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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/ftrace.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/kernel/ftrace.c670
1 files changed, 670 insertions, 0 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
new file mode 100644
index 000000000..5e7ead52c
--- /dev/null
+++ b/arch/x86/kernel/ftrace.c
@@ -0,0 +1,670 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Dynamic function tracing support.
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ *
+ * Thanks goes to Ingo Molnar, for suggesting the idea.
+ * Mathieu Desnoyers, for suggesting postponing the modifications.
+ * Arjan van de Ven, for keeping me straight, and explaining to me
+ * the dangers of modifying code on the run.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/spinlock.h>
+#include <linux/hardirq.h>
+#include <linux/uaccess.h>
+#include <linux/ftrace.h>
+#include <linux/percpu.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/memory.h>
+#include <linux/vmalloc.h>
+#include <linux/set_memory.h>
+
+#include <trace/syscall.h>
+
+#include <asm/kprobes.h>
+#include <asm/ftrace.h>
+#include <asm/nops.h>
+#include <asm/text-patching.h>
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+static int ftrace_poke_late = 0;
+
+void ftrace_arch_code_modify_prepare(void)
+ __acquires(&text_mutex)
+{
+ /*
+ * Need to grab text_mutex to prevent a race from module loading
+ * and live kernel patching from changing the text permissions while
+ * ftrace has it set to "read/write".
+ */
+ mutex_lock(&text_mutex);
+ ftrace_poke_late = 1;
+}
+
+void ftrace_arch_code_modify_post_process(void)
+ __releases(&text_mutex)
+{
+ /*
+ * ftrace_make_{call,nop}() may be called during
+ * module load, and we need to finish the text_poke_queue()
+ * that they do, here.
+ */
+ text_poke_finish();
+ ftrace_poke_late = 0;
+ mutex_unlock(&text_mutex);
+}
+
+static const char *ftrace_nop_replace(void)
+{
+ return x86_nops[5];
+}
+
+static const char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+{
+ /*
+ * No need to translate into a callthunk. The trampoline does
+ * the depth accounting itself.
+ */
+ return text_gen_insn(CALL_INSN_OPCODE, (void *)ip, (void *)addr);
+}
+
+static int ftrace_verify_code(unsigned long ip, const char *old_code)
+{
+ char cur_code[MCOUNT_INSN_SIZE];
+
+ /*
+ * Note:
+ * We are paranoid about modifying text, as if a bug was to happen, it
+ * could cause us to read or write to someplace that could cause harm.
+ * Carefully read and modify the code with probe_kernel_*(), and make
+ * sure what we read is what we expected it to be before modifying it.
+ */
+ /* read the text we want to modify */
+ if (copy_from_kernel_nofault(cur_code, (void *)ip, MCOUNT_INSN_SIZE)) {
+ WARN_ON(1);
+ return -EFAULT;
+ }
+
+ /* Make sure it is what we expect it to be */
+ if (memcmp(cur_code, old_code, MCOUNT_INSN_SIZE) != 0) {
+ ftrace_expected = old_code;
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Marked __ref because it calls text_poke_early() which is .init.text. That is
+ * ok because that call will happen early, during boot, when .init sections are
+ * still present.
+ */
+static int __ref
+ftrace_modify_code_direct(unsigned long ip, const char *old_code,
+ const char *new_code)
+{
+ int ret = ftrace_verify_code(ip, old_code);
+ if (ret)
+ return ret;
+
+ /* replace the text with the new text */
+ if (ftrace_poke_late)
+ text_poke_queue((void *)ip, new_code, MCOUNT_INSN_SIZE, NULL);
+ else
+ text_poke_early((void *)ip, new_code, MCOUNT_INSN_SIZE);
+ return 0;
+}
+
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ const char *new, *old;
+
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop_replace();
+
+ /*
+ * On boot up, and when modules are loaded, the MCOUNT_ADDR
+ * is converted to a nop, and will never become MCOUNT_ADDR
+ * again. This code is either running before SMP (on boot up)
+ * or before the code will ever be executed (module load).
