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freebsd-skq/sys/kern/imgact_elf.c
Konstantin Belousov 673e2dd652 Add ELF flag to disable ASLR stack gap. 
Also centralize and unify checks to enable ASLR stack gap in a new
helper exec_stackgap().

PR:	239873
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-12-18 23:14:39 +00:00

2832 lines
76 KiB
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2017 Dell EMC
* Copyright (c) 2000-2001, 2003 David O'Brien
* Copyright (c) 1995-1996 Søren Schmidt
* Copyright (c) 1996 Peter Wemm
* All rights reserved.
*
* 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
* in this position and unchanged.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_capsicum.h"
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/compressor.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mman.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/ptrace.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/sf_buf.h>
#include <sys/smp.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/eventhandler.h>
#include <sys/user.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <machine/elf.h>
#include <machine/md_var.h>
#define ELF_NOTE_ROUNDSIZE 4
#define OLD_EI_BRAND 8
static int __elfN(check_header)(const Elf_Ehdr *hdr);
static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
const char *interp, int32_t *osrel, uint32_t *fctl0);
static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
u_long *entry);
static int __elfN(load_section)(struct image_params *imgp, vm_ooffset_t offset,
caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot);
static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
static bool __elfN(freebsd_trans_osrel)(const Elf_Note *note,
int32_t *osrel);
static bool kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel);
static boolean_t __elfN(check_note)(struct image_params *imgp,
Elf_Brandnote *checknote, int32_t *osrel, boolean_t *has_fctl0,
uint32_t *fctl0);
static vm_prot_t __elfN(trans_prot)(Elf_Word);
static Elf_Word __elfN(untrans_prot)(vm_prot_t);
SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE),
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
#define CORE_BUF_SIZE (16 * 1024)
int __elfN(fallback_brand) = -1;
SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
fallback_brand, CTLFLAG_RWTUN, &__elfN(fallback_brand), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort");
static int elf_legacy_coredump = 0;
SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW,
&elf_legacy_coredump, 0,
"include all and only RW pages in core dumps");
int __elfN(nxstack) =
#if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */ || \
(defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__) || \
defined(__riscv)
1;
#else
0;
#endif
SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");
#if __ELF_WORD_SIZE == 32 && (defined(__amd64__) || defined(__i386__))
int i386_read_exec = 0;
SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_RW, &i386_read_exec, 0,
"enable execution from readable segments");
#endif
static u_long __elfN(pie_base) = ET_DYN_LOAD_ADDR;
static int
sysctl_pie_base(SYSCTL_HANDLER_ARGS)
{
u_long val;
int error;
val = __elfN(pie_base);
error = sysctl_handle_long(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if ((val & PAGE_MASK) != 0)
return (EINVAL);
__elfN(pie_base) = val;
return (0);
}
SYSCTL_PROC(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, pie_base,
CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0,
sysctl_pie_base, "LU",
"PIE load base without randomization");
SYSCTL_NODE(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, aslr,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
#define ASLR_NODE_OID __CONCAT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), _aslr)
static int __elfN(aslr_enabled) = 0;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, enable, CTLFLAG_RWTUN,
&__elfN(aslr_enabled), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
": enable address map randomization");
static int __elfN(pie_aslr_enabled) = 0;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, pie_enable, CTLFLAG_RWTUN,
&__elfN(pie_aslr_enabled), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
": enable address map randomization for PIE binaries");
static int __elfN(aslr_honor_sbrk) = 1;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, honor_sbrk, CTLFLAG_RW,
&__elfN(aslr_honor_sbrk), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": assume sbrk is used");
static int __elfN(aslr_stack_gap) = 3;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, stack_gap, CTLFLAG_RW,
&__elfN(aslr_stack_gap), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
": maximum percentage of main stack to waste on a random gap");
static int __elfN(sigfastblock) = 1;
SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, sigfastblock,
CTLFLAG_RWTUN, &__elfN(sigfastblock), 0,
"enable sigfastblock for new processes");
static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
#define aligned(a, t) (rounddown2((u_long)(a), sizeof(t)) == (u_long)(a))
static const char FREEBSD_ABI_VENDOR[] = "FreeBSD";
Elf_Brandnote __elfN(freebsd_brandnote) = {
.hdr.n_namesz = sizeof(FREEBSD_ABI_VENDOR),
.hdr.n_descsz = sizeof(int32_t),
.hdr.n_type = NT_FREEBSD_ABI_TAG,
.vendor = FREEBSD_ABI_VENDOR,
.flags = BN_TRANSLATE_OSREL,
.trans_osrel = __elfN(freebsd_trans_osrel)
};
static bool
__elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
{
uintptr_t p;
p = (uintptr_t)(note + 1);
p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
*osrel = *(const int32_t *)(p);
return (true);
}
static const char GNU_ABI_VENDOR[] = "GNU";
static int GNU_KFREEBSD_ABI_DESC = 3;
Elf_Brandnote __elfN(kfreebsd_brandnote) = {
.hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
.hdr.n_descsz = 16, /* XXX at least 16 */
.hdr.n_type = 1,
.vendor = GNU_ABI_VENDOR,
.flags = BN_TRANSLATE_OSREL,
.trans_osrel = kfreebsd_trans_osrel
};
static bool
kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel)
{
const Elf32_Word *desc;
uintptr_t p;
p = (uintptr_t)(note + 1);
p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
desc = (const Elf32_Word *)p;
if (desc[0] != GNU_KFREEBSD_ABI_DESC)
return (false);
/*
* Debian GNU/kFreeBSD embed the earliest compatible kernel version
* (__FreeBSD_version: <major><two digit minor>Rxx) in the LSB way.
*/
*osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3];
return (true);
}
int
__elfN(insert_brand_entry)(Elf_Brandinfo *entry)
{
int i;
for (i = 0; i < MAX_BRANDS; i++) {
if (elf_brand_list[i] == NULL) {
elf_brand_list[i] = entry;
break;
}
}
if (i == MAX_BRANDS) {
printf("WARNING: %s: could not insert brandinfo entry: %p\n",
__func__, entry);
return (-1);
}
return (0);
}
int
__elfN(remove_brand_entry)(Elf_Brandinfo *entry)
{
int i;
for (i = 0; i < MAX_BRANDS; i++) {
if (elf_brand_list[i] == entry) {
elf_brand_list[i] = NULL;
break;
}
}
if (i == MAX_BRANDS)
return (-1);
return (0);
}
int
__elfN(brand_inuse)(Elf_Brandinfo *entry)
{
struct proc *p;
int rval = FALSE;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
if (p->p_sysent == entry->sysvec) {
rval = TRUE;
break;
}
}
sx_sunlock(&allproc_lock);
return (rval);
}
static Elf_Brandinfo *
__elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
int32_t *osrel, uint32_t *fctl0)
{
const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
Elf_Brandinfo *bi, *bi_m;
boolean_t ret, has_fctl0;
int i, interp_name_len;
interp_name_len = interp != NULL ? strlen(interp) + 1 : 0;
/*
* We support four types of branding -- (1) the ELF EI_OSABI field
* that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
* branding w/in the ELF header, (3) path of the `interp_path'
* field, and (4) the ".note.ABI-tag" ELF section.
*/
/* Look for an ".note.ABI-tag" ELF section */
bi_m = NULL;
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi == NULL)
continue;
if (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0)
continue;
if (hdr->e_machine == bi->machine && (bi->flags &
(BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
has_fctl0 = false;
*fctl0 = 0;
*osrel = 0;
ret = __elfN(check_note)(imgp, bi->brand_note, osrel,
&has_fctl0, fctl0);
/* Give brand a chance to veto check_note's guess */
if (ret && bi->header_supported) {
ret = bi->header_supported(imgp, osrel,
has_fctl0 ? fctl0 : NULL);
}
/*
* If note checker claimed the binary, but the
* interpreter path in the image does not
* match default one for the brand, try to
* search for other brands with the same
* interpreter. Either there is better brand
* with the right interpreter, or, failing
* this, we return first brand which accepted
* our note and, optionally, header.
*/
if (ret && bi_m == NULL && interp != NULL &&
(bi->interp_path == NULL ||
(strlen(bi->interp_path) + 1 != interp_name_len ||
strncmp(interp, bi->interp_path, interp_name_len)
!= 0))) {
bi_m = bi;
ret = 0;
}
if (ret)
return (bi);
}
}
if (bi_m != NULL)
return (bi_m);
/* If the executable has a brand, search for it in the brand list. */
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi == NULL || (bi->flags & BI_BRAND_NOTE_MANDATORY) != 0 ||
(interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0))
continue;
if (hdr->e_machine == bi->machine &&
(hdr->e_ident[EI_OSABI] == bi->brand ||
(bi->compat_3_brand != NULL &&
strcmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
bi->compat_3_brand) == 0))) {
/* Looks good, but give brand a chance to veto */
if (bi->header_supported == NULL ||
bi->header_supported(imgp, NULL, NULL)) {
/*
* Again, prefer strictly matching
* interpreter path.
*/
if (interp_name_len == 0 &&
bi->interp_path == NULL)
return (bi);
if (bi->interp_path != NULL &&
strlen(bi->interp_path) + 1 ==
interp_name_len && strncmp(interp,
bi->interp_path, interp_name_len) == 0)
return (bi);
if (bi_m == NULL)
bi_m = bi;
}
}
}
if (bi_m != NULL)
return (bi_m);
/* No known brand, see if the header is recognized by any brand */
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY ||
bi->header_supported == NULL)
continue;
if (hdr->e_machine == bi->machine) {
ret = bi->header_supported(imgp, NULL, NULL);
if (ret)
return (bi);
}
}
/* Lacking a known brand, search for a recognized interpreter. */
if (interp != NULL) {
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi == NULL || (bi->flags &
(BI_BRAND_NOTE_MANDATORY | BI_BRAND_ONLY_STATIC))
!= 0)
continue;
if (hdr->e_machine == bi->machine &&
bi->interp_path != NULL &&
/* ELF image p_filesz includes terminating zero */
strlen(bi->interp_path) + 1 == interp_name_len &&
strncmp(interp, bi->interp_path, interp_name_len)
== 0 && (bi->header_supported == NULL ||
bi->header_supported(imgp, NULL, NULL)))
return (bi);
}
}
/* Lacking a recognized interpreter, try the default brand */
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi == NULL || (bi->flags & BI_BRAND_NOTE_MANDATORY) != 0 ||
(interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0))
continue;
if (hdr->e_machine == bi->machine &&
__elfN(fallback_brand) == bi->brand &&
(bi->header_supported == NULL ||
bi->header_supported(imgp, NULL, NULL)))
return (bi);
}
return (NULL);
}
static bool
__elfN(phdr_in_zero_page)(const Elf_Ehdr *hdr)
{
return (hdr->e_phoff <= PAGE_SIZE &&
(u_int)hdr->e_phentsize * hdr->e_phnum <= PAGE_SIZE - hdr->e_phoff);
}
static int
__elfN(check_header)(const Elf_Ehdr *hdr)
{
Elf_Brandinfo *bi;
int i;
if (!IS_ELF(*hdr) ||
hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
hdr->e_ident[EI_VERSION] != EV_CURRENT ||
hdr->e_phentsize != sizeof(Elf_Phdr) ||
hdr->e_version != ELF_TARG_VER)
return (ENOEXEC);
/*
* Make sure we have at least one brand for this machine.
