mirror of
https://gitlab.com/qemu-project/qemu
synced 2024-09-06 18:05:37 +00:00
![Richard Henderson](/assets/img/avatar_default.png)
Handle combined host and guest alignment requirements. Handle host and guest page size differences. Handle SHM_EXEC. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/115 Tested-by: Richard Purdie <richard.purdie@linuxfoundation.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
1441 lines
44 KiB
C
1441 lines
44 KiB
C
/*
|
|
* mmap support for qemu
|
|
*
|
|
* Copyright (c) 2003 Fabrice Bellard
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#include "qemu/osdep.h"
|
|
#include <sys/shm.h>
|
|
#include "trace.h"
|
|
#include "exec/log.h"
|
|
#include "qemu.h"
|
|
#include "user-internals.h"
|
|
#include "user-mmap.h"
|
|
#include "target_mman.h"
|
|
#include "qemu/interval-tree.h"
|
|
|
|
#ifdef TARGET_ARM
|
|
#include "target/arm/cpu-features.h"
|
|
#endif
|
|
|
|
static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER;
|
|
static __thread int mmap_lock_count;
|
|
|
|
void mmap_lock(void)
|
|
{
|
|
if (mmap_lock_count++ == 0) {
|
|
pthread_mutex_lock(&mmap_mutex);
|
|
}
|
|
}
|
|
|
|
void mmap_unlock(void)
|
|
{
|
|
assert(mmap_lock_count > 0);
|
|
if (--mmap_lock_count == 0) {
|
|
pthread_mutex_unlock(&mmap_mutex);
|
|
}
|
|
}
|
|
|
|
bool have_mmap_lock(void)
|
|
{
|
|
return mmap_lock_count > 0 ? true : false;
|
|
}
|
|
|
|
/* Grab lock to make sure things are in a consistent state after fork(). */
|
|
void mmap_fork_start(void)
|
|
{
|
|
if (mmap_lock_count)
|
|
abort();
|
|
pthread_mutex_lock(&mmap_mutex);
|
|
}
|
|
|
|
void mmap_fork_end(int child)
|
|
{
|
|
if (child) {
|
|
pthread_mutex_init(&mmap_mutex, NULL);
|
|
} else {
|
|
pthread_mutex_unlock(&mmap_mutex);
|
|
}
|
|
}
|
|
|
|
/* Protected by mmap_lock. */
|
|
static IntervalTreeRoot shm_regions;
|
|
|
|
static void shm_region_add(abi_ptr start, abi_ptr last)
|
|
{
|
|
IntervalTreeNode *i = g_new0(IntervalTreeNode, 1);
|
|
|
|
i->start = start;
|
|
i->last = last;
|
|
interval_tree_insert(i, &shm_regions);
|
|
}
|
|
|
|
static abi_ptr shm_region_find(abi_ptr start)
|
|
{
|
|
IntervalTreeNode *i;
|
|
|
|
for (i = interval_tree_iter_first(&shm_regions, start, start); i;
|
|
i = interval_tree_iter_next(i, start, start)) {
|
|
if (i->start == start) {
|
|
return i->last;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void shm_region_rm_complete(abi_ptr start, abi_ptr last)
|
|
{
|
|
IntervalTreeNode *i, *n;
|
|
|
|
for (i = interval_tree_iter_first(&shm_regions, start, last); i; i = n) {
|
|
n = interval_tree_iter_next(i, start, last);
|
|
if (i->start >= start && i->last <= last) {
|
|
interval_tree_remove(i, &shm_regions);
|
|
g_free(i);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Validate target prot bitmask.
|
|
* Return the prot bitmask for the host in *HOST_PROT.
|
|
* Return 0 if the target prot bitmask is invalid, otherwise
|
|
* the internal qemu page_flags (which will include PAGE_VALID).
|
|
*/
|
|
static int validate_prot_to_pageflags(int prot)
|
|
{
|
|
int valid = PROT_READ | PROT_WRITE | PROT_EXEC | TARGET_PROT_SEM;
|
|
int page_flags = (prot & PAGE_BITS) | PAGE_VALID;
|
|
|
|
#ifdef TARGET_AARCH64
|
|
{
|
|
ARMCPU *cpu = ARM_CPU(thread_cpu);
|
|
|
|
/*
|
|
* The PROT_BTI bit is only accepted if the cpu supports the feature.
|
|
* Since this is the unusual case, don't bother checking unless
|
|
* the bit has been requested. If set and valid, record the bit
|
|
* within QEMU's page_flags.
|
|
*/
|
|
if ((prot & TARGET_PROT_BTI) && cpu_isar_feature(aa64_bti, cpu)) {
|
|
valid |= TARGET_PROT_BTI;
|
|
page_flags |= PAGE_BTI;
|
|
}
|
|
/* Similarly for the PROT_MTE bit. */
|
|
if ((prot & TARGET_PROT_MTE) && cpu_isar_feature(aa64_mte, cpu)) {
|
|
valid |= TARGET_PROT_MTE;
|
|
page_flags |= PAGE_MTE;
|
|
}
|
|
}
|
|
#elif defined(TARGET_HPPA)
|
|
valid |= PROT_GROWSDOWN | PROT_GROWSUP;
|
|
#endif
|
|
|
|
return prot & ~valid ? 0 : page_flags;
|
|
}
|
|
|
|
/*
|
|
* For the host, we need not pass anything except read/write/exec.
|
|
* While PROT_SEM is allowed by all hosts, it is also ignored, so
|
|
* don't bother transforming guest bit to host bit. Any other
|
|
* target-specific prot bits will not be understood by the host
|
|
* and will need to be encoded into page_flags for qemu emulation.
|
|
*
|
|
* Pages that are executable by the guest will never be executed
|
|
* by the host, but the host will need to be able to read them.
