Hi Anshuman,
On 7/19/21 3:41 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 access 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 old implementation.
PATCH[12] fixes the issue of corrupted page flag for ARM64
Changelog
=========
v2:
* Rename struct vm_pgtable_debug to struct pgtable_debug_args.
The parameter name to various test functions are renamed
to "@args" (Anshuman)
* Code changes as suggested by Anshuman (Anshuman)
Please ignore v2. I will post v3 to fix couple of issues in v2:
(1) The subjects of PATCH[5/12] and PATCH[9/12] should be fixed to
start with "mm/debug_vm_pgtable".
(2) "WARN_ON(!pud_none(pud))" is missed in PATCH[9/12]. Otherwise,
build warning for unused variable @pud is raised.
(3) Build warnings for unused variables in separate patches are
raised, reported by 0-DAY CI Kernel Test Service.
Thanks,
Gavin
Gavin Shan (12):
mm/debug_vm_pgtable: Introduce struct pgtable_debug_args
mm/debug_vm_pgtable: Use struct pgtable_debug_args in basic tests
mm/debug_vm_pgtable: Use struct pgtable_debug_args in leaf and
savewrite tests
mm/debug_vm_pgtable: Use struct pgtable_debug_args in protnone and
devmap tests
mm/vm_debug_pgtable: Use struct pgtable_debug_args in soft_dirty and
swap tests
mm/debug_vm_pgtable: Use struct pgtable_debug_args in migration and
thp tests
mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying
tests
mm/debug_vm_pgtable: Use struct pgtable_debug_args in PMD
mm/vm_debug_pgtable: Use struct pgtable_debug_args in PUD modifying
tests
mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D
modifying tests
mm/debug_vm_pgtable: Remove unused code
mm/debug_vm_pgtable: Fix corrupted page flag
mm/debug_vm_pgtable.c | 849 ++++++++++++++++++++++++------------------
1 file changed, 479 insertions(+), 370 deletions(-)
