diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 475d243f3b..b5cb21384a 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; }