|
|
*/
|
|
static int target_to_host_prot(int prot)
|
|
{
|
|
return (prot & (PROT_READ | PROT_WRITE)) |
|
|
(prot & PROT_EXEC ? PROT_READ : 0);
|
|
}
|
|
|
|
/* NOTE: all the constants are the HOST ones, but addresses are target. */
|
|
int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
|
|
{
|
|
int host_page_size = qemu_real_host_page_size();
|
|
abi_ulong starts[3];
|
|
abi_ulong lens[3];
|
|
int prots[3];
|
|
abi_ulong host_start, host_last, last;
|
|
int prot1, ret, page_flags, nranges;
|
|
|
|
trace_target_mprotect(start, len, target_prot);
|
|
|
|
if ((start & ~TARGET_PAGE_MASK) != 0) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
page_flags = validate_prot_to_pageflags(target_prot);
|
|
if (!page_flags) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
if (len == 0) {
|
|
return 0;
|
|
}
|
|
len = TARGET_PAGE_ALIGN(len);
|
|
if (!guest_range_valid_untagged(start, len)) {
|
|
return -TARGET_ENOMEM;
|
|
}
|
|
|
|
last = start + len - 1;
|
|
host_start = start & -host_page_size;
|
|
host_last = ROUND_UP(last, host_page_size) - 1;
|
|
nranges = 0;
|
|
|
|
mmap_lock();
|
|
|
|
if (host_last - host_start < host_page_size) {
|
|
/* Single host page contains all guest pages: sum the prot. */
|
|
prot1 = target_prot;
|
|
for (abi_ulong a = host_start; a < start; a += TARGET_PAGE_SIZE) {
|
|
prot1 |= page_get_flags(a);
|
|
}
|
|
for (abi_ulong a = last; a < host_last; a += TARGET_PAGE_SIZE) {
|
|
prot1 |= page_get_flags(a + 1);
|
|
}
|
|
starts[nranges] = host_start;
|
|
lens[nranges] = host_page_size;
|
|
prots[nranges] = prot1;
|
|
nranges++;
|
|
} else {
|
|
if (host_start < start) {
|
|
/* Host page contains more than one guest page: sum the prot. */
|
|
prot1 = target_prot;
|
|
for (abi_ulong a = host_start; a < start; a += TARGET_PAGE_SIZE) {
|
|
prot1 |= page_get_flags(a);
|
|
}
|
|
/* If the resulting sum differs, create a new range. */
|
|
if (prot1 != target_prot) {
|
|
starts[nranges] = host_start;
|
|
lens[nranges] = host_page_size;
|
|
prots[nranges] = prot1;
|
|
nranges++;
|
|
host_start += host_page_size;
|
|
}
|
|
}
|
|
|
|
if (last < host_last) {
|
|
/* Host page contains more than one guest page: sum the prot. */
|
|
prot1 = target_prot;
|
|
for (abi_ulong a = last; a < host_last; a += TARGET_PAGE_SIZE) {
|
|
prot1 |= page_get_flags(a + 1);
|
|
}
|
|
/* If the resulting sum differs, create a new range. */
|
|
if (prot1 != target_prot) {
|
|
host_last -= host_page_size;
|
|
starts[nranges] = host_last + 1;
|
|
lens[nranges] = host_page_size;
|
|
prots[nranges] = prot1;
|
|
nranges++;
|
|
}
|
|
}
|
|
|
|
/* Create a range for the middle, if any remains. */
|
|
if (host_start < host_last) {
|
|
starts[nranges] = host_start;
|
|
lens[nranges] = host_last - host_start + 1;
|
|
prots[nranges] = target_prot;
|
|
nranges++;
|
|
}
|
|
}
|
|
|
|
for (int i = 0; i < nranges; ++i) {
|
|
ret = mprotect(g2h_untagged(starts[i]), lens[i],
|
|
target_to_host_prot(prots[i]));
|
|
if (ret != 0) {
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
page_set_flags(start, last, page_flags);
|
|
ret = 0;
|
|
|
|
error:
|
|
mmap_unlock();
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Perform munmap on behalf of the target, with host parameters.
|
|
* If reserved_va, we must replace the memory reservation.
|
|
*/
|
|
static int do_munmap(void *addr, size_t len)
|
|
{
|
|
if (reserved_va) {
|
|
void *ptr = mmap(addr, len, PROT_NONE,
|
|
MAP_FIXED | MAP_ANONYMOUS
|
|
| MAP_PRIVATE | MAP_NORESERVE, -1, 0);
|
|
return ptr == addr ? 0 : -1;
|
|
}
|
|
return munmap(addr, len);
|
|
}
|
|
|
|
/*
|
|
* Map an incomplete host page.
|
|
*
|
|
* Here be dragons. This case will not work if there is an existing
|
|
* overlapping host page, which is file mapped, and for which the mapping
|
|
* is beyond the end of the file. In that case, we will see SIGBUS when
|
|
* trying to write a portion of this page.
|
|
*
|
|
* FIXME: Work around this with a temporary signal handler and longjmp.
|
|
*/
|
|
static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
|
|
int prot, int flags, int fd, off_t offset)
|
|
{
|
|
int host_page_size = qemu_real_host_page_size();
|
|
abi_ulong real_last;
|
|
void *host_start;
|
|
int prot_old, prot_new;
|
|
int host_prot_old, host_prot_new;
|
|
|
|
if (!(flags & MAP_ANONYMOUS)
|
|
&& (flags & MAP_TYPE) == MAP_SHARED
|
|
&& (prot & PROT_WRITE)) {
|
|
/*
|
|
* msync() won't work with the partial page, so we return an
|
|
* error if write is possible while it is a shared mapping.
|
|
*/
|
|
errno = EINVAL;
|
|
return false;
|
|
}
|
|
|
|
real_last = real_start + host_page_size - 1;
|
|
host_start = g2h_untagged(real_start);
|
|
|
|
/* Get the protection of the target pages outside the mapping. */
|
|
prot_old = 0;
|
|
for (abi_ulong a = real_start; a < start; a += TARGET_PAGE_SIZE) {
|
|
prot_old |= page_get_flags(a);
|
|
}
|
|
for (abi_ulong a = real_last; a > last; a -= TARGET_PAGE_SIZE) {
|
|
prot_old |= page_get_flags(a);
|
|
}
|
|
|
|
if (prot_old == 0) {
|
|
/*
|
|
* Since !(prot_old & PAGE_VALID), there were no guest pages
|
|
* outside of the fragment we need to map. Allocate a new host
|
|
* page to cover, discarding whatever else may have been present.
|
|
*/
|
|
void *p = mmap(host_start, host_page_size,
|
|
target_to_host_prot(prot),
|
|
flags | MAP_ANONYMOUS, -1, 0);
|
|
if (p != host_start) {
|
|
if (p != MAP_FAILED) {
|
|
do_munmap(p, host_page_size);
|
|
errno = EEXIST;
|
|
}
|
|
return false;
|
|
}
|
|
prot_old = prot;
|
|
}
|
|
prot_new = prot | prot_old;
|
|
|
|
host_prot_old = target_to_host_prot(prot_old);
|
|
host_prot_new = target_to_host_prot(prot_new);
|
|
|
|
/* Adjust protection to be able to write. */
|
|
if (!(host_prot_old & PROT_WRITE)) {
|
|
host_prot_old |= PROT_WRITE;
|
|
mprotect(host_start, host_page_size, host_prot_old);
|
|
}
|
|
|
|
/* Read or zero the new guest pages. */
|
|
if (flags & MAP_ANONYMOUS) {
|
|
memset(g2h_untagged(start), 0, last - start + 1);
|
|
} else {
|
|
if (pread(fd, g2h_untagged(start), last - start + 1, offset) == -1) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/* Put final protection */
|
|
if (host_prot_new != host_prot_old) {
|
|
mprotect(host_start, host_page_size, host_prot_new);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
abi_ulong task_unmapped_base;
|
|
abi_ulong elf_et_dyn_base;
|
|
abi_ulong mmap_next_start;
|
|
|
|
/*
|
|
* Subroutine of mmap_find_vma, used when we have pre-allocated
|
|
* a chunk of guest address space.
