diff options
Diffstat (limited to 'arch/arm64/mm/mmap.c')
| -rw-r--r-- | arch/arm64/mm/mmap.c | 105 |
1 files changed, 80 insertions, 25 deletions
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 3028bacbc4e9..c86c348857c4 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -5,20 +5,34 @@ * Copyright (C) 2012 ARM Ltd. */ -#include <linux/elf.h> -#include <linux/fs.h> +#include <linux/io.h> #include <linux/memblock.h> #include <linux/mm.h> -#include <linux/mman.h> -#include <linux/export.h> -#include <linux/shm.h> -#include <linux/sched/signal.h> -#include <linux/sched/mm.h> -#include <linux/io.h> -#include <linux/personality.h> -#include <linux/random.h> +#include <linux/types.h> + +#include <asm/cpufeature.h> +#include <asm/page.h> -#include <asm/cputype.h> +static pgprot_t protection_map[16] __ro_after_init = { + [VM_NONE] = PAGE_NONE, + [VM_READ] = PAGE_READONLY, + [VM_WRITE] = PAGE_READONLY, + [VM_WRITE | VM_READ] = PAGE_READONLY, + /* PAGE_EXECONLY if Enhanced PAN */ + [VM_EXEC] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_WRITE] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_WRITE | VM_READ] = PAGE_READONLY_EXEC, + [VM_SHARED] = PAGE_NONE, + [VM_SHARED | VM_READ] = PAGE_READONLY, + [VM_SHARED | VM_WRITE] = PAGE_SHARED, + [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, + /* PAGE_EXECONLY if Enhanced PAN */ + [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC +}; /* * You really shouldn't be using read() or write() on /dev/mem. This might go @@ -48,23 +62,64 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK); } -#ifdef CONFIG_STRICT_DEVMEM +static int __init adjust_protection_map(void) +{ + /* + * With Enhanced PAN we can honour the execute-only permissions as + * there is no PAN override with such mappings. + */ + if (cpus_have_cap(ARM64_HAS_EPAN)) { + protection_map[VM_EXEC] = PAGE_EXECONLY; + protection_map[VM_EXEC | VM_SHARED] = PAGE_EXECONLY; + } -#include <linux/ioport.h> + if (lpa2_is_enabled()) + for (int i = 0; i < ARRAY_SIZE(protection_map); i++) + pgprot_val(protection_map[i]) &= ~PTE_SHARED; -/* - * devmem_is_allowed() checks to see if /dev/mem access to a certain address - * is valid. The argument is a physical page number. We mimic x86 here by - * disallowing access to system RAM as well as device-exclusive MMIO regions. - * This effectively disable read()/write() on /dev/mem. - */ -int devmem_is_allowed(unsigned long pfn) -{ - if (iomem_is_exclusive(pfn << PAGE_SHIFT)) - return 0; - if (!page_is_ram(pfn)) - return 1; return 0; } +arch_initcall(adjust_protection_map); +pgprot_t vm_get_page_prot(unsigned long vm_flags) +{ + ptdesc_t prot; + + /* Short circuit GCS to avoid bloating the table. */ + if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { + prot = _PAGE_GCS_RO; + } else { + prot = pgprot_val(protection_map[vm_flags & + (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); + } + + if (vm_flags & VM_ARM64_BTI) + prot |= PTE_GP; + + /* + * There are two conditions required for returning a Normal Tagged + * memory type: (1) the user requested it via PROT_MTE passed to + * mmap() or mprotect() and (2) the corresponding vma supports MTE. We + * register (1) as VM_MTE in the vma->vm_flags and (2) as + * VM_MTE_ALLOWED. Note that the latter can only be set during the + * mmap() call since mprotect() does not accept MAP_* flags. + * Checking for VM_MTE only is sufficient since arch_validate_flags() + * does not permit (VM_MTE & !VM_MTE_ALLOWED). + */ + if (vm_flags & VM_MTE) + prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED); + +#ifdef CONFIG_ARCH_HAS_PKEYS + if (system_supports_poe()) { + if (vm_flags & VM_PKEY_BIT0) + prot |= PTE_PO_IDX_0; + if (vm_flags & VM_PKEY_BIT1) + prot |= PTE_PO_IDX_1; + if (vm_flags & VM_PKEY_BIT2) + prot |= PTE_PO_IDX_2; + } #endif + + return __pgprot(prot); +} +EXPORT_SYMBOL(vm_get_page_prot); |