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-rw-r--r--linux-user/mmap.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index b5e31f5821..794b1d05eb 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -157,6 +157,8 @@ static abi_ulong mmap_next_start = 0x18000000;
static abi_ulong mmap_next_start = 0x40000000;
#endif
+unsigned long last_brk;
+
/* find a free memory area of size 'size'. The search starts at
'start'. If 'start' == 0, then a default start address is used.
Return -1 if error.
@@ -167,6 +169,20 @@ static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
{
abi_ulong addr, addr1, addr_start;
int prot;
+ unsigned long new_brk;
+
+ new_brk = (unsigned long)sbrk(0);
+ if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) {
+ /* This is a hack to catch the host allocating memory with brk().
+ If it uses mmap then we loose.
+ FIXME: We really want to avoid the host allocating memory in
+ the first place, and maybe leave some slack to avoid switching
+ to mmap. */
+ page_set_flags(last_brk & TARGET_PAGE_MASK,
+ TARGET_PAGE_ALIGN(new_brk),
+ PAGE_RESERVED);
+ }
+ last_brk = new_brk;
size = HOST_PAGE_ALIGN(size);
start = start & qemu_host_page_mask;