|
|
*/
|
|
static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
|
|
abi_ulong align)
|
|
{
|
|
target_ulong ret;
|
|
|
|
ret = page_find_range_empty(start, reserved_va, size, align);
|
|
if (ret == -1 && start > mmap_min_addr) {
|
|
/* Restart at the beginning of the address space. */
|
|
ret = page_find_range_empty(mmap_min_addr, start - 1, size, align);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Find and reserve a free memory area of size 'size'. The search
|
|
* starts at 'start'.
|
|
* It must be called with mmap_lock() held.
|
|
* Return -1 if error.
|
|
*/
|
|
abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align)
|
|
{
|
|
int host_page_size = qemu_real_host_page_size();
|
|
void *ptr, *prev;
|
|
abi_ulong addr;
|
|
int wrapped, repeat;
|
|
|
|
align = MAX(align, host_page_size);
|
|
|
|
/* If 'start' == 0, then a default start address is used. */
|
|
if (start == 0) {
|
|
start = mmap_next_start;
|
|
} else {
|
|
start &= -host_page_size;
|
|
}
|
|
start = ROUND_UP(start, align);
|
|
size = ROUND_UP(size, host_page_size);
|
|
|
|
if (reserved_va) {
|
|
return mmap_find_vma_reserved(start, size, align);
|
|
}
|
|
|
|
addr = start;
|
|
wrapped = repeat = 0;
|
|
prev = 0;
|
|
|
|
for (;; prev = ptr) {
|
|
/*
|
|
* Reserve needed memory area to avoid a race.
|
|
* It should be discarded using:
|
|
* - mmap() with MAP_FIXED flag
|
|
* - mremap() with MREMAP_FIXED flag
|
|
* - shmat() with SHM_REMAP flag
|
|
*/
|
|
ptr = mmap(g2h_untagged(addr), size, PROT_NONE,
|
|
MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0);
|
|
|
|
/* ENOMEM, if host address space has no memory */
|
|
if (ptr == MAP_FAILED) {
|
|
return (abi_ulong)-1;
|
|
}
|
|
|
|
/*
|
|
* Count the number of sequential returns of the same address.
|
|
* This is used to modify the search algorithm below.
|
|
*/
|
|
repeat = (ptr == prev ? repeat + 1 : 0);
|
|
|
|
if (h2g_valid(ptr + size - 1)) {
|
|
addr = h2g(ptr);
|
|
|
|
if ((addr & (align - 1)) == 0) {
|
|
/* Success. */
|
|
if (start == mmap_next_start && addr >= task_unmapped_base) {
|
|
mmap_next_start = addr + size;
|
|
}
|
|
return addr;
|
|
}
|
|
|
|
/* The address is not properly aligned for the target. */
|
|
switch (repeat) {
|
|
case 0:
|
|
/*
|
|
* Assume the result that the kernel gave us is the
|
|
* first with enough free space, so start again at the
|
|
* next higher target page.
|
|
*/
|
|
addr = ROUND_UP(addr, align);
|
|
break;
|
|
case 1:
|
|
/*
|
|
* Sometimes the kernel decides to perform the allocation
|
|
* at the top end of memory instead.
|
|
*/
|
|
addr &= -align;
|
|
break;
|
|
case 2:
|
|
/* Start over at low memory. */
|
|
addr = 0;
|
|
break;
|
|
default:
|
|
/* Fail. This unaligned block must the last. */
|
|
addr = -1;
|
|
break;
|
|
}
|
|
} else {
|
|
/*
|
|
* Since the result the kernel gave didn't fit, start
|
|
* again at low memory. If any repetition, fail.
|
|
*/
|
|
addr = (repeat ? -1 : 0);
|
|
}
|
|
|
|
/* Unmap and try again. */
|
|
munmap(ptr, size);
|
|
|
|
/* ENOMEM if we checked the whole of the target address space. */
|
|
if (addr == (abi_ulong)-1) {
|
|
return (abi_ulong)-1;
|
|
} else if (addr == 0) {
|
|
if (wrapped) {
|
|
return (abi_ulong)-1;
|
|
}
|
|
wrapped = 1;
|
|
/*
|
|
* Don't actually use 0 when wrapping, instead indicate
|
|
* that we'd truly like an allocation in low memory.
|
|
*/
|
|
addr = (mmap_min_addr > TARGET_PAGE_SIZE
|
|
? TARGET_PAGE_ALIGN(mmap_min_addr)
|
|
: TARGET_PAGE_SIZE);
|
|
} else if (wrapped && addr >= start) {
|
|
return (abi_ulong)-1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Record a successful mmap within the user-exec interval tree.
|
|
*/
|
|
static abi_long mmap_end(abi_ulong start, abi_ulong last,
|
|
abi_ulong passthrough_start,
|
|
abi_ulong passthrough_last,
|
|
int flags, int page_flags)
|
|
{
|
|
if (flags & MAP_ANONYMOUS) {
|
|
page_flags |= PAGE_ANON;
|
|
}
|
|
page_flags |= PAGE_RESET;
|
|
if (passthrough_start > passthrough_last) {
|
|
page_set_flags(start, last, page_flags);
|
|
} else {
|
|
if (start < passthrough_start) {
|
|
page_set_flags(start, passthrough_start - 1, page_flags);
|
|
}
|
|
page_set_flags(passthrough_start, passthrough_last,
|
|
page_flags | PAGE_PASSTHROUGH);
|
|
if (passthrough_last < last) {
|
|
page_set_flags(passthrough_last + 1, last, page_flags);
|
|
}
|
|
}
|
|
shm_region_rm_complete(start, last);
|
|
trace_target_mmap_complete(start);
|
|
if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
|
|
FILE *f = qemu_log_trylock();
|
|
if (f) {
|
|
fprintf(f, "page layout changed following mmap\n");
|
|
page_dump(f);
|
|
qemu_log_unlock(f);
|
|
}
|
|
}
|
|
return start;
|
|
}
|
|
|
|
/*
|
|
* Special case host page size == target page size,
|
|
* where there are no edge conditions.