*/
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi != NULL && bi->machine == hdr->e_machine)
break;
}
if (i == MAX_BRANDS)
return (ENOEXEC);
return (0);
}
static int
__elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
vm_offset_t start, vm_offset_t end, vm_prot_t prot)
{
struct sf_buf *sf;
int error;
vm_offset_t off;
/*
* Create the page if it doesn't exist yet. Ignore errors.
*/
vm_map_fixed(map, NULL, 0, trunc_page(start), round_page(end) -
trunc_page(start), VM_PROT_ALL, VM_PROT_ALL, MAP_CHECK_EXCL);
/*
* Find the page from the underlying object.
*/
if (object != NULL) {
sf = vm_imgact_map_page(object, offset);
if (sf == NULL)
return (KERN_FAILURE);
off = offset - trunc_page(offset);
error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start,
end - start);
vm_imgact_unmap_page(sf);
if (error != 0)
return (KERN_FAILURE);
}
return (KERN_SUCCESS);
}
static int
__elfN(map_insert)(struct image_params *imgp, vm_map_t map, vm_object_t object,
vm_ooffset_t offset, vm_offset_t start, vm_offset_t end, vm_prot_t prot,
int cow)
{
struct sf_buf *sf;
vm_offset_t off;
vm_size_t sz;
int error, locked, rv;
if (start != trunc_page(start)) {
rv = __elfN(map_partial)(map, object, offset, start,
round_page(start), prot);
if (rv != KERN_SUCCESS)
return (rv);
offset += round_page(start) - start;
start = round_page(start);
}
if (end != round_page(end)) {
rv = __elfN(map_partial)(map, object, offset +
trunc_page(end) - start, trunc_page(end), end, prot);
if (rv != KERN_SUCCESS)
return (rv);
end = trunc_page(end);
}
if (start >= end)
return (KERN_SUCCESS);
if ((offset & PAGE_MASK) != 0) {
/*
* The mapping is not page aligned. This means that we have
* to copy the data.
*/
rv = vm_map_fixed(map, NULL, 0, start, end - start,
prot | VM_PROT_WRITE, VM_PROT_ALL, MAP_CHECK_EXCL);
if (rv != KERN_SUCCESS)
return (rv);
if (object == NULL)
return (KERN_SUCCESS);
for (; start < end; start += sz) {
sf = vm_imgact_map_page(object, offset);
if (sf == NULL)
return (KERN_FAILURE);
off = offset - trunc_page(offset);
sz = end - start;
if (sz > PAGE_SIZE - off)
sz = PAGE_SIZE - off;
error = copyout((caddr_t)sf_buf_kva(sf) + off,
(caddr_t)start, sz);
vm_imgact_unmap_page(sf);
if (error != 0)
return (KERN_FAILURE);
offset += sz;
}
} else {
vm_object_reference(object);
rv = vm_map_fixed(map, object, offset, start, end - start,
prot, VM_PROT_ALL, cow | MAP_CHECK_EXCL |
(object != NULL ? MAP_VN_EXEC : 0));
if (rv != KERN_SUCCESS) {
locked = VOP_ISLOCKED(imgp->vp);
VOP_UNLOCK(imgp->vp);
vm_object_deallocate(object);
vn_lock(imgp->vp, locked | LK_RETRY);
return (rv);
} else if (object != NULL) {
MPASS(imgp->vp->v_object == object);
VOP_SET_TEXT_CHECKED(imgp->vp);
}
}
return (KERN_SUCCESS);
}
static int
__elfN(load_section)(struct image_params *imgp, vm_ooffset_t offset,
caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot)
{
struct sf_buf *sf;
size_t map_len;
vm_map_t map;
vm_object_t object;
vm_offset_t map_addr;
int error, rv, cow;
size_t copy_len;
vm_ooffset_t file_addr;
/*
* It's necessary to fail if the filsz + offset taken from the
* header is greater than the actual file pager object's size.
* If we were to allow this, then the vm_map_find() below would
* walk right off the end of the file object and into the ether.
*
* While I'm here, might as well check for something else that
* is invalid: filsz cannot be greater than memsz.
*/
if ((filsz != 0 && (off_t)filsz + offset > imgp->attr->va_size) ||
filsz > memsz) {
uprintf("elf_load_section: truncated ELF file\n");
return (ENOEXEC);
}
object = imgp->object;
map = &imgp->proc->p_vmspace->vm_map;
map_addr = trunc_page((vm_offset_t)vmaddr);
file_addr = trunc_page(offset);
/*
* We have two choices. We can either clear the data in the last page
* of an oversized mapping, or we can start the anon mapping a page
* early and copy the initialized data into that first page. We
* choose the second.
*/
if (filsz == 0)
map_len = 0;
else if (memsz > filsz)
map_len = trunc_page(offset + filsz) - file_addr;
else
map_len = round_page(offset + filsz) - file_addr;
if (map_len != 0) {
/* cow flags: don't dump readonly sections in core */
cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
(prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
rv = __elfN(map_insert)(imgp, map, object, file_addr,
map_addr, map_addr + map_len, prot, cow);
if (rv != KERN_SUCCESS)
return (EINVAL);
/* we can stop now if we've covered it all */
if (memsz == filsz)
return (0);
}
/*
* We have to get the remaining bit of the file into the first part
* of the oversized map segment. This is normally because the .data
* segment in the file is extended to provide bss. It's a neat idea
* to try and save a page, but it's a pain in the behind to implement.
*/
copy_len = filsz == 0 ? 0 : (offset + filsz) - trunc_page(offset +
filsz);
map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
/* This had damn well better be true! */
if (map_len != 0) {
rv = __elfN(map_insert)(imgp, map, NULL, 0, map_addr,
map_addr + map_len, prot, 0);
if (rv != KERN_SUCCESS)
return (EINVAL);
}
if (copy_len != 0) {
sf = vm_imgact_map_page(object, offset + filsz);
if (sf == NULL)
return (EIO);
/* send the page fragment to user space */
error = copyout((caddr_t)sf_buf_kva(sf), (caddr_t)map_addr,
copy_len);
vm_imgact_unmap_page(sf);
if (error != 0)
return (error);
}
/*
* Remove write access to the page if it was only granted by map_insert
* to allow copyout.
*/
if ((prot & VM_PROT_WRITE) == 0)
vm_map_protect(map, trunc_page(map_addr), round_page(map_addr +
map_len), prot, FALSE);
return (0);
}
static int
__elfN(load_sections)(struct image_params *imgp, const Elf_Ehdr *hdr,
const Elf_Phdr *phdr, u_long rbase, u_long *base_addrp)
{
vm_prot_t prot;
u_long base_addr;
bool first;
int error, i;
ASSERT_VOP_LOCKED(imgp->vp, __func__);
base_addr = 0;
first = true;
for (i = 0; i < hdr->e_phnum; i++) {
if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
continue;
/* Loadable segment */
prot = __elfN(trans_prot)(phdr[i].p_flags);
error = __elfN(load_section)(imgp, phdr[i].p_offset,
(caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase,
phdr[i].p_memsz, phdr[i].p_filesz, prot);
if (error != 0)
return (error);
/*
* Establish the base address if this is the first segment.
*/
if (first) {
base_addr = trunc_page(phdr[i].p_vaddr + rbase);
first = false;
}
}
if (base_addrp != NULL)
*base_addrp = base_addr;
return (0);
}
/*
* Load the file "file" into memory. It may be either a shared object
* or an executable.
*
* The "addr" reference parameter is in/out. On entry, it specifies
* the address where a shared object should be loaded. If the file is
* an executable, this value is ignored. On exit, "addr" specifies
* where the file was actually loaded.
*
* The "entry" reference parameter is out only. On exit, it specifies
* the entry point for the loaded file.
*/
static int
__elfN(load_file)(struct proc *p, const char *file, u_long *addr,
u_long *entry)
{
struct {
struct nameidata nd;
struct vattr attr;
struct image_params image_params;
} *tempdata;
const Elf_Ehdr *hdr = NULL;
const Elf_Phdr *phdr = NULL;
struct nameidata *nd;
struct vattr *attr;
struct image_params *imgp;
u_long rbase;
u_long base_addr = 0;
int error;
#ifdef CAPABILITY_MODE
/*
* XXXJA: This check can go away once we are sufficiently confident
* that the checks in namei() are correct.
*/
if (IN_CAPABILITY_MODE(curthread))
return (ECAPMODE);
#endif
tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK | M_ZERO);
nd = &tempdata->nd;
attr = &tempdata->attr;
imgp = &tempdata->image_params;
/*
* Initialize part of the common data
*/
imgp->proc = p;
imgp->attr = attr;
NDINIT(nd, LOOKUP, ISOPEN | FOLLOW | LOCKSHARED | LOCKLEAF,
UIO_SYSSPACE, file, curthread);
if ((error = namei(nd)) != 0) {
nd->ni_vp = NULL;
goto fail;
}
NDFREE(nd, NDF_ONLY_PNBUF);
imgp->vp = nd->ni_vp;
/*
* Check permissions, modes, uid, etc on the file, and "open" it.
