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-rw-r--r--linux-user/elfload.c31
1 files changed, 17 insertions, 14 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 475d243..b5cb213 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -389,7 +389,7 @@ static bool init_guest_commpage(void)
{
void *want = g2h(ARM_COMMPAGE & -qemu_host_page_size);
void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
- MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
if (addr == MAP_FAILED) {
perror("Allocating guest commpage");
@@ -2113,7 +2113,8 @@ static void pgb_have_guest_base(const char *image_name, abi_ulong guest_loaddr,
* only dumbly iterate up the host address space seeing if the
* allocation would work.
*/
-static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, long align)
+static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk,
+ long align, uintptr_t offset)
{
uintptr_t base;
@@ -2123,7 +2124,7 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, lon
while (true) {
uintptr_t align_start, end;
align_start = ROUND_UP(base, align);
- end = align_start + guest_size;
+ end = align_start + guest_size + offset;
/* if brk is anywhere in the range give ourselves some room to grow. */
if (align_start <= brk && brk < end) {
@@ -2138,7 +2139,7 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, lon
PROT_NONE, flags, -1, 0);
if (mmap_start != MAP_FAILED) {
munmap((void *) align_start, guest_size);
- return (uintptr_t) mmap_start;
+ return (uintptr_t) mmap_start + offset;
}
base += qemu_host_page_size;
}
@@ -2147,7 +2148,7 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, lon
/* Return value for guest_base, or -1 if no hole found. */
static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
- long align)
+ long align, uintptr_t offset)
{
GSList *maps, *iter;
uintptr_t this_start, this_end, next_start, brk;
@@ -2161,7 +2162,7 @@ static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
brk = (uintptr_t)sbrk(0);
if (!maps) {
- return pgd_find_hole_fallback(guest_size, brk, align);
+ return pgd_find_hole_fallback(guest_size, brk, align, offset);
}
/* The first hole is before the first map entry. */
@@ -2173,7 +2174,7 @@ static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
this_end = ((MapInfo *)iter->data)->start;
next_start = ((MapInfo *)iter->data)->end;
- align_start = ROUND_UP(this_start, align);
+ align_start = ROUND_UP(this_start + offset, align);
/* Skip holes that are too small. */
if (align_start >= this_end) {
@@ -2223,6 +2224,7 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
{
uintptr_t loaddr = orig_loaddr;
uintptr_t hiaddr = orig_hiaddr;
+ uintptr_t offset = 0;
uintptr_t addr;
if (hiaddr != orig_hiaddr) {
@@ -2236,18 +2238,19 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
if (ARM_COMMPAGE) {
/*
* Extend the allocation to include the commpage.
- * For a 64-bit host, this is just 4GiB; for a 32-bit host,
- * the address arithmetic will wrap around, but the difference
- * will produce the correct allocation size.
+ * For a 64-bit host, this is just 4GiB; for a 32-bit host we
+ * need to ensure there is space bellow the guest_base so we
+ * can map the commpage in the place needed when the address
+ * arithmetic wraps around.
*/
if (sizeof(uintptr_t) == 8 || loaddr >= 0x80000000u) {
- hiaddr = (uintptr_t)4 << 30;
+ hiaddr = (uintptr_t) 4 << 30;
} else {
- loaddr = ARM_COMMPAGE & -align;
+ offset = -(ARM_COMMPAGE & -align);
}
}
- addr = pgb_find_hole(loaddr, hiaddr - loaddr, align);
+ addr = pgb_find_hole(loaddr, hiaddr - loaddr, align, offset);
if (addr == -1) {
/*
* If ARM_COMMPAGE, there *might* be a non-consecutive allocation
@@ -2282,7 +2285,7 @@ static void pgb_dynamic(const char *image_name, long align)
* just above that, and maximises the positive guest addresses.
*/
commpage = ARM_COMMPAGE & -align;
- addr = pgb_find_hole(commpage, -commpage, align);
+ addr = pgb_find_hole(commpage, -commpage, align, 0);
assert(addr != -1);
guest_base = addr;
}