On 8/13/21 2:25 AM, Gavin Shan wrote:
Hi Anshuman and Vineet,
On 8/12/21 9:11 PM, Anshuman Khandual wrote:
On 8/9/21 2:56 PM, Gavin Shan wrote:
There are couple of issues with current implementations and this series
tries to resolve the issues:
(a) All needed information are scattered in variables, passed to
various
test functions. The code is organized in pretty much relaxed
fashion.
(b) The page isn't allocated from buddy during page table entry
modifying
tests. The page can be invalid, conflicting to the
implementations
of set_xxx_at() on ARM64. The target page is accessed so that
the
iCache can be flushed when execution permission is given on
ARM64.
Besides, the target page can be unmapped and accessing to it
causes
kernel crash.
"struct pgtable_debug_args" is introduced to address issue (a). For
issue
(b), the used page is allocated from buddy in page table entry
modifying
tests. The corresponding tets will be skipped if we fail to allocate
the
(huge) page. For other test cases, the original page around to kernel
symbol (@start_kernel) is still used.
The patches are organized as below. PATCH[2-10] could be combined to
one
patch, but it will make the review harder:
PATCH[1] introduces "struct pgtable_debug_args" as place holder
of all
needed information. With it, the old and new implementation
can coexist.
PATCH[2-10] uses "struct pgtable_debug_args" in various test
functions.
PATCH[11] removes the unused code for old implementation.
PATCH[12] fixes the issue of corrupted page flag for ARM64
Changelog
=========
v6:
* Populate saved page table entry pointers after
they're allocated in init_args() (Anshuman)
* Fix imbalanced preemption count issue by replacing
pte_alloc_mmap() with pte_alloc() in init_args() (syzbot)
+ vgupta@xxxxxxxxxx
Please also keep linux-snps-arc CC'ed for ARC changes.
Hello Gavin/Vineet,
This series still need to be tested on ARC ?
Yes, I'm unable to test ARC as it's not supported by QEMU yet.
It would great if Vineet can give it a try on ARC :)
We do have a working QEMU (in the process of being upstreamed) you could try
https://github.com/foss-for-synopsys-dwc-arc-processors/qemu #master
Is this code in some shared git repo we can pull - instead of apply 8 files.
Thx,
-Vineet
