Commit 56842841 authored by popcornmix's avatar popcornmix
Browse files

vcsm: Treat EBUSY as success rather than SIGBUS 



Currently if two cores access the same page concurrently one will return VM_FAULT_NOPAGE
and the other VM_FAULT_SIGBUS crashing the user code.

Also report when mapping fails.

Signed-off-by: default avatarpopcornmix <popcornmix@gmail.com>
parent e1b1d822

drivers/char/broadcom/vc_sm/vmcs_sm.c

+9 −0
Original line number Diff line number Diff line
@@ -1181,11 +1181,20 @@ static int vcsm_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 
	switch (ret) {

	case 0:

	case -ERESTARTSYS:

	/*

	* EBUSY is ok: this just means that another thread

	* already did the job.

	*/

	case -EBUSY:

		return VM_FAULT_NOPAGE;

	case -ENOMEM:

	case -EAGAIN:

		pr_err("[%s]: failed to map page pfn:%lx virt:%lx ret:%d\n", __func__,

			pfn, (unsigned long)vmf->virtual_address, ret);

		return VM_FAULT_OOM;

	default:

		pr_err("[%s]: failed to map page pfn:%lx virt:%lx ret:%d\n", __func__,

			pfn, (unsigned long)vmf->virtual_address, ret);

		return VM_FAULT_SIGBUS;

	}

}