*/
error = exec_check_permissions(imgp);
if (error)
goto fail;
error = exec_map_first_page(imgp);
if (error)
goto fail;
imgp->object = nd->ni_vp->v_object;
hdr = (const Elf_Ehdr *)imgp->image_header;
if ((error = __elfN(check_header)(hdr)) != 0)
goto fail;
if (hdr->e_type == ET_DYN)
rbase = *addr;
else if (hdr->e_type == ET_EXEC)
rbase = 0;
else {
error = ENOEXEC;
goto fail;
}
/* Only support headers that fit within first page for now */
if (!__elfN(phdr_in_zero_page)(hdr)) {
error = ENOEXEC;
goto fail;
}
phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
if (!aligned(phdr, Elf_Addr)) {
error = ENOEXEC;
goto fail;
}
error = __elfN(load_sections)(imgp, hdr, phdr, rbase, &base_addr);
if (error != 0)
goto fail;
*addr = base_addr;
*entry = (unsigned long)hdr->e_entry + rbase;
fail:
if (imgp->firstpage)
exec_unmap_first_page(imgp);
if (nd->ni_vp) {
if (imgp->textset)
VOP_UNSET_TEXT_CHECKED(nd->ni_vp);
vput(nd->ni_vp);
}
free(tempdata, M_TEMP);
return (error);
}
static u_long
__CONCAT(rnd_, __elfN(base))(vm_map_t map __unused, u_long minv, u_long maxv,
u_int align)
{
u_long rbase, res;
MPASS(vm_map_min(map) <= minv);
MPASS(maxv <= vm_map_max(map));
MPASS(minv < maxv);
MPASS(minv + align < maxv);
arc4rand(&rbase, sizeof(rbase), 0);
res = roundup(minv, (u_long)align) + rbase % (maxv - minv);
res &= ~((u_long)align - 1);
if (res >= maxv)
res -= align;
KASSERT(res >= minv,
("res %#lx < minv %#lx, maxv %#lx rbase %#lx",
res, minv, maxv, rbase));
KASSERT(res < maxv,
("res %#lx > maxv %#lx, minv %#lx rbase %#lx",
res, maxv, minv, rbase));
return (res);
}
static int
__elfN(enforce_limits)(struct image_params *imgp, const Elf_Ehdr *hdr,
const Elf_Phdr *phdr, u_long et_dyn_addr)
{
struct vmspace *vmspace;
const char *err_str;
u_long text_size, data_size, total_size, text_addr, data_addr;
u_long seg_size, seg_addr;
int i;
err_str = NULL;
text_size = data_size = total_size = text_addr = data_addr = 0;
for (i = 0; i < hdr->e_phnum; i++) {
if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
continue;
seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
seg_size = round_page(phdr[i].p_memsz +
phdr[i].p_vaddr + et_dyn_addr - seg_addr);
/*
* Make the largest executable segment the official
* text segment and all others data.
*
* Note that obreak() assumes that data_addr + data_size == end
* of data load area, and the ELF file format expects segments
* to be sorted by address. If multiple data segments exist,
* the last one will be used.
*/
if ((phdr[i].p_flags & PF_X) != 0 && text_size < seg_size) {
text_size = seg_size;
text_addr = seg_addr;
} else {
data_size = seg_size;
data_addr = seg_addr;
}
total_size += seg_size;
}
if (data_addr == 0 && data_size == 0) {
data_addr = text_addr;
data_size = text_size;
}
/*
* Check limits. It should be safe to check the
* limits after loading the segments since we do
* not actually fault in all the segments pages.
*/
PROC_LOCK(imgp->proc);
if (data_size > lim_cur_proc(imgp->proc, RLIMIT_DATA))
err_str = "Data segment size exceeds process limit";
else if (text_size > maxtsiz)
err_str = "Text segment size exceeds system limit";
else if (total_size > lim_cur_proc(imgp->proc, RLIMIT_VMEM))
err_str = "Total segment size exceeds process limit";
else if (racct_set(imgp->proc, RACCT_DATA, data_size) != 0)
err_str = "Data segment size exceeds resource limit";
else if (racct_set(imgp->proc, RACCT_VMEM, total_size) != 0)
err_str = "Total segment size exceeds resource limit";
PROC_UNLOCK(imgp->proc);
if (err_str != NULL) {
uprintf("%s\n", err_str);
return (ENOMEM);
}
vmspace = imgp->proc->p_vmspace;
vmspace->vm_tsize = text_size >> PAGE_SHIFT;
vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
vmspace->vm_dsize = data_size >> PAGE_SHIFT;
vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
return (0);
}
static int
__elfN(get_interp)(struct image_params *imgp, const Elf_Phdr *phdr,
char **interpp, bool *free_interpp)
{
struct thread *td;
char *interp;
int error, interp_name_len;
KASSERT(phdr->p_type == PT_INTERP,
("%s: p_type %u != PT_INTERP", __func__, phdr->p_type));
ASSERT_VOP_LOCKED(imgp->vp, __func__);
td = curthread;
/* Path to interpreter */
if (phdr->p_filesz < 2 || phdr->p_filesz > MAXPATHLEN) {
uprintf("Invalid PT_INTERP\n");
return (ENOEXEC);
}
interp_name_len = phdr->p_filesz;
if (phdr->p_offset > PAGE_SIZE ||
interp_name_len > PAGE_SIZE - phdr->p_offset) {
/*
* The vnode lock might be needed by the pagedaemon to
* clean pages owned by the vnode. Do not allow sleep
* waiting for memory with the vnode locked, instead
* try non-sleepable allocation first, and if it
* fails, go to the slow path were we drop the lock
* and do M_WAITOK. A text reference prevents
* modifications to the vnode content.
*/
interp = malloc(interp_name_len + 1, M_TEMP, M_NOWAIT);
if (interp == NULL) {
VOP_UNLOCK(imgp->vp);
interp = malloc(interp_name_len + 1, M_TEMP, M_WAITOK);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
}
error = vn_rdwr(UIO_READ, imgp->vp, interp,
interp_name_len, phdr->p_offset,
UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
NOCRED, NULL, td);
if (error != 0) {
free(interp, M_TEMP);
uprintf("i/o error PT_INTERP %d\n", error);
return (error);
}
interp[interp_name_len] = '\0';
*interpp = interp;
*free_interpp = true;
return (0);
}
interp = __DECONST(char *, imgp->image_header) + phdr->p_offset;
if (interp[interp_name_len - 1] != '\0') {
uprintf("Invalid PT_INTERP\n");
return (ENOEXEC);
}
*interpp = interp;
*free_interpp = false;
return (0);
}
static int
__elfN(load_interp)(struct image_params *imgp, const Elf_Brandinfo *brand_info,
const char *interp, u_long *addr, u_long *entry)
{
char *path;
int error;
if (brand_info->emul_path != NULL &&
brand_info->emul_path[0] != '\0') {
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
snprintf(path, MAXPATHLEN, "%s%s",
brand_info->emul_path, interp);
error = __elfN(load_file)(imgp->proc, path, addr, entry);
free(path, M_TEMP);
if (error == 0)
return (0);
}
if (brand_info->interp_newpath != NULL &&
(brand_info->interp_path == NULL ||
strcmp(interp, brand_info->interp_path) == 0)) {
error = __elfN(load_file)(imgp->proc,
brand_info->interp_newpath, addr, entry);
if (error == 0)
return (0);
}
error = __elfN(load_file)(imgp->proc, interp, addr, entry);
if (error == 0)
return (0);
uprintf("ELF interpreter %s not found, error %d\n", interp, error);
return (error);
}
/*
* Impossible et_dyn_addr initial value indicating that the real base
* must be calculated later with some randomization applied.
*/
#define ET_DYN_ADDR_RAND 1
static int
__CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
{
struct thread *td;
const Elf_Ehdr *hdr;
const Elf_Phdr *phdr;
Elf_Auxargs *elf_auxargs;
struct vmspace *vmspace;
vm_map_t map;
char *interp;
Elf_Brandinfo *brand_info;
struct sysentvec *sv;
u_long addr, baddr, et_dyn_addr, entry, proghdr;
u_long maxalign, mapsz, maxv, maxv1;
uint32_t fctl0;
int32_t osrel;
bool free_interp;
int error, i, n;
hdr = (const Elf_Ehdr *)imgp->image_header;
/*
* Do we have a valid ELF header ?
*
* Only allow ET_EXEC & ET_DYN here, reject ET_DYN later
* if particular brand doesn't support it.
*/
if (__elfN(check_header)(hdr) != 0 ||
(hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
return (-1);
/*
* From here on down, we return an errno, not -1, as we've
* detected an ELF file.
*/
if (!__elfN(phdr_in_zero_page)(hdr)) {
uprintf("Program headers not in the first page\n");
return (ENOEXEC);
}
phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
if (!aligned(phdr, Elf_Addr)) {
uprintf("Unaligned program headers\n");
return (ENOEXEC);
}
n = error = 0;
baddr = 0;
osrel = 0;
fctl0 = 0;
entry = proghdr = 0;
interp = NULL;
free_interp = false;
td = curthread;
maxalign = PAGE_SIZE;
mapsz = 0;
for (i = 0; i < hdr->e_phnum; i++) {
switch (phdr[i].p_type) {
case PT_LOAD:
if (n == 0)
baddr = phdr[i].p_vaddr;
if (phdr[i].p_align > maxalign)
maxalign = phdr[i].p_align;
mapsz += phdr[i].p_memsz;
n++;
/*
* If this segment contains the program headers,
* remember their virtual address for the AT_PHDR
* aux entry. Static binaries don't usually include
* a PT_PHDR entry.
*/
if (phdr[i].p_offset == 0 &&
hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
<= phdr[i].p_filesz)
proghdr = phdr[i].p_vaddr + hdr->e_phoff;
break;
case PT_INTERP:
/* Path to interpreter */
if (interp != NULL) {
uprintf("Multiple PT_INTERP headers\n");
error = ENOEXEC;
goto ret;
}
error = __elfN(get_interp)(imgp, &phdr[i], &interp,
&free_interp);
if (error != 0)
goto ret;
break;
case PT_GNU_STACK:
if (__elfN(nxstack))
imgp->stack_prot =
__elfN(trans_prot)(phdr[i].p_flags);
imgp->stack_sz = phdr[i].p_memsz;
break;
case PT_PHDR: /* Program header table info */
proghdr = phdr[i].p_vaddr;
break;
}
}
brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel, &fctl0);
if (brand_info == NULL) {
uprintf("ELF binary type \"%u\" not known.\n",
hdr->e_ident[EI_OSABI]);
error = ENOEXEC;
goto ret;
}
sv = brand_info->sysvec;
et_dyn_addr = 0;
if (hdr->e_type == ET_DYN) {
if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) {
uprintf("Cannot execute shared object\n");
error = ENOEXEC;
goto ret;
}
/*
* Honour the base load address from the dso if it is
* non-zero for some reason.
