Message ID | 4DABE25F.8000203@samsung.com |
---|---|
State | New |
Headers | show |
On Mon, Apr 18, 2011 at 8:03 AM, Mike McCormack <mj.mccormack@samsung.com> wrote: > The kernel doesn't fill the buffer provided to sched_getaffinity > with zero bytes, so neither should QEMU. > > Depends on sched_getaffinity buffer overrun fix, but submitted > separately to make rollback easier. > > --- > linux-user/syscall.c | 13 +------------ > 1 files changed, 1 insertions(+), 12 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 19209a2..e2a5fd9 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6382,20 +6382,9 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, ret = get_errno(sys_sched_getaffinity(arg1, mask_size, mask)); if (!is_error(ret)) { - if (arg2 > ret) { - /* Zero out any extra space kernel didn't fill */ - unsigned long zero = arg2 - ret; - p = alloca(zero); - memset(p, 0, zero); - if (copy_to_user(arg3 + ret, p, zero)) { - goto efault; - } - arg2 = ret; - } - if (copy_to_user(arg3, mask, arg2)) { + if (copy_to_user(arg3, mask, ret)) { goto efault; } - ret = arg2; } } break;