Re: [PATCH] misc: cxl: Change return type to vm_fault_t

From: Frederic Barrat
Date: Fri May 11 2018 - 06:24:42 EST




Le 17/04/2018 Ã 16:53, Souptick Joarder a ÃcritÂ:
Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.

Reference id -> 1c8f422059ae ("mm: change return type to
vm_fault_t")

previously cxl_mmap_fault returns VM_FAULT_NOPAGE as
default value irrespective of vm_insert_pfn() return
value. This bug is fixed with new vmf_insert_pfn()
which will return VM_FAULT_ type based on err.

Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
---

It looks ok, and it passed some basic testing.

Acked-by: Frederic Barrat <fbarrat@xxxxxxxxxxxxxxxxxx>

Fred


drivers/misc/cxl/context.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index 7ff315a..c6ec872 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -128,11 +128,12 @@ void cxl_context_set_mapping(struct cxl_context *ctx,
mutex_unlock(&ctx->mapping_lock);
}

-static int cxl_mmap_fault(struct vm_fault *vmf)
+static vm_fault_t cxl_mmap_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct cxl_context *ctx = vma->vm_file->private_data;
u64 area, offset;
+ vm_fault_t ret;

offset = vmf->pgoff << PAGE_SHIFT;

@@ -169,11 +170,11 @@ static int cxl_mmap_fault(struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}

- vm_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);
+ ret = vmf_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);

mutex_unlock(&ctx->status_mutex);

- return VM_FAULT_NOPAGE;
+ return ret;
}

static const struct vm_operations_struct cxl_mmap_vmops = {
--
1.9.1