|
|
*/
|
|
static abi_long mmap_h_eq_g(abi_ulong start, abi_ulong len,
|
|
int host_prot, int flags, int page_flags,
|
|
int fd, off_t offset)
|
|
{
|
|
void *p, *want_p = g2h_untagged(start);
|
|
abi_ulong last;
|
|
|
|
p = mmap(want_p, len, host_prot, flags, fd, offset);
|
|
if (p == MAP_FAILED) {
|
|
return -1;
|
|
}
|
|
/* If the host kernel does not support MAP_FIXED_NOREPLACE, emulate. */
|
|
if ((flags & MAP_FIXED_NOREPLACE) && p != want_p) {
|
|
do_munmap(p, len);
|
|
errno = EEXIST;
|
|
return -1;
|
|
}
|
|
|
|
start = h2g(p);
|
|
last = start + len - 1;
|
|
return mmap_end(start, last, start, last, flags, page_flags);
|
|
}
|
|
|
|
/*
|
|
* Special case host page size < target page size.
|
|
*
|
|
* The two special cases are increased guest alignment, and mapping
|
|
* past the end of a file.
|
|
*
|
|
* When mapping files into a memory area larger than the file,
|
|
* accesses to pages beyond the file size will cause a SIGBUS.
|
|
*
|
|
* For example, if mmaping a file of 100 bytes on a host with 4K
|
|
* pages emulating a target with 8K pages, the target expects to
|
|
* be able to access the first 8K. But the host will trap us on
|
|
* any access beyond 4K.
|
|
*
|
|
* When emulating a target with a larger page-size than the hosts,
|
|
* we may need to truncate file maps at EOF and add extra anonymous
|
|
* pages up to the targets page boundary.
|
|
*
|
|
* This workaround only works for files that do not change.
|
|
* If the file is later extended (e.g. ftruncate), the SIGBUS
|
|
* vanishes and the proper behaviour is that changes within the
|
|
* anon page should be reflected in the file.
|
|
*
|
|
* However, this case is rather common with executable images,
|
|
* so the workaround is important for even trivial tests, whereas
|
|
* the mmap of of a file being extended is less common.
|
|
*/
|
|
static abi_long mmap_h_lt_g(abi_ulong start, abi_ulong len, int host_prot,
|
|
int mmap_flags, int page_flags, int fd,
|
|
off_t offset, int host_page_size)
|
|
{
|
|
void *p, *want_p = g2h_untagged(start);
|
|
off_t fileend_adj = 0;
|
|
int flags = mmap_flags;
|
|
abi_ulong last, pass_last;
|
|
|
|
if (!(flags & MAP_ANONYMOUS)) {
|
|
struct stat sb;
|
|
|
|
if (fstat(fd, &sb) == -1) {
|
|
return -1;
|
|
}
|
|
if (offset >= sb.st_size) {
|
|
/*
|
|
* The entire map is beyond the end of the file.
|
|
* Transform it to an anonymous mapping.
|
|
*/
|
|
flags |= MAP_ANONYMOUS;
|
|
fd = -1;
|
|
offset = 0;
|
|
} else if (offset + len > sb.st_size) {
|
|
/*
|
|
* A portion of the map is beyond the end of the file.
|
|
* Truncate the file portion of the allocation.
|
|
*/
|
|
fileend_adj = offset + len - sb.st_size;
|
|
}
|
|
}
|
|
|
|
if (flags & (MAP_FIXED | MAP_FIXED_NOREPLACE)) {
|
|
if (fileend_adj) {
|
|
p = mmap(want_p, len, host_prot, flags | MAP_ANONYMOUS, -1, 0);
|
|
} else {
|
|
p = mmap(want_p, len, host_prot, flags, fd, offset);
|
|
}
|
|
if (p != want_p) {
|
|
if (p != MAP_FAILED) {
|
|
/* Host does not support MAP_FIXED_NOREPLACE: emulate. */
|
|
do_munmap(p, len);
|
|
errno = EEXIST;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
if (fileend_adj) {
|
|
void *t = mmap(p, len - fileend_adj, host_prot,
|
|
(flags & ~MAP_FIXED_NOREPLACE) | MAP_FIXED,
|
|
fd, offset);
|
|
|
|
if (t == MAP_FAILED) {
|
|
int save_errno = errno;
|
|
|
|
/*
|
|
* We failed a map over the top of the successful anonymous
|
|
* mapping above. The only failure mode is running out of VMAs,
|
|
* and there's nothing that we can do to detect that earlier.
|
|
* If we have replaced an existing mapping with MAP_FIXED,
|
|
* then we cannot properly recover. It's a coin toss whether
|
|
* it would be better to exit or continue here.
|
|
*/
|
|
if (!(flags & MAP_FIXED_NOREPLACE) &&
|
|
!page_check_range_empty(start, start + len - 1)) {
|
|
qemu_log("QEMU target_mmap late failure: %s",
|
|
strerror(save_errno));
|
|
}
|
|
|
|
do_munmap(want_p, len);
|
|
errno = save_errno;
|
|
return -1;
|
|
}
|
|
}
|
|
} else {
|
|
size_t host_len, part_len;
|
|
|
|
/*
|
|
* Take care to align the host memory. Perform a larger anonymous
|
|
* allocation and extract the aligned portion. Remap the file on
|
|
* top of that.
|
|
*/
|
|
host_len = len + TARGET_PAGE_SIZE - host_page_size;
|
|
p = mmap(want_p, host_len, host_prot, flags | MAP_ANONYMOUS, -1, 0);
|
|
if (p == MAP_FAILED) {
|
|
return -1;
|
|
}
|
|
|
|
part_len = (uintptr_t)p & (TARGET_PAGE_SIZE - 1);
|
|
if (part_len) {
|
|
part_len = TARGET_PAGE_SIZE - part_len;
|
|
do_munmap(p, part_len);
|
|
p += part_len;
|
|
host_len -= part_len;
|
|
}
|
|
if (len < host_len) {
|
|
do_munmap(p + len, host_len - len);
|
|
}
|
|
|
|
if (!(flags & MAP_ANONYMOUS)) {
|
|
void *t = mmap(p, len - fileend_adj, host_prot,
|
|
flags | MAP_FIXED, fd, offset);
|
|
|
|
if (t == MAP_FAILED) {
|
|
int save_errno = errno;
|
|
do_munmap(p, len);
|
|
errno = save_errno;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
start = h2g(p);
|
|
}
|
|
|
|
last = start + len - 1;
|
|
if (fileend_adj) {
|
|
pass_last = ROUND_UP(last - fileend_adj, host_page_size) - 1;
|
|
} else {
|
|
pass_last = last;
|
|
}
|
|
return mmap_end(start, last, start, pass_last, mmap_flags, page_flags);
|
|
}
|
|
|
|
/*
|
|
* Special case host page size > target page size.
