^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * PowerPC Memory Protection Keys management
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright 2017, Ram Pai, IBM Corporation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <asm/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <asm/mmu_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/mmu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/setup.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/pkeys.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/of_fdt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) int num_pkey; /* Max number of pkeys supported */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Keys marked in the reservation list cannot be allocated by userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) u32 reserved_allocation_mask __ro_after_init;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) /* Bits set for the initially allocated keys */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) static u32 initial_allocation_mask __ro_after_init;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * Even if we allocate keys with sys_pkey_alloc(), we need to make sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * other thread still find the access denied using the same keys.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static u64 default_amr = ~0x0UL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) static u64 default_iamr = 0x5555555555555555UL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) u64 default_uamor __ro_after_init;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * Key used to implement PROT_EXEC mmap. Denies READ/WRITE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * We pick key 2 because 0 is special key and 1 is reserved as per ISA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) static int execute_only_key = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static bool pkey_execute_disable_supported;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #define AMR_BITS_PER_PKEY 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #define AMR_RD_BIT 0x1UL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #define AMR_WR_BIT 0x2UL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #define IAMR_EX_BIT 0x1UL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #define PKEY_REG_BITS (sizeof(u64) * 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static int __init dt_scan_storage_keys(unsigned long node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) const char *uname, int depth,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) const __be32 *prop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) int *pkeys_total = (int *) data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /* We are scanning "cpu" nodes only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) if (type == NULL || strcmp(type, "cpu") != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) prop = of_get_flat_dt_prop(node, "ibm,processor-storage-keys", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (!prop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) *pkeys_total = be32_to_cpu(prop[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) static int scan_pkey_feature(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) int pkeys_total = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * Pkey is not supported with Radix translation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) if (early_radix_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) ret = of_scan_flat_dt(dt_scan_storage_keys, &pkeys_total);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (ret == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * Let's assume 32 pkeys on P8/P9 bare metal, if its not defined by device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * tree. We make this exception since some version of skiboot forgot to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * expose this property on power8/9.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (!firmware_has_feature(FW_FEATURE_LPAR)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) unsigned long pvr = mfspr(SPRN_PVR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) if (PVR_VER(pvr) == PVR_POWER8 || PVR_VER(pvr) == PVR_POWER8E ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) PVR_VER(pvr) == PVR_POWER8NVL || PVR_VER(pvr) == PVR_POWER9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) pkeys_total = 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) * Adjust the upper limit, based on the number of bits supported by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * arch-neutral code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) pkeys_total = min_t(int, pkeys_total,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) ((ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) + 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return pkeys_total;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) void __init pkey_early_init_devtree(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) int pkeys_total, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * We define PKEY_DISABLE_EXECUTE in addition to the arch-neutral
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) * generic defines for PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * Ensure that the bits a distinct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) BUILD_BUG_ON(PKEY_DISABLE_EXECUTE &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * pkey_to_vmflag_bits() assumes that the pkey bits are contiguous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * in the vmaflag. Make sure that is really the case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) BUILD_BUG_ON(__builtin_clzl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) __builtin_popcountl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) != (sizeof(u64) * BITS_PER_BYTE));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * Only P7 and above supports SPRN_AMR update with MSR[PR] = 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) if (!early_cpu_has_feature(CPU_FTR_ARCH_206))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /* scan the device tree for pkey feature */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) pkeys_total = scan_pkey_feature();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (!pkeys_total)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) /* Allow all keys to be modified by default */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) default_uamor = ~0x0UL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) cur_cpu_spec->mmu_features |= MMU_FTR_PKEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * The device tree cannot be relied to indicate support for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * execute_disable support. Instead we use a PVR check.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (pvr_version_is(PVR_POWER7) || pvr_version_is(PVR_POWER7p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) pkey_execute_disable_supported = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) pkey_execute_disable_supported = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) #ifdef CONFIG_PPC_4K_PAGES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * The OS can manage only 8 pkeys due to its inability to represent them
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) * in the Linux 4K PTE. Mark all other keys reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) num_pkey = min(8, pkeys_total);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) num_pkey = pkeys_total;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) if (unlikely(num_pkey <= execute_only_key) || !pkey_execute_disable_supported) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * Insufficient number of keys to support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * execute only key. Mark it unavailable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) execute_only_key = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * Mark the execute_only_pkey as not available for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * user allocation via pkey_alloc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) reserved_allocation_mask |= (0x1 << execute_only_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * Deny READ/WRITE for execute_only_key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * Allow execute in IAMR.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) default_amr |= (0x3ul << pkeyshift(execute_only_key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) default_iamr &= ~(0x1ul << pkeyshift(execute_only_key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * Clear the uamor bits for this key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) default_uamor &= ~(0x3ul << pkeyshift(execute_only_key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) * Allow access for only key 0. And prevent any other modification.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) default_amr &= ~(0x3ul << pkeyshift(0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) default_iamr &= ~(0x1ul << pkeyshift(0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) default_uamor &= ~(0x3ul << pkeyshift(0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) * key 0 is special in that we want to consider it an allocated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * key which is preallocated. We don't allow changing AMR bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) * w.r.t key 0. But one can pkey_free(key0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) initial_allocation_mask |= (0x1 << 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * programming note.