From: Michael Kerrisk Date: Fri, 9 May 2014 14:54:15 +0000 (+0200) Subject: sched: Make sched_setattr() correctly return -EFBIG X-Git-Tag: v3.14.7~46 X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=49123dda5f51ebb79ec4359b5244a21cf122844b;p=unionfs-2.6.39.y.git sched: Make sched_setattr() correctly return -EFBIG commit 143cf23df25b7082cd706c3c53188e741e7881c3 upstream. The documented[1] behavior of sched_attr() in the proposed man page text is: sched_attr::size must be set to the size of the structure, as in sizeof(struct sched_attr), if the provided structure is smaller than the kernel structure, any additional fields are assumed '0'. If the provided structure is larger than the kernel structure, the kernel verifies all additional fields are '0' if not the syscall will fail with -E2BIG. As currently implemented, sched_copy_attr() returns -EFBIG for for this case, but the logic in sys_sched_setattr() converts that error to -EFAULT. This patch fixes the behavior. [1] http://thread.gmane.org/gmane.linux.kernel/1615615/focus=1697760 Signed-off-by: Michael Kerrisk Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/r/536CEC17.9070903@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index dbe44b5c02f..55dc8036ea7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3680,8 +3680,9 @@ SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, if (!uattr || pid < 0 || flags) return -EINVAL; - if (sched_copy_attr(uattr, &attr)) - return -EFAULT; + retval = sched_copy_attr(uattr, &attr); + if (retval) + return retval; if (attr.sched_policy < 0) return -EINVAL;