|
|
*
|
|
* The two special cases are address and file offsets that are valid
|
|
* for the guest that cannot be directly represented by the host.
|
|
*/
|
|
static abi_long mmap_h_gt_g(abi_ulong start, abi_ulong len,
|
|
int target_prot, int host_prot,
|
|
int flags, int page_flags, int fd,
|
|
off_t offset, int host_page_size)
|
|
{
|
|
void *p, *want_p = g2h_untagged(start);
|
|
off_t host_offset = offset & -host_page_size;
|
|
abi_ulong last, real_start, real_last;
|
|
bool misaligned_offset = false;
|
|
size_t host_len;
|
|
|
|
if (!(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
|
|
/*
|
|
* Adjust the offset to something representable on the host.
|
|
*/
|
|
host_len = len + offset - host_offset;
|
|
p = mmap(want_p, host_len, host_prot, flags, fd, host_offset);
|
|
if (p == MAP_FAILED) {
|
|
return -1;
|
|
}
|
|
|
|
/* Update start to the file position at offset. */
|
|
p += offset - host_offset;
|
|
|
|
start = h2g(p);
|
|
last = start + len - 1;
|
|
return mmap_end(start, last, start, last, flags, page_flags);
|
|
}
|
|
|
|
if (!(flags & MAP_ANONYMOUS)) {
|
|
misaligned_offset = (start ^ offset) & (host_page_size - 1);
|
|
|
|
/*
|
|
* The fallback for misalignment is a private mapping + read.
|
|
* This carries none of semantics required of MAP_SHARED.
|
|
*/
|
|
if (misaligned_offset && (flags & MAP_TYPE) != MAP_PRIVATE) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
last = start + len - 1;
|
|
real_start = start & -host_page_size;
|
|
real_last = ROUND_UP(last, host_page_size) - 1;
|
|
|
|
/*
|
|
* Handle the start and end of the mapping.
|
|
*/
|
|
if (real_start < start) {
|
|
abi_ulong real_page_last = real_start + host_page_size - 1;
|
|
if (last <= real_page_last) {
|
|
/* Entire allocation a subset of one host page. */
|
|
if (!mmap_frag(real_start, start, last, target_prot,
|
|
flags, fd, offset)) {
|
|
return -1;
|
|
}
|
|
return mmap_end(start, last, -1, 0, flags, page_flags);
|
|
}
|
|
|
|
if (!mmap_frag(real_start, start, real_page_last, target_prot,
|
|
flags, fd, offset)) {
|
|
return -1;
|
|
}
|
|
real_start = real_page_last + 1;
|
|
}
|
|
|
|
if (last < real_last) {
|
|
abi_ulong real_page_start = real_last - host_page_size + 1;
|
|
if (!mmap_frag(real_page_start, real_page_start, last,
|
|
target_prot, flags, fd,
|
|
offset + real_page_start - start)) {
|
|
return -1;
|
|
}
|
|
real_last = real_page_start - 1;
|
|
}
|
|
|
|
if (real_start > real_last) {
|
|
return mmap_end(start, last, -1, 0, flags, page_flags);
|
|
}
|
|
|
|
/*
|
|
* Handle the middle of the mapping.
|
|
*/
|
|
|
|
host_len = real_last - real_start + 1;
|
|
want_p += real_start - start;
|
|
|
|
if (flags & MAP_ANONYMOUS) {
|
|
p = mmap(want_p, host_len, host_prot, flags, -1, 0);
|
|
} else if (!misaligned_offset) {
|
|
p = mmap(want_p, host_len, host_prot, flags, fd,
|
|
offset + real_start - start);
|
|
} else {
|
|
p = mmap(want_p, host_len, host_prot | PROT_WRITE,
|
|
flags | MAP_ANONYMOUS, -1, 0);
|
|
}
|
|
if (p != want_p) {
|
|
if (p != MAP_FAILED) {
|
|
do_munmap(p, host_len);
|
|
errno = EEXIST;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
if (misaligned_offset) {
|
|
/* TODO: The read could be short. */
|
|
if (pread(fd, p, host_len, offset + real_start - start) != host_len) {
|
|
do_munmap(p, host_len);
|
|
return -1;
|
|
}
|
|
if (!(host_prot & PROT_WRITE)) {
|
|
mprotect(p, host_len, host_prot);
|
|
}
|
|
}
|
|
|
|
return mmap_end(start, last, -1, 0, flags, page_flags);
|
|
}
|
|
|
|
static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
|
|
int target_prot, int flags, int page_flags,
|
|
int fd, off_t offset)
|
|
{
|
|
int host_page_size = qemu_real_host_page_size();
|
|
int host_prot;
|
|
|
|
/*
|
|
* For reserved_va, we are in full control of the allocation.
|
|
* Find a suitable hole and convert to MAP_FIXED.
