_UPDATE_CREDS_ONPROC(p);
}
#if CONFIG_MACF
/*
* If a policy has indicated that it will transition the label,
* before making the call into the MAC policies, get a new
* duplicate credential, so they can modify it without
* modifying any others sharing it.
*/
if (mac_transition) {
kauth_proc_label_update_execve(p,
imgp->ip_vfs_context,
imgp->ip_vp,
imgp->ip_arch_offset,
imgp->ip_scriptvp,
imgp->ip_scriptlabelp,
imgp->ip_execlabelp,
&imgp->ip_csflags,
imgp->ip_px_smpx,
&disjoint_cred, /* will be non zero if disjoint */
&label_update_return);
if (disjoint_cred) {
/*
* If updating the MAC label resulted in a
* disjoint credential, flag that we need to
* set the P_SUGID bit. This protects
* against debuggers being attached by an
* insufficiently privileged process onto the
* result of a transition to a more privileged
* credential.
*/
leave_sugid_clear = 0;
}
imgp->ip_mac_return = label_update_return;
}
mac_reset_ipc = mac_proc_check_inherit_ipc_ports(p, p->p_textvp, p->p_textoff, imgp->ip_vp, imgp->ip_arch_offset, imgp->ip_scriptvp);
#endif /* CONFIG_MACF */
/*
* If 'leave_sugid_clear' is non-zero, then we passed the
* VSUID and MACF checks, and successfully determined that
* the previous cred was a member of the VSGID group, but
* that it was not the default at the time of the execve,
* and that the post-labelling credential was not disjoint.
* So we don't set the P_SUGID or reset mach ports and fds
* on the basis of simply running this code.
*/
if (mac_reset_ipc || !leave_sugid_clear) {
/*
* Have mach reset the task and thread ports.
* We don't want anyone who had the ports before
* a setuid exec to be able to access/control the
* task/thread after.
*/
ipc_task_reset(p->task);
ipc_thread_reset((imgp->ip_new_thread != NULL) ?
imgp->ip_new_thread : current_thread());
}
if (!leave_sugid_clear) {
/*
* Flag the process as setuid.
*/
OSBitOrAtomic(P_SUGID, &p->p_flag);
/*
* Radar 2261856; setuid security hole fix
* XXX For setuid processes, attempt to ensure that
* stdin, stdout, and stderr are already allocated.
* We do not want userland to accidentally allocate
* descriptors in this range which has implied meaning
* to libc.
*/
for (i = 0; i < 3; i++) {
if (p->p_fd->fd_ofiles[i] != NULL)
continue;
/*
* Do the kernel equivalent of
*
* if i == 0
* (void) open("/dev/null", O_RDONLY);
* else
* (void) open("/dev/null", O_WRONLY);
*/
struct fileproc *fp;
int indx;
int flag;
struct nameidata *ndp = NULL;
if (i == 0)
flag = FREAD;
else
flag = FWRITE;
if ((error = falloc(p,
&fp, &indx, imgp->ip_vfs_context)) != 0)
continue;
MALLOC(ndp, struct nameidata *, sizeof(*ndp), M_TEMP, M_WAITOK | M_ZERO);
if (ndp == NULL) {
error = ENOMEM;
break;
}
NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
CAST_USER_ADDR_T("/dev/null"),
imgp->ip_vfs_context);
if ((error = vn_open(ndp, flag, 0)) != 0) {
fp_free(p, indx, fp);
break;
}
struct fileglob *fg = fp->f_fglob;
fg->fg_flag = flag;
fg->fg_ops = &vnops;
fg->fg_data = ndp->ni_vp;
vnode_put(ndp->ni_vp);
proc_fdlock(p);
procfdtbl_releasefd(p, indx, NULL);
fp_drop(p, indx, fp, 1);
proc_fdunlock(p);
FREE(ndp, M_TEMP);
}
}
}
#if CONFIG_MACF
else {
/*
* We are here because we were told that the MAC label will
* be transitioned, and the binary is not VSUID or VSGID; to
* deal with this case, we could either duplicate a lot of
* code, or we can indicate we want to default the P_SUGID
* bit clear and jump back up.
