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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/powerpc/mm/book3s64/pkeys.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'arch/powerpc/mm/book3s64/pkeys.c')
-rw-r--r--arch/powerpc/mm/book3s64/pkeys.c470
1 files changed, 470 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
new file mode 100644
index 000000000..1d2675ab6
--- /dev/null
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PowerPC Memory Protection Keys management
+ *
+ * Copyright 2017, Ram Pai, IBM Corporation.
+ */
+
+#include <asm/mman.h>
+#include <asm/mmu_context.h>
+#include <asm/mmu.h>
+#include <asm/setup.h>
+#include <asm/smp.h>
+#include <asm/firmware.h>
+
+#include <linux/pkeys.h>
+#include <linux/of_fdt.h>
+
+
+int num_pkey; /* Max number of pkeys supported */
+/*
+ * Keys marked in the reservation list cannot be allocated by userspace
+ */
+u32 reserved_allocation_mask __ro_after_init;
+
+/* Bits set for the initially allocated keys */
+static u32 initial_allocation_mask __ro_after_init;
+
+/*
+ * Even if we allocate keys with sys_pkey_alloc(), we need to make sure
+ * other thread still find the access denied using the same keys.
+ */
+u64 default_amr __ro_after_init = ~0x0UL;
+u64 default_iamr __ro_after_init = 0x5555555555555555UL;
+u64 default_uamor __ro_after_init;
+EXPORT_SYMBOL(default_amr);
+/*
+ * Key used to implement PROT_EXEC mmap. Denies READ/WRITE
+ * We pick key 2 because 0 is special key and 1 is reserved as per ISA.
+ */
+static int execute_only_key = 2;
+static bool pkey_execute_disable_supported;
+
+
+#define AMR_BITS_PER_PKEY 2
+#define AMR_RD_BIT 0x1UL
+#define AMR_WR_BIT 0x2UL
+#define IAMR_EX_BIT 0x1UL
+#define PKEY_REG_BITS (sizeof(u64) * 8)
+#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
+
+static int __init dt_scan_storage_keys(unsigned long node,
+ const char *uname, int depth,
+ void *data)
+{
+ const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ const __be32 *prop;
+ int *pkeys_total = (int *) data;
+
+ /* We are scanning "cpu" nodes only */
+ if (type == NULL || strcmp(type, "cpu") != 0)
+ return 0;
+
+ prop = of_get_flat_dt_prop(node, "ibm,processor-storage-keys", NULL);
+ if (!prop)
+ return 0;
+ *pkeys_total = be32_to_cpu(prop[0]);
+ return 1;
+}
+
+static int __init scan_pkey_feature(void)
+{
+ int ret;
+ int pkeys_total = 0;
+
+ /*
+ * Pkey is not supported with Radix translation.
+ */
+ if (early_radix_enabled())
+ return 0;
+
+ ret = of_scan_flat_dt(dt_scan_storage_keys, &pkeys_total);
+ if (ret == 0) {
+ /*
+ * Let's assume 32 pkeys on P8/P9 bare metal, if its not defined by device
+ * tree. We make this exception since some version of skiboot forgot to
+ * expose this property on power8/9.
+ */
+ if (!firmware_has_feature(FW_FEATURE_LPAR)) {
+ unsigned long pvr = mfspr(SPRN_PVR);
+
+ if (PVR_VER(pvr) == PVR_POWER8 || PVR_VER(pvr) == PVR_POWER8E ||
+ PVR_VER(pvr) == PVR_POWER8NVL || PVR_VER(pvr) == PVR_POWER9)
+ pkeys_total = 32;
+ }
+ }
+
+#ifdef CONFIG_PPC_MEM_KEYS
+ /*
+ * Adjust the upper limit, based on the number of bits supported by
+ * arch-neutral code.