|
|
*/
|
|
if (reserved_va) {
|
|
if (flags & MAP_FIXED_NOREPLACE) {
|
|
/* Validate that the chosen range is empty. */
|
|
if (!page_check_range_empty(start, start + len - 1)) {
|
|
errno = EEXIST;
|
|
return -1;
|
|
}
|
|
flags = (flags & ~MAP_FIXED_NOREPLACE) | MAP_FIXED;
|
|
} else if (!(flags & MAP_FIXED)) {
|
|
abi_ulong real_start = start & -host_page_size;
|
|
off_t host_offset = offset & -host_page_size;
|
|
size_t real_len = len + offset - host_offset;
|
|
abi_ulong align = MAX(host_page_size, TARGET_PAGE_SIZE);
|
|
|
|
start = mmap_find_vma(real_start, real_len, align);
|
|
if (start == (abi_ulong)-1) {
|
|
errno = ENOMEM;
|
|
return -1;
|
|
}
|
|
start += offset - host_offset;
|
|
flags |= MAP_FIXED;
|
|
}
|
|
}
|
|
|
|
host_prot = target_to_host_prot(target_prot);
|
|
|
|
if (host_page_size == TARGET_PAGE_SIZE) {
|
|
return mmap_h_eq_g(start, len, host_prot, flags,
|
|
page_flags, fd, offset);
|
|
} else if (host_page_size < TARGET_PAGE_SIZE) {
|
|
return mmap_h_lt_g(start, len, host_prot, flags,
|
|
page_flags, fd, offset, host_page_size);
|
|
} else {
|
|
return mmap_h_gt_g(start, len, target_prot, host_prot, flags,
|
|
page_flags, fd, offset, host_page_size);
|
|
}
|
|
}
|
|
|
|
/* NOTE: all the constants are the HOST ones */
|
|
abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
|
|
int flags, int fd, off_t offset)
|
|
{
|
|
abi_long ret;
|
|
int page_flags;
|
|
|
|
trace_target_mmap(start, len, target_prot, flags, fd, offset);
|
|
|
|
if (!len) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
page_flags = validate_prot_to_pageflags(target_prot);
|
|
if (!page_flags) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
/* Also check for overflows... */
|
|
len = TARGET_PAGE_ALIGN(len);
|
|
if (!len || len != (size_t)len) {
|
|
errno = ENOMEM;
|
|
return -1;
|
|
}
|
|
|
|
if (offset & ~TARGET_PAGE_MASK) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
if (flags & (MAP_FIXED | MAP_FIXED_NOREPLACE)) {
|
|
if (start & ~TARGET_PAGE_MASK) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
if (!guest_range_valid_untagged(start, len)) {
|
|
errno = ENOMEM;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
mmap_lock();
|
|
|
|
ret = target_mmap__locked(start, len, target_prot, flags,
|
|
page_flags, fd, offset);
|
|
|
|
mmap_unlock();
|
|
|
|
/*
|
|
* If we're mapping shared memory, ensure we generate code for parallel
|
|
* execution and flush old translations. This will work up to the level
|
|
* supported by the host -- anything that requires EXCP_ATOMIC will not
|
|
* be atomic with respect to an external process.
|
|
*/
|
|
if (ret != -1 && (flags & MAP_TYPE) != MAP_PRIVATE) {
|
|
CPUState *cpu = thread_cpu;
|
|
if (!(cpu->tcg_cflags & CF_PARALLEL)) {
|
|
cpu->tcg_cflags |= CF_PARALLEL;
|
|
tb_flush(cpu);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
|
|
{
|
|
int host_page_size = qemu_real_host_page_size();
|
|
abi_ulong real_start;
|
|
abi_ulong real_last;
|
|
abi_ulong real_len;
|
|
abi_ulong last;
|
|
abi_ulong a;
|
|
void *host_start;
|
|
int prot;
|
|
|
|
last = start + len - 1;
|
|
real_start = start & -host_page_size;
|
|
real_last = ROUND_UP(last, host_page_size) - 1;
|
|
|
|
/*
|
|
* If guest pages remain on the first or last host pages,
|
|
* adjust the deallocation to retain those guest pages.
|
|
* The single page special case is required for the last page,
|
|
* lest real_start overflow to zero.
|
|
*/
|
|
if (real_last - real_start < host_page_size) {
|
|
prot = 0;
|
|
for (a = real_start; a < start; a += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(a);
|
|
}
|
|
for (a = last; a < real_last; a += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(a + 1);
|
|
}
|
|
if (prot != 0) {
|
|
return 0;
|
|
}
|
|
} else {
|
|
for (prot = 0, a = real_start; a < start; a += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(a);
|
|
}
|
|
if (prot != 0) {
|
|
real_start += host_page_size;
|
|
}
|
|
|
|
for (prot = 0, a = last; a < real_last; a += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(a + 1);
|
|
}
|
|
if (prot != 0) {
|
|
real_last -= host_page_size;
|
|
}
|
|
|
|
if (real_last < real_start) {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
real_len = real_last - real_start + 1;
|
|
host_start = g2h_untagged(real_start);
|
|
|
|
return do_munmap(host_start, real_len);
|
|
}
|
|
|
|
int target_munmap(abi_ulong start, abi_ulong len)
|
|
{
|
|
int ret;
|
|
|
|
trace_target_munmap(start, len);
|
|
|
|
if (start & ~TARGET_PAGE_MASK) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
len = TARGET_PAGE_ALIGN(len);
|
|
if (len == 0 || !guest_range_valid_untagged(start, len)) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
mmap_lock();
|
|
ret = mmap_reserve_or_unmap(start, len);
|
|
if (likely(ret == 0)) {
|
|
page_set_flags(start, start + len - 1, 0);
|
|
shm_region_rm_complete(start, start + len - 1);
|
|
}
|
|
mmap_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
|
|
abi_ulong new_size, unsigned long flags,
|
|
abi_ulong new_addr)
|
|
{
|
|
int prot;
|
|
void *host_addr;
|
|
|
|
if (!guest_range_valid_untagged(old_addr, old_size) ||
|
|
((flags & MREMAP_FIXED) &&
|
|
!guest_range_valid_untagged(new_addr, new_size)) ||
|
|
((flags & MREMAP_MAYMOVE) == 0 &&
|
|
!guest_range_valid_untagged(old_addr, new_size))) {
|
|
errno = ENOMEM;
|
|
return -1;
|
|
}
|
|
|
|
mmap_lock();
|
|
|
|
if (flags & MREMAP_FIXED) {
|
|
host_addr = mremap(g2h_untagged(old_addr), old_size, new_size,
|
|
flags, g2h_untagged(new_addr));
|
|
|
|
if (reserved_va && host_addr != MAP_FAILED) {
|
|
/*
|
|
* If new and old addresses overlap then the above mremap will
|
|
* already have failed with EINVAL.
