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-rw-r--r--arch/ia64/kernel/kprobes.c911
1 files changed, 911 insertions, 0 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
new file mode 100644
index 0000000000..ca34e51e84
--- /dev/null
+++ b/arch/ia64/kernel/kprobes.c
@@ -0,0 +1,911 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Kernel Probes (KProbes)
+ * arch/ia64/kernel/kprobes.c
+ *
+ * Copyright (C) IBM Corporation, 2002, 2004
+ * Copyright (C) Intel Corporation, 2005
+ *
+ * 2005-Apr Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
+ * <anil.s.keshavamurthy@intel.com> adapted from i386
+ */
+
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/preempt.h>
+#include <linux/extable.h>
+#include <linux/kdebug.h>
+#include <linux/pgtable.h>
+
+#include <asm/sections.h>
+#include <asm/exception.h>
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
+
+enum instruction_type {A, I, M, F, B, L, X, u};
+static enum instruction_type bundle_encoding[32][3] = {
+ [0x00] = { M, I, I },
+ [0x01] = { M, I, I },
+ [0x02] = { M, I, I },
+ [0x03] = { M, I, I },
+ [0x04] = { M, L, X },
+ [0x05] = { M, L, X },
+ [0x06] = { u, u, u },
+ [0x07] = { u, u, u },
+ [0x08] = { M, M, I },
+ [0x09] = { M, M, I },
+ [0x0A] = { M, M, I },
+ [0x0B] = { M, M, I },
+ [0x0C] = { M, F, I },
+ [0x0D] = { M, F, I },
+ [0x0E] = { M, M, F },
+ [0x0F] = { M, M, F },
+ [0x10] = { M, I, B },
+ [0x11] = { M, I, B },
+ [0x12] = { M, B, B },
+ [0x13] = { M, B, B },
+ [0x14] = { u, u, u },
+ [0x15] = { u, u, u },
+ [0x16] = { B, B, B },
+ [0x17] = { B, B, B },
+ [0x18] = { M, M, B },
+ [0x19] = { M, M, B },
+ [0x1A] = { u, u, u },
+ [0x1B] = { u, u, u },
+ [0x1C] = { M, F, B },
+ [0x1D] = { M, F, B },
+ [0x1E] = { u, u, u },
+ [0x1F] = { u, u, u },
+};
+
+/* Insert a long branch code */
+static void __kprobes set_brl_inst(void *from, void *to)
+{
+ s64 rel = ((s64) to - (s64) from) >> 4;
+ bundle_t *brl;
+ brl = (bundle_t *) ((u64) from & ~0xf);
+ brl->quad0.template = 0x05; /* [MLX](stop) */
+ brl->quad0.slot0 = NOP_M_INST; /* nop.m 0x0 */
+ brl->quad0.slot1_p0 = ((rel >> 20) & 0x7fffffffff) << 2;
+ brl->quad1.slot1_p1 = (((rel >> 20) & 0x7fffffffff) << 2) >> (64 - 46);
+ /* brl.cond.sptk.many.clr rel<<4 (qp=0) */
+ brl->quad1.slot2 = BRL_INST(rel >> 59, rel & 0xfffff);
+}
+
+/*
+ * In this function we check to see if the instruction
+ * is IP relative instruction and update the kprobe
+ * inst flag accordingly
+ */
+static void __kprobes update_kprobe_inst_flag(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p)
+{
+ p->ainsn.inst_flag = 0;
+ p->ainsn.target_br_reg = 0;
+ p->ainsn.slot = slot;
+
+ /* Check for Break instruction
+ * Bits 37:40 Major opcode to be zero
+ * Bits 27:32 X6 to be zero
+ * Bits 32:35 X3 to be zero
+ */
+ if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) {
+ /* is a break instruction */
+ p->ainsn.inst_flag |= INST_FLAG_BREAK_INST;
+ return;
+ }
+
+ if (bundle_encoding[template][slot] == B) {
+ switch (major_opcode) {
+ case INDIRECT_CALL_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
+ p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
+ break;
+ case IP_RELATIVE_PREDICT_OPCODE:
+ case IP_RELATIVE_BRANCH_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
+ break;
+ case IP_RELATIVE_CALL_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
+ p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
+ p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
+ break;
+ }
+ } else if (bundle_encoding[template][slot] == X) {
+ switch (major_opcode) {
+ case LONG_CALL_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
+ p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
+ break;
+ }
+ }
+ return;
+}
+
+/*
+ * In this function we check to see if the instruction
+ * (qp) cmpx.crel.ctype p1,p2=r2,r3
+ * on which we are inserting kprobe is cmp instruction
+ * with ctype as unc.