+ * We do not want to use the breakpoint version in this case,
+ * just modify the code directly.
+ */
+ if (addr == MCOUNT_ADDR)
+ return ftrace_modify_code_direct(ip, old, new);
+
+ /*
+ * x86 overrides ftrace_replace_code -- this function will never be used
+ * in this case.
+ */
+ WARN_ONCE(1, "invalid use of ftrace_make_nop");
+ return -EINVAL;
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ const char *new, *old;
+
+ old = ftrace_nop_replace();
+ new = ftrace_call_replace(ip, addr);
+
+ /* Should only be called when module is loaded */
+ return ftrace_modify_code_direct(rec->ip, old, new);
+}
+
+/*
+ * Should never be called:
+ * As it is only called by __ftrace_replace_code() which is called by
+ * ftrace_replace_code() that x86 overrides, and by ftrace_update_code()
+ * which is called to turn mcount into nops or nops into function calls
+ * but not to convert a function from not using regs to one that uses
+ * regs, which ftrace_modify_call() is for.
+ */
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+ unsigned long addr)
+{
+ WARN_ON(1);
+ return -EINVAL;
+}
+
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+ unsigned long ip;
+ const char *new;
+
+ ip = (unsigned long)(&ftrace_call);
+ new = ftrace_call_replace(ip, (unsigned long)func);
+ text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
+
+ ip = (unsigned long)(&ftrace_regs_call);
+ new = ftrace_call_replace(ip, (unsigned long)func);
+ text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
+
+ return 0;
+}
+
+void ftrace_replace_code(int enable)
+{
+ struct ftrace_rec_iter *iter;
+ struct dyn_ftrace *rec;
+ const char *new, *old;
+ int ret;
+
+ for_ftrace_rec_iter(iter) {
+ rec = ftrace_rec_iter_record(iter);
+
+ switch (ftrace_test_record(rec, enable)) {
+ case FTRACE_UPDATE_IGNORE:
+ default:
+ continue;
+
+ case FTRACE_UPDATE_MAKE_CALL:
+ old = ftrace_nop_replace();
+ break;
+
+ case FTRACE_UPDATE_MODIFY_CALL:
+ case FTRACE_UPDATE_MAKE_NOP:
+ old = ftrace_call_replace(rec->ip, ftrace_get_addr_curr(rec));
+ break;
+ }
+
+ ret = ftrace_verify_code(rec->ip, old);
+ if (ret) {
+ ftrace_expected = old;
+ ftrace_bug(ret, rec);
+ ftrace_expected = NULL;
+ return;
+ }
+ }
+
+ for_ftrace_rec_iter(iter) {
+ rec = ftrace_rec_iter_record(iter);
+
+ switch (ftrace_test_record(rec, enable)) {
+ case FTRACE_UPDATE_IGNORE:
+ default:
+ continue;
+
+ case FTRACE_UPDATE_MAKE_CALL:
+ case FTRACE_UPDATE_MODIFY_CALL:
+ new = ftrace_call_replace(rec->ip, ftrace_get_addr_new(rec));
+ break;
+
+ case FTRACE_UPDATE_MAKE_NOP:
+ new = ftrace_nop_replace();
+ break;
+ }
+
+ text_poke_queue((void *)rec->ip, new, MCOUNT_INSN_SIZE, NULL);
+ ftrace_update_record(rec, enable);
+ }
+ text_poke_finish();
+}
+
+void arch_ftrace_update_code(int command)
+{
+ ftrace_modify_all_code(command);
+}
+
+/* Currently only x86_64 supports dynamic trampolines */
+#ifdef CONFIG_X86_64
+
+#ifdef CONFIG_MODULES
+#include <linux/moduleloader.h>
+/* Module allocation simplifies allocating memory for code */
+static inline void *alloc_tramp(unsigned long size)
+{
+ return module_alloc(size);
+}
+static inline void tramp_free(void *tramp)
+{
+ module_memfree(tramp);
+}
+#else
+/* Trampolines can only be created if modules are supported */
+static inline void *alloc_tramp(unsigned long size)
+{
+ return NULL;
+}
+static inline void tramp_free(void *tramp) { }
+#endif
+
+/* Defined as markers to the end of the ftrace default trampolines */
+extern void ftrace_regs_caller_end(void);
+extern void ftrace_regs_caller_ret(void);
+extern void ftrace_caller_end(void);
+extern void ftrace_caller_op_ptr(void);
+extern void ftrace_regs_caller_op_ptr(void);
+extern void ftrace_regs_caller_jmp(void);
+
+/* movq function_trace_op(%rip), %rdx */
+/* 0x48 0x8b 0x15 <offset-to-ftrace_trace_op (4 bytes)> */
+#define OP_REF_SIZE 7
+
+/*
+ * The ftrace_ops is passed to the function callback. Since the
+ * trampoline only services a single ftrace_ops, we can pass in
+ * that ops directly.