|
|
*/
|
|
mmap_reserve_or_unmap(old_addr, old_size);
|
|
}
|
|
} else if (flags & MREMAP_MAYMOVE) {
|
|
abi_ulong mmap_start;
|
|
|
|
mmap_start = mmap_find_vma(0, new_size, TARGET_PAGE_SIZE);
|
|
|
|
if (mmap_start == -1) {
|
|
errno = ENOMEM;
|
|
host_addr = MAP_FAILED;
|
|
} else {
|
|
host_addr = mremap(g2h_untagged(old_addr), old_size, new_size,
|
|
flags | MREMAP_FIXED,
|
|
g2h_untagged(mmap_start));
|
|
if (reserved_va) {
|
|
mmap_reserve_or_unmap(old_addr, old_size);
|
|
}
|
|
}
|
|
} else {
|
|
int page_flags = 0;
|
|
if (reserved_va && old_size < new_size) {
|
|
abi_ulong addr;
|
|
for (addr = old_addr + old_size;
|
|
addr < old_addr + new_size;
|
|
addr++) {
|
|
page_flags |= page_get_flags(addr);
|
|
}
|
|
}
|
|
if (page_flags == 0) {
|
|
host_addr = mremap(g2h_untagged(old_addr),
|
|
old_size, new_size, flags);
|
|
|
|
if (host_addr != MAP_FAILED) {
|
|
/* Check if address fits target address space */
|
|
if (!guest_range_valid_untagged(h2g(host_addr), new_size)) {
|
|
/* Revert mremap() changes */
|
|
host_addr = mremap(g2h_untagged(old_addr),
|
|
new_size, old_size, flags);
|
|
errno = ENOMEM;
|
|
host_addr = MAP_FAILED;
|
|
} else if (reserved_va && old_size > new_size) {
|
|
mmap_reserve_or_unmap(old_addr + old_size,
|
|
old_size - new_size);
|
|
}
|
|
}
|
|
} else {
|
|
errno = ENOMEM;
|
|
host_addr = MAP_FAILED;
|
|
}
|
|
}
|
|
|
|
if (host_addr == MAP_FAILED) {
|
|
new_addr = -1;
|
|
} else {
|
|
new_addr = h2g(host_addr);
|
|
prot = page_get_flags(old_addr);
|
|
page_set_flags(old_addr, old_addr + old_size - 1, 0);
|
|
shm_region_rm_complete(old_addr, old_addr + old_size - 1);
|
|
page_set_flags(new_addr, new_addr + new_size - 1,
|
|
prot | PAGE_VALID | PAGE_RESET);
|
|
shm_region_rm_complete(new_addr, new_addr + new_size - 1);
|
|
}
|
|
mmap_unlock();
|
|
return new_addr;
|
|
}
|
|
|
|
abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice)
|
|
{
|
|
abi_ulong len;
|
|
int ret = 0;
|
|
|
|
if (start & ~TARGET_PAGE_MASK) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
if (len_in == 0) {
|
|
return 0;
|
|
}
|
|
len = TARGET_PAGE_ALIGN(len_in);
|
|
if (len == 0 || !guest_range_valid_untagged(start, len)) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
|
|
/* Translate for some architectures which have different MADV_xxx values */
|
|
switch (advice) {
|
|
case TARGET_MADV_DONTNEED: /* alpha */
|
|
advice = MADV_DONTNEED;
|
|
break;
|
|
case TARGET_MADV_WIPEONFORK: /* parisc */
|
|
advice = MADV_WIPEONFORK;
|
|
break;
|
|
case TARGET_MADV_KEEPONFORK: /* parisc */
|
|
advice = MADV_KEEPONFORK;
|
|
break;
|
|
/* we do not care about the other MADV_xxx values yet */
|
|
}
|
|
|
|
/*
|
|
* Most advice values are hints, so ignoring and returning success is ok.
|
|
*
|
|
* However, some advice values such as MADV_DONTNEED, MADV_WIPEONFORK and
|
|
* MADV_KEEPONFORK are not hints and need to be emulated.
|
|
*
|
|
* A straight passthrough for those may not be safe because qemu sometimes
|
|
* turns private file-backed mappings into anonymous mappings.
|
|
* If all guest pages have PAGE_PASSTHROUGH set, mappings have the
|
|
* same semantics for the host as for the guest.
|
|
*
|
|
* We pass through MADV_WIPEONFORK and MADV_KEEPONFORK if possible and
|
|
* return failure if not.
|
|
*
|
|
* MADV_DONTNEED is passed through as well, if possible.
|
|
* If passthrough isn't possible, we nevertheless (wrongly!) return
|
|
* success, which is broken but some userspace programs fail to work
|
|
* otherwise. Completely implementing such emulation is quite complicated
|
|
* though.
|
|
*/
|
|
mmap_lock();
|
|
switch (advice) {
|
|
case MADV_WIPEONFORK:
|
|
case MADV_KEEPONFORK:
|
|
ret = -EINVAL;
|
|
/* fall through */
|
|
case MADV_DONTNEED:
|
|
if (page_check_range(start, len, PAGE_PASSTHROUGH)) {
|
|
ret = get_errno(madvise(g2h_untagged(start), len, advice));
|
|
if ((advice == MADV_DONTNEED) && (ret == 0)) {
|
|
page_reset_target_data(start, start + len - 1);
|
|
}
|
|
}
|
|
}
|
|
mmap_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifndef TARGET_FORCE_SHMLBA
|
|
/*
|
|
* For most architectures, SHMLBA is the same as the page size;
|
|
* some architectures have larger values, in which case they should
|
|
* define TARGET_FORCE_SHMLBA and provide a target_shmlba() function.
|
|
* This corresponds to the kernel arch code defining __ARCH_FORCE_SHMLBA
|
|
* and defining its own value for SHMLBA.
|
|
*
|
|
* The kernel also permits SHMLBA to be set by the architecture to a
|
|
* value larger than the page size without setting __ARCH_FORCE_SHMLBA;
|
|
* this means that addresses are rounded to the large size if
|
|
* SHM_RND is set but addresses not aligned to that size are not rejected
|
|
* as long as they are at least page-aligned. Since the only architecture
|
|
* which uses this is ia64 this code doesn't provide for that oddity.
|
|
*/
|
|
static inline abi_ulong target_shmlba(CPUArchState *cpu_env)
|
|
{
|
|
return TARGET_PAGE_SIZE;
|
|
}
|
|
#endif
|
|
|
|
#if defined(__arm__) || defined(__mips__) || defined(__sparc__)
|
|
#define HOST_FORCE_SHMLBA 1
|
|
#else
|
|
#define HOST_FORCE_SHMLBA 0
|
|
#endif
|
|
|
|
abi_ulong target_shmat(CPUArchState *cpu_env, int shmid,
|
|
abi_ulong shmaddr, int shmflg)
|
|
{
|
|
CPUState *cpu = env_cpu(cpu_env);
|
|
struct shmid_ds shm_info;
|
|
int ret;
|
|
int h_pagesize;
|
|
int t_shmlba, h_shmlba, m_shmlba;
|
|
size_t t_len, h_len, m_len;
|
|
|
|
/* shmat pointers are always untagged */
|
|
|
|
/*
|
|
* Because we can't use host shmat() unless the address is sufficiently
|
|
* aligned for the host, we'll need to check both.
|
|
* TODO: Could be fixed with softmmu.
