On 8/13/21 2:25 AM, Gavin Shan wrote:

Hi Anshuman and Vineet,

On 8/12/21 9:11 PM, Anshuman Khandual wrote:

quoted

On 8/9/21 2:56 PM, Gavin Shan wrote:

quoted

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@kernel.org

Please also keep linux-snps-arc CC'ed for ARC changes.

quoted

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