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-rw-r--r--arch/tile/kernel/kprobes.c527
1 files changed, 0 insertions, 527 deletions
diff --git a/arch/tile/kernel/kprobes.c b/arch/tile/kernel/kprobes.c
deleted file mode 100644
index c68694bb1ad2..000000000000
--- a/arch/tile/kernel/kprobes.c
+++ /dev/null
@@ -1,527 +0,0 @@
-/*
- * arch/tile/kernel/kprobes.c
- * Kprobes on TILE-Gx
- *
- * Some portions copied from the MIPS version.
- *
- * Copyright (C) IBM Corporation, 2002, 2004
- * Copyright 2006 Sony Corp.
- * Copyright 2010 Cavium Networks
- *
- * Copyright 2012 Tilera Corporation. All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation, version 2.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
- * NON INFRINGEMENT. See the GNU General Public License for
- * more details.
- */
-
-#include <linux/kprobes.h>
-#include <linux/kdebug.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
-
-#include <arch/opcode.h>
-
-DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
-DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
-
-tile_bundle_bits breakpoint_insn = TILEGX_BPT_BUNDLE;
-tile_bundle_bits breakpoint2_insn = TILEGX_BPT_BUNDLE | DIE_SSTEPBP;
-
-/*
- * Check whether instruction is branch or jump, or if executing it
- * has different results depending on where it is executed (e.g. lnk).
- */
-static int __kprobes insn_has_control(kprobe_opcode_t insn)
-{
- if (get_Mode(insn) != 0) { /* Y-format bundle */
- if (get_Opcode_Y1(insn) != RRR_1_OPCODE_Y1 ||
- get_RRROpcodeExtension_Y1(insn) != UNARY_RRR_1_OPCODE_Y1)
- return 0;
-
- switch (get_UnaryOpcodeExtension_Y1(insn)) {
- case JALRP_UNARY_OPCODE_Y1:
- case JALR_UNARY_OPCODE_Y1:
- case JRP_UNARY_OPCODE_Y1:
- case JR_UNARY_OPCODE_Y1:
- case LNK_UNARY_OPCODE_Y1:
- return 1;
- default:
- return 0;
- }
- }
-
- switch (get_Opcode_X1(insn)) {
- case BRANCH_OPCODE_X1: /* branch instructions */
- case JUMP_OPCODE_X1: /* jump instructions: j and jal */
- return 1;
-
- case RRR_0_OPCODE_X1: /* other jump instructions */
- if (get_RRROpcodeExtension_X1(insn) != UNARY_RRR_0_OPCODE_X1)
- return 0;
- switch (get_UnaryOpcodeExtension_X1(insn)) {
- case JALRP_UNARY_OPCODE_X1:
- case JALR_UNARY_OPCODE_X1:
- case JRP_UNARY_OPCODE_X1:
- case JR_UNARY_OPCODE_X1:
- case LNK_UNARY_OPCODE_X1:
- return 1;
- default:
- return 0;
- }
- default:
- return 0;
- }
-}
-
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
- unsigned long addr = (unsigned long)p->addr;
-
- if (addr & (sizeof(kprobe_opcode_t) - 1))
- return -EINVAL;
-
- if (insn_has_control(*p->addr)) {
- pr_notice("Kprobes for control instructions are not supported\n");
- return -EINVAL;
- }
-
- /* insn: must be on special executable page on tile. */
- p->ainsn.insn = get_insn_slot();
- if (!p->ainsn.insn)
- return -ENOMEM;
-
- /*
- * In the kprobe->ainsn.insn[] array we store the original
- * instruction at index zero and a break trap instruction at
- * index one.