+ */
+static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst)
+{
+ cmp_inst_t cmp_inst;
+ uint ctype_unc = 0;
+
+ if (!((bundle_encoding[template][slot] == I) ||
+ (bundle_encoding[template][slot] == M)))
+ goto out;
+
+ if (!((major_opcode == 0xC) || (major_opcode == 0xD) ||
+ (major_opcode == 0xE)))
+ goto out;
+
+ cmp_inst.l = kprobe_inst;
+ if ((cmp_inst.f.x2 == 0) || (cmp_inst.f.x2 == 1)) {
+ /* Integer compare - Register Register (A6 type)*/
+ if ((cmp_inst.f.tb == 0) && (cmp_inst.f.ta == 0)
+ &&(cmp_inst.f.c == 1))
+ ctype_unc = 1;
+ } else if ((cmp_inst.f.x2 == 2)||(cmp_inst.f.x2 == 3)) {
+ /* Integer compare - Immediate Register (A8 type)*/
+ if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1))
+ ctype_unc = 1;
+ }
+out:
+ return ctype_unc;
+}
+
+/*
+ * In this function we check to see if the instruction
+ * on which we are inserting kprobe is supported.
+ * Returns qp value if supported
+ * Returns -EINVAL if unsupported
+ */
+static int __kprobes unsupported_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ unsigned long addr)
+{
+ int qp;
+
+ qp = kprobe_inst & 0x3f;
+ if (is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst)) {
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on cmp unc "
+ "instruction on slot 1 at <0x%lx> "
+ "is not supported\n", addr);
+ return -EINVAL;
+
+ }
+ qp = 0;
+ }
+ else if (bundle_encoding[template][slot] == I) {
+ if (major_opcode == 0) {
+ /*
+ * Check for Integer speculation instruction
+ * - Bit 33-35 to be equal to 0x1
+ */
+ if (((kprobe_inst >> 33) & 0x7) == 1) {
+ printk(KERN_WARNING
+ "Kprobes on speculation inst at <0x%lx> not supported\n",
+ addr);
+ return -EINVAL;
+ }
+ /*
+ * IP relative mov instruction
+ * - Bit 27-35 to be equal to 0x30
+ */
+ if (((kprobe_inst >> 27) & 0x1FF) == 0x30) {
+ printk(KERN_WARNING
+ "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n",
+ addr);
+ return -EINVAL;
+
+ }
+ }
+ else if ((major_opcode == 5) && !(kprobe_inst & (0xFUl << 33)) &&
+ (kprobe_inst & (0x1UL << 12))) {
+ /* test bit instructions, tbit,tnat,tf
+ * bit 33-36 to be equal to 0
+ * bit 12 to be equal to 1
+ */
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on test bit "
+ "instruction on slot at <0x%lx> "
+ "is not supported\n", addr);
+ return -EINVAL;
+ }
+ qp = 0;
+ }
+ }
+ else if (bundle_encoding[template][slot] == B) {
+ if (major_opcode == 7) {
+ /* IP-Relative Predict major code is 7 */
+ printk(KERN_WARNING "Kprobes on IP-Relative"
+ "Predict is not supported\n");
+ return -EINVAL;
+ }
+ else if (major_opcode == 2) {
+ /* Indirect Predict, major code is 2
+ * bit 27-32 to be equal to 10 or 11
+ */
+ int x6=(kprobe_inst >> 27) & 0x3F;
+ if ((x6 == 0x10) || (x6 == 0x11)) {
+ printk(KERN_WARNING "Kprobes on "
+ "Indirect Predict is not supported\n");
+ return -EINVAL;
+ }
+ }
+ }
+ /* kernel does not use float instruction, here for safety kprobe
+ * will judge whether it is fcmp/flass/float approximation instruction
+ */
+ else if (unlikely(bundle_encoding[template][slot] == F)) {
+ if ((major_opcode == 4 || major_opcode == 5) &&
+ (kprobe_inst & (0x1 << 12))) {
+ /* fcmp/fclass unc instruction */
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on fcmp/fclass "
+ "instruction on slot at <0x%lx> "
+ "is not supported\n", addr);
+ return -EINVAL;
+
+ }
+ qp = 0;
+ }
+ if ((major_opcode == 0 || major_opcode == 1) &&
+ (kprobe_inst & (0x1UL << 33))) {
+ /* float Approximation instruction */
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on float Approx "
+ "instr at <0x%lx> is not supported\n",
+ addr);
+ return -EINVAL;
+ }
+ qp = 0;
+ }
+ }
+ return qp;
+}
+
+/*
+ * In this function we override the bundle with
+ * the break instruction at the given slot.