*/
if (baddr == 0) {
if ((sv->sv_flags & SV_ASLR) == 0 ||
(fctl0 & NT_FREEBSD_FCTL_ASLR_DISABLE) != 0)
et_dyn_addr = __elfN(pie_base);
else if ((__elfN(pie_aslr_enabled) &&
(imgp->proc->p_flag2 & P2_ASLR_DISABLE) == 0) ||
(imgp->proc->p_flag2 & P2_ASLR_ENABLE) != 0)
et_dyn_addr = ET_DYN_ADDR_RAND;
else
et_dyn_addr = __elfN(pie_base);
}
}
/*
* Avoid a possible deadlock if the current address space is destroyed
* and that address space maps the locked vnode. In the common case,
* the locked vnode's v_usecount is decremented but remains greater
* than zero. Consequently, the vnode lock is not needed by vrele().
* However, in cases where the vnode lock is external, such as nullfs,
* v_usecount may become zero.
*
* The VV_TEXT flag prevents modifications to the executable while
* the vnode is unlocked.
*/
VOP_UNLOCK(imgp->vp);
/*
* Decide whether to enable randomization of user mappings.
* First, reset user preferences for the setid binaries.
* Then, account for the support of the randomization by the
* ABI, by user preferences, and make special treatment for
* PIE binaries.
*/
if (imgp->credential_setid) {
PROC_LOCK(imgp->proc);
imgp->proc->p_flag2 &= ~(P2_ASLR_ENABLE | P2_ASLR_DISABLE);
PROC_UNLOCK(imgp->proc);
}
if ((sv->sv_flags & SV_ASLR) == 0 ||
(imgp->proc->p_flag2 & P2_ASLR_DISABLE) != 0 ||
(fctl0 & NT_FREEBSD_FCTL_ASLR_DISABLE) != 0) {
KASSERT(et_dyn_addr != ET_DYN_ADDR_RAND,
("et_dyn_addr == RAND and !ASLR"));
} else if ((imgp->proc->p_flag2 & P2_ASLR_ENABLE) != 0 ||
(__elfN(aslr_enabled) && hdr->e_type == ET_EXEC) ||
et_dyn_addr == ET_DYN_ADDR_RAND) {
imgp->map_flags |= MAP_ASLR;
/*
* If user does not care about sbrk, utilize the bss
* grow region for mappings as well. We can select
* the base for the image anywere and still not suffer
* from the fragmentation.
*/
if (!__elfN(aslr_honor_sbrk) ||
(imgp->proc->p_flag2 & P2_ASLR_IGNSTART) != 0)
imgp->map_flags |= MAP_ASLR_IGNSTART;
}
error = exec_new_vmspace(imgp, sv);
vmspace = imgp->proc->p_vmspace;
map = &vmspace->vm_map;
imgp->proc->p_sysent = sv;
maxv = vm_map_max(map) - lim_max(td, RLIMIT_STACK);
if (et_dyn_addr == ET_DYN_ADDR_RAND) {
KASSERT((map->flags & MAP_ASLR) != 0,
("ET_DYN_ADDR_RAND but !MAP_ASLR"));
et_dyn_addr = __CONCAT(rnd_, __elfN(base))(map,
vm_map_min(map) + mapsz + lim_max(td, RLIMIT_DATA),
/* reserve half of the address space to interpreter */
maxv / 2, 1UL << flsl(maxalign));
}
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
if (error != 0)
goto ret;
error = __elfN(load_sections)(imgp, hdr, phdr, et_dyn_addr, NULL);
if (error != 0)
goto ret;
error = __elfN(enforce_limits)(imgp, hdr, phdr, et_dyn_addr);
if (error != 0)
goto ret;
entry = (u_long)hdr->e_entry + et_dyn_addr;
/*
* We load the dynamic linker where a userland call
* to mmap(0, ...) would put it. The rationale behind this
* calculation is that it leaves room for the heap to grow to
* its maximum allowed size.
*/
addr = round_page((vm_offset_t)vmspace->vm_daddr + lim_max(td,
RLIMIT_DATA));
if ((map->flags & MAP_ASLR) != 0) {
maxv1 = maxv / 2 + addr / 2;
MPASS(maxv1 >= addr); /* No overflow */
map->anon_loc = __CONCAT(rnd_, __elfN(base))(map, addr, maxv1,
MAXPAGESIZES > 1 ? pagesizes[1] : pagesizes[0]);
} else {
map->anon_loc = addr;
}
imgp->entry_addr = entry;
if (interp != NULL) {
VOP_UNLOCK(imgp->vp);
if ((map->flags & MAP_ASLR) != 0) {
/* Assume that interpeter fits into 1/4 of AS */
maxv1 = maxv / 2 + addr / 2;
MPASS(maxv1 >= addr); /* No overflow */
addr = __CONCAT(rnd_, __elfN(base))(map, addr,
maxv1, PAGE_SIZE);
}
error = __elfN(load_interp)(imgp, brand_info, interp, &addr,
&imgp->entry_addr);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
if (error != 0)
goto ret;
} else
addr = et_dyn_addr;
/*
* Construct auxargs table (used by the copyout_auxargs routine)
*/
elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_NOWAIT);
if (elf_auxargs == NULL) {
VOP_UNLOCK(imgp->vp);
elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
}
elf_auxargs->execfd = -1;
elf_auxargs->phdr = proghdr + et_dyn_addr;
elf_auxargs->phent = hdr->e_phentsize;
elf_auxargs->phnum = hdr->e_phnum;
elf_auxargs->pagesz = PAGE_SIZE;
elf_auxargs->base = addr;
elf_auxargs->flags = 0;
elf_auxargs->entry = entry;
elf_auxargs->hdr_eflags = hdr->e_flags;
imgp->auxargs = elf_auxargs;
imgp->interpreted = 0;
imgp->reloc_base = addr;
imgp->proc->p_osrel = osrel;
imgp->proc->p_fctl0 = fctl0;
imgp->proc->p_elf_machine = hdr->e_machine;
imgp->proc->p_elf_flags = hdr->e_flags;
ret:
if (free_interp)
free(interp, M_TEMP);
return (error);
}
#define suword __CONCAT(suword, __ELF_WORD_SIZE)
int
__elfN(freebsd_copyout_auxargs)(struct image_params *imgp, uintptr_t base)
{
Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
Elf_Auxinfo *argarray, *pos;
int error;
argarray = pos = malloc(AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
if (args->execfd != -1)
AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
AUXARGS_ENTRY(pos, AT_BASE, args->base);
AUXARGS_ENTRY(pos, AT_EHDRFLAGS, args->hdr_eflags);
if (imgp->execpathp != 0)
AUXARGS_ENTRY_PTR(pos, AT_EXECPATH, imgp->execpathp);
AUXARGS_ENTRY(pos, AT_OSRELDATE,
imgp->proc->p_ucred->cr_prison->pr_osreldate);
if (imgp->canary != 0) {
AUXARGS_ENTRY_PTR(pos, AT_CANARY, imgp->canary);
AUXARGS_ENTRY(pos, AT_CANARYLEN, imgp->canarylen);
}
AUXARGS_ENTRY(pos, AT_NCPUS, mp_ncpus);
if (imgp->pagesizes != 0) {
AUXARGS_ENTRY_PTR(pos, AT_PAGESIZES, imgp->pagesizes);
AUXARGS_ENTRY(pos, AT_PAGESIZESLEN, imgp->pagesizeslen);
}
if (imgp->sysent->sv_timekeep_base != 0) {
AUXARGS_ENTRY(pos, AT_TIMEKEEP,
imgp->sysent->sv_timekeep_base);
}
AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj
!= NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
imgp->sysent->sv_stackprot);
if (imgp->sysent->sv_hwcap != NULL)
AUXARGS_ENTRY(pos, AT_HWCAP, *imgp->sysent->sv_hwcap);
if (imgp->sysent->sv_hwcap2 != NULL)
AUXARGS_ENTRY(pos, AT_HWCAP2, *imgp->sysent->sv_hwcap2);
AUXARGS_ENTRY(pos, AT_BSDFLAGS, __elfN(sigfastblock) ?
ELF_BSDF_SIGFASTBLK : 0);
AUXARGS_ENTRY(pos, AT_ARGC, imgp->args->argc);
AUXARGS_ENTRY_PTR(pos, AT_ARGV, imgp->argv);
AUXARGS_ENTRY(pos, AT_ENVC, imgp->args->envc);
AUXARGS_ENTRY_PTR(pos, AT_ENVV, imgp->envv);
AUXARGS_ENTRY_PTR(pos, AT_PS_STRINGS, imgp->ps_strings);
if (imgp->sysent->sv_fxrng_gen_base != 0)
AUXARGS_ENTRY(pos, AT_FXRNG, imgp->sysent->sv_fxrng_gen_base);
AUXARGS_ENTRY(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
KASSERT(pos - argarray <= AT_COUNT, ("Too many auxargs"));
error = copyout(argarray, (void *)base, sizeof(*argarray) * AT_COUNT);
free(argarray, M_TEMP);
return (error);
}
int
__elfN(freebsd_fixup)(uintptr_t *stack_base, struct image_params *imgp)
{
Elf_Addr *base;
base = (Elf_Addr *)*stack_base;
base--;
if (suword(base, imgp->args->argc) == -1)
return (EFAULT);
*stack_base = (uintptr_t)base;
return (0);
}
/*
* Code for generating ELF core dumps.