- */
- memcpy(&p->ainsn.insn[0], p->addr, sizeof(kprobe_opcode_t));
- p->ainsn.insn[1] = breakpoint2_insn;
- p->opcode = *p->addr;
-
- return 0;
-}
-
-void __kprobes arch_arm_kprobe(struct kprobe *p)
-{
- unsigned long addr_wr;
-
- /* Operate on writable kernel text mapping. */
- addr_wr = ktext_writable_addr(p->addr);
-
- if (probe_kernel_write((void *)addr_wr, &breakpoint_insn,
- sizeof(breakpoint_insn)))
- pr_err("%s: failed to enable kprobe\n", __func__);
-
- smp_wmb();
- flush_insn_slot(p);
-}
-
-void __kprobes arch_disarm_kprobe(struct kprobe *kp)
-{
- unsigned long addr_wr;
-
- /* Operate on writable kernel text mapping. */
- addr_wr = ktext_writable_addr(kp->addr);
-
- if (probe_kernel_write((void *)addr_wr, &kp->opcode,
- sizeof(kp->opcode)))
- pr_err("%s: failed to enable kprobe\n", __func__);
-
- smp_wmb();
- flush_insn_slot(kp);
-}
-
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
- if (p->ainsn.insn) {
- free_insn_slot(p->ainsn.insn, 0);
- p->ainsn.insn = NULL;
- }
-}
-
-static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
-{
- kcb->prev_kprobe.kp = kprobe_running();
- kcb->prev_kprobe.status = kcb->kprobe_status;
- kcb->prev_kprobe.saved_pc = kcb->kprobe_saved_pc;
-}
-
-static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
-{
- __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
- kcb->kprobe_status = kcb->prev_kprobe.status;
- kcb->kprobe_saved_pc = kcb->prev_kprobe.saved_pc;
-}
-
-static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- __this_cpu_write(current_kprobe, p);
- kcb->kprobe_saved_pc = regs->pc;
-}
-
-static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
-{
- /* Single step inline if the instruction is a break. */
- if (p->opcode == breakpoint_insn ||
- p->opcode == breakpoint2_insn)
- regs->pc = (unsigned long)p->addr;
- else
- regs->pc = (unsigned long)&p->ainsn.insn[0];
-}
-
-static int __kprobes kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *p;
- int ret = 0;
- kprobe_opcode_t *addr;
- struct kprobe_ctlblk *kcb;
-
- addr = (kprobe_opcode_t *)regs->pc;
-
- /*
- * We don't want to be preempted for the entire
- * duration of kprobe processing.
- */
- preempt_disable();
- kcb = get_kprobe_ctlblk();
-
- /* Check we're not actually recursing. */
- if (kprobe_running()) {
- p = get_kprobe(addr);
- if (p) {
- if (kcb->kprobe_status == KPROBE_HIT_SS &&
- p->ainsn.insn[0] == breakpoint_insn) {
- goto no_kprobe;
- }
- /*
- * We have reentered the kprobe_handler(), since
- * another probe was hit while within the handler.
- * We here save the original kprobes variables and
- * just single step on the instruction of the new probe
- * without calling any user handlers.
- */
- save_previous_kprobe(kcb);
- set_current_kprobe(p, regs, kcb);
- kprobes_inc_nmissed_count(p);
- prepare_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_REENTER;
- return 1;
- } else {
- if (*addr != breakpoint_insn) {
- /*
- * The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate.
- */
- ret = 1;
- goto no_kprobe;
- }
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs))
- goto ss_probe;
- }
- goto no_kprobe;
- }
-
- p = get_kprobe(addr);
- if (!p) {
- if (*addr != breakpoint_insn) {
- /*
- * The breakpoint instruction was removed right
- * after we hit it. Another cpu has removed
- * either a probepoint or a debugger breakpoint
- * at this address. In either case, no further
- * handling of this interrupt is appropriate.
- */
- ret = 1;
- }
- /* Not one of ours: let kernel handle it. */
- goto no_kprobe;
- }
-
- set_current_kprobe(p, regs, kcb);
- kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-
- if (p->pre_handler && p->pre_handler(p, regs)) {
- /* Handler has already set things up, so skip ss setup. */
- return 1;
- }
-
-ss_probe:
- prepare_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_HIT_SS;
- return 1;
-
-no_kprobe:
- preempt_enable_no_resched();
- return ret;
-}
-
-/*
- * Called after single-stepping. p->addr is the address of the
- * instruction that has been replaced by the breakpoint. To avoid the
- * SMP problems that can occur when we temporarily put back the
- * original opcode to single-step, we single-stepped a copy of the
- * instruction. The address of this copy is p->ainsn.insn.
- *
- * This function prepares to return from the post-single-step
- * breakpoint trap.
- */
-static void __kprobes resume_execution(struct kprobe *p,
- struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- unsigned long orig_pc = kcb->kprobe_saved_pc;
- regs->pc = orig_pc + 8;
-}
-
-static inline int post_kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *cur = kprobe_running();
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (!cur)
- return 0;
-
- if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- cur->post_handler(cur, regs, 0);
- }
-
- resume_execution(cur, regs, kcb);
-
- /* Restore back the original saved kprobes variables and continue. */
- if (kcb->kprobe_status == KPROBE_REENTER) {
- restore_previous_kprobe(kcb);
- goto out;
- }
- reset_current_kprobe();
-out:
- preempt_enable_no_resched();
-
- return 1;
-}
-
-static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
-{
- struct kprobe *cur = kprobe_running();
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
- return 1;
-
- if (kcb->kprobe_status & KPROBE_HIT_SS) {
- /*
- * We are here because the instruction being single
- * stepped caused a page fault. We reset the current
- * kprobe and the ip points back to the probe address
- * and allow the page fault handler to continue as a
- * normal page fault.