+ */
+static void __kprobes prepare_break_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p,
+ int qp)
+{
+ unsigned long break_inst = BREAK_INST;
+ bundle_t *bundle = &p->opcode.bundle;
+
+ /*
+ * Copy the original kprobe_inst qualifying predicate(qp)
+ * to the break instruction
+ */
+ break_inst |= qp;
+
+ switch (slot) {
+ case 0:
+ bundle->quad0.slot0 = break_inst;
+ break;
+ case 1:
+ bundle->quad0.slot1_p0 = break_inst;
+ bundle->quad1.slot1_p1 = break_inst >> (64-46);
+ break;
+ case 2:
+ bundle->quad1.slot2 = break_inst;
+ break;
+ }
+
+ /*
+ * Update the instruction flag, so that we can
+ * emulate the instruction properly after we
+ * single step on original instruction
+ */
+ update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p);
+}
+
+static void __kprobes get_kprobe_inst(bundle_t *bundle, uint slot,
+ unsigned long *kprobe_inst, uint *major_opcode)
+{
+ unsigned long kprobe_inst_p0, kprobe_inst_p1;
+ unsigned int template;
+
+ template = bundle->quad0.template;
+
+ switch (slot) {
+ case 0:
+ *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
+ *kprobe_inst = bundle->quad0.slot0;
+ break;
+ case 1:
+ *major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT);
+ kprobe_inst_p0 = bundle->quad0.slot1_p0;
+ kprobe_inst_p1 = bundle->quad1.slot1_p1;
+ *kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46));
+ break;
+ case 2:
+ *major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT);
+ *kprobe_inst = bundle->quad1.slot2;
+ break;
+ }
+}
+
+/* Returns non-zero if the addr is in the Interrupt Vector Table */
+static int __kprobes in_ivt_functions(unsigned long addr)
+{
+ return (addr >= (unsigned long)__start_ivt_text
+ && addr < (unsigned long)__end_ivt_text);
+}
+
+static int __kprobes valid_kprobe_addr(int template, int slot,
+ unsigned long addr)
+{
+ if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) {
+ printk(KERN_WARNING "Attempting to insert unaligned kprobe "
+ "at 0x%lx\n", addr);
+ return -EINVAL;
+ }
+
+ if (in_ivt_functions(addr)) {
+ printk(KERN_WARNING "Kprobes can't be inserted inside "
+ "IVT functions at 0x%lx\n", addr);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+ unsigned int i;
+ i = atomic_add_return(1, &kcb->prev_kprobe_index);
+ kcb->prev_kprobe[i-1].kp = kprobe_running();
+ kcb->prev_kprobe[i-1].status = kcb->kprobe_status;
+}
+
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+ unsigned int i;
+ i = atomic_read(&kcb->prev_kprobe_index);
+ __this_cpu_write(current_kprobe, kcb->prev_kprobe[i-1].kp);
+ kcb->kprobe_status = kcb->prev_kprobe[i-1].status;
+ atomic_sub(1, &kcb->prev_kprobe_index);
+}
+
+static void __kprobes set_current_kprobe(struct kprobe *p,
+ struct kprobe_ctlblk *kcb)
+{
+ __this_cpu_write(current_kprobe, p);
+}
+
+void __kretprobe_trampoline(void)
+{
+}
+
+int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ regs->cr_iip = __kretprobe_trampoline_handler(regs, NULL);
+ /*
+ * 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;
+}
+
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+{
+ ri->ret_addr = (kprobe_opcode_t *)regs->b0;
+ ri->fp = NULL;
+
+ /* Replace the return addr with trampoline addr */
+ regs->b0 = (unsigned long)dereference_function_descriptor(__kretprobe_trampoline);
+}
+
+/* Check the instruction in the slot is break */
+static int __kprobes __is_ia64_break_inst(bundle_t *bundle, uint slot)
+{
+ unsigned int major_opcode;
+ unsigned int template = bundle->quad0.template;
+ unsigned long kprobe_inst;
+
+ /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot++;
+
+ /* Get Kprobe probe instruction at given slot*/
+ get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
+
+ /* For break instruction,
+ * Bits 37:40 Major opcode to be zero
+ * Bits 27:32 X6 to be zero
+ * Bits 32:35 X3 to be zero
+ */
+ if (major_opcode || ((kprobe_inst >> 27) & 0x1FF)) {
+ /* Not a break instruction */
+ return 0;
+ }
+
+ /* Is a break instruction */
+ return 1;
+}
+
+/*
+ * In this function, we check whether the target bundle modifies IP or
+ * it triggers an exception. If so, it cannot be boostable.
