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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/x86/mm/cpu_entry_area.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 '')
-rw-r--r--arch/x86/mm/cpu_entry_area.c272
1 files changed, 272 insertions, 0 deletions
diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
new file mode 100644
index 000000000..7316a8224
--- /dev/null
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/spinlock.h>
+#include <linux/percpu.h>
+#include <linux/kallsyms.h>
+#include <linux/kcore.h>
+#include <linux/pgtable.h>
+
+#include <asm/cpu_entry_area.h>
+#include <asm/fixmap.h>
+#include <asm/desc.h>
+#include <asm/kasan.h>
+
+static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page, entry_stack_storage);
+
+#ifdef CONFIG_X86_64
+static DEFINE_PER_CPU_PAGE_ALIGNED(struct exception_stacks, exception_stacks);
+DEFINE_PER_CPU(struct cea_exception_stacks*, cea_exception_stacks);
+
+static DEFINE_PER_CPU_READ_MOSTLY(unsigned long, _cea_offset);
+
+static __always_inline unsigned int cea_offset(unsigned int cpu)
+{
+ return per_cpu(_cea_offset, cpu);
+}
+
+static __init void init_cea_offsets(void)
+{
+ unsigned int max_cea;
+ unsigned int i, j;
+
+ max_cea = (CPU_ENTRY_AREA_MAP_SIZE - PAGE_SIZE) / CPU_ENTRY_AREA_SIZE;
+
+ /* O(sodding terrible) */
+ for_each_possible_cpu(i) {
+ unsigned int cea;
+
+again:
+ cea = get_random_u32_below(max_cea);
+
+ for_each_possible_cpu(j) {
+ if (cea_offset(j) == cea)
+ goto again;
+
+ if (i == j)
+ break;
+ }
+
+ per_cpu(_cea_offset, i) = cea;
+ }
+}
+#else /* !X86_64 */
+DECLARE_PER_CPU_PAGE_ALIGNED(struct doublefault_stack, doublefault_stack);
+
+static __always_inline unsigned int cea_offset(unsigned int cpu)
+{
+ return cpu;
+}
+static inline void init_cea_offsets(void) { }
+#endif
+
+/* Is called from entry code, so must be noinstr */
+noinstr struct cpu_entry_area *get_cpu_entry_area(int cpu)
+{
+ unsigned long va = CPU_ENTRY_AREA_PER_CPU + cea_offset(cpu) * CPU_ENTRY_AREA_SIZE;
+ BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
+
+ return (struct cpu_entry_area *) va;
+}
+EXPORT_SYMBOL(get_cpu_entry_area);
+
+void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags)
+{
+ unsigned long va = (unsigned long) cea_vaddr;
+ pte_t pte = pfn_pte(pa >> PAGE_SHIFT, flags);
+
+ /*
+ * The cpu_entry_area is shared between the user and kernel
+ * page tables. All of its ptes can safely be global.
+ * _PAGE_GLOBAL gets reused to help indicate PROT_NONE for
+ * non-present PTEs, so be careful not to set it in that
+ * case to avoid confusion.
+ */
+ if (boot_cpu_has(X86_FEATURE_PGE) &&
+ (pgprot_val(flags) & _PAGE_PRESENT))
+ pte = pte_set_flags(pte, _PAGE_GLOBAL);
+
+ set_pte_vaddr(va, pte);
+}
+
+static void __init
+cea_map_percpu_pages(void *cea_vaddr, void *ptr, int pages, pgprot_t prot)
+{
+ for ( ; pages; pages--, cea_vaddr+= PAGE_SIZE, ptr += PAGE_SIZE)
+ cea_set_pte(cea_vaddr, per_cpu_ptr_to_phys(ptr), prot);
+}
+
+static void __init percpu_setup_debug_store(unsigned int cpu)
+{
+#ifdef CONFIG_CPU_SUP_INTEL
+ unsigned int npages;
+ void *cea;
+
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+ return;
+
+ cea = &get_cpu_entry_area(cpu)->cpu_debug_store;
+ npages = sizeof(struct debug_store) / PAGE_SIZE;
+ BUILD_BUG_ON(sizeof(struct debug_store) % PAGE_SIZE != 0);
+ cea_map_percpu_pages(cea, &per_cpu(cpu_debug_store, cpu), npages,
+ PAGE_KERNEL);
+
+ cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers;
+ /*
+ * Force the population of PMDs for not yet allocated per cpu
+ * memory like debug store buffers.
+ */
+ npages = sizeof(struct debug_store_buffers) / PAGE_SIZE;
+ for (; npages; npages--, cea += PAGE_SIZE)
+ cea_set_pte(cea, 0, PAGE_NONE);
+#endif
+}
+
+#ifdef CONFIG_X86_64
+
+#define cea_map_stack(name) do { \
+ npages = sizeof(estacks->name## _stack) / PAGE_SIZE; \
+ cea_map_percpu_pages(cea->estacks.name## _stack, \
+ estacks->name## _stack, npages, PAGE_KERNEL); \
+ } while (0)
+
+static void __init percpu_setup_exception_stacks(unsigned int cpu)
+{
+ struct exception_stacks *estacks = per_cpu_ptr(&exception_stacks, cpu);
+ struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
+ unsigned int npages;
+
+ BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0);
+
+ per_cpu(cea_exception_stacks, cpu) = &cea->estacks;
+
+ /*
+ * The exceptions stack mappings in the per cpu area are protected
+ * by guard pages so each stack must be mapped separately. DB2 is
+ * not mapped; it just exists to catch triple nesting of #DB.