*/
typedef void (*segment_callback)(vm_map_entry_t, void *);
/* Closure for cb_put_phdr(). */
struct phdr_closure {
Elf_Phdr *phdr; /* Program header to fill in */
Elf_Off offset; /* Offset of segment in core file */
};
/* Closure for cb_size_segment(). */
struct sseg_closure {
int count; /* Count of writable segments. */
size_t size; /* Total size of all writable segments. */
};
typedef void (*outfunc_t)(void *, struct sbuf *, size_t *);
struct note_info {
int type; /* Note type. */
outfunc_t outfunc; /* Output function. */
void *outarg; /* Argument for the output function. */
size_t outsize; /* Output size. */
TAILQ_ENTRY(note_info) link; /* Link to the next note info. */
};
TAILQ_HEAD(note_info_list, note_info);
/* Coredump output parameters. */
struct coredump_params {
off_t offset;
struct ucred *active_cred;
struct ucred *file_cred;
struct thread *td;
struct vnode *vp;
struct compressor *comp;
};
extern int compress_user_cores;
extern int compress_user_cores_level;
static void cb_put_phdr(vm_map_entry_t, void *);
static void cb_size_segment(vm_map_entry_t, void *);
static int core_write(struct coredump_params *, const void *, size_t, off_t,
enum uio_seg, size_t *);
static void each_dumpable_segment(struct thread *, segment_callback, void *);
static int __elfN(corehdr)(struct coredump_params *, int, void *, size_t,
struct note_info_list *, size_t);
static void __elfN(prepare_notes)(struct thread *, struct note_info_list *,
size_t *);
static void __elfN(puthdr)(struct thread *, void *, size_t, int, size_t);
static void __elfN(putnote)(struct note_info *, struct sbuf *);
static size_t register_note(struct note_info_list *, int, outfunc_t, void *);
static int sbuf_drain_core_output(void *, const char *, int);
static void __elfN(note_fpregset)(void *, struct sbuf *, size_t *);
static void __elfN(note_prpsinfo)(void *, struct sbuf *, size_t *);
static void __elfN(note_prstatus)(void *, struct sbuf *, size_t *);
static void __elfN(note_threadmd)(void *, struct sbuf *, size_t *);
static void __elfN(note_thrmisc)(void *, struct sbuf *, size_t *);
static void __elfN(note_ptlwpinfo)(void *, struct sbuf *, size_t *);
static void __elfN(note_procstat_auxv)(void *, struct sbuf *, size_t *);
static void __elfN(note_procstat_proc)(void *, struct sbuf *, size_t *);
static void __elfN(note_procstat_psstrings)(void *, struct sbuf *, size_t *);
static void note_procstat_files(void *, struct sbuf *, size_t *);
static void note_procstat_groups(void *, struct sbuf *, size_t *);
static void note_procstat_osrel(void *, struct sbuf *, size_t *);
static void note_procstat_rlimit(void *, struct sbuf *, size_t *);
static void note_procstat_umask(void *, struct sbuf *, size_t *);
static void note_procstat_vmmap(void *, struct sbuf *, size_t *);
/*
* Write out a core segment to the compression stream.
*/
static int
compress_chunk(struct coredump_params *p, char *base, char *buf, u_int len)
{
u_int chunk_len;
int error;
while (len > 0) {
chunk_len = MIN(len, CORE_BUF_SIZE);
/*
* We can get EFAULT error here.
* In that case zero out the current chunk of the segment.
*/
error = copyin(base, buf, chunk_len);
if (error != 0)
bzero(buf, chunk_len);
error = compressor_write(p->comp, buf, chunk_len);
if (error != 0)
break;
base += chunk_len;
len -= chunk_len;
}
return (error);
}
static int
core_compressed_write(void *base, size_t len, off_t offset, void *arg)
{
return (core_write((struct coredump_params *)arg, base, len, offset,
UIO_SYSSPACE, NULL));
}
static int
core_write(struct coredump_params *p, const void *base, size_t len,
off_t offset, enum uio_seg seg, size_t *resid)
{
return (vn_rdwr_inchunks(UIO_WRITE, p->vp, __DECONST(void *, base),
len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED,
p->active_cred, p->file_cred, resid, p->td));
}
static int
core_output(char *base, size_t len, off_t offset, struct coredump_params *p,
void *tmpbuf)
{
vm_map_t map;
struct mount *mp;
size_t resid, runlen;
int error;
bool success;
KASSERT((uintptr_t)base % PAGE_SIZE == 0,
("%s: user address %p is not page-aligned", __func__, base));
if (p->comp != NULL)
return (compress_chunk(p, base, tmpbuf, len));
map = &p->td->td_proc->p_vmspace->vm_map;
for (; len > 0; base += runlen, offset += runlen, len -= runlen) {
/*
* Attempt to page in all virtual pages in the range. If a
* virtual page is not backed by the pager, it is represented as
* a hole in the file. This can occur with zero-filled
* anonymous memory or truncated files, for example.
*/
for (runlen = 0; runlen < len; runlen += PAGE_SIZE) {
error = vm_fault(map, (uintptr_t)base + runlen,
VM_PROT_READ, VM_FAULT_NOFILL, NULL);
if (runlen == 0)
success = error == KERN_SUCCESS;
else if ((error == KERN_SUCCESS) != success)
break;
}
if (success) {
error = core_write(p, base, runlen, offset,
UIO_USERSPACE, &resid);
if (error != 0) {
if (error != EFAULT)
break;
/*
* EFAULT may be returned if the user mapping
* could not be accessed, e.g., because a mapped
* file has been truncated. Skip the page if no
* progress was made, to protect against a
* hypothetical scenario where vm_fault() was
* successful but core_write() returns EFAULT
* anyway.
*/
runlen -= resid;
if (runlen == 0) {
success = false;
runlen = PAGE_SIZE;
}
}
}
if (!success) {
error = vn_start_write(p->vp, &mp, V_WAIT);
if (error != 0)
break;
vn_lock(p->vp, LK_EXCLUSIVE | LK_RETRY);
error = vn_truncate_locked(p->vp, offset + runlen,
false, p->td->td_ucred);
VOP_UNLOCK(p->vp);
vn_finished_write(mp);
if (error != 0)
break;
}
}
return (error);
}
/*
* Drain into a core file.
*/
static int
sbuf_drain_core_output(void *arg, const char *data, int len)
{
struct coredump_params *p;
int error, locked;
p = (struct coredump_params *)arg;
/*
* Some kern_proc out routines that print to this sbuf may
* call us with the process lock held. Draining with the
* non-sleepable lock held is unsafe. The lock is needed for
* those routines when dumping a live process. In our case we
* can safely release the lock before draining and acquire
* again after.
*/
locked = PROC_LOCKED(p->td->td_proc);
if (locked)
PROC_UNLOCK(p->td->td_proc);
if (p->comp != NULL)
error = compressor_write(p->comp, __DECONST(char *, data), len);
else
error = core_write(p, __DECONST(void *, data), len, p->offset,
UIO_SYSSPACE, NULL);
if (locked)
PROC_LOCK(p->td->td_proc);
if (error != 0)
return (-error);
p->offset += len;
return (len);
}
int
__elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags)
{
struct ucred *cred = td->td_ucred;
int error = 0;
struct sseg_closure seginfo;
struct note_info_list notelst;
struct coredump_params params;
struct note_info *ninfo;
void *hdr, *tmpbuf;
size_t hdrsize, notesz, coresize;
hdr = NULL;
tmpbuf = NULL;
TAILQ_INIT(&notelst);
/* Size the program segments. */
seginfo.count = 0;
seginfo.size = 0;
each_dumpable_segment(td, cb_size_segment, &seginfo);
/*
* Collect info about the core file header area.
*/
hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
if (seginfo.count + 1 >= PN_XNUM)
hdrsize += sizeof(Elf_Shdr);
__elfN(prepare_notes)(td, &notelst, &notesz);
coresize = round_page(hdrsize + notesz) + seginfo.size;
/* Set up core dump parameters. */
params.offset = 0;
params.active_cred = cred;
params.file_cred = NOCRED;
params.td = td;
params.vp = vp;
params.comp = NULL;
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(td->td_proc);
error = racct_add(td->td_proc, RACCT_CORE, coresize);
PROC_UNLOCK(td->td_proc);
if (error != 0) {
error = EFAULT;
goto done;
}
}
#endif
if (coresize >= limit) {
error = EFAULT;
goto done;
}
/* Create a compression stream if necessary. */
if (compress_user_cores != 0) {
params.comp = compressor_init(core_compressed_write,
compress_user_cores, CORE_BUF_SIZE,
compress_user_cores_level, &params);
if (params.comp == NULL) {
error = EFAULT;
goto done;
}
tmpbuf = malloc(CORE_BUF_SIZE, M_TEMP, M_WAITOK | M_ZERO);
}
/*
* Allocate memory for building the header, fill it up,
* and write it out following the notes.
*/
hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
error = __elfN(corehdr)(&params, seginfo.count, hdr, hdrsize, &notelst,
notesz);
/* Write the contents of all of the writable segments. */
if (error == 0) {
Elf_Phdr *php;
off_t offset;
int i;
php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
offset = round_page(hdrsize + notesz);
for (i = 0; i < seginfo.count; i++) {
error = core_output((char *)(uintptr_t)php->p_vaddr,
php->p_filesz, offset, &params, tmpbuf);
if (error != 0)
break;
offset += php->p_filesz;
php++;
}
if (error == 0 && params.comp != NULL)
error = compressor_flush(params.comp);
}
if (error) {
log(LOG_WARNING,
"Failed to write core file for process %s (error %d)\n",
curproc->p_comm, error);
}
done:
free(tmpbuf, M_TEMP);
if (params.comp != NULL)
compressor_fini(params.comp);
while ((ninfo = TAILQ_FIRST(&notelst)) != NULL) {
TAILQ_REMOVE(&notelst, ninfo, link);
free(ninfo, M_TEMP);
}
if (hdr != NULL)
free(hdr, M_TEMP);
return (error);
}
/*
* A callback for each_dumpable_segment() to write out the segment's
* program header entry.
*/
static void
cb_put_phdr(vm_map_entry_t entry, void *closure)
{
struct phdr_closure *phc = (struct phdr_closure *)closure;
Elf_Phdr *phdr = phc->phdr;
phc->offset = round_page(phc->offset);
phdr->p_type = PT_LOAD;
phdr->p_offset = phc->offset;
phdr->p_vaddr = entry->start;
phdr->p_paddr = 0;
phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
phdr->p_align = PAGE_SIZE;
phdr->p_flags = __elfN(untrans_prot)(entry->protection);
phc->offset += phdr->p_filesz;
phc->phdr++;
}
/*
* A callback for each_dumpable_segment() to gather information about
* the number of segments and their total size.
*/
static void
cb_size_segment(vm_map_entry_t entry, void *closure)
{
struct sseg_closure *ssc = (struct sseg_closure *)closure;
ssc->count++;
ssc->size += entry->end - entry->start;
}
/*
* For each writable segment in the process's memory map, call the given
* function with a pointer to the map entry and some arbitrary
* caller-supplied data.
*/
static void
each_dumpable_segment(struct thread *td, segment_callback func, void *closure)
{
struct proc *p = td->td_proc;
vm_map_t map = &p->p_vmspace->vm_map;
vm_map_entry_t entry;
vm_object_t backing_object, object;
bool ignore_entry;
vm_map_lock_read(map);
VM_MAP_ENTRY_FOREACH(entry, map) {
/*
* Don't dump inaccessible mappings, deal with legacy
* coredump mode.