+ *
+ * The ftrace_op_code_union is used to create a pointer to the
+ * ftrace_ops that will be passed to the callback function.
+ */
+union ftrace_op_code_union {
+ char code[OP_REF_SIZE];
+ struct {
+ char op[3];
+ int offset;
+ } __attribute__((packed));
+};
+
+#define RET_SIZE (IS_ENABLED(CONFIG_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))
+
+static unsigned long
+create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
+{
+ unsigned long start_offset;
+ unsigned long end_offset;
+ unsigned long op_offset;
+ unsigned long call_offset;
+ unsigned long jmp_offset;
+ unsigned long offset;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long *ptr;
+ void *trampoline;
+ void *ip, *dest;
+ /* 48 8b 15 <offset> is movq <offset>(%rip), %rdx */
+ unsigned const char op_ref[] = { 0x48, 0x8b, 0x15 };
+ unsigned const char retq[] = { RET_INSN_OPCODE, INT3_INSN_OPCODE };
+ union ftrace_op_code_union op_ptr;
+ int ret;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ start_offset = (unsigned long)ftrace_regs_caller;
+ end_offset = (unsigned long)ftrace_regs_caller_end;
+ op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
+ call_offset = (unsigned long)ftrace_regs_call;
+ jmp_offset = (unsigned long)ftrace_regs_caller_jmp;
+ } else {
+ start_offset = (unsigned long)ftrace_caller;
+ end_offset = (unsigned long)ftrace_caller_end;
+ op_offset = (unsigned long)ftrace_caller_op_ptr;
+ call_offset = (unsigned long)ftrace_call;
+ jmp_offset = 0;
+ }
+
+ size = end_offset - start_offset;
+
+ /*
+ * Allocate enough size to store the ftrace_caller code,
+ * the iret , as well as the address of the ftrace_ops this
+ * trampoline is used for.
+ */
+ trampoline = alloc_tramp(size + RET_SIZE + sizeof(void *));
+ if (!trampoline)
+ return 0;
+
+ *tramp_size = size + RET_SIZE + sizeof(void *);
+ npages = DIV_ROUND_UP(*tramp_size, PAGE_SIZE);
+
+ /* Copy ftrace_caller onto the trampoline memory */
+ ret = copy_from_kernel_nofault(trampoline, (void *)start_offset, size);
+ if (WARN_ON(ret < 0))
+ goto fail;
+
+ ip = trampoline + size;
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+ __text_gen_insn(ip, JMP32_INSN_OPCODE, ip, x86_return_thunk, JMP32_INSN_SIZE);
+ else
+ memcpy(ip, retq, sizeof(retq));
+
+ /* No need to test direct calls on created trampolines */
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ /* NOP the jnz 1f; but make sure it's a 2 byte jnz */
+ ip = trampoline + (jmp_offset - start_offset);
+ if (WARN_ON(*(char *)ip != 0x75))
+ goto fail;
+ ret = copy_from_kernel_nofault(ip, x86_nops[2], 2);
+ if (ret < 0)
+ goto fail;
+ }
+
+ /*
+ * The address of the ftrace_ops that is used for this trampoline
+ * is stored at the end of the trampoline. This will be used to
+ * load the third parameter for the callback. Basically, that
+ * location at the end of the trampoline takes the place of
+ * the global function_trace_op variable.