+ */
+ pkeys_total = min_t(int, pkeys_total,
+ ((ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) + 1));
+#endif
+ return pkeys_total;
+}
+
+void __init pkey_early_init_devtree(void)
+{
+ int pkeys_total, i;
+
+#ifdef CONFIG_PPC_MEM_KEYS
+ /*
+ * We define PKEY_DISABLE_EXECUTE in addition to the arch-neutral
+ * generic defines for PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE.
+ * Ensure that the bits a distinct.
+ */
+ BUILD_BUG_ON(PKEY_DISABLE_EXECUTE &
+ (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
+
+ /*
+ * pkey_to_vmflag_bits() assumes that the pkey bits are contiguous
+ * in the vmaflag. Make sure that is really the case.
+ */
+ BUILD_BUG_ON(__builtin_clzl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) +
+ __builtin_popcountl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT)
+ != (sizeof(u64) * BITS_PER_BYTE));
+#endif
+ /*
+ * Only P7 and above supports SPRN_AMR update with MSR[PR] = 1
+ */
+ if (!early_cpu_has_feature(CPU_FTR_ARCH_206))
+ return;
+
+ /* scan the device tree for pkey feature */
+ pkeys_total = scan_pkey_feature();
+ if (!pkeys_total)
+ goto out;
+
+ /* Allow all keys to be modified by default */
+ default_uamor = ~0x0UL;
+
+ cur_cpu_spec->mmu_features |= MMU_FTR_PKEY;
+
+ /*
+ * The device tree cannot be relied to indicate support for
+ * execute_disable support. Instead we use a PVR check.
+ */
+ if (pvr_version_is(PVR_POWER7) || pvr_version_is(PVR_POWER7p))
+ pkey_execute_disable_supported = false;
+ else
+ pkey_execute_disable_supported = true;
+
+#ifdef CONFIG_PPC_4K_PAGES
+ /*
+ * The OS can manage only 8 pkeys due to its inability to represent them
+ * in the Linux 4K PTE. Mark all other keys reserved.
+ */
+ num_pkey = min(8, pkeys_total);
+#else
+ num_pkey = pkeys_total;
+#endif
+
+ if (unlikely(num_pkey <= execute_only_key) || !pkey_execute_disable_supported) {
+ /*
+ * Insufficient number of keys to support
+ * execute only key. Mark it unavailable.
+ */
+ execute_only_key = -1;
+ } else {
+ /*
+ * Mark the execute_only_pkey as not available for
+ * user allocation via pkey_alloc.
+ */
+ reserved_allocation_mask |= (0x1 << execute_only_key);
+
+ /*
+ * Deny READ/WRITE for execute_only_key.
+ * Allow execute in IAMR.
+ */
+ default_amr |= (0x3ul << pkeyshift(execute_only_key));
+ default_iamr &= ~(0x1ul << pkeyshift(execute_only_key));
+
+ /*
+ * Clear the uamor bits for this key.
+ */
+ default_uamor &= ~(0x3ul << pkeyshift(execute_only_key));
+ }
+
+ if (unlikely(num_pkey <= 3)) {
+ /*
+ * Insufficient number of keys to support
+ * KUAP/KUEP feature.
+ */
+ disable_kuep = true;
+ disable_kuap = true;
+ WARN(1, "Disabling kernel user protection due to low (%d) max supported keys\n", num_pkey);
+ } else {
+ /* handle key which is used by kernel for KAUP */
+ reserved_allocation_mask |= (0x1 << 3);
+ /*
+ * Mark access for kup_key in default amr so that
+ * we continue to operate with that AMR in
+ * copy_to/from_user().
+ */
+ default_amr &= ~(0x3ul << pkeyshift(3));
+ default_iamr &= ~(0x1ul << pkeyshift(3));
+ default_uamor &= ~(0x3ul << pkeyshift(3));
+ }
+
+ /*
+ * Allow access for only key 0. And prevent any other modification.