*
* Note that read-only segments related to the elf binary
* are marked MAP_ENTRY_NOCOREDUMP now so we no longer
* need to arbitrarily ignore such segments.
*/
if (elf_legacy_coredump) {
if ((entry->protection & VM_PROT_RW) != VM_PROT_RW)
continue;
} else {
if ((entry->protection & VM_PROT_ALL) == 0)
continue;
}
/*
* Dont include memory segment in the coredump if
* MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
* madvise(2). Do not dump submaps (i.e. parts of the
* kernel map).
*/
if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP))
continue;
if ((object = entry->object.vm_object) == NULL)
continue;
/* Ignore memory-mapped devices and such things. */
VM_OBJECT_RLOCK(object);
while ((backing_object = object->backing_object) != NULL) {
VM_OBJECT_RLOCK(backing_object);
VM_OBJECT_RUNLOCK(object);
object = backing_object;
}
ignore_entry = (object->flags & OBJ_FICTITIOUS) != 0;
VM_OBJECT_RUNLOCK(object);
if (ignore_entry)
continue;
(*func)(entry, closure);
}
vm_map_unlock_read(map);
}
/*
* Write the core file header to the file, including padding up to
* the page boundary.
*/
static int
__elfN(corehdr)(struct coredump_params *p, int numsegs, void *hdr,
size_t hdrsize, struct note_info_list *notelst, size_t notesz)
{
struct note_info *ninfo;
struct sbuf *sb;
int error;
/* Fill in the header. */
bzero(hdr, hdrsize);
__elfN(puthdr)(p->td, hdr, hdrsize, numsegs, notesz);
sb = sbuf_new(NULL, NULL, CORE_BUF_SIZE, SBUF_FIXEDLEN);
sbuf_set_drain(sb, sbuf_drain_core_output, p);
sbuf_start_section(sb, NULL);
sbuf_bcat(sb, hdr, hdrsize);
TAILQ_FOREACH(ninfo, notelst, link)
__elfN(putnote)(ninfo, sb);
/* Align up to a page boundary for the program segments. */
sbuf_end_section(sb, -1, PAGE_SIZE, 0);
error = sbuf_finish(sb);
sbuf_delete(sb);
return (error);
}
static void
__elfN(prepare_notes)(struct thread *td, struct note_info_list *list,
size_t *sizep)
{
struct proc *p;
struct thread *thr;
size_t size;
p = td->td_proc;
size = 0;
size += register_note(list, NT_PRPSINFO, __elfN(note_prpsinfo), p);
/*
* To have the debugger select the right thread (LWP) as the initial
* thread, we dump the state of the thread passed to us in td first.
* This is the thread that causes the core dump and thus likely to
* be the right thread one wants to have selected in the debugger.
*/
thr = td;
while (thr != NULL) {
size += register_note(list, NT_PRSTATUS,
__elfN(note_prstatus), thr);
size += register_note(list, NT_FPREGSET,
__elfN(note_fpregset), thr);
size += register_note(list, NT_THRMISC,
__elfN(note_thrmisc), thr);
size += register_note(list, NT_PTLWPINFO,
__elfN(note_ptlwpinfo), thr);
size += register_note(list, -1,
__elfN(note_threadmd), thr);
thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) :
TAILQ_NEXT(thr, td_plist);
if (thr == td)
thr = TAILQ_NEXT(thr, td_plist);
}
size += register_note(list, NT_PROCSTAT_PROC,
__elfN(note_procstat_proc), p);
size += register_note(list, NT_PROCSTAT_FILES,
note_procstat_files, p);
size += register_note(list, NT_PROCSTAT_VMMAP,
note_procstat_vmmap, p);
size += register_note(list, NT_PROCSTAT_GROUPS,
note_procstat_groups, p);
size += register_note(list, NT_PROCSTAT_UMASK,
note_procstat_umask, p);
size += register_note(list, NT_PROCSTAT_RLIMIT,
note_procstat_rlimit, p);
size += register_note(list, NT_PROCSTAT_OSREL,
note_procstat_osrel, p);
size += register_note(list, NT_PROCSTAT_PSSTRINGS,
__elfN(note_procstat_psstrings), p);
size += register_note(list, NT_PROCSTAT_AUXV,
__elfN(note_procstat_auxv), p);
*sizep = size;
}
static void
__elfN(puthdr)(struct thread *td, void *hdr, size_t hdrsize, int numsegs,
size_t notesz)
{
Elf_Ehdr *ehdr;
Elf_Phdr *phdr;
Elf_Shdr *shdr;
struct phdr_closure phc;
ehdr = (Elf_Ehdr *)hdr;
ehdr->e_ident[EI_MAG0] = ELFMAG0;
ehdr->e_ident[EI_MAG1] = ELFMAG1;
ehdr->e_ident[EI_MAG2] = ELFMAG2;
ehdr->e_ident[EI_MAG3] = ELFMAG3;
ehdr->e_ident[EI_CLASS] = ELF_CLASS;
ehdr->e_ident[EI_DATA] = ELF_DATA;
ehdr->e_ident[EI_VERSION] = EV_CURRENT;
ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
ehdr->e_ident[EI_ABIVERSION] = 0;
ehdr->e_ident[EI_PAD] = 0;
ehdr->e_type = ET_CORE;
ehdr->e_machine = td->td_proc->p_elf_machine;
ehdr->e_version = EV_CURRENT;
ehdr->e_entry = 0;
ehdr->e_phoff = sizeof(Elf_Ehdr);
ehdr->e_flags = td->td_proc->p_elf_flags;
ehdr->e_ehsize = sizeof(Elf_Ehdr);
ehdr->e_phentsize = sizeof(Elf_Phdr);
ehdr->e_shentsize = sizeof(Elf_Shdr);
ehdr->e_shstrndx = SHN_UNDEF;
if (numsegs + 1 < PN_XNUM) {
ehdr->e_phnum = numsegs + 1;
ehdr->e_shnum = 0;
} else {
ehdr->e_phnum = PN_XNUM;
ehdr->e_shnum = 1;
ehdr->e_shoff = ehdr->e_phoff +
(numsegs + 1) * ehdr->e_phentsize;
KASSERT(ehdr->e_shoff == hdrsize - sizeof(Elf_Shdr),
("e_shoff: %zu, hdrsize - shdr: %zu",
(size_t)ehdr->e_shoff, hdrsize - sizeof(Elf_Shdr)));
shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff);
memset(shdr, 0, sizeof(*shdr));
/*
* A special first section is used to hold large segment and
* section counts. This was proposed by Sun Microsystems in
* Solaris and has been adopted by Linux; the standard ELF
* tools are already familiar with the technique.
*
* See table 7-7 of the Solaris "Linker and Libraries Guide"
* (or 12-7 depending on the version of the document) for more
* details.
*/
shdr->sh_type = SHT_NULL;
shdr->sh_size = ehdr->e_shnum;
shdr->sh_link = ehdr->e_shstrndx;
shdr->sh_info = numsegs + 1;
}
/*
* Fill in the program header entries.
*/
phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff);
/* The note segement. */
phdr->p_type = PT_NOTE;
phdr->p_offset = hdrsize;
phdr->p_vaddr = 0;
phdr->p_paddr = 0;
phdr->p_filesz = notesz;
phdr->p_memsz = 0;
phdr->p_flags = PF_R;
phdr->p_align = ELF_NOTE_ROUNDSIZE;
phdr++;
/* All the writable segments from the program. */
phc.phdr = phdr;
phc.offset = round_page(hdrsize + notesz);
each_dumpable_segment(td, cb_put_phdr, &phc);
}
static size_t
register_note(struct note_info_list *list, int type, outfunc_t out, void *arg)
{
struct note_info *ninfo;
size_t size, notesize;
size = 0;
out(arg, NULL, &size);
ninfo = malloc(sizeof(*ninfo), M_TEMP, M_ZERO | M_WAITOK);
ninfo->type = type;
ninfo->outfunc = out;
ninfo->outarg = arg;
ninfo->outsize = size;
TAILQ_INSERT_TAIL(list, ninfo, link);
if (type == -1)
return (size);
notesize = sizeof(Elf_Note) + /* note header */
roundup2(sizeof(FREEBSD_ABI_VENDOR), ELF_NOTE_ROUNDSIZE) +
/* note name */
roundup2(size, ELF_NOTE_ROUNDSIZE); /* note description */
return (notesize);
}
static size_t
append_note_data(const void *src, void *dst, size_t len)
{
size_t padded_len;
padded_len = roundup2(len, ELF_NOTE_ROUNDSIZE);
if (dst != NULL) {
bcopy(src, dst, len);
bzero((char *)dst + len, padded_len - len);
}
return (padded_len);
}
size_t
__elfN(populate_note)(int type, void *src, void *dst, size_t size, void **descp)
{
Elf_Note *note;
char *buf;
size_t notesize;
buf = dst;
if (buf != NULL) {
note = (Elf_Note *)buf;
note->n_namesz = sizeof(FREEBSD_ABI_VENDOR);
note->n_descsz = size;
note->n_type = type;
buf += sizeof(*note);
buf += append_note_data(FREEBSD_ABI_VENDOR, buf,
sizeof(FREEBSD_ABI_VENDOR));
append_note_data(src, buf, size);
if (descp != NULL)
*descp = buf;
}
notesize = sizeof(Elf_Note) + /* note header */
roundup2(sizeof(FREEBSD_ABI_VENDOR), ELF_NOTE_ROUNDSIZE) +
/* note name */
roundup2(size, ELF_NOTE_ROUNDSIZE); /* note description */
return (notesize);
}
static void
__elfN(putnote)(struct note_info *ninfo, struct sbuf *sb)
{
Elf_Note note;
ssize_t old_len, sect_len;
size_t new_len, descsz, i;
if (ninfo->type == -1) {
ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize);
return;
}
note.n_namesz = sizeof(FREEBSD_ABI_VENDOR);
note.n_descsz = ninfo->outsize;
note.n_type = ninfo->type;
sbuf_bcat(sb, &note, sizeof(note));
sbuf_start_section(sb, &old_len);
sbuf_bcat(sb, FREEBSD_ABI_VENDOR, sizeof(FREEBSD_ABI_VENDOR));
sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0);
if (note.n_descsz == 0)
return;
sbuf_start_section(sb, &old_len);
ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize);
sect_len = sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0);
if (sect_len < 0)
return;
new_len = (size_t)sect_len;
descsz = roundup(note.n_descsz, ELF_NOTE_ROUNDSIZE);
if (new_len < descsz) {
/*
* It is expected that individual note emitters will correctly
* predict their expected output size and fill up to that size
* themselves, padding in a format-specific way if needed.