+ */
+
+ ptr = (unsigned long *)(trampoline + size + RET_SIZE);
+ *ptr = (unsigned long)ops;
+
+ op_offset -= start_offset;
+ memcpy(&op_ptr, trampoline + op_offset, OP_REF_SIZE);
+
+ /* Are we pointing to the reference? */
+ if (WARN_ON(memcmp(op_ptr.op, op_ref, 3) != 0))
+ goto fail;
+
+ /* Load the contents of ptr into the callback parameter */
+ offset = (unsigned long)ptr;
+ offset -= (unsigned long)trampoline + op_offset + OP_REF_SIZE;
+
+ op_ptr.offset = offset;
+
+ /* put in the new offset to the ftrace_ops */
+ memcpy(trampoline + op_offset, &op_ptr, OP_REF_SIZE);
+
+ /* put in the call to the function */
+ mutex_lock(&text_mutex);
+ call_offset -= start_offset;
+ /*
+ * No need to translate into a callthunk. The trampoline does
+ * the depth accounting before the call already.
+ */
+ dest = ftrace_ops_get_func(ops);
+ memcpy(trampoline + call_offset,
+ text_gen_insn(CALL_INSN_OPCODE, trampoline + call_offset, dest),
+ CALL_INSN_SIZE);
+ mutex_unlock(&text_mutex);
+
+ /* ALLOC_TRAMP flags lets us know we created it */
+ ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
+
+ set_memory_rox((unsigned long)trampoline, npages);
+ return (unsigned long)trampoline;
+fail:
+ tramp_free(trampoline);
+ return 0;
+}
+
+void set_ftrace_ops_ro(void)
+{
+ struct ftrace_ops *ops;
+ unsigned long start_offset;
+ unsigned long end_offset;
+ unsigned long npages;
+ unsigned long size;
+
+ do_for_each_ftrace_op(ops, ftrace_ops_list) {
+ if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ continue;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ start_offset = (unsigned long)ftrace_regs_caller;
+ end_offset = (unsigned long)ftrace_regs_caller_end;
+ } else {
+ start_offset = (unsigned long)ftrace_caller;
+ end_offset = (unsigned long)ftrace_caller_end;
+ }
+ size = end_offset - start_offset;
+ size = size + RET_SIZE + sizeof(void *);
+ npages = DIV_ROUND_UP(size, PAGE_SIZE);
+ set_memory_ro((unsigned long)ops->trampoline, npages);
+ } while_for_each_ftrace_op(ops);
+}
+
+static unsigned long calc_trampoline_call_offset(bool save_regs)
+{
+ unsigned long start_offset;
+ unsigned long call_offset;
+
+ if (save_regs) {
+ start_offset = (unsigned long)ftrace_regs_caller;
+ call_offset = (unsigned long)ftrace_regs_call;
+ } else {
+ start_offset = (unsigned long)ftrace_caller;
+ call_offset = (unsigned long)ftrace_call;
+ }
+
+ return call_offset - start_offset;
+}
+
+void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+ ftrace_func_t func;
+ unsigned long offset;
+ unsigned long ip;
+ unsigned int size;
+ const char *new;
+
+ if (!ops->trampoline) {
+ ops->trampoline = create_trampoline(ops, &size);
+ if (!ops->trampoline)
+ return;
+ ops->trampoline_size = size;
+ return;
+ }
+
+ /*
+ * The ftrace_ops caller may set up its own trampoline.
+ * In such a case, this code must not modify it.
