Commit 473aaf52 authored Oct 22, 2024 by Claudio Imbrenda Committed by Heiko Carstens Oct 29, 2024

s390/mm/gmap: Fix __gmap_fault() return code



Errors in fixup_user_fault() were masked and -EFAULT was returned for
any error, including out of memory.

Fix this by returning the correct error code. This means that in many
cases the error code will be propagated all the way to userspace.

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20241022120601.167009-5-imbrenda@linux.ibm.com


Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

parent 075fd736

arch/s390/mm/gmap.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -718,13 +718,12 @@ static int __gmap_fault(struct gmap *gmap, unsigned long gaddr, unsigned int fau
		if (IS_ERR_VALUE(vmaddr))
		return vmaddr;

		if (fault_flags & FAULT_FLAG_RETRY_NOWAIT) {
		if (fault_flags & FAULT_FLAG_RETRY_NOWAIT)
		rc = fixup_user_fault_nowait(gmap->mm, vmaddr, fault_flags, &unlocked);
		else
		rc = fixup_user_fault(gmap->mm, vmaddr, fault_flags, &unlocked);
		if (rc)
		return rc;
		} else if (fixup_user_fault(gmap->mm, vmaddr, fault_flags, &unlocked)) {
		return -EFAULT;
		}
		/*
		* In the case that fixup_user_fault unlocked the mmap_lock during
		* fault-in, redo __gmap_translate() to avoid racing with a