+ */
+ default_amr &= ~(0x3ul << pkeyshift(0));
+ default_iamr &= ~(0x1ul << pkeyshift(0));
+ default_uamor &= ~(0x3ul << pkeyshift(0));
+ /*
+ * key 0 is special in that we want to consider it an allocated
+ * key which is preallocated. We don't allow changing AMR bits
+ * w.r.t key 0. But one can pkey_free(key0)
+ */
+ initial_allocation_mask |= (0x1 << 0);
+
+ /*
+ * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
+ * programming note.
+ */
+ reserved_allocation_mask |= (0x1 << 1);
+ default_uamor &= ~(0x3ul << pkeyshift(1));
+
+ /*
+ * Prevent the usage of OS reserved keys. Update UAMOR
+ * for those keys. Also mark the rest of the bits in the
+ * 32 bit mask as reserved.
+ */
+ for (i = num_pkey; i < 32 ; i++) {
+ reserved_allocation_mask |= (0x1 << i);
+ default_uamor &= ~(0x3ul << pkeyshift(i));
+ }
+ /*
+ * Prevent the allocation of reserved keys too.
+ */
+ initial_allocation_mask |= reserved_allocation_mask;
+
+ pr_info("Enabling pkeys with max key count %d\n", num_pkey);
+out:
+ /*
+ * Setup uamor on boot cpu
+ */
+ mtspr(SPRN_UAMOR, default_uamor);
+
+ return;
+}
+
+#ifdef CONFIG_PPC_KUEP
+void setup_kuep(bool disabled)
+{
+ if (disabled)
+ return;
+ /*
+ * On hash if PKEY feature is not enabled, disable KUAP too.
+ */
+ if (!early_radix_enabled() && !early_mmu_has_feature(MMU_FTR_PKEY))
+ return;
+
+ if (smp_processor_id() == boot_cpuid) {
+ pr_info("Activating Kernel Userspace Execution Prevention\n");
+ cur_cpu_spec->mmu_features |= MMU_FTR_BOOK3S_KUEP;
+ }
+
+ /*
+ * Radix always uses key0 of the IAMR to determine if an access is
+ * allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction
+ * fetch.
+ */
+ mtspr(SPRN_IAMR, AMR_KUEP_BLOCKED);
+ isync();
+}
+#endif
+
+#ifdef CONFIG_PPC_KUAP
+void setup_kuap(bool disabled)
+{
+ if (disabled)
+ return;
+ /*
+ * On hash if PKEY feature is not enabled, disable KUAP too.
+ */
+ if (!early_radix_enabled() && !early_mmu_has_feature(MMU_FTR_PKEY))
+ return;
+
+ if (smp_processor_id() == boot_cpuid) {
+ pr_info("Activating Kernel Userspace Access Prevention\n");
+ cur_cpu_spec->mmu_features |= MMU_FTR_BOOK3S_KUAP;
+ }
+
+ /*
+ * Set the default kernel AMR values on all cpus.
+ */
+ mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+ isync();
+}
+#endif
+
+#ifdef CONFIG_PPC_MEM_KEYS
+void pkey_mm_init(struct mm_struct *mm)
+{
+ if (!mmu_has_feature(MMU_FTR_PKEY))
+ return;
+ mm_pkey_allocation_map(mm) = initial_allocation_mask;
+ mm->context.execute_only_pkey = execute_only_key;
+}
+
+static inline void init_amr(int pkey, u8 init_bits)
+{
+ u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
+ u64 old_amr = current_thread_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
+
+ current->thread.regs->amr = old_amr | new_amr_bits;
+}
+
+static inline void init_iamr(int pkey, u8 init_bits)
+{
+ u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
+ u64 old_iamr = current_thread_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
+
+ if (!likely(pkey_execute_disable_supported))
+ return;
+
+ current->thread.regs->iamr = old_iamr | new_iamr_bits;
+}
+
+/*
+ * Set the access rights in AMR IAMR and UAMOR registers for @pkey to that
+ * specified in @init_val.
+ */
+int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val)
+{
+ u64 new_amr_bits = 0x0ul;
+ u64 new_iamr_bits = 0x0ul;
+ u64 pkey_bits, uamor_pkey_bits;
+
+ /*
+ * Check whether the key is disabled by UAMOR.