* However, in case they don't, just do it here with zeros.
*/
for (i = 0; i < descsz - new_len; i++)
sbuf_putc(sb, 0);
} else if (new_len > descsz) {
/*
* We can't always truncate sb -- we may have drained some
* of it already.
*/
KASSERT(new_len == descsz, ("%s: Note type %u changed as we "
"read it (%zu > %zu). Since it is longer than "
"expected, this coredump's notes are corrupt. THIS "
"IS A BUG in the note_procstat routine for type %u.\n",
__func__, (unsigned)note.n_type, new_len, descsz,
(unsigned)note.n_type));
}
}
/*
* Miscellaneous note out functions.
*/
#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
#include <compat/freebsd32/freebsd32.h>
#include <compat/freebsd32/freebsd32_signal.h>
typedef struct prstatus32 elf_prstatus_t;
typedef struct prpsinfo32 elf_prpsinfo_t;
typedef struct fpreg32 elf_prfpregset_t;
typedef struct fpreg32 elf_fpregset_t;
typedef struct reg32 elf_gregset_t;
typedef struct thrmisc32 elf_thrmisc_t;
#define ELF_KERN_PROC_MASK KERN_PROC_MASK32
typedef struct kinfo_proc32 elf_kinfo_proc_t;
typedef uint32_t elf_ps_strings_t;
#else
typedef prstatus_t elf_prstatus_t;
typedef prpsinfo_t elf_prpsinfo_t;
typedef prfpregset_t elf_prfpregset_t;
typedef prfpregset_t elf_fpregset_t;
typedef gregset_t elf_gregset_t;
typedef thrmisc_t elf_thrmisc_t;
#define ELF_KERN_PROC_MASK 0
typedef struct kinfo_proc elf_kinfo_proc_t;
typedef vm_offset_t elf_ps_strings_t;
#endif
static void
__elfN(note_prpsinfo)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct sbuf sbarg;
size_t len;
char *cp, *end;
struct proc *p;
elf_prpsinfo_t *psinfo;
int error;
p = (struct proc *)arg;
if (sb != NULL) {
KASSERT(*sizep == sizeof(*psinfo), ("invalid size"));
psinfo = malloc(sizeof(*psinfo), M_TEMP, M_ZERO | M_WAITOK);
psinfo->pr_version = PRPSINFO_VERSION;
psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t);
strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
PROC_LOCK(p);
if (p->p_args != NULL) {
len = sizeof(psinfo->pr_psargs) - 1;
if (len > p->p_args->ar_length)
len = p->p_args->ar_length;
memcpy(psinfo->pr_psargs, p->p_args->ar_args, len);
PROC_UNLOCK(p);
error = 0;
} else {
_PHOLD(p);
PROC_UNLOCK(p);
sbuf_new(&sbarg, psinfo->pr_psargs,
sizeof(psinfo->pr_psargs), SBUF_FIXEDLEN);
error = proc_getargv(curthread, p, &sbarg);
PRELE(p);
if (sbuf_finish(&sbarg) == 0)
len = sbuf_len(&sbarg) - 1;
else
len = sizeof(psinfo->pr_psargs) - 1;
sbuf_delete(&sbarg);
}
if (error || len == 0)
strlcpy(psinfo->pr_psargs, p->p_comm,
sizeof(psinfo->pr_psargs));
else {
KASSERT(len < sizeof(psinfo->pr_psargs),
("len is too long: %zu vs %zu", len,
sizeof(psinfo->pr_psargs)));
cp = psinfo->pr_psargs;
end = cp + len - 1;
for (;;) {
cp = memchr(cp, '\0', end - cp);
if (cp == NULL)
break;
*cp = ' ';
}
}
psinfo->pr_pid = p->p_pid;
sbuf_bcat(sb, psinfo, sizeof(*psinfo));
free(psinfo, M_TEMP);
}
*sizep = sizeof(*psinfo);
}
static void
__elfN(note_prstatus)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct thread *td;
elf_prstatus_t *status;
td = (struct thread *)arg;
if (sb != NULL) {
KASSERT(*sizep == sizeof(*status), ("invalid size"));
status = malloc(sizeof(*status), M_TEMP, M_ZERO | M_WAITOK);
status->pr_version = PRSTATUS_VERSION;
status->pr_statussz = sizeof(elf_prstatus_t);
status->pr_gregsetsz = sizeof(elf_gregset_t);
status->pr_fpregsetsz = sizeof(elf_fpregset_t);
status->pr_osreldate = osreldate;
status->pr_cursig = td->td_proc->p_sig;
status->pr_pid = td->td_tid;
#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
fill_regs32(td, &status->pr_reg);
#else
fill_regs(td, &status->pr_reg);
#endif
sbuf_bcat(sb, status, sizeof(*status));
free(status, M_TEMP);
}
*sizep = sizeof(*status);
}
static void
__elfN(note_fpregset)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct thread *td;
elf_prfpregset_t *fpregset;
td = (struct thread *)arg;
if (sb != NULL) {
KASSERT(*sizep == sizeof(*fpregset), ("invalid size"));
fpregset = malloc(sizeof(*fpregset), M_TEMP, M_ZERO | M_WAITOK);
#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
fill_fpregs32(td, fpregset);
#else
fill_fpregs(td, fpregset);
#endif
sbuf_bcat(sb, fpregset, sizeof(*fpregset));
free(fpregset, M_TEMP);
}
*sizep = sizeof(*fpregset);
}
static void
__elfN(note_thrmisc)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct thread *td;
elf_thrmisc_t thrmisc;
td = (struct thread *)arg;
if (sb != NULL) {
KASSERT(*sizep == sizeof(thrmisc), ("invalid size"));
bzero(&thrmisc, sizeof(thrmisc));
strcpy(thrmisc.pr_tname, td->td_name);
sbuf_bcat(sb, &thrmisc, sizeof(thrmisc));
}
*sizep = sizeof(thrmisc);
}
static void
__elfN(note_ptlwpinfo)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct thread *td;
size_t size;
int structsize;
#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
struct ptrace_lwpinfo32 pl;
#else
struct ptrace_lwpinfo pl;
#endif
td = (struct thread *)arg;
size = sizeof(structsize) + sizeof(pl);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(pl);
sbuf_bcat(sb, &structsize, sizeof(structsize));
bzero(&pl, sizeof(pl));
pl.pl_lwpid = td->td_tid;
pl.pl_event = PL_EVENT_NONE;
pl.pl_sigmask = td->td_sigmask;
pl.pl_siglist = td->td_siglist;
if (td->td_si.si_signo != 0) {
pl.pl_event = PL_EVENT_SIGNAL;
pl.pl_flags |= PL_FLAG_SI;
#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
siginfo_to_siginfo32(&td->td_si, &pl.pl_siginfo);
#else
pl.pl_siginfo = td->td_si;
#endif
}
strcpy(pl.pl_tdname, td->td_name);
/* XXX TODO: supply more information in struct ptrace_lwpinfo*/
sbuf_bcat(sb, &pl, sizeof(pl));
}
*sizep = size;
}
/*
* Allow for MD specific notes, as well as any MD
* specific preparations for writing MI notes.
