diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2025-11-28 23:01:05 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2025-12-07 16:15:19 +0100 |
| commit | 6a35d02fec5a1e2ab6c0c94ccc5b0c57a580b098 (patch) | |
| tree | b52b25e9b8bfc537485330acd65b05777766f8b1 /arch/s390/include | |
| parent | 1442bb87b878f889442c7e8e83d9125e31ef5072 (diff) | |
s390/vmem: Support 2G page splitting for KASAN shadow freeing
Export split_pud_page() so it can be used from the vmem code and teach
modify_pud_table() to split PUD-sized mappings when only a subrange
needs to be removed.
If the range to be removed covers a full PUD-sized mapping, keep the
existing behavior: clear the PUD entry and free the backing large page
(for non-direct mappings). Otherwise, split the PUD-mapped page into
PMD mappings and let the walker handle the smaller ranges.
This is needed for KASAN early shadow removal support: memory hotplug
freeing the KASAN early shadow is the only expected caller that will
try to free 2G PUD-mapped regions of non-direct mappings.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/page.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h index 9240a363c893..c1d63b613bf9 100644 --- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -166,6 +166,8 @@ static inline int page_reset_referenced(unsigned long addr) return CC_TRANSFORM(cc); } +int split_pud_page(pud_t *pudp, unsigned long addr); + /* Bits int the storage key */ #define _PAGE_CHANGED 0x02 /* HW changed bit */ #define _PAGE_REFERENCED 0x04 /* HW referenced bit */ |