From d566bea4a638ff0ae824df804bc08818bace41a5 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Tue, 8 Aug 2023 15:07:09 +0200 Subject: [PATCH] riscv: Do not allow vmap pud mappings for 3-level page table The vmalloc_fault() path was removed and to avoid syncing the vmalloc PGD mappings, they are now preallocated. But if the kernel can use a PUD mapping (which in sv39 is actually a PGD mapping) for large vmalloc allocation, it will free the current unused preallocated PGD mapping and install a new leaf one. Since there is no sync anymore, some page tables lack this new mapping and that triggers a panic. So only allow PUD mappings for sv48 and sv57. Fixes: 7d3332be011e ("riscv: mm: Pre-allocate PGD entries for vmalloc/modules area") Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20230808130709.1502614-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vmalloc.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/vmalloc.h b/arch/riscv/include/asm/vmalloc.h index 58d3e44..924d01b 100644 --- a/arch/riscv/include/asm/vmalloc.h +++ b/arch/riscv/include/asm/vmalloc.h @@ -3,12 +3,14 @@ #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +extern bool pgtable_l4_enabled, pgtable_l5_enabled; + #define IOREMAP_MAX_ORDER (PUD_SHIFT) #define arch_vmap_pud_supported arch_vmap_pud_supported static inline bool arch_vmap_pud_supported(pgprot_t prot) { - return true; + return pgtable_l4_enabled || pgtable_l5_enabled; } #define arch_vmap_pmd_supported arch_vmap_pmd_supported -- 2.7.4