map_range() uses HW PTE pointers to build early translation tables at each level. Directly testing, decoding, or assigning *tbl treats an HW PTE as a SW PTE value, which requires explicit conversion once hw_pte_t becomes distinct. Use __ptep_get() to load a SW PTE value for the empty-entry check and child-table address, and __set_pte_nosync() to convert SW PTE values to HW PTEs on stores. The no-sync helper performs WRITE_ONCE() without adding the completion barriers used by __set_pte(). Reviewed-by: Ryan Roberts Signed-off-by: Muhammad Usama Anjum --- arch/arm64/kernel/pi/map_range.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kernel/pi/map_range.c b/arch/arm64/kernel/pi/map_range.c index 94f06da76e333..9c4c8060c5df4 100644 --- a/arch/arm64/kernel/pi/map_range.c +++ b/arch/arm64/kernel/pi/map_range.c @@ -51,19 +51,21 @@ void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa, while (start < end) { u64 next = min((start | lmask) + 1, PAGE_ALIGN(end)); + pte_t entry = __ptep_get(tbl); if (level < 2 || (level == 2 && (start | next | pa) & lmask)) { /* * This chunk needs a finer grained mapping. Create a * table mapping if necessary and recurse. */ - if (pte_none(*tbl)) { - *tbl = __pte(__phys_to_pte_val(*pte) | + if (pte_none(entry)) { + entry = __pte(__phys_to_pte_val(*pte) | PMD_TYPE_TABLE | PMD_TABLE_UXN); - *pte += PTRS_PER_PTE * sizeof(pte_t); + __set_pte_nosync(tbl, entry); + *pte += PTRS_PER_PTE * sizeof(hw_pte_t); } map_range(pte, start, next, pa, prot, level + 1, - (hw_pte_t *)(__pte_to_phys(*tbl) + va_offset), + (hw_pte_t *)(__pte_to_phys(entry) + va_offset), may_use_cont, va_offset); } else { /* @@ -81,7 +83,8 @@ void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa, protval &= ~PTE_CONT; /* Put down a block or page mapping */ - *tbl = __pte(__phys_to_pte_val(pa) | protval); + entry = __pte(__phys_to_pte_val(pa) | protval); + __set_pte_nosync(tbl, entry); } pa += next - start; start = next; -- 2.47.3