| Message ID | 1473772468-2579745-1-git-send-email-snarpix@gmail.com |
|---|---|
| State | New |
| Headers | show |
Please ignore this patch. Issue was in another place, and proposed solution is simply wrong. 2016-09-13 16:14 GMT+03:00 Stanislav Shmarov <snarpix@gmail.com>: > When application is trying to allocate memory through brk > QEMU is allocating host memory using mmap. > Without MAP_FIXED attribute it is possible that memory will > never be allocated in desired place, and brk syscall will > act like there is no avalible memory. > > Signed-off-by: Stanislav Shmarov <snarpix@gmail.com> > --- > linux-user/syscall.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index ca06943..2861db2 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -1030,7 +1030,8 @@ abi_long do_brk(abi_ulong new_brk) > new_alloc_size = HOST_PAGE_ALIGN(new_brk - brk_page); > mapped_addr = get_errno(target_mmap(brk_page, new_alloc_size, > PROT_READ|PROT_WRITE, > - MAP_ANON|MAP_PRIVATE, 0, 0)); > + MAP_ANON | MAP_PRIVATE | > MAP_FIXED, > + 0, 0)); > > if (mapped_addr == brk_page) { > /* Heap contents are initialized to zero, as for anonymous > -- > 1.9.3 > >
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index ca06943..2861db2 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -1030,7 +1030,8 @@ abi_long do_brk(abi_ulong new_brk) new_alloc_size = HOST_PAGE_ALIGN(new_brk - brk_page); mapped_addr = get_errno(target_mmap(brk_page, new_alloc_size, PROT_READ|PROT_WRITE, - MAP_ANON|MAP_PRIVATE, 0, 0)); + MAP_ANON | MAP_PRIVATE | MAP_FIXED, + 0, 0)); if (mapped_addr == brk_page) { /* Heap contents are initialized to zero, as for anonymous
When application is trying to allocate memory through brk QEMU is allocating host memory using mmap. Without MAP_FIXED attribute it is possible that memory will never be allocated in desired place, and brk syscall will act like there is no avalible memory. Signed-off-by: Stanislav Shmarov <snarpix@gmail.com> --- linux-user/syscall.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)