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) reserved_allocation_mask |= (0x1 << 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) default_uamor &= ~(0x3ul << pkeyshift(1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) * Prevent the usage of OS reserved keys. Update UAMOR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) * for those keys. Also mark the rest of the bits in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) * 32 bit mask as reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) for (i = num_pkey; i < 32 ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) reserved_allocation_mask |= (0x1 << i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) default_uamor &= ~(0x3ul << pkeyshift(i));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) * Prevent the allocation of reserved keys too.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) initial_allocation_mask |= reserved_allocation_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) pr_info("Enabling pkeys with max key count %d\n", num_pkey);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * Setup uamor on boot cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) mtspr(SPRN_UAMOR, default_uamor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) void pkey_mm_init(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) mm_pkey_allocation_map(mm) = initial_allocation_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) mm->context.execute_only_pkey = execute_only_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) static inline u64 read_amr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) return mfspr(SPRN_AMR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) static inline void write_amr(u64 value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) mtspr(SPRN_AMR, value);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) static inline u64 read_iamr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) if (!likely(pkey_execute_disable_supported))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) return 0x0UL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) return mfspr(SPRN_IAMR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) static inline void write_iamr(u64 value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) if (!likely(pkey_execute_disable_supported))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) mtspr(SPRN_IAMR, value);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) static inline void init_amr(int pkey, u8 init_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) u64 old_amr = read_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) write_amr(old_amr | new_amr_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) static inline void init_iamr(int pkey, u8 init_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) u64 old_iamr = read_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) write_iamr(old_iamr | new_iamr_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * Set the access rights in AMR IAMR and UAMOR registers for @pkey to that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * specified in @init_val.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) unsigned long init_val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) u64 new_amr_bits = 0x0ul;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) u64 new_iamr_bits = 0x0ul;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) u64 pkey_bits, uamor_pkey_bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * Check whether the key is disabled by UAMOR.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) pkey_bits = 0x3ul << pkeyshift(pkey);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) uamor_pkey_bits = (default_uamor & pkey_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * Both the bits in UAMOR corresponding to the key should be set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) if (uamor_pkey_bits != pkey_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) if (init_val & PKEY_DISABLE_EXECUTE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) if (!pkey_execute_disable_supported)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) new_iamr_bits |= IAMR_EX_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) init_iamr(pkey, new_iamr_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) /* Set the bits we need in AMR: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) if (init_val & PKEY_DISABLE_ACCESS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) new_amr_bits |= AMR_RD_BIT | AMR_WR_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) else if (init_val & PKEY_DISABLE_WRITE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) new_amr_bits |= AMR_WR_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) init_amr(pkey, new_amr_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) void thread_pkey_regs_save(struct thread_struct *thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * TODO: Skip saving registers if @thread hasn't used any keys yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) thread->amr = read_amr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) thread->iamr = read_iamr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) void thread_pkey_regs_restore(struct thread_struct *new_thread,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) struct thread_struct *old_thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) if (old_thread->amr != new_thread->amr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) write_amr(new_thread->amr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) if (old_thread->iamr != new_thread->iamr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) write_iamr(new_thread->iamr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) void thread_pkey_regs_init(struct thread_struct *thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) thread->amr = default_amr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) thread->iamr = default_iamr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) write_amr(default_amr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) write_iamr(default_iamr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) int execute_only_pkey(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) return mm->context.execute_only_pkey;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) /* Do this check first since the vm_flags should be hot */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) * This should only be called for *plain* mprotect calls.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) int pkey)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) * If the currently associated pkey is execute-only, but the requested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * protection is not execute-only, move it back to the default pkey.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if (vma_is_pkey_exec_only(vma) && (prot != PROT_EXEC))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) * The requested protection is execute-only. Hence let's use an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * execute-only pkey.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) if (prot == PROT_EXEC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) pkey = execute_only_pkey(vma->vm_mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) if (pkey > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) return pkey;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) /* Nothing to override. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) return vma_pkey(vma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) static bool pkey_access_permitted(int pkey, bool write, bool execute)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) int pkey_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) u64 amr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) pkey_shift = pkeyshift(pkey);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) if (execute)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) return !(read_iamr() & (IAMR_EX_BIT << pkey_shift));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) amr = read_amr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) if (write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) return !(amr & (AMR_WR_BIT << pkey_shift));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return !(amr & (AMR_RD_BIT << pkey_shift));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) return pkey_access_permitted(pte_to_pkey_bits(pte), write, execute);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * We only want to enforce protection keys on the current thread because we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * effectively have no access to AMR/IAMR for other threads or any way to tell
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) * which AMR/IAMR in a threaded process we could use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) * So do not enforce things if the VMA is not from the current mm, or if we are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) * in a kernel thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) bool execute, bool foreign)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) * Do not enforce our key-permissions on a foreign vma.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) if (foreign || vma_is_foreign(vma))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) return pkey_access_permitted(vma_pkey(vma), write, execute);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) if (!mmu_has_feature(MMU_FTR_PKEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) /* Duplicate the oldmm pkey state in mm: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) mm_pkey_allocation_map(mm) = mm_pkey_allocation_map(oldmm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) mm->context.execute_only_pkey = oldmm->context.execute_only_pkey;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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