diff options
| -rw-r--r-- | exec.c | 1 | ||||
| -rw-r--r-- | linux-user/mmap.c | 16 | ||||
| -rw-r--r-- | linux-user/qemu.h | 1 |
3 files changed, 18 insertions, 0 deletions
diff --git a/exec.c b/exec.c index 544e111366..a2e71f0b80 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 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; diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 8b114954f0..093b8ff8a3 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 */ |