summaryrefslogtreecommitdiffstats
path: root/drivers/misc
diff options
context:
space:
mode:
authorChristophe Lombard <clombard@linux.vnet.ibm.com>2017-09-26 10:15:21 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2017-09-29 14:19:44 +1000
commit4fc0870d7e462fe3b86e0f938ae75ce884728c7d (patch)
tree8158b9a7dff59c19adef53198ecd7f89dc8ac4ed /drivers/misc
parentbca73f595a566f0262967535bb5b2ea9c4271d9a (diff)
downloadlinux-4fc0870d7e462fe3b86e0f938ae75ce884728c7d.tar.bz2
cxl: Fix memory page not handled
The in-kernel 'library' API can be called by drivers to help interaction with an IBM XSL on a POWER9 system. The cxllib_handle_fault() API is used to handle memory fault. All memory pages of the specified buffer have to be handled but under certain conditions,the last page may not be touched, and the address the adapter is trying to access is never sent to the kernel for resolution. This patch reworks start address of the loop with an address aligned on the page size. In this context, the last page is not missed. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Fixes: 3ced8d730063 ("cxl: Export library to support IBM XSL"); Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/cxl/cxllib.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/misc/cxl/cxllib.c b/drivers/misc/cxl/cxllib.c
index 5dba23ca2e5f..dc9bc1807fdf 100644
--- a/drivers/misc/cxl/cxllib.c
+++ b/drivers/misc/cxl/cxllib.c
@@ -219,8 +219,17 @@ int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags)
down_read(&mm->mmap_sem);
- for (dar = addr; dar < addr + size; dar += page_size) {
- if (!vma || dar < vma->vm_start || dar > vma->vm_end) {
+ vma = find_vma(mm, addr);
+ if (!vma) {
+ pr_err("Can't find vma for addr %016llx\n", addr);
+ rc = -EFAULT;
+ goto out;
+ }
+ /* get the size of the pages allocated */
+ page_size = vma_kernel_pagesize(vma);
+
+ for (dar = (addr & ~(page_size - 1)); dar < (addr + size); dar += page_size) {
+ if (dar < vma->vm_start || dar >= vma->vm_end) {
vma = find_vma(mm, addr);
if (!vma) {
pr_err("Can't find vma for addr %016llx\n", addr);