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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/kernel/callthunks.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/x86/kernel/callthunks.c')
-rw-r--r--arch/x86/kernel/callthunks.c388
1 files changed, 388 insertions, 0 deletions
diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c
new file mode 100644
index 000000000..ffea98f90
--- /dev/null
+++ b/arch/x86/kernel/callthunks.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define pr_fmt(fmt) "callthunks: " fmt
+
+#include <linux/debugfs.h>
+#include <linux/kallsyms.h>
+#include <linux/memory.h>
+#include <linux/moduleloader.h>
+#include <linux/static_call.h>
+
+#include <asm/alternative.h>
+#include <asm/asm-offsets.h>
+#include <asm/cpu.h>
+#include <asm/ftrace.h>
+#include <asm/insn.h>
+#include <asm/kexec.h>
+#include <asm/nospec-branch.h>
+#include <asm/paravirt.h>
+#include <asm/sections.h>
+#include <asm/switch_to.h>
+#include <asm/sync_core.h>
+#include <asm/text-patching.h>
+#include <asm/xen/hypercall.h>
+
+static int __initdata_or_module debug_callthunks;
+
+#define prdbg(fmt, args...) \
+do { \
+ if (debug_callthunks) \
+ printk(KERN_DEBUG pr_fmt(fmt), ##args); \
+} while(0)
+
+static int __init debug_thunks(char *str)
+{
+ debug_callthunks = 1;
+ return 1;
+}
+__setup("debug-callthunks", debug_thunks);
+
+#ifdef CONFIG_CALL_THUNKS_DEBUG
+DEFINE_PER_CPU(u64, __x86_call_count);
+DEFINE_PER_CPU(u64, __x86_ret_count);
+DEFINE_PER_CPU(u64, __x86_stuffs_count);
+DEFINE_PER_CPU(u64, __x86_ctxsw_count);
+EXPORT_SYMBOL_GPL(__x86_ctxsw_count);
+EXPORT_SYMBOL_GPL(__x86_call_count);
+#endif
+
+extern s32 __call_sites[], __call_sites_end[];
+
+struct thunk_desc {
+ void *template;
+ unsigned int template_size;
+};
+
+struct core_text {
+ unsigned long base;
+ unsigned long end;
+ const char *name;
+};
+
+static bool thunks_initialized __ro_after_init;
+
+static const struct core_text builtin_coretext = {
+ .base = (unsigned long)_text,
+ .end = (unsigned long)_etext,
+ .name = "builtin",
+};
+
+asm (
+ ".pushsection .rodata \n"
+ ".global skl_call_thunk_template \n"
+ "skl_call_thunk_template: \n"
+ __stringify(INCREMENT_CALL_DEPTH)" \n"
+ ".global skl_call_thunk_tail \n"
+ "skl_call_thunk_tail: \n"
+ ".popsection \n"
+);
+
+extern u8 skl_call_thunk_template[];
+extern u8 skl_call_thunk_tail[];
+
+#define SKL_TMPL_SIZE \
+ ((unsigned int)(skl_call_thunk_tail - skl_call_thunk_template))
+
+extern void error_entry(void);
+extern void xen_error_entry(void);
+extern void paranoid_entry(void);
+
+static inline bool within_coretext(const struct core_text *ct, void *addr)
+{
+ unsigned long p = (unsigned long)addr;
+
+ return ct->base <= p && p < ct->end;
+}
+
+static inline bool within_module_coretext(void *addr)
+{
+ bool ret = false;
+
+#ifdef CONFIG_MODULES
+ struct module *mod;
+
+ preempt_disable();
+ mod = __module_address((unsigned long)addr);
+ if (mod && within_module_core((unsigned long)addr, mod))
+ ret = true;
+ preempt_enable();
+#endif
+ return ret;
+}
+
+static bool is_coretext(const struct core_text *ct, void *addr)
+{
+ if (ct && within_coretext(ct, addr))
+ return true;
