diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-09 09:36:17 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-09 09:36:17 -0700 |
commit | 0f506c7f7d3d8d68a1a020c3d914390b3ffc30d0 (patch) | |
tree | 01db087426b3bac0e553cbf2ddee1e0dedf43291 | |
parent | 87aceaa7f083cd4e77e28943bc5535ef34ead498 (diff) | |
parent | 99a670b2069c725a7b50318aa681d9cae8f89325 (diff) |
Merge tag 'riscv-for-linus-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
- A fix to avoid ISA-disallowed privilege mappings that can result from
WRITE+EXEC mmap requests from userspace.
- A fix for kfence to handle the huge pages.
- A fix to avoid converting misaligned VAs to huge pages.
- ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE has been selected so kprobe
can understand user pointers.
* tag 'riscv-for-linus-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: fix kprobe __user string arg print fault issue
riscv: Check the virtual alignment before choosing a map size
riscv: Fix kfence now that the linear mapping can be backed by PUD/P4D/PGD
riscv: mm: Ensure prot of VM_WRITE and VM_EXEC must be readable
-rw-r--r-- | arch/riscv/Kconfig | 1 | ||||
-rw-r--r-- | arch/riscv/include/asm/kfence.h | 33 | ||||
-rw-r--r-- | arch/riscv/include/asm/pgtable.h | 3 | ||||
-rw-r--r-- | arch/riscv/mm/init.c | 48 |
4 files changed, 39 insertions, 46 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 2bb0c38419ff..5966ad97c30c 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -26,6 +26,7 @@ config RISCV select ARCH_HAS_GIGANTIC_PAGE select ARCH_HAS_KCOV select ARCH_HAS_MMIOWB + select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SET_DIRECT_MAP if MMU diff --git a/arch/riscv/include/asm/kfence.h b/arch/riscv/include/asm/kfence.h index d887a54042aa..0bbffd528096 100644 --- a/arch/riscv/include/asm/kfence.h +++ b/arch/riscv/include/asm/kfence.h @@ -8,41 +8,8 @@ #include <asm-generic/pgalloc.h> #include <asm/pgtable.h> -static inline int split_pmd_page(unsigned long addr) -{ - int i; - unsigned long pfn = PFN_DOWN(__pa((addr & PMD_MASK))); - pmd_t *pmd = pmd_off_k(addr); - pte_t *pte = pte_alloc_one_kernel(&init_mm); - - if (!pte) - return -ENOMEM; - - for (i = 0; i < PTRS_PER_PTE; i++) - set_pte(pte + i, pfn_pte(pfn + i, PAGE_KERNEL)); - set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(pte)), PAGE_TABLE)); - - flush_tlb_kernel_range(addr, addr + PMD_SIZE); - return 0; -} - static inline bool arch_kfence_init_pool(void) { - int ret; - unsigned long addr; - pmd_t *pmd; - - for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr); - addr += PAGE_SIZE) { - pmd = pmd_off_k(addr); - - if (pmd_leaf(*pmd)) { - ret = split_pmd_page(addr); - if (ret) - return false; - } - } - return true; } diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 2258b27173b0..75970ee2bda2 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -165,8 +165,7 @@ extern struct pt_alloc_ops pt_ops __initdata; _PAGE_EXEC | _PAGE_WRITE) #define PAGE_COPY PAGE_READ -#define PAGE_COPY_EXEC PAGE_EXEC -#define PAGE_COPY_READ_EXEC PAGE_READ_EXEC +#define PAGE_COPY_EXEC PAGE_READ_EXEC #define PAGE_SHARED PAGE_WRITE #define PAGE_SHARED_EXEC PAGE_WRITE_EXEC diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index c6bb966e4123..4fa420faa780 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -23,6 +23,7 @@ #ifdef CONFIG_RELOCATABLE #include <linux/elf.h> #endif +#include <linux/kfence.h> #include <asm/fixmap.h> #include <asm/tlbflush.h> @@ -293,7 +294,7 @@ static const pgprot_t protection_map[16] = { [VM_EXEC] = PAGE_EXEC, [VM_EXEC | VM_READ] = PAGE_READ_EXEC, [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC, - [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_READ_EXEC, + [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC, [VM_SHARED] = PAGE_NONE, [VM_SHARED | VM_READ] = PAGE_READ, [VM_SHARED | VM_WRITE] = PAGE_SHARED, @@ -659,18 +660,19 @@ void __init create_pgd_mapping(pgd_t *pgdp, create_pgd_next_mapping(nextp, va, pa, sz, prot); } -static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) +static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va, + phys_addr_t size) { - if (!(base & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE) + if (!(pa & (PGDIR_SIZE - 1)) && !(va & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE) return PGDIR_SIZE; - if (!(base & (P4D_SIZE - 1)) && size >= P4D_SIZE) + if (!(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) return P4D_SIZE; - if (!(base & (PUD_SIZE - 1)) && size >= PUD_SIZE) + if (!(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) return PUD_SIZE; - if (!(base & (PMD_SIZE - 1)) && size >= PMD_SIZE) + if (!(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) return PMD_SIZE; return PAGE_SIZE; @@ -1167,14 +1169,16 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) } static void __init create_linear_mapping_range(phys_addr_t start, - phys_addr_t end) + phys_addr_t end, + uintptr_t fixed_map_size) { phys_addr_t pa; uintptr_t va, map_size; for (pa = start; pa < end; pa += map_size) { va = (uintptr_t)__va(pa); - map_size = best_map_size(pa, end - pa); + map_size = fixed_map_size ? fixed_map_size : + best_map_size(pa, va, end - pa); create_pgd_mapping(swapper_pg_dir, va, pa, map_size, pgprot_from_va(va)); @@ -1184,6 +1188,7 @@ static void __init create_linear_mapping_range(phys_addr_t start, static void __init create_linear_mapping_page_table(void) { phys_addr_t start, end; + phys_addr_t kfence_pool __maybe_unused; u64 i; #ifdef CONFIG_STRICT_KERNEL_RWX @@ -1197,6 +1202,19 @@ static void __init create_linear_mapping_page_table(void) memblock_mark_nomap(krodata_start, krodata_size); #endif +#ifdef CONFIG_KFENCE + /* + * kfence pool must be backed by PAGE_SIZE mappings, so allocate it + * before we setup the linear mapping so that we avoid using hugepages + * for this region. + */ + kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); + BUG_ON(!kfence_pool); + + memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE); + __kfence_pool = __va(kfence_pool); +#endif + /* Map all memory banks in the linear mapping */ for_each_mem_range(i, &start, &end) { if (start >= end) @@ -1207,17 +1225,25 @@ static void __init create_linear_mapping_page_table(void) if (end >= __pa(PAGE_OFFSET) + memory_limit) end = __pa(PAGE_OFFSET) + memory_limit; - create_linear_mapping_range(start, end); + create_linear_mapping_range(start, end, 0); } #ifdef CONFIG_STRICT_KERNEL_RWX - create_linear_mapping_range(ktext_start, ktext_start + ktext_size); + create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0); create_linear_mapping_range(krodata_start, - krodata_start + krodata_size); + krodata_start + krodata_size, 0); memblock_clear_nomap(ktext_start, ktext_size); memblock_clear_nomap(krodata_start, krodata_size); #endif + +#ifdef CONFIG_KFENCE + create_linear_mapping_range(kfence_pool, + kfence_pool + KFENCE_POOL_SIZE, + PAGE_SIZE); + + memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); +#endif } static void __init setup_vm_final(void) |