+ */
+static int __kprobes can_boost(bundle_t *bundle, uint slot,
+ unsigned long bundle_addr)
+{
+ unsigned int template = bundle->quad0.template;
+
+ do {
+ if (search_exception_tables(bundle_addr + slot) ||
+ __is_ia64_break_inst(bundle, slot))
+ return 0; /* exception may occur in this bundle*/
+ } while ((++slot) < 3);
+ template &= 0x1e;
+ if (template >= 0x10 /* including B unit */ ||
+ template == 0x04 /* including X unit */ ||
+ template == 0x06) /* undefined */
+ return 0;
+
+ return 1;
+}
+
+/* Prepare long jump bundle and disables other boosters if need */
+static void __kprobes prepare_booster(struct kprobe *p)
+{
+ unsigned long addr = (unsigned long)p->addr & ~0xFULL;
+ unsigned int slot = (unsigned long)p->addr & 0xf;
+ struct kprobe *other_kp;
+
+ if (can_boost(&p->ainsn.insn[0].bundle, slot, addr)) {
+ set_brl_inst(&p->ainsn.insn[1].bundle, (bundle_t *)addr + 1);
+ p->ainsn.inst_flag |= INST_FLAG_BOOSTABLE;
+ }
+
+ /* disables boosters in previous slots */
+ for (; addr < (unsigned long)p->addr; addr++) {
+ other_kp = get_kprobe((void *)addr);
+ if (other_kp)
+ other_kp->ainsn.inst_flag &= ~INST_FLAG_BOOSTABLE;
+ }
+}
+
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
+{
+ unsigned long addr = (unsigned long) p->addr;
+ unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
+ unsigned long kprobe_inst=0;
+ unsigned int slot = addr & 0xf, template, major_opcode = 0;
+ bundle_t *bundle;
+ int qp;
+
+ bundle = &((kprobe_opcode_t *)kprobe_addr)->bundle;
+ template = bundle->quad0.template;
+
+ if(valid_kprobe_addr(template, slot, addr))
+ return -EINVAL;
+
+ /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot++;
+
+ /* Get kprobe_inst and major_opcode from the bundle */
+ get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
+
+ qp = unsupported_inst(template, slot, major_opcode, kprobe_inst, addr);
+ if (qp < 0)
+ return -EINVAL;
+
+ p->ainsn.insn = get_insn_slot();
+ if (!p->ainsn.insn)
+ return -ENOMEM;
+ memcpy(&p->opcode, kprobe_addr, sizeof(kprobe_opcode_t));
+ memcpy(p->ainsn.insn, kprobe_addr, sizeof(kprobe_opcode_t));
+
+ prepare_break_inst(template, slot, major_opcode, kprobe_inst, p, qp);
+
+ prepare_booster(p);
+
+ return 0;
+}
+
+void __kprobes arch_arm_kprobe(struct kprobe *p)
+{
+ unsigned long arm_addr;
+ bundle_t *src, *dest;
+
+ arm_addr = ((unsigned long)p->addr) & ~0xFUL;
+ dest = &((kprobe_opcode_t *)arm_addr)->bundle;
+ src = &p->opcode.bundle;
+
+ flush_icache_range((unsigned long)p->ainsn.insn,
+ (unsigned long)p->ainsn.insn +
+ sizeof(kprobe_opcode_t) * MAX_INSN_SIZE);
+
+ switch (p->ainsn.slot) {
+ case 0:
+ dest->quad0.slot0 = src->quad0.slot0;
+ break;
+ case 1:
+ dest->quad1.slot1_p1 = src->quad1.slot1_p1;
+ break;
+ case 2:
+ dest->quad1.slot2 = src->quad1.slot2;
+ break;
+ }
+ flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
+}
+
+void __kprobes arch_disarm_kprobe(struct kprobe *p)
+{
+ unsigned long arm_addr;
+ bundle_t *src, *dest;
+
+ arm_addr = ((unsigned long)p->addr) & ~0xFUL;
+ dest = &((kprobe_opcode_t *)arm_addr)->bundle;
+ /* p->ainsn.insn contains the original unaltered kprobe_opcode_t */
+ src = &p->ainsn.insn->bundle;
+ switch (p->ainsn.slot) {
+ case 0:
+ dest->quad0.slot0 = src->quad0.slot0;
+ break;
+ case 1:
+ dest->quad1.slot1_p1 = src->quad1.slot1_p1;
+ break;
+ case 2:
+ dest->quad1.slot2 = src->quad1.slot2;
+ break;
+ }
+ flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
+}
+
+void __kprobes arch_remove_kprobe(struct kprobe *p)
+{
+ if (p->ainsn.insn) {
+ free_insn_slot(p->ainsn.insn,
+ p->ainsn.inst_flag & INST_FLAG_BOOSTABLE);
+ p->ainsn.insn = NULL;
+ }
+}
+/*
+ * We are resuming execution after a single step fault, so the pt_regs
+ * structure reflects the register state after we executed the instruction
+ * located in the kprobe (p->ainsn.insn->bundle). We still need to adjust
+ * the ip to point back to the original stack address. To set the IP address
+ * to original stack address, handle the case where we need to fixup the
+ * relative IP address and/or fixup branch register.
