1021 lines
27 KiB
C
1021 lines
27 KiB
C
/*
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* Kernel Probes (KProbes)
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* arch/ia64/kernel/kprobes.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright (C) IBM Corporation, 2002, 2004
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* Copyright (C) Intel Corporation, 2005
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*
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* 2005-Apr Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
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* <anil.s.keshavamurthy@intel.com> adapted from i386
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*/
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#include <linux/kprobes.h>
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#include <linux/ptrace.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/preempt.h>
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#include <linux/moduleloader.h>
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#include <linux/kdebug.h>
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#include <asm/pgtable.h>
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#include <asm/sections.h>
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#include <asm/uaccess.h>
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extern void jprobe_inst_return(void);
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DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
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DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
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enum instruction_type {A, I, M, F, B, L, X, u};
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static enum instruction_type bundle_encoding[32][3] = {
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{ M, I, I }, /* 00 */
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{ M, I, I }, /* 01 */
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{ M, I, I }, /* 02 */
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{ M, I, I }, /* 03 */
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{ M, L, X }, /* 04 */
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{ M, L, X }, /* 05 */
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{ u, u, u }, /* 06 */
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{ u, u, u }, /* 07 */
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{ M, M, I }, /* 08 */
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{ M, M, I }, /* 09 */
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{ M, M, I }, /* 0A */
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{ M, M, I }, /* 0B */
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{ M, F, I }, /* 0C */
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{ M, F, I }, /* 0D */
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{ M, M, F }, /* 0E */
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{ M, M, F }, /* 0F */
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{ M, I, B }, /* 10 */
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{ M, I, B }, /* 11 */
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{ M, B, B }, /* 12 */
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{ M, B, B }, /* 13 */
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{ u, u, u }, /* 14 */
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{ u, u, u }, /* 15 */
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{ B, B, B }, /* 16 */
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{ B, B, B }, /* 17 */
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{ M, M, B }, /* 18 */
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{ M, M, B }, /* 19 */
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{ u, u, u }, /* 1A */
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{ u, u, u }, /* 1B */
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{ M, F, B }, /* 1C */
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{ M, F, B }, /* 1D */
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{ u, u, u }, /* 1E */
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{ u, u, u }, /* 1F */
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};
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/*
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* In this function we check to see if the instruction
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* is IP relative instruction and update the kprobe
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* inst flag accordingly
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*/
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static void __kprobes update_kprobe_inst_flag(uint template, uint slot,
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uint major_opcode,
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unsigned long kprobe_inst,
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struct kprobe *p)
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{
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p->ainsn.inst_flag = 0;
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p->ainsn.target_br_reg = 0;
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p->ainsn.slot = slot;
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/* Check for Break instruction
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* Bits 37:40 Major opcode to be zero
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* Bits 27:32 X6 to be zero
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* Bits 32:35 X3 to be zero
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*/
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if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) {
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/* is a break instruction */
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p->ainsn.inst_flag |= INST_FLAG_BREAK_INST;
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return;
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}
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if (bundle_encoding[template][slot] == B) {
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switch (major_opcode) {
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case INDIRECT_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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case IP_RELATIVE_PREDICT_OPCODE:
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case IP_RELATIVE_BRANCH_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
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break;
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case IP_RELATIVE_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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}
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} else if (bundle_encoding[template][slot] == X) {
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switch (major_opcode) {
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case LONG_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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}
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}
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return;
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}
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/*
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* In this function we check to see if the instruction
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* (qp) cmpx.crel.ctype p1,p2=r2,r3
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* on which we are inserting kprobe is cmp instruction
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* with ctype as unc.
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*/
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static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot,
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uint major_opcode,
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unsigned long kprobe_inst)
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{
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cmp_inst_t cmp_inst;
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uint ctype_unc = 0;
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if (!((bundle_encoding[template][slot] == I) ||
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(bundle_encoding[template][slot] == M)))
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goto out;
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if (!((major_opcode == 0xC) || (major_opcode == 0xD) ||
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(major_opcode == 0xE)))
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goto out;
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cmp_inst.l = kprobe_inst;
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if ((cmp_inst.f.x2 == 0) || (cmp_inst.f.x2 == 1)) {
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/* Integer compare - Register Register (A6 type)*/
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if ((cmp_inst.f.tb == 0) && (cmp_inst.f.ta == 0)
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&&(cmp_inst.f.c == 1))
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ctype_unc = 1;
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} else if ((cmp_inst.f.x2 == 2)||(cmp_inst.f.x2 == 3)) {
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/* Integer compare - Immediate Register (A8 type)*/
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if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1))
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ctype_unc = 1;
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}
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out:
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return ctype_unc;
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}
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/*
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* In this function we check to see if the instruction
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* on which we are inserting kprobe is supported.