+ */
+ pkey_bits = 0x3ul << pkeyshift(pkey);
+ uamor_pkey_bits = (default_uamor & pkey_bits);
+
+ /*
+ * Both the bits in UAMOR corresponding to the key should be set
+ */
+ if (uamor_pkey_bits != pkey_bits)
+ return -EINVAL;
+
+ if (init_val & PKEY_DISABLE_EXECUTE) {
+ if (!pkey_execute_disable_supported)
+ return -EINVAL;
+ new_iamr_bits |= IAMR_EX_BIT;
+ }
+ init_iamr(pkey, new_iamr_bits);
+
+ /* Set the bits we need in AMR: */
+ if (init_val & PKEY_DISABLE_ACCESS)
+ new_amr_bits |= AMR_RD_BIT | AMR_WR_BIT;
+ else if (init_val & PKEY_DISABLE_WRITE)
+ new_amr_bits |= AMR_WR_BIT;
+
+ init_amr(pkey, new_amr_bits);
+ return 0;
+}
+
+int execute_only_pkey(struct mm_struct *mm)
+{
+ return mm->context.execute_only_pkey;
+}
+
+static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
+{
+ /* Do this check first since the vm_flags should be hot */
+ if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
+ return false;
+
+ return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey);
+}
+
+/*
+ * This should only be called for *plain* mprotect calls.
+ */
+int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot,
+ int pkey)
+{
+ /*
+ * If the currently associated pkey is execute-only, but the requested
+ * protection is not execute-only, move it back to the default pkey.
+ */
+ if (vma_is_pkey_exec_only(vma) && (prot != PROT_EXEC))
+ return 0;
+
+ /*
+ * The requested protection is execute-only. Hence let's use an
+ * execute-only pkey.
+ */
+ if (prot == PROT_EXEC) {
+ pkey = execute_only_pkey(vma->vm_mm);
+ if (pkey > 0)
+ return pkey;
+ }
+
+ /* Nothing to override. */
+ return vma_pkey(vma);
+}
+
+static bool pkey_access_permitted(int pkey, bool write, bool execute)
+{
+ int pkey_shift;
+ u64 amr;
+
+ pkey_shift = pkeyshift(pkey);
+ if (execute)
+ return !(current_thread_iamr() & (IAMR_EX_BIT << pkey_shift));
+
+ amr = current_thread_amr();
+ if (write)
+ return !(amr & (AMR_WR_BIT << pkey_shift));
+
+ return !(amr & (AMR_RD_BIT << pkey_shift));
+}
+
+bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
+{
+ if (!mmu_has_feature(MMU_FTR_PKEY))
+ return true;
+
+ return pkey_access_permitted(pte_to_pkey_bits(pte), write, execute);
+}
+
+/*
+ * We only want to enforce protection keys on the current thread because we
+ * effectively have no access to AMR/IAMR for other threads or any way to tell
+ * which AMR/IAMR in a threaded process we could use.
+ *
+ * So do not enforce things if the VMA is not from the current mm, or if we are
+ * in a kernel thread.
+ */
+bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
+ bool execute, bool foreign)
+{
+ if (!mmu_has_feature(MMU_FTR_PKEY))
+ return true;
+ /*
+ * Do not enforce our key-permissions on a foreign vma.
+ */
+ if (foreign || vma_is_foreign(vma))
+ return true;
+
+ return pkey_access_permitted(vma_pkey(vma), write, execute);
+}
+
+void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm)
+{
+ if (!mmu_has_feature(MMU_FTR_PKEY))
+ return;
+
+ /* Duplicate the oldmm pkey state in mm: */
+ mm_pkey_allocation_map(mm) = mm_pkey_allocation_map(oldmm);
+ mm->context.execute_only_pkey = oldmm->context.execute_only_pkey;
+}
+
+#endif /* CONFIG_PPC_MEM_KEYS */