+ */
+static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
+{
+ unsigned long bundle_addr = (unsigned long) (&p->ainsn.insn->bundle);
+ unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
+ unsigned long template;
+ int slot = ((unsigned long)p->addr & 0xf);
+
+ template = p->ainsn.insn->bundle.quad0.template;
+
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot = 2;
+
+ if (p->ainsn.inst_flag & ~INST_FLAG_BOOSTABLE) {
+
+ if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) {
+ /* Fix relative IP address */
+ regs->cr_iip = (regs->cr_iip - bundle_addr) +
+ resume_addr;
+ }
+
+ if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) {
+ /*
+ * Fix target branch register, software convention is
+ * to use either b0 or b6 or b7, so just checking
+ * only those registers
+ */
+ switch (p->ainsn.target_br_reg) {
+ case 0:
+ if ((regs->b0 == bundle_addr) ||
+ (regs->b0 == bundle_addr + 0x10)) {
+ regs->b0 = (regs->b0 - bundle_addr) +
+ resume_addr;
+ }
+ break;
+ case 6:
+ if ((regs->b6 == bundle_addr) ||
+ (regs->b6 == bundle_addr + 0x10)) {
+ regs->b6 = (regs->b6 - bundle_addr) +
+ resume_addr;
+ }
+ break;
+ case 7:
+ if ((regs->b7 == bundle_addr) ||
+ (regs->b7 == bundle_addr + 0x10)) {
+ regs->b7 = (regs->b7 - bundle_addr) +
+ resume_addr;
+ }
+ break;
+ } /* end switch */
+ }
+ goto turn_ss_off;
+ }
+
+ if (slot == 2) {
+ if (regs->cr_iip == bundle_addr + 0x10) {
+ regs->cr_iip = resume_addr + 0x10;
+ }
+ } else {
+ if (regs->cr_iip == bundle_addr) {
+ regs->cr_iip = resume_addr;
+ }
+ }
+
+turn_ss_off:
+ /* Turn off Single Step bit */
+ ia64_psr(regs)->ss = 0;
+}
+
+static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)
+{
+ unsigned long bundle_addr = (unsigned long) &p->ainsn.insn->bundle;
+ unsigned long slot = (unsigned long)p->addr & 0xf;
+
+ /* single step inline if break instruction */
+ if (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)
+ regs->cr_iip = (unsigned long)p->addr & ~0xFULL;
+ else
+ regs->cr_iip = bundle_addr & ~0xFULL;
+
+ if (slot > 2)
+ slot = 0;
+
+ ia64_psr(regs)->ri = slot;
+
+ /* turn on single stepping */
+ ia64_psr(regs)->ss = 1;
+}
+
+static int __kprobes is_ia64_break_inst(struct pt_regs *regs)
+{
+ unsigned int slot = ia64_psr(regs)->ri;
+ unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip;
+ bundle_t bundle;
+
+ memcpy(&bundle, kprobe_addr, sizeof(bundle_t));
+
+ return __is_ia64_break_inst(&bundle, slot);
+}
+
+static int __kprobes pre_kprobes_handler(struct die_args *args)
+{
+ struct kprobe *p;
+ int ret = 0;
+ struct pt_regs *regs = args->regs;
+ kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
+ struct kprobe_ctlblk *kcb;
+
+ /*
+ * We don't want to be preempted for the entire
+ * duration of kprobe processing
+ */
+ preempt_disable();
+ kcb = get_kprobe_ctlblk();
+
+ /* Handle recursion cases */
+ if (kprobe_running()) {
+ p = get_kprobe(addr);
+ if (p) {
+ if ((kcb->kprobe_status == KPROBE_HIT_SS) &&
+ (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
+ ia64_psr(regs)->ss = 0;
+ goto no_kprobe;
+ }
+ /* We have reentered the pre_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, kcb);
+ kprobes_inc_nmissed_count(p);
+ prepare_ss(p, regs);
+ kcb->kprobe_status = KPROBE_REENTER;
+ return 1;