*/
if (mac_transition) {
leave_sugid_clear = 1;
goto handle_mac_transition;
}
}
#endif /* CONFIG_MACF */
/*
* Implement the semantic where the effective user and group become
* the saved user and group in exec'ed programs.
*/
p->p_ucred = kauth_cred_setsvuidgid(p->p_ucred, kauth_cred_getuid(p->p_ucred), kauth_cred_getgid(p->p_ucred));
/* update cred on proc */
PROC_UPDATE_CREDS_ONPROC(p);
/* Update the process' identity version and set the security token */
p->p_idversion++;
set_security_token(p);
return(error);
}
/*
* create_unix_stack
*
* Description: Set the user stack address for the process to the provided
* address. If a custom stack was not set as a result of the
* load process (i.e. as specified by the image file for the
* executable), then allocate the stack in the provided map and
* set up appropriate guard pages for enforcing administrative
* limits on stack growth, if they end up being needed.
*
* Parameters: p Process to set stack on
* load_result Information from mach-o load commands
* map Address map in which to allocate the new stack
*
* Returns: KERN_SUCCESS Stack successfully created
* !KERN_SUCCESS Mach failure code
*/
static kern_return_t
create_unix_stack(vm_map_t map, load_result_t* load_result,
proc_t p)
{
mach_vm_size_t size, prot_size;
mach_vm_offset_t addr, prot_addr;
kern_return_t kr;
mach_vm_address_t user_stack = load_result->user_stack;
proc_lock(p);
p->user_stack = user_stack;
proc_unlock(p);
if (!load_result->prog_allocated_stack) {
/*
* Allocate enough space for the maximum stack size we
* will ever authorize and an extra page to act as
* a guard page for stack overflows. For default stacks,
* vm_initial_limit_stack takes care of the extra guard page.
* Otherwise we must allocate it ourselves.
*/
size = mach_vm_round_page(load_result->user_stack_size);
if (load_result->prog_stack_size)
size += PAGE_SIZE;
addr = mach_vm_trunc_page(load_result->user_stack - size);
kr = mach_vm_allocate(map, &addr, size,
VM_MAKE_TAG(VM_MEMORY_STACK) |
VM_FLAGS_FIXED);
if (kr != KERN_SUCCESS) {
/* If can't allocate at default location, try anywhere */
addr = 0;
kr = mach_vm_allocate(map, &addr, size,
VM_MAKE_TAG(VM_MEMORY_STACK) |
VM_FLAGS_ANYWHERE);
if (kr != KERN_SUCCESS)
return kr;
user_stack = addr + size;
load_result->user_stack = user_stack;
proc_lock(p);
p->user_stack = user_stack;
proc_unlock(p);
}
/*
* And prevent access to what's above the current stack
* size limit for this process.
*/
prot_addr = addr;
if (load_result->prog_stack_size)
prot_size = PAGE_SIZE;
else
prot_size = mach_vm_trunc_page(size - unix_stack_size(p));
kr = mach_vm_protect(map,
prot_addr,
prot_size,
FALSE,
VM_PROT_NONE);
if (kr != KERN_SUCCESS) {
(void) mach_vm_deallocate(map, addr, size);
return kr;
}
}
return KERN_SUCCESS;
}
#include <sys/reboot.h>
static const char * init_programs[] = {
#if DEVELOPMENT || DEBUG
"/usr/local/sbin/launchd.development",
#endif
"/sbin/launchd",
};
/*
* load_init_program
*
* Description: Load the "init" program; in most cases, this will be "launchd"
*
* Parameters: p Process to call execve() to create
* the "init" program
*
* Returns: (void)
*
* Notes: The process that is passed in is the first manufactured
* process on the system, and gets here via bsd_ast() firing
* for the first time. This is done to ensure that bsd_init()
* has run to completion.
*/
void
load_init_program(proc_t p)
{
vm_offset_t init_addr, addr;
int argc;
uint32_t argv[3];
unsigned int i;
int error;
int retval[2];
const char *init_program_name;
struct execve_args init_exec_args;
init_addr = VM_MIN_ADDRESS;
(void) vm_allocate(current_map(), &init_addr, PAGE_SIZE, VM_FLAGS_ANYWHERE);
if (init_addr == 0)
init_addr++;
for (i = 0; i < sizeof(init_programs)/sizeof(init_programs[0]); i++) {