From: Anton Blanchard On success getaffinity should return the size of mask. It looks like Randy's patch (which fixed a bogus return) missed this bit. In reality I'm not sure if we care, and with cpu bitmasks this stuff is going to break. kernel/compat.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletion(-) diff -puN kernel/compat.c~getaffinity-return-val-fix kernel/compat.c --- 25/kernel/compat.c~getaffinity-return-val-fix 2003-07-13 19:55:11.000000000 -0700 +++ 25-akpm/kernel/compat.c 2003-07-13 19:55:11.000000000 -0700 @@ -425,9 +425,11 @@ asmlinkage int compat_sys_sched_getaffin &kernel_mask); set_fs(old_fs); - if (ret > 0) + if (ret > 0) { + ret = sizeof(compat_ulong_t); if (put_user(kernel_mask, user_mask_ptr)) return -EFAULT; + } return ret; } _