From 143cf23df25b7082cd706c3c53188e741e7881c3 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Fri, 9 May 2014 16:54:15 +0200 Subject: [PATCH] sched: Make sched_setattr() correctly return -EFBIG 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: Cc: Linus Torvalds Link: http://lkml.kernel.org/r/536CEC17.9070903@gmail.com Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 13584f1cccfc..f2205f02eb70 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3658,8 +3658,9 @@ 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; rcu_read_lock(); retval = -ESRCH; -- 2.20.1