From patchwork Wed Sep 19 02:39:53 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: linux-user: fix statfs Date: Tue, 18 Sep 2012 16:39:53 -0000 From: Alexander Graf X-Patchwork-Id: 185387 Message-Id: <1348022393-11312-1-git-send-email-agraf@suse.de> To: qemu-devel qemu-devel Cc: Peter Maydell , riku.voipio@linaro.org The statfs syscall should always memset(0) its full struct extent before writing to it. Newer versions of the syscall use one of the reserved fields for flags, which would otherwise get stale values from uncleaned memory. This fixes libarchive for me, which got confused about the return value of pathconf("/", _PC_REC_XFER_ALIGN) otherwise, as it some times gave old pointers as return value. Signed-off-by: Alexander Graf --- v1 -> v2: - use memset(0, sizeof(arr)) as suggested by peter maydell --- linux-user/syscall.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 6257a04..0dc1efc 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6531,6 +6531,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, __put_user(stfs.f_fsid.__val[0], &target_stfs->f_fsid.val[0]); __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]); __put_user(stfs.f_namelen, &target_stfs->f_namelen); + __put_user(stfs.f_frsize, &target_stfs->f_frsize); + memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare)); unlock_user_struct(target_stfs, arg2, 1); } break; @@ -6559,6 +6561,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, __put_user(stfs.f_fsid.__val[0], &target_stfs->f_fsid.val[0]); __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]); __put_user(stfs.f_namelen, &target_stfs->f_namelen); + __put_user(stfs.f_frsize, &target_stfs->f_frsize); + memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare)); unlock_user_struct(target_stfs, arg3, 1); } break;