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-rw-r--r--exec.c1
-rw-r--r--linux-user/mmap.c16
-rw-r--r--linux-user/qemu.h1
3 files changed, 18 insertions, 0 deletions
diff --git a/exec.c b/exec.c
index 544e111..a2e71f0 100644
--- a/exec.c
+++ b/exec.c
@@ -234,6 +234,7 @@ static void page_init(void)
FILE *f;
int n;
+ last_brk = (unsigned long)sbrk(0);
f = fopen("/proc/self/maps", "r");
if (f) {
do {
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index b5e31f5..794b1d0 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;
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 8b11495..093b8ff 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -232,6 +232,7 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
abi_ulong new_size, unsigned long flags,
abi_ulong new_addr);
int target_msync(abi_ulong start, abi_ulong len, int flags);
+extern unsigned long last_brk;
/* user access */