|
|
*/
|
|
t_shmlba = target_shmlba(cpu_env);
|
|
h_pagesize = qemu_real_host_page_size();
|
|
h_shmlba = (HOST_FORCE_SHMLBA ? SHMLBA : h_pagesize);
|
|
m_shmlba = MAX(t_shmlba, h_shmlba);
|
|
|
|
if (shmaddr) {
|
|
if (shmaddr & (m_shmlba - 1)) {
|
|
if (shmflg & SHM_RND) {
|
|
/*
|
|
* The guest is allowing the kernel to round the address.
|
|
* Assume that the guest is ok with us rounding to the
|
|
* host required alignment too. Anyway if we don't, we'll
|
|
* get an error from the kernel.
|
|
*/
|
|
shmaddr &= ~(m_shmlba - 1);
|
|
if (shmaddr == 0 && (shmflg & SHM_REMAP)) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
} else {
|
|
int require = TARGET_PAGE_SIZE;
|
|
#ifdef TARGET_FORCE_SHMLBA
|
|
require = t_shmlba;
|
|
#endif
|
|
/*
|
|
* Include host required alignment, as otherwise we cannot
|
|
* use host shmat at all.
|
|
*/
|
|
require = MAX(require, h_shmlba);
|
|
if (shmaddr & (require - 1)) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if (shmflg & SHM_REMAP) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
}
|
|
/* All rounding now manually concluded. */
|
|
shmflg &= ~SHM_RND;
|
|
|
|
/* Find out the length of the shared memory segment. */
|
|
ret = get_errno(shmctl(shmid, IPC_STAT, &shm_info));
|
|
if (is_error(ret)) {
|
|
/* can't get length, bail out */
|
|
return ret;
|
|
}
|
|
t_len = TARGET_PAGE_ALIGN(shm_info.shm_segsz);
|
|
h_len = ROUND_UP(shm_info.shm_segsz, h_pagesize);
|
|
m_len = MAX(t_len, h_len);
|
|
|
|
if (!guest_range_valid_untagged(shmaddr, m_len)) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
|
|
WITH_MMAP_LOCK_GUARD() {
|
|
bool mapped = false;
|
|
void *want, *test;
|
|
abi_ulong last;
|
|
|
|
if (!shmaddr) {
|
|
shmaddr = mmap_find_vma(0, m_len, m_shmlba);
|
|
if (shmaddr == -1) {
|
|
return -TARGET_ENOMEM;
|
|
}
|
|
mapped = !reserved_va;
|
|
} else if (shmflg & SHM_REMAP) {
|
|
/*
|
|
* If host page size > target page size, the host shmat may map
|
|
* more memory than the guest expects. Reject a mapping that
|
|
* would replace memory in the unexpected gap.
|
|
* TODO: Could be fixed with softmmu.
|
|
*/
|
|
if (t_len < h_len &&
|
|
!page_check_range_empty(shmaddr + t_len,
|
|
shmaddr + h_len - 1)) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
} else {
|
|
if (!page_check_range_empty(shmaddr, shmaddr + m_len - 1)) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
}
|
|
|
|
/* All placement is now complete. */
|
|
want = (void *)g2h_untagged(shmaddr);
|
|
|
|
/*
|
|
* Map anonymous pages across the entire range, then remap with
|
|
* the shared memory. This is required for a number of corner
|
|
* cases for which host and guest page sizes differ.
|
|
*/
|
|
if (h_len != t_len) {
|
|
int mmap_p = PROT_READ | (shmflg & SHM_RDONLY ? 0 : PROT_WRITE);
|
|
int mmap_f = MAP_PRIVATE | MAP_ANONYMOUS
|
|
| (reserved_va || (shmflg & SHM_REMAP)
|
|
? MAP_FIXED : MAP_FIXED_NOREPLACE);
|
|
|
|
test = mmap(want, m_len, mmap_p, mmap_f, -1, 0);
|
|
if (unlikely(test != want)) {
|
|
/* shmat returns EINVAL not EEXIST like mmap. */
|
|
ret = (test == MAP_FAILED && errno != EEXIST
|
|
? get_errno(-1) : -TARGET_EINVAL);
|
|
if (mapped) {
|
|
do_munmap(want, m_len);
|
|
}
|
|
return ret;
|
|
}
|
|
mapped = true;
|
|
}
|
|
|
|
if (reserved_va || mapped) {
|
|
shmflg |= SHM_REMAP;
|
|
}
|
|
test = shmat(shmid, want, shmflg);
|
|
if (test == MAP_FAILED) {
|
|
ret = get_errno(-1);
|
|
if (mapped) {
|
|
do_munmap(want, m_len);
|
|
}
|
|
return ret;
|
|
}
|
|
assert(test == want);
|
|
|
|
last = shmaddr + m_len - 1;
|
|
page_set_flags(shmaddr, last,
|
|
PAGE_VALID | PAGE_RESET | PAGE_READ |
|
|
(shmflg & SHM_RDONLY ? 0 : PAGE_WRITE) |
|
|
(shmflg & SHM_EXEC ? PAGE_EXEC : 0));
|
|
|
|
shm_region_rm_complete(shmaddr, last);
|
|
shm_region_add(shmaddr, last);
|
|
}
|
|
|
|
/*
|
|
* We're mapping shared memory, so ensure we generate code for parallel
|
|
* execution and flush old translations. This will work up to the level
|
|
* supported by the host -- anything that requires EXCP_ATOMIC will not
|
|
* be atomic with respect to an external process.
|
|
*/
|
|
if (!(cpu->tcg_cflags & CF_PARALLEL)) {
|
|
cpu->tcg_cflags |= CF_PARALLEL;
|
|
tb_flush(cpu);
|
|
}
|
|
|
|
if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
|
|
FILE *f = qemu_log_trylock();
|
|
if (f) {
|
|
fprintf(f, "page layout changed following shmat\n");
|
|
page_dump(f);
|
|
qemu_log_unlock(f);
|
|
}
|
|
}
|
|
return shmaddr;
|
|
}
|
|
|
|
abi_long target_shmdt(abi_ulong shmaddr)
|
|
{
|
|
abi_long rv;
|
|
|
|
/* shmdt pointers are always untagged */
|
|
|
|
WITH_MMAP_LOCK_GUARD() {
|
|
abi_ulong last = shm_region_find(shmaddr);
|
|
if (last == 0) {
|
|
return -TARGET_EINVAL;
|
|
}
|
|
|
|
rv = get_errno(shmdt(g2h_untagged(shmaddr)));
|
|
if (rv == 0) {
|
|
abi_ulong size = last - shmaddr + 1;
|
|
|
|
page_set_flags(shmaddr, last, 0);
|
|
shm_region_rm_complete(shmaddr, last);
|
|
mmap_reserve_or_unmap(shmaddr, size);
|
|
}
|
|
}
|
|
return rv;
|
|
}
|