riscv: Fix kasan pud population

In sv48, the kasan inner regions are not aligned on PGDIR_SIZE and then
when we populate the kasan linear mapping region, we clear the kasan
vmalloc region which is in the same PGD.

Fix this by copying the content of the kasan early pud after allocating a
new PGD for the first time.

Fixes: e8a62cc26ddf ("riscv: Implement sv48 support")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index 85e849318389c6ae62b91ce388089c43a0e3e27a..cd1a145257b7cd9f2a4ad8d225925772bf2151d3 100644 (file)
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -113,8 +113,11 @@ static void __init kasan_populate_pud(pgd_t *pgd,
                base_pud = pt_ops.get_pud_virt(pfn_to_phys(_pgd_pfn(*pgd)));
        } else {
                base_pud = (pud_t *)pgd_page_vaddr(*pgd);
-               if (base_pud == lm_alias(kasan_early_shadow_pud))
+               if (base_pud == lm_alias(kasan_early_shadow_pud)) {
                        base_pud = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE);
+                       memcpy(base_pud, (void *)kasan_early_shadow_pud,
+                              sizeof(pud_t) * PTRS_PER_PUD);
+               }
        }
 
        pudp = base_pud + pud_index(vaddr);