linux-next: build warnings

From: Stephen Rothwell
Date: Tue May 02 2017 - 02:05:57 EST


Hi all,

The linux-next build (powerpc allyesconfig) produced these warnings
(and have for a while):

arch/powerpc/kvm/book3s_pr_papr.c: In function 'kvmppc_h_pr_enter':
arch/powerpc/kvm/book3s_pr_papr.c:53:2: warning: ignoring return value of 'copy_from_user', declared with attribute warn_unused_result [-Wunused-result]
copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg));
^
arch/powerpc/kvm/book3s_pr_papr.c:74:2: warning: ignoring return value of 'copy_to_user', declared with attribute warn_unused_result [-Wunused-result]
copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE);
^
arch/powerpc/kvm/book3s_pr_papr.c: In function 'kvmppc_h_pr_remove':
arch/powerpc/kvm/book3s_pr_papr.c:96:2: warning: ignoring return value of 'copy_from_user', declared with attribute warn_unused_result [-Wunused-result]
copy_from_user(pte, (void __user *)pteg, sizeof(pte));
^
arch/powerpc/kvm/book3s_pr_papr.c:106:2: warning: ignoring return value of 'copy_to_user', declared with attribute warn_unused_result [-Wunused-result]
copy_to_user((void __user *)pteg, &v, sizeof(v));
^
arch/powerpc/kvm/book3s_pr_papr.c: In function 'kvmppc_h_pr_protect':
arch/powerpc/kvm/book3s_pr_papr.c:214:2: warning: ignoring return value of 'copy_from_user', declared with attribute warn_unused_result [-Wunused-result]
copy_from_user(pte, (void __user *)pteg, sizeof(pte));
^
arch/powerpc/kvm/book3s_pr_papr.c:237:2: warning: ignoring return value of 'copy_to_user', declared with attribute warn_unused_result [-Wunused-result]
copy_to_user((void __user *)pteg, pte, sizeof(pte));
^
arch/powerpc/kvm/book3s_pr_papr.c: In function 'kvmppc_h_pr_bulk_remove':
arch/powerpc/kvm/book3s_pr_papr.c:174:3: warning: ignoring return value of 'copy_from_user', declared with attribute warn_unused_result [-Wunused-result]
copy_from_user(pte, (void __user *)pteg, sizeof(pte));
^
arch/powerpc/kvm/book3s_pr_papr.c:187:4: warning: ignoring return value of 'copy_to_user', declared with attribute warn_unused_result [-Wunused-result]
copy_to_user((void __user *)pteg, &v, sizeof(v));
^

These calls have been there since about v3.1-rc8. I assume the
copy_to/from_user() work has pointed them out.

--
Cheers,
Stephen Rothwell