+ */
+ if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ return;
+
+ offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
+ ip = ops->trampoline + offset;
+ func = ftrace_ops_get_func(ops);
+
+ mutex_lock(&text_mutex);
+ /* Do a safe modify in case the trampoline is executing */
+ new = ftrace_call_replace(ip, (unsigned long)func);
+ text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
+ mutex_unlock(&text_mutex);
+}
+
+/* Return the address of the function the trampoline calls */
+static void *addr_from_call(void *ptr)
+{
+ union text_poke_insn call;
+ int ret;
+
+ ret = copy_from_kernel_nofault(&call, ptr, CALL_INSN_SIZE);
+ if (WARN_ON_ONCE(ret < 0))
+ return NULL;
+
+ /* Make sure this is a call */
+ if (WARN_ON_ONCE(call.opcode != CALL_INSN_OPCODE)) {
+ pr_warn("Expected E8, got %x\n", call.opcode);
+ return NULL;
+ }
+
+ return ptr + CALL_INSN_SIZE + call.disp;
+}
+
+void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
+ unsigned long frame_pointer);
+
+/*
+ * If the ops->trampoline was not allocated, then it probably
+ * has a static trampoline func, or is the ftrace caller itself.
+ */
+static void *static_tramp_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ unsigned long offset;
+ bool save_regs = rec->flags & FTRACE_FL_REGS_EN;
+ void *ptr;
+
+ if (ops && ops->trampoline) {
+#if !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS) && \
+ defined(CONFIG_FUNCTION_GRAPH_TRACER)
+ /*
+ * We only know about function graph tracer setting as static
+ * trampoline.
+ */
+ if (ops->trampoline == FTRACE_GRAPH_ADDR)
+ return (void *)prepare_ftrace_return;
+#endif
+ return NULL;
+ }
+
+ offset = calc_trampoline_call_offset(save_regs);
+
+ if (save_regs)
+ ptr = (void *)FTRACE_REGS_ADDR + offset;
+ else
+ ptr = (void *)FTRACE_ADDR + offset;
+
+ return addr_from_call(ptr);
+}
+
+void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ unsigned long offset;
+
+ /* If we didn't allocate this trampoline, consider it static */
+ if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ return static_tramp_func(ops, rec);
+
+ offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
+ return addr_from_call((void *)ops->trampoline + offset);
+}
+
+void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+ if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ return;
+
+ tramp_free((void *)ops->trampoline);
+ ops->trampoline = 0;
+}
+
+#endif /* CONFIG_X86_64 */
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+#if defined(CONFIG_DYNAMIC_FTRACE) && !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)
+extern void ftrace_graph_call(void);
+static const char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
+{
+ return text_gen_insn(JMP32_INSN_OPCODE, (void *)ip, (void *)addr);
+}
+
+static int ftrace_mod_jmp(unsigned long ip, void *func)
+{
+ const char *new;
+
+ new = ftrace_jmp_replace(ip, (unsigned long)func);
+ text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
+ return 0;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+
+ return ftrace_mod_jmp(ip, &ftrace_graph_caller);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+
+ return ftrace_mod_jmp(ip, &ftrace_stub);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE && !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
+ unsigned long frame_pointer)
+{
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+ int bit;
+
+ /*
+ * When resuming from suspend-to-ram, this function can be indirectly
+ * called from early CPU startup code while the CPU is in real mode,
+ * which would fail miserably. Make sure the stack pointer is a
+ * virtual address.
+ *
+ * This check isn't as accurate as virt_addr_valid(), but it should be
+ * good enough for this purpose, and it's fast.
+ */
+ if (unlikely((long)__builtin_frame_address(0) >= 0))
+ return;
+
+ if (unlikely(ftrace_graph_is_dead()))
+ return;
+
+ if (unlikely(atomic_read(&current->tracing_graph_pause)))
+ return;
+
+ bit = ftrace_test_recursion_trylock(ip, *parent);
+ if (bit < 0)
+ return;
+
+ if (!function_graph_enter(*parent, ip, frame_pointer, parent))
+ *parent = return_hooker;
+
+ ftrace_test_recursion_unlock(bit);
+}
+
+#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ struct pt_regs *regs = &fregs->regs;
+ unsigned long *stack = (unsigned long *)kernel_stack_pointer(regs);
+
+ prepare_ftrace_return(ip, (unsigned long *)stack, 0);
+}
+#endif
+
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */