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freebsd-skq/sys/kern/imgact_elf.c
Conrad Meyer f8e8a06d23 random(4) FenestrasX: Push root seed version to arc4random(3) 
Push the root seed version to userspace through the VDSO page, if
the RANDOM_FENESTRASX algorithm is enabled.  Otherwise, there is no
functional change.  The mechanism can be disabled with
debug.fxrng_vdso_enable=0.

arc4random(3) obtains a pointer to the root seed version published by
the kernel in the shared page at allocation time.  Like arc4random(9),
it maintains its own per-process copy of the seed version corresponding
to the root seed version at the time it last rekeyed.  On read requests,
the process seed version is compared with the version published in the
shared page; if they do not match, arc4random(3) reseeds from the
kernel before providing generated output.

This change does not implement the FenestrasX concept of PCPU userspace
generators seeded from a per-process base generator.  That change is
left for future discussion/work.

Reviewed by:	kib (previous version)
Approved by:	csprng (me -- only touching FXRNG here)
Differential Revision:	https://reviews.freebsd.org/D22839
2020-10-10 21:52:00 +00:00

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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_fd->fd_cmask);
if (sb != NULL) {
KASSERT(*sizep == size, ("invalid size"));
structsize = sizeof(p->p_fd->fd_cmask);
sbuf_bcat(sb, &structsize, sizeof(structsize));
sbuf_bcat(sb, &p->p_fd->fd_cmask, sizeof(p->p_fd->fd_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;
if ((imgp->map_flags & MAP_ASLR) == 0)
return;
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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