+ } else if (!is_ia64_break_inst(regs)) {
+ /* 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;
+ } else {
+ /* Not our break */
+ goto no_kprobe;
+ }
+ }
+
+ p = get_kprobe(addr);
+ if (!p) {
+ if (!is_ia64_break_inst(regs)) {
+ /*
+ * 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 our break, let kernel handle it */
+ goto no_kprobe;
+ }
+
+ set_current_kprobe(p, kcb);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+ if (p->pre_handler && p->pre_handler(p, regs)) {
+ reset_current_kprobe();
+ preempt_enable_no_resched();
+ return 1;
+ }
+
+#if !defined(CONFIG_PREEMPTION)
+ if (p->ainsn.inst_flag == INST_FLAG_BOOSTABLE && !p->post_handler) {
+ /* Boost up -- we can execute copied instructions directly */
+ ia64_psr(regs)->ri = p->ainsn.slot;
+ regs->cr_iip = (unsigned long)&p->ainsn.insn->bundle & ~0xFULL;
+ /* turn single stepping off */
+ ia64_psr(regs)->ss = 0;
+
+ reset_current_kprobe();
+ preempt_enable_no_resched();
+ return 1;
+ }
+#endif
+ prepare_ss(p, regs);
+ kcb->kprobe_status = KPROBE_HIT_SS;
+ return 1;
+
+no_kprobe:
+ preempt_enable_no_resched();
+ return ret;
+}
+
+static int __kprobes post_kprobes_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);
+
+ /*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;
+}
+
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+ struct kprobe *cur = kprobe_running();
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+
+ switch(kcb->kprobe_status) {
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ /*
+ * We are here because the instruction being single
+ * stepped caused a page fault. We reset the current
+ * kprobe and the instruction pointer points back to
+ * the probe address and allow the page fault handler
+ * to continue as a normal page fault.
+ */
+ regs->cr_iip = ((unsigned long)cur->addr) & ~0xFULL;
+ ia64_psr(regs)->ri = ((unsigned long)cur->addr) & 0xf;
+ if (kcb->kprobe_status == KPROBE_REENTER)
+ restore_previous_kprobe(kcb);
+ else
+ reset_current_kprobe();
+ preempt_enable_no_resched();
+ break;
+ case KPROBE_HIT_ACTIVE:
+ case KPROBE_HIT_SSDONE:
+ /*
+ * In case the user-specified fault handler returned
+ * zero, try to fix up.
+ */
+ if (ia64_done_with_exception(regs))
+ return 1;
+
+ /*
+ * Let ia64_do_page_fault() fix it.
+ */
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+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;
+
+ if (args->regs && user_mode(args->regs))
+ return ret;
+
+ switch(val) {
+ case DIE_BREAK:
+ /* err is break number from ia64_bad_break() */
+ if ((args->err >> 12) == (__IA64_BREAK_KPROBE >> 12)
+ || args->err == 0)
+ if (pre_kprobes_handler(args))
+ ret = NOTIFY_STOP;
+ break;
+ case DIE_FAULT:
+ /* err is vector number from ia64_fault() */
+ if (args->err == 36)
+ if (post_kprobes_handler(args->regs))
+ ret = NOTIFY_STOP;
+ break;
+ default:
+ break;
+ }
+ return ret;
+}
+
+static struct kprobe trampoline_p = {
+ .pre_handler = trampoline_probe_handler
+};
+
+int __init arch_init_kprobes(void)
+{
+ trampoline_p.addr =
+ dereference_function_descriptor(__kretprobe_trampoline);
+ return register_kprobe(&trampoline_p);
+}
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+ if (p->addr ==
+ dereference_function_descriptor(__kretprobe_trampoline))
+ return 1;
+
+ return 0;
+}