diff options
Diffstat (limited to 'arch/ia64/kernel/kprobes.c')
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 911 |
1 files changed, 0 insertions, 911 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c deleted file mode 100644 index ca34e51e84b4..000000000000 --- a/arch/ia64/kernel/kprobes.c +++ /dev/null @@ -1,911 +0,0 @@ -// 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; -} |