+ */
+ cea_map_stack(DF);
+ cea_map_stack(NMI);
+ cea_map_stack(DB);
+ cea_map_stack(MCE);
+
+ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
+ if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
+ cea_map_stack(VC);
+ cea_map_stack(VC2);
+ }
+ }
+}
+#else
+static inline void percpu_setup_exception_stacks(unsigned int cpu)
+{
+ struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
+
+ cea_map_percpu_pages(&cea->doublefault_stack,
+ &per_cpu(doublefault_stack, cpu), 1, PAGE_KERNEL);
+}
+#endif
+
+/* Setup the fixmap mappings only once per-processor */
+static void __init setup_cpu_entry_area(unsigned int cpu)
+{
+ struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
+#ifdef CONFIG_X86_64
+ /* On 64-bit systems, we use a read-only fixmap GDT and TSS. */
+ pgprot_t gdt_prot = PAGE_KERNEL_RO;
+ pgprot_t tss_prot = PAGE_KERNEL_RO;
+#else
+ /*
+ * On 32-bit systems, the GDT cannot be read-only because
+ * our double fault handler uses a task gate, and entering through
+ * a task gate needs to change an available TSS to busy. If the
+ * GDT is read-only, that will triple fault. The TSS cannot be
+ * read-only because the CPU writes to it on task switches.
+ */
+ pgprot_t gdt_prot = PAGE_KERNEL;
+ pgprot_t tss_prot = PAGE_KERNEL;
+#endif
+
+ kasan_populate_shadow_for_vaddr(cea, CPU_ENTRY_AREA_SIZE,
+ early_cpu_to_node(cpu));
+
+ cea_set_pte(&cea->gdt, get_cpu_gdt_paddr(cpu), gdt_prot);
+
+ cea_map_percpu_pages(&cea->entry_stack_page,
+ per_cpu_ptr(&entry_stack_storage, cpu), 1,
+ PAGE_KERNEL);
+
+ /*
+ * The Intel SDM says (Volume 3, 7.2.1):
+ *
+ * Avoid placing a page boundary in the part of the TSS that the
+ * processor reads during a task switch (the first 104 bytes). The
+ * processor may not correctly perform address translations if a
+ * boundary occurs in this area. During a task switch, the processor
+ * reads and writes into the first 104 bytes of each TSS (using
+ * contiguous physical addresses beginning with the physical address
+ * of the first byte of the TSS). So, after TSS access begins, if
+ * part of the 104 bytes is not physically contiguous, the processor
+ * will access incorrect information without generating a page-fault
+ * exception.
+ *
+ * There are also a lot of errata involving the TSS spanning a page
+ * boundary. Assert that we're not doing that.
+ */
+ BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^
+ offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK);
+ BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0);
+ /*
+ * VMX changes the host TR limit to 0x67 after a VM exit. This is
+ * okay, since 0x67 covers the size of struct x86_hw_tss. Make sure
+ * that this is correct.
+ */
+ BUILD_BUG_ON(offsetof(struct tss_struct, x86_tss) != 0);
+ BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68);
+
+ cea_map_percpu_pages(&cea->tss, &per_cpu(cpu_tss_rw, cpu),
+ sizeof(struct tss_struct) / PAGE_SIZE, tss_prot);
+
+#ifdef CONFIG_X86_32
+ per_cpu(cpu_entry_area, cpu) = cea;
+#endif
+
+ percpu_setup_exception_stacks(cpu);
+
+ percpu_setup_debug_store(cpu);
+}
+
+static __init void setup_cpu_entry_area_ptes(void)
+{
+#ifdef CONFIG_X86_32
+ unsigned long start, end;
+
+ /* The +1 is for the readonly IDT: */
+ BUILD_BUG_ON((CPU_ENTRY_AREA_PAGES+1)*PAGE_SIZE != CPU_ENTRY_AREA_MAP_SIZE);
+ BUG_ON(CPU_ENTRY_AREA_BASE & ~PMD_MASK);
+
+ start = CPU_ENTRY_AREA_BASE;
+ end = start + CPU_ENTRY_AREA_MAP_SIZE;
+
+ /* Careful here: start + PMD_SIZE might wrap around */
+ for (; start < end && start >= CPU_ENTRY_AREA_BASE; start += PMD_SIZE)
+ populate_extra_pte(start);
+#endif
+}
+
+void __init setup_cpu_entry_areas(void)
+{
+ unsigned int cpu;
+
+ init_cea_offsets();
+
+ setup_cpu_entry_area_ptes();
+
+ for_each_possible_cpu(cpu)
+ setup_cpu_entry_area(cpu);
+
+ /*
+ * This is the last essential update to swapper_pgdir which needs
+ * to be synchronized to initial_page_table on 32bit.
+ */
+ sync_initial_page_table();
+}