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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/arm64/kernel/alternative.c
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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/arm64/kernel/alternative.c')
-rw-r--r--arch/arm64/kernel/alternative.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
new file mode 100644
index 000000000..d32d4ed55
--- /dev/null
+++ b/arch/arm64/kernel/alternative.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * alternative runtime patching
+ * inspired by the x86 version
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) "alternatives: " fmt
+
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/elf.h>
+#include <asm/cacheflush.h>
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
+#include <asm/insn.h>
+#include <asm/module.h>
+#include <asm/sections.h>
+#include <asm/vdso.h>
+#include <linux/stop_machine.h>
+
+#define __ALT_PTR(a, f) ((void *)&(a)->f + (a)->f)
+#define ALT_ORIG_PTR(a) __ALT_PTR(a, orig_offset)
+#define ALT_REPL_PTR(a) __ALT_PTR(a, alt_offset)
+
+#define ALT_CAP(a) ((a)->cpufeature & ~ARM64_CB_BIT)
+#define ALT_HAS_CB(a) ((a)->cpufeature & ARM64_CB_BIT)
+
+/* Volatile, as we may be patching the guts of READ_ONCE() */
+static volatile int all_alternatives_applied;
+
+static DECLARE_BITMAP(applied_alternatives, ARM64_NCAPS);
+
+struct alt_region {
+ struct alt_instr *begin;
+ struct alt_instr *end;
+};
+
+bool alternative_is_applied(u16 cpufeature)
+{
+ if (WARN_ON(cpufeature >= ARM64_NCAPS))
+ return false;
+
+ return test_bit(cpufeature, applied_alternatives);
+}
+
+/*
+ * Check if the target PC is within an alternative block.
+ */
+static __always_inline bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc)
+{
+ unsigned long replptr = (unsigned long)ALT_REPL_PTR(alt);
+ return !(pc >= replptr && pc <= (replptr + alt->alt_len));
+}
+
+#define align_down(x, a) ((unsigned long)(x) & ~(((unsigned long)(a)) - 1))
+
+static __always_inline u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr)
+{
+ u32 insn;
+
+ insn = le32_to_cpu(*altinsnptr);
+
+ if (aarch64_insn_is_branch_imm(insn)) {
+ s32 offset = aarch64_get_branch_offset(insn);
+ unsigned long target;
+
+ target = (unsigned long)altinsnptr + offset;
+
+ /*
+ * If we're branching inside the alternate sequence,
+ * do not rewrite the instruction, as it is already
+ * correct. Otherwise, generate the new instruction.
+ */
+ if (branch_insn_requires_update(alt, target)) {
+ offset = target - (unsigned long)insnptr;
+ insn = aarch64_set_branch_offset(insn, offset);
+ }
+ } else if (aarch64_insn_is_adrp(insn)) {
+ s32 orig_offset, new_offset;
+ unsigned long target;
+
+ /*
+ * If we're replacing an adrp instruction, which uses PC-relative
+ * immediate addressing, adjust the offset to reflect the new
+ * PC. adrp operates on 4K aligned addresses.
+ */
+ orig_offset = aarch64_insn_adrp_get_offset(insn);
+ target = align_down(altinsnptr, SZ_4K) + orig_offset;
+ new_offset = target - align_down(insnptr, SZ_4K);
+ insn = aarch64_insn_adrp_set_offset(insn, new_offset);
+ } else if (aarch64_insn_uses_literal(insn)) {
+ /*
+ * Disallow patching unhandled instructions using PC relative
+ * literal addresses
+ */
+ BUG();
+ }
+
+ return insn;
+}
+
+static noinstr void patch_alternative(struct alt_instr *alt,
+ __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+ __le32 *replptr;
+ int i;
+
+ replptr = ALT_REPL_PTR(alt);
+ for (i = 0; i < nr_inst; i++) {
+ u32 insn;
+
+ insn = get_alt_insn(alt, origptr + i, replptr + i);
+ updptr[i] = cpu_to_le32(insn);
+ }
+}
+
+/*
+ * We provide our own, private D-cache cleaning function so that we don't
+ * accidentally call into the cache.S code, which is patched by us at
+ * runtime.
+ */
+static void clean_dcache_range_nopatch(u64 start, u64 end)
+{
+ u64 cur, d_size, ctr_el0;
+
+ ctr_el0 = read_sanitised_ftr_reg(SYS_CTR_EL0);
+ d_size = 4 << cpuid_feature_extract_unsigned_field(ctr_el0,
+ CTR_EL0_DminLine_SHIFT);
+ cur = start & ~(d_size - 1);
+ do {
+ /*
+ * We must clean+invalidate to the PoC in order to avoid
+ * Cortex-A53 errata 826319, 827319, 824069 and 819472
+ * (this corresponds to ARM64_WORKAROUND_CLEAN_CACHE)
+ */
+ asm volatile("dc civac, %0" : : "r" (cur) : "memory");
+ } while (cur += d_size, cur < end);
+}
+
+static void __apply_alternatives(const struct alt_region *region,
+ bool is_module,
+ unsigned long *feature_mask)
+{
+ struct alt_instr *alt;
+ __le32 *origptr, *updptr;
+ alternative_cb_t alt_cb;
+
+ for (alt = region->begin; alt < region->end; alt++) {
+ int nr_inst;
+ int cap = ALT_CAP(alt);
+
+ if (!test_bit(cap, feature_mask))
+ continue;
+
+ if (!cpus_have_cap(cap))
+ continue;
+
+ if (ALT_HAS_CB(alt))
+ BUG_ON(alt->alt_len != 0);
+ else
+ BUG_ON(alt->alt_len != alt->orig_len);
+
+ origptr = ALT_ORIG_PTR(alt);
+ updptr = is_module ? origptr : lm_alias(origptr);
+ nr_inst = alt->orig_len / AARCH64_INSN_SIZE;
+
+ if (ALT_HAS_CB(alt))
+ alt_cb = ALT_REPL_PTR(alt);
+ else
+ alt_cb = patch_alternative;
+
+ alt_cb(alt, origptr, updptr, nr_inst);
+
+ if (!is_module) {
+ clean_dcache_range_nopatch((u64)origptr,
+ (u64)(origptr + nr_inst));
+ }
+ }
+
+ /*
+ * The core module code takes care of cache maintenance in
+ * flush_module_icache().
+ */
+ if (!is_module) {
+ dsb(ish);
+ icache_inval_all_pou();
+ isb();
+
+ /* Ignore ARM64_CB bit from feature mask */
+ bitmap_or(applied_alternatives, applied_alternatives,
+ feature_mask, ARM64_NCAPS);
+ bitmap_and(applied_alternatives, applied_alternatives,
+ cpu_hwcaps, ARM64_NCAPS);
+ }
+}
+
+static void __init apply_alternatives_vdso(void)
+{
+ struct alt_region region;
+ const struct elf64_hdr *hdr;
+ const struct elf64_shdr *shdr;
+ const struct elf64_shdr *alt;
+ DECLARE_BITMAP(all_capabilities, ARM64_NCAPS);
+
+ bitmap_fill(all_capabilities, ARM64_NCAPS);
+
+ hdr = (struct elf64_hdr *)vdso_start;
+ shdr = (void *)hdr + hdr->e_shoff;
+ alt = find_section(hdr, shdr, ".altinstructions");
+ if (!alt)
+ return;
+
+ region = (struct alt_region){
+ .begin = (void *)hdr + alt->sh_offset,
+ .end = (void *)hdr + alt->sh_offset + alt->sh_size,
+ };
+
+ __apply_alternatives(&region, false, &all_capabilities[0]);
+}
+
+static const struct alt_region kernel_alternatives __initconst = {
+ .begin = (struct alt_instr *)__alt_instructions,
+ .end = (struct alt_instr *)__alt_instructions_end,
+};
+
+/*
+ * We might be patching the stop_machine state machine, so implement a
+ * really simple polling protocol here.
+ */
+static int __init __apply_alternatives_multi_stop(void *unused)
+{
+ /* We always have a CPU 0 at this point (__init) */
+ if (smp_processor_id()) {
+ while (!all_alternatives_applied)
+ cpu_relax();
+ isb();
+ } else {
+ DECLARE_BITMAP(remaining_capabilities, ARM64_NCAPS);
+
+ bitmap_complement(remaining_capabilities, boot_capabilities,
+ ARM64_NCAPS);
+
+ BUG_ON(all_alternatives_applied);
+ __apply_alternatives(&kernel_alternatives, false,
+ remaining_capabilities);
+ /* Barriers provided by the cache flushing */
+ all_alternatives_applied = 1;
+ }
+
+ return 0;
+}
+
+void __init apply_alternatives_all(void)
+{
+ pr_info("applying system-wide alternatives\n");
+
+ apply_alternatives_vdso();
+ /* better not try code patching on a live SMP system */
+ stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask);
+}
+
+/*
+ * This is called very early in the boot process (directly after we run
+ * a feature detect on the boot CPU). No need to worry about other CPUs
+ * here.
+ */
+void __init apply_boot_alternatives(void)
+{
+ /* If called on non-boot cpu things could go wrong */
+ WARN_ON(smp_processor_id() != 0);
+
+ pr_info("applying boot alternatives\n");
+
+ __apply_alternatives(&kernel_alternatives, false,
+ &boot_capabilities[0]);
+}
+
+#ifdef CONFIG_MODULES
+void apply_alternatives_module(void *start, size_t length)
+{
+ struct alt_region region = {
+ .begin = start,
+ .end = start + length,
+ };
+ DECLARE_BITMAP(all_capabilities, ARM64_NCAPS);
+
+ bitmap_fill(all_capabilities, ARM64_NCAPS);
+
+ __apply_alternatives(&region, true, &all_capabilities[0]);
+}
+#endif
+
+noinstr void alt_cb_patch_nops(struct alt_instr *alt, __le32 *origptr,
+ __le32 *updptr, int nr_inst)
+{
+ for (int i = 0; i < nr_inst; i++)
+ updptr[i] = cpu_to_le32(aarch64_insn_gen_nop());
+}
+EXPORT_SYMBOL(alt_cb_patch_nops);