+ if (within_coretext(&builtin_coretext, addr))
+ return true;
+ return within_module_coretext(addr);
+}
+
+static bool skip_addr(void *dest)
+{
+ if (dest == error_entry)
+ return true;
+ if (dest == paranoid_entry)
+ return true;
+ if (dest == xen_error_entry)
+ return true;
+ /* Does FILL_RSB... */
+ if (dest == __switch_to_asm)
+ return true;
+ /* Accounts directly */
+ if (dest == ret_from_fork)
+ return true;
+#ifdef CONFIG_HOTPLUG_CPU
+ if (dest == start_cpu0)
+ return true;
+#endif
+#ifdef CONFIG_FUNCTION_TRACER
+ if (dest == __fentry__)
+ return true;
+#endif
+#ifdef CONFIG_KEXEC_CORE
+ if (dest >= (void *)relocate_kernel &&
+ dest < (void*)relocate_kernel + KEXEC_CONTROL_CODE_MAX_SIZE)
+ return true;
+#endif
+#ifdef CONFIG_XEN
+ if (dest >= (void *)hypercall_page &&
+ dest < (void*)hypercall_page + PAGE_SIZE)
+ return true;
+#endif
+ return false;
+}
+
+static __init_or_module void *call_get_dest(void *addr)
+{
+ struct insn insn;
+ void *dest;
+ int ret;
+
+ ret = insn_decode_kernel(&insn, addr);
+ if (ret)
+ return ERR_PTR(ret);
+
+ /* Patched out call? */
+ if (insn.opcode.bytes[0] != CALL_INSN_OPCODE)
+ return NULL;
+
+ dest = addr + insn.length + insn.immediate.value;
+ if (skip_addr(dest))
+ return NULL;
+ return dest;
+}
+
+static const u8 nops[] = {
+ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
+ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
+ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
+ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
+};
+
+static void *patch_dest(void *dest, bool direct)
+{
+ unsigned int tsize = SKL_TMPL_SIZE;
+ u8 *pad = dest - tsize;
+
+ /* Already patched? */
+ if (!bcmp(pad, skl_call_thunk_template, tsize))
+ return pad;
+
+ /* Ensure there are nops */
+ if (bcmp(pad, nops, tsize)) {
+ pr_warn_once("Invalid padding area for %pS\n", dest);
+ return NULL;
+ }
+
+ if (direct)
+ memcpy(pad, skl_call_thunk_template, tsize);
+ else
+ text_poke_copy_locked(pad, skl_call_thunk_template, tsize, true);
+ return pad;
+}
+
+static __init_or_module void patch_call(void *addr, const struct core_text *ct)
+{
+ void *pad, *dest;
+ u8 bytes[8];
+
+ if (!within_coretext(ct, addr))
+ return;
+
+ dest = call_get_dest(addr);
+ if (!dest || WARN_ON_ONCE(IS_ERR(dest)))
+ return;
+
+ if (!is_coretext(ct, dest))
+ return;
+
+ pad = patch_dest(dest, within_coretext(ct, dest));
+ if (!pad)
+ return;
+
+ prdbg("Patch call at: %pS %px to %pS %px -> %px \n", addr, addr,
+ dest, dest, pad);
+ __text_gen_insn(bytes, CALL_INSN_OPCODE, addr, pad, CALL_INSN_SIZE);
+ text_poke_early(addr, bytes, CALL_INSN_SIZE);
+}
+
+static __init_or_module void
+patch_call_sites(s32 *start, s32 *end, const struct core_text *ct)
+{
+ s32 *s;
+
+ for (s = start; s < end; s++)
+ patch_call((void *)s + *s, ct);
+}
+
+static __init_or_module void
+patch_paravirt_call_sites(struct paravirt_patch_site *start,
+ struct paravirt_patch_site *end,
+ const struct core_text *ct)
+{
+ struct paravirt_patch_site *p;
+
+ for (p = start; p < end; p++)
+ patch_call(p->instr, ct);
+}
+
+static __init_or_module void
+callthunks_setup(struct callthunk_sites *cs, const struct core_text *ct)
+{
+ prdbg("Patching call sites %s\n", ct->name);