*/
static void
__elfN(note_threadmd)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct thread *td;
void *buf;
size_t size;
td = (struct thread *)arg;
size = *sizep;
if (size != 0 && sb != NULL)
buf = malloc(size, M_TEMP, M_ZERO | M_WAITOK);
else
buf = NULL;
size = 0;
__elfN(dump_thread)(td, buf, &size);
KASSERT(sb == NULL || *sizep == size, ("invalid size"));
if (size != 0 && sb != NULL)
sbuf_bcat(sb, buf, size);
free(buf, M_TEMP);
*sizep = size;
}
#ifdef KINFO_PROC_SIZE
CTASSERT(sizeof(struct kinfo_proc) == KINFO_PROC_SIZE);
#endif
static void
__elfN(note_procstat_proc)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size;
int structsize;
p = (struct proc *)arg;
size = sizeof(structsize) + p->p_numthreads *
sizeof(elf_kinfo_proc_t);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(elf_kinfo_proc_t);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PROC_LOCK(p);
kern_proc_out(p, sb, ELF_KERN_PROC_MASK);
}
*sizep = size;
}
#ifdef KINFO_FILE_SIZE
CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
#endif
static void
note_procstat_files(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size, sect_sz, i;
ssize_t start_len, sect_len;
int structsize, filedesc_flags;
if (coredump_pack_fileinfo)
filedesc_flags = KERN_FILEDESC_PACK_KINFO;
else
filedesc_flags = 0;
p = (struct proc *)arg;
structsize = sizeof(struct kinfo_file);
if (sb == NULL) {
size = 0;
sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
sbuf_set_drain(sb, sbuf_count_drain, &size);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PROC_LOCK(p);
kern_proc_filedesc_out(p, sb, -1, filedesc_flags);
sbuf_finish(sb);
sbuf_delete(sb);
*sizep = size;
} else {
sbuf_start_section(sb, &start_len);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PROC_LOCK(p);
kern_proc_filedesc_out(p, sb, *sizep - sizeof(structsize),
filedesc_flags);
sect_len = sbuf_end_section(sb, start_len, 0, 0);
if (sect_len < 0)
return;
sect_sz = sect_len;
KASSERT(sect_sz <= *sizep,
("kern_proc_filedesc_out did not respect maxlen; "
"requested %zu, got %zu", *sizep - sizeof(structsize),
sect_sz - sizeof(structsize)));
for (i = 0; i < *sizep - sect_sz && sb->s_error == 0; i++)
sbuf_putc(sb, 0);
}
}
#ifdef KINFO_VMENTRY_SIZE
CTASSERT(sizeof(struct kinfo_vmentry) == KINFO_VMENTRY_SIZE);
#endif
static void
note_procstat_vmmap(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size;
int structsize, vmmap_flags;
if (coredump_pack_vmmapinfo)
vmmap_flags = KERN_VMMAP_PACK_KINFO;
else
vmmap_flags = 0;
p = (struct proc *)arg;
structsize = sizeof(struct kinfo_vmentry);
if (sb == NULL) {
size = 0;
sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
sbuf_set_drain(sb, sbuf_count_drain, &size);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PROC_LOCK(p);
kern_proc_vmmap_out(p, sb, -1, vmmap_flags);
sbuf_finish(sb);
sbuf_delete(sb);
*sizep = size;
} else {
sbuf_bcat(sb, &structsize, sizeof(structsize));
PROC_LOCK(p);
kern_proc_vmmap_out(p, sb, *sizep - sizeof(structsize),
vmmap_flags);
}
}
static void
note_procstat_groups(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size;
int structsize;
p = (struct proc *)arg;
size = sizeof(structsize) + p->p_ucred->cr_ngroups * sizeof(gid_t);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(gid_t);
sbuf_bcat(sb, &structsize, sizeof(structsize));
sbuf_bcat(sb, p->p_ucred->cr_groups, p->p_ucred->cr_ngroups *
sizeof(gid_t));
}
*sizep = size;
}
static void
note_procstat_umask(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size;
int structsize;
p = (struct proc *)arg;
size = sizeof(structsize) + sizeof(p->p_pd->pd_cmask);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(p->p_pd->pd_cmask);
sbuf_bcat(sb, &structsize, sizeof(structsize));
sbuf_bcat(sb, &p->p_pd->pd_cmask, sizeof(p->p_pd->pd_cmask));
}
*sizep = size;
}
static void
note_procstat_rlimit(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
struct rlimit rlim[RLIM_NLIMITS];
size_t size;
int structsize, i;
p = (struct proc *)arg;
size = sizeof(structsize) + sizeof(rlim);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(rlim);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PROC_LOCK(p);
for (i = 0; i < RLIM_NLIMITS; i++)
lim_rlimit_proc(p, i, &rlim[i]);
PROC_UNLOCK(p);
sbuf_bcat(sb, rlim, sizeof(rlim));
}
*sizep = size;
}
static void
note_procstat_osrel(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size;
int structsize;
p = (struct proc *)arg;
size = sizeof(structsize) + sizeof(p->p_osrel);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(p->p_osrel);
sbuf_bcat(sb, &structsize, sizeof(structsize));
sbuf_bcat(sb, &p->p_osrel, sizeof(p->p_osrel));
}
*sizep = size;
}
static void
__elfN(note_procstat_psstrings)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
elf_ps_strings_t ps_strings;
size_t size;
int structsize;
p = (struct proc *)arg;
size = sizeof(structsize) + sizeof(ps_strings);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(ps_strings);
#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
ps_strings = PTROUT(p->p_sysent->sv_psstrings);
#else
ps_strings = p->p_sysent->sv_psstrings;
#endif
sbuf_bcat(sb, &structsize, sizeof(structsize));
sbuf_bcat(sb, &ps_strings, sizeof(ps_strings));
}
*sizep = size;
}
static void
__elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep)
{
struct proc *p;
size_t size;
int structsize;
p = (struct proc *)arg;
if (sb == NULL) {
size = 0;
sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
sbuf_set_drain(sb, sbuf_count_drain, &size);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PHOLD(p);
proc_getauxv(curthread, p, sb);
PRELE(p);
sbuf_finish(sb);
sbuf_delete(sb);
*sizep = size;
} else {
structsize = sizeof(Elf_Auxinfo);
sbuf_bcat(sb, &structsize, sizeof(structsize));
PHOLD(p);
proc_getauxv(curthread, p, sb);
PRELE(p);
}
}
static boolean_t
__elfN(parse_notes)(struct image_params *imgp, Elf_Note *checknote,
const char *note_vendor, const Elf_Phdr *pnote,
boolean_t (*cb)(const Elf_Note *, void *, boolean_t *), void *cb_arg)
{
const Elf_Note *note, *note0, *note_end;
const char *note_name;
char *buf;
int i, error;
boolean_t res;
/* We need some limit, might as well use PAGE_SIZE. */
if (pnote == NULL || pnote->p_filesz > PAGE_SIZE)
return (FALSE);
ASSERT_VOP_LOCKED(imgp->vp, "parse_notes");
if (pnote->p_offset > PAGE_SIZE ||
pnote->p_filesz > PAGE_SIZE - pnote->p_offset) {
buf = malloc(pnote->p_filesz, M_TEMP, M_NOWAIT);
if (buf == NULL) {
VOP_UNLOCK(imgp->vp);
buf = malloc(pnote->p_filesz, M_TEMP, M_WAITOK);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
}
error = vn_rdwr(UIO_READ, imgp->vp, buf, pnote->p_filesz,
pnote->p_offset, UIO_SYSSPACE, IO_NODELOCKED,
curthread->td_ucred, NOCRED, NULL, curthread);
if (error != 0) {
uprintf("i/o error PT_NOTE\n");
goto retf;
}
note = note0 = (const Elf_Note *)buf;
note_end = (const Elf_Note *)(buf + pnote->p_filesz);
} else {
note = note0 = (const Elf_Note *)(imgp->image_header +
pnote->p_offset);
note_end = (const Elf_Note *)(imgp->image_header +
pnote->p_offset + pnote->p_filesz);
buf = NULL;
}
for (i = 0; i < 100 && note >= note0 && note < note_end; i++) {
if (!aligned(note, Elf32_Addr) || (const char *)note_end -
(const char *)note < sizeof(Elf_Note)) {
goto retf;
}
if (note->n_namesz != checknote->n_namesz ||
note->n_descsz != checknote->n_descsz ||
note->n_type != checknote->n_type)
goto nextnote;
note_name = (const char *)(note + 1);
if (note_name + checknote->n_namesz >=
(const char *)note_end || strncmp(note_vendor,
note_name, checknote->n_namesz) != 0)
goto nextnote;
if (cb(note, cb_arg, &res))
goto ret;
nextnote:
note = (const Elf_Note *)((const char *)(note + 1) +
roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) +
roundup2(note->n_descsz, ELF_NOTE_ROUNDSIZE));
}
retf:
res = FALSE;
ret:
free(buf, M_TEMP);
return (res);
}
struct brandnote_cb_arg {
Elf_Brandnote *brandnote;
int32_t *osrel;
};
static boolean_t
brandnote_cb(const Elf_Note *note, void *arg0, boolean_t *res)
{
struct brandnote_cb_arg *arg;
arg = arg0;
/*
* Fetch the osreldate for binary from the ELF OSABI-note if
* necessary.
*/
*res = (arg->brandnote->flags & BN_TRANSLATE_OSREL) != 0 &&
arg->brandnote->trans_osrel != NULL ?
arg->brandnote->trans_osrel(note, arg->osrel) : TRUE;
return (TRUE);
}
static Elf_Note fctl_note = {
.n_namesz = sizeof(FREEBSD_ABI_VENDOR),
.n_descsz = sizeof(uint32_t),
.n_type = NT_FREEBSD_FEATURE_CTL,
};
struct fctl_cb_arg {
boolean_t *has_fctl0;
uint32_t *fctl0;
};
static boolean_t
note_fctl_cb(const Elf_Note *note, void *arg0, boolean_t *res)
{
struct fctl_cb_arg *arg;
const Elf32_Word *desc;
uintptr_t p;
arg = arg0;
p = (uintptr_t)(note + 1);
p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
desc = (const Elf32_Word *)p;
*arg->has_fctl0 = TRUE;
*arg->fctl0 = desc[0];
return (TRUE);
}
/*
* Try to find the appropriate ABI-note section for checknote, fetch
* the osreldate and feature control flags for binary from the ELF
* OSABI-note. Only the first page of the image is searched, the same
* as for headers.
*/
static boolean_t
__elfN(check_note)(struct image_params *imgp, Elf_Brandnote *brandnote,
int32_t *osrel, boolean_t *has_fctl0, uint32_t *fctl0)
{
const Elf_Phdr *phdr;
const Elf_Ehdr *hdr;
struct brandnote_cb_arg b_arg;
struct fctl_cb_arg f_arg;
int i, j;
hdr = (const Elf_Ehdr *)imgp->image_header;
phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
b_arg.brandnote = brandnote;
b_arg.osrel = osrel;
f_arg.has_fctl0 = has_fctl0;
f_arg.fctl0 = fctl0;
for (i = 0; i < hdr->e_phnum; i++) {
if (phdr[i].p_type == PT_NOTE && __elfN(parse_notes)(imgp,
&brandnote->hdr, brandnote->vendor, &phdr[i], brandnote_cb,
&b_arg)) {
for (j = 0; j < hdr->e_phnum; j++) {
if (phdr[j].p_type == PT_NOTE &&
__elfN(parse_notes)(imgp, &fctl_note,
FREEBSD_ABI_VENDOR, &phdr[j],
note_fctl_cb, &f_arg))
break;
}
return (TRUE);
}
}
return (FALSE);
}
/*
* Tell kern_execve.c about it, with a little help from the linker.
*/
static struct execsw __elfN(execsw) = {
.ex_imgact = __CONCAT(exec_, __elfN(imgact)),
.ex_name = __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
};
EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));
static vm_prot_t
__elfN(trans_prot)(Elf_Word flags)
{
vm_prot_t prot;
prot = 0;
if (flags & PF_X)
prot |= VM_PROT_EXECUTE;
if (flags & PF_W)
prot |= VM_PROT_WRITE;
if (flags & PF_R)
prot |= VM_PROT_READ;
#if __ELF_WORD_SIZE == 32 && (defined(__amd64__) || defined(__i386__))
if (i386_read_exec && (flags & PF_R))
prot |= VM_PROT_EXECUTE;
#endif
return (prot);
}
static Elf_Word
__elfN(untrans_prot)(vm_prot_t prot)
{
Elf_Word flags;
flags = 0;
if (prot & VM_PROT_EXECUTE)
flags |= PF_X;
if (prot & VM_PROT_READ)
flags |= PF_R;
if (prot & VM_PROT_WRITE)
flags |= PF_W;
return (flags);
}
void
__elfN(stackgap)(struct image_params *imgp, uintptr_t *stack_base)
{
uintptr_t range, rbase, gap;
int pct;
pct = __elfN(aslr_stack_gap);
if (pct == 0)
return;
if (pct > 50)
pct = 50;
range = imgp->eff_stack_sz * pct / 100;
arc4rand(&rbase, sizeof(rbase), 0);
gap = rbase % range;
gap &= ~(sizeof(u_long) - 1);
*stack_base -= gap;
}
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