[PATCH 0/9] Use vm_insert_range and vm_insert_range_buggy

From: Souptick Joarder
Date: Fri Jan 11 2019 - 10:01:48 EST


Previouly drivers have their own way of mapping range of
kernel pages/memory into user vma and this was done by
invoking vm_insert_page() within a loop.

As this pattern is common across different drivers, it can
be generalized by creating new functions and use it across
the drivers.

vm_insert_range() is the API which could be used to mapped
kernel memory/pages in drivers which has considered vm_pgoff

vm_insert_range_buggy() is the API which could be used to map
range of kernel memory/pages in drivers which has not considered
vm_pgoff. vm_pgoff is passed default as 0 for those drivers.

We _could_ then at a later "fix" these drivers which are using
vm_insert_range_buggy() to behave according to the normal vm_pgoff
offsetting simply by removing the _buggy suffix on the function
name and if that causes regressions, it gives us an easy way to revert.

There is an existing bug in [7/9], where user passed length is not
verified against object_count. For any value of length > object_count
it will end up overrun page array which could lead to a potential bug.
This is fixed as part of these conversion.

Souptick Joarder (9):
mm: Introduce new vm_insert_range and vm_insert_range_buggy API
arch/arm/mm/dma-mapping.c: Convert to use vm_insert_range
drivers/firewire/core-iso.c: Convert to use vm_insert_range_buggy
drm/rockchip/rockchip_drm_gem.c: Convert to use vm_insert_range
drm/xen/xen_drm_front_gem.c: Convert to use vm_insert_range
iommu/dma-iommu.c: Convert to use vm_insert_range
videobuf2/videobuf2-dma-sg.c: Convert to use vm_insert_range_buggy
xen/gntdev.c: Convert to use vm_insert_range
xen/privcmd-buf.c: Convert to use vm_insert_range_buggy

arch/arm/mm/dma-mapping.c | 22 ++----
drivers/firewire/core-iso.c | 15 +----
drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 17 +----
drivers/gpu/drm/xen/xen_drm_front_gem.c | 18 ++---
drivers/iommu/dma-iommu.c | 12 +---
drivers/media/common/videobuf2/videobuf2-dma-sg.c | 22 ++----
drivers/xen/gntdev.c | 16 ++---
drivers/xen/privcmd-buf.c | 8 +--
include/linux/mm.h | 4 ++
mm/memory.c | 81 +++++++++++++++++++++++
mm/nommu.c | 14 ++++
11 files changed, 129 insertions(+), 100 deletions(-)

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1.9.1