Re: [PATCH] mm/vmalloc: Fix regression caused by needless vmalloc_sync_all()

From: Joerg Roedel
Date: Thu Nov 14 2019 - 12:14:47 EST


On Thu, Nov 14, 2019 at 10:40:22PM +0800, Shile Zhang wrote:
> Could you please help to recall the original issue you encountered before?

The original issue was data corruption because old mappings did not get
removed from the vmalloc area, and thus also new mappings did not get
faulted in. So depending on the page-table currently loaded one
vmalloc/ioremap area pointed to different (often already freed or
re-used) memory and caused the corruption.

Regards,

Joerg