- */
- resume_execution(cur, regs, kcb);
- reset_current_kprobe();
- preempt_enable_no_resched();
- }
- return 0;
-}
-
-/*
- * Wrapper routine for handling exceptions.
- */
-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- struct die_args *args = (struct die_args *)data;
- int ret = NOTIFY_DONE;
-
- switch (val) {
- case DIE_BREAK:
- if (kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_SSTEPBP:
- if (post_kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_PAGE_FAULT:
- /* kprobe_running() needs smp_processor_id(). */
- preempt_disable();
-
- if (kprobe_running()
- && kprobe_fault_handler(args->regs, args->trapnr))
- ret = NOTIFY_STOP;
- preempt_enable();
- break;
- default:
- break;
- }
- return ret;
-}
-
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_sp = regs->sp;
-
- memcpy(kcb->jprobes_stack, (void *)kcb->jprobe_saved_sp,
- MIN_JPROBES_STACK_SIZE(kcb->jprobe_saved_sp));
-
- regs->pc = (unsigned long)(jp->entry);
-
- return 1;
-}
-
-/* Defined in the inline asm below. */
-void jprobe_return_end(void);
-
-void __kprobes jprobe_return(void)
-{
- asm volatile(
- "bpt\n\t"
- ".globl jprobe_return_end\n"
- "jprobe_return_end:\n");
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (regs->pc >= (unsigned long)jprobe_return &&
- regs->pc <= (unsigned long)jprobe_return_end) {
- *regs = kcb->jprobe_saved_regs;
- memcpy((void *)kcb->jprobe_saved_sp, kcb->jprobes_stack,
- MIN_JPROBES_STACK_SIZE(kcb->jprobe_saved_sp));
- preempt_enable_no_resched();
-
- return 1;
- }
- return 0;
-}
-
-/*
- * Function return probe trampoline:
- * - init_kprobes() establishes a probepoint here
- * - When the probed function returns, this probe causes the
- * handlers to fire
- */
-static void __used kretprobe_trampoline_holder(void)
-{
- asm volatile(
- "nop\n\t"
- ".global kretprobe_trampoline\n"
- "kretprobe_trampoline:\n\t"
- "nop\n\t"
- : : : "memory");
-}
-
-void kretprobe_trampoline(void);
-
-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs)
-{
- ri->ret_addr = (kprobe_opcode_t *) regs->lr;
-
- /* Replace the return addr with trampoline addr */
- regs->lr = (unsigned long)kretprobe_trampoline;
-}
-
-/*
- * Called when the probe at kretprobe trampoline is hit.
- */
-static int __kprobes trampoline_probe_handler(struct kprobe *p,
- struct pt_regs *regs)
-{
- struct kretprobe_instance *ri = NULL;
- struct hlist_head *head, empty_rp;
- struct hlist_node *tmp;
- unsigned long flags, orig_ret_address = 0;
- unsigned long trampoline_address = (unsigned long)kretprobe_trampoline;
-
- INIT_HLIST_HEAD(&empty_rp);
- kretprobe_hash_lock(current, &head, &flags);
-
- /*
- * It is possible to have multiple instances associated with a given
- * task either because multiple functions in the call path have
- * a return probe installed on them, and/or more than one return
- * return probe was registered for a target function.
- *
- * We can handle this because:
- * - instances are always inserted at the head of the list
- * - when multiple return probes are registered for the same
- * function, the first instance's ret_addr will point to the
- * real return address, and all the rest will point to
- * kretprobe_trampoline
- */
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
-
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
-
- orig_ret_address = (unsigned long)ri->ret_addr;
- recycle_rp_inst(ri, &empty_rp);
-
- if (orig_ret_address != trampoline_address) {
- /*
- * This is the real return address. Any other
- * instances associated with this task are for
- * other calls deeper on the call stack
- */
- break;
- }
- }
-
- kretprobe_assert(ri, orig_ret_address, trampoline_address);
- instruction_pointer(regs) = orig_ret_address;
-
- reset_current_kprobe();
- kretprobe_hash_unlock(current, &flags);
- preempt_enable_no_resched();
-
- hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
- /*
- * By returning a non-zero value, we are telling
- * kprobe_handler() that we don't want the post_handler
- * to run (and have re-enabled preemption)
- */
- return 1;
-}
-
-int __kprobes arch_trampoline_kprobe(struct kprobe *p)
-{
- if (p->addr == (kprobe_opcode_t *)kretprobe_trampoline)
- return 1;
-
- return 0;
-}
-
-static struct kprobe trampoline_p = {
- .addr = (kprobe_opcode_t *)kretprobe_trampoline,
- .pre_handler = trampoline_probe_handler
-};
-
-int __init arch_init_kprobes(void)
-{
- register_kprobe(&trampoline_p);
- return 0;
-}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.