+ patch_call_sites(cs->call_start, cs->call_end, ct);
+ patch_paravirt_call_sites(cs->pv_start, cs->pv_end, ct);
+ prdbg("Patching call sites done%s\n", ct->name);
+}
+
+void __init callthunks_patch_builtin_calls(void)
+{
+ struct callthunk_sites cs = {
+ .call_start = __call_sites,
+ .call_end = __call_sites_end,
+ .pv_start = __parainstructions,
+ .pv_end = __parainstructions_end
+ };
+
+ if (!cpu_feature_enabled(X86_FEATURE_CALL_DEPTH))
+ return;
+
+ pr_info("Setting up call depth tracking\n");
+ mutex_lock(&text_mutex);
+ callthunks_setup(&cs, &builtin_coretext);
+ static_call_force_reinit();
+ thunks_initialized = true;
+ mutex_unlock(&text_mutex);
+}
+
+void *callthunks_translate_call_dest(void *dest)
+{
+ void *target;
+
+ lockdep_assert_held(&text_mutex);
+
+ if (!thunks_initialized || skip_addr(dest))
+ return dest;
+
+ if (!is_coretext(NULL, dest))
+ return dest;
+
+ target = patch_dest(dest, false);
+ return target ? : dest;
+}
+
+bool is_callthunk(void *addr)
+{
+ unsigned int tmpl_size = SKL_TMPL_SIZE;
+ void *tmpl = skl_call_thunk_template;
+ unsigned long dest;
+
+ dest = roundup((unsigned long)addr, CONFIG_FUNCTION_ALIGNMENT);
+ if (!thunks_initialized || skip_addr((void *)dest))
+ return false;
+
+ return !bcmp((void *)(dest - tmpl_size), tmpl, tmpl_size);
+}
+
+#ifdef CONFIG_BPF_JIT
+int x86_call_depth_emit_accounting(u8 **pprog, void *func)
+{
+ unsigned int tmpl_size = SKL_TMPL_SIZE;
+ void *tmpl = skl_call_thunk_template;
+
+ if (!thunks_initialized)
+ return 0;
+
+ /* Is function call target a thunk? */
+ if (func && is_callthunk(func))
+ return 0;
+
+ memcpy(*pprog, tmpl, tmpl_size);
+ *pprog += tmpl_size;
+ return tmpl_size;
+}
+#endif
+
+#ifdef CONFIG_MODULES
+void noinline callthunks_patch_module_calls(struct callthunk_sites *cs,
+ struct module *mod)
+{
+ struct core_text ct = {
+ .base = (unsigned long)mod->core_layout.base,
+ .end = (unsigned long)mod->core_layout.base + mod->core_layout.size,
+ .name = mod->name,
+ };
+
+ if (!thunks_initialized)
+ return;
+
+ mutex_lock(&text_mutex);
+ callthunks_setup(cs, &ct);
+ mutex_unlock(&text_mutex);
+}
+#endif /* CONFIG_MODULES */
+
+#if defined(CONFIG_CALL_THUNKS_DEBUG) && defined(CONFIG_DEBUG_FS)
+static int callthunks_debug_show(struct seq_file *m, void *p)
+{
+ unsigned long cpu = (unsigned long)m->private;
+
+ seq_printf(m, "C: %16llu R: %16llu S: %16llu X: %16llu\n,",
+ per_cpu(__x86_call_count, cpu),
+ per_cpu(__x86_ret_count, cpu),
+ per_cpu(__x86_stuffs_count, cpu),
+ per_cpu(__x86_ctxsw_count, cpu));
+ return 0;
+}
+
+static int callthunks_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, callthunks_debug_show, inode->i_private);
+}
+
+static const struct file_operations dfs_ops = {
+ .open = callthunks_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init callthunks_debugfs_init(void)
+{
+ struct dentry *dir;
+ unsigned long cpu;
+
+ dir = debugfs_create_dir("callthunks", NULL);
+ for_each_possible_cpu(cpu) {
+ void *arg = (void *)cpu;
+ char name [10];
+
+ sprintf(name, "cpu%lu", cpu);
+ debugfs_create_file(name, 0644, dir, arg, &dfs_ops);
+ }
+ return 0;
+}
+__initcall(callthunks_debugfs_init);
+#endif