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* Returns qp value if supported
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* Returns -EINVAL if unsupported
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*/
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static int __kprobes unsupported_inst(uint template, uint slot,
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uint major_opcode,
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unsigned long kprobe_inst,
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unsigned long addr)
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{
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int qp;
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qp = kprobe_inst & 0x3f;
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if (is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst)) {
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if (slot == 1 && qp) {
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printk(KERN_WARNING "Kprobes on cmp unc"
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"instruction on slot 1 at <0x%lx>"
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"is not supported\n", addr);
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return -EINVAL;
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}
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qp = 0;
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}
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else if (bundle_encoding[template][slot] == I) {
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if (major_opcode == 0) {
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/*
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* Check for Integer speculation instruction
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* - Bit 33-35 to be equal to 0x1
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*/
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if (((kprobe_inst >> 33) & 0x7) == 1) {
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printk(KERN_WARNING
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"Kprobes on speculation inst at <0x%lx> not supported\n",
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addr);
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return -EINVAL;
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}
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/*
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* IP relative mov instruction
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* - Bit 27-35 to be equal to 0x30
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*/
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if (((kprobe_inst >> 27) & 0x1FF) == 0x30) {
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printk(KERN_WARNING
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"Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n",
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addr);
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return -EINVAL;
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}
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}
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else if ((major_opcode == 5) && !(kprobe_inst & (0xFUl << 33)) &&
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(kprobe_inst & (0x1UL << 12))) {
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/* test bit instructions, tbit,tnat,tf
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* bit 33-36 to be equal to 0
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* bit 12 to be equal to 1
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*/
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if (slot == 1 && qp) {
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printk(KERN_WARNING "Kprobes on test bit"
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"instruction on slot at <0x%lx>"
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"is not supported\n", addr);
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return -EINVAL;
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}
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qp = 0;
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}
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}
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else if (bundle_encoding[template][slot] == B) {
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if (major_opcode == 7) {
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/* IP-Relative Predict major code is 7 */
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printk(KERN_WARNING "Kprobes on IP-Relative"
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"Predict is not supported\n");
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return -EINVAL;
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}
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else if (major_opcode == 2) {
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/* Indirect Predict, major code is 2
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* bit 27-32 to be equal to 10 or 11
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*/
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int x6=(kprobe_inst >> 27) & 0x3F;
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if ((x6 == 0x10) || (x6 == 0x11)) {
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printk(KERN_WARNING "Kprobes on"
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"Indirect Predict is not supported\n");
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return -EINVAL;
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}
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}
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}
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/* kernel does not use float instruction, here for safety kprobe
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* will judge whether it is fcmp/flass/float approximation instruction
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*/
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else if (unlikely(bundle_encoding[template][slot] == F)) {
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if ((major_opcode == 4 || major_opcode == 5) &&
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(kprobe_inst & (0x1 << 12))) {
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/* fcmp/fclass unc instruction */
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if (slot == 1 && qp) {
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printk(KERN_WARNING "Kprobes on fcmp/fclass "
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"instruction on slot at <0x%lx> "
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"is not supported\n", addr);
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return -EINVAL;
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}
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qp = 0;
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}
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if ((major_opcode == 0 || major_opcode == 1) &&
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(kprobe_inst & (0x1UL << 33))) {
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/* float Approximation instruction */
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if (slot == 1 && qp) {
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printk(KERN_WARNING "Kprobes on float Approx "
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"instr at <0x%lx> is not supported\n",
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addr);
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return -EINVAL;
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}
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qp = 0;
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}
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}
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return qp;
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}
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/*
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* In this function we override the bundle with
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* the break instruction at the given slot.
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*/
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static void __kprobes prepare_break_inst(uint template, uint slot,
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uint major_opcode,
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unsigned long kprobe_inst,
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struct kprobe *p,
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int qp)
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{
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unsigned long break_inst = BREAK_INST;
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bundle_t *bundle = &p->opcode.bundle;
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/*
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* Copy the original kprobe_inst qualifying predicate(qp)
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* to the break instruction
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*/
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break_inst |= qp;
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switch (slot) {
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case 0:
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bundle->quad0.slot0 = break_inst;
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break;
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case 1:
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bundle->quad0.slot1_p0 = break_inst;
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bundle->quad1.slot1_p1 = break_inst >> (64-46);
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break;
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case 2:
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bundle->quad1.slot2 = break_inst;
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break;
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}
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/*
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* Update the instruction flag, so that we can
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* emulate the instruction properly after we
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* single step on original instruction
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*/
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update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p);
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}
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static void __kprobes get_kprobe_inst(bundle_t *bundle, uint slot,
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unsigned long *kprobe_inst, uint *major_opcode)
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{
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unsigned long kprobe_inst_p0, kprobe_inst_p1;
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unsigned int template;
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template = bundle->quad0.template;
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switch (slot) {
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case 0:
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*major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
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*kprobe_inst = bundle->quad0.slot0;
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break;
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case 1:
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*major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT);
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kprobe_inst_p0 = bundle->quad0.slot1_p0;
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kprobe_inst_p1 = bundle->quad1.slot1_p1;
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*kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46));
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break;
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case 2:
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*major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT);
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*kprobe_inst = bundle->quad1.slot2;
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break;
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}
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}
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/* Returns non-zero if the addr is in the Interrupt Vector Table */
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static int __kprobes in_ivt_functions(unsigned long addr)
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{
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return (addr >= (unsigned long)__start_ivt_text
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&& addr < (unsigned long)__end_ivt_text);
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}
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static int __kprobes valid_kprobe_addr(int template, int slot,
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unsigned long addr)
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{
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if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) {
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printk(KERN_WARNING "Attempting to insert unaligned kprobe "
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"at 0x%lx\n", addr);
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return -EINVAL;
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}
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if (in_ivt_functions(addr)) {
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printk(KERN_WARNING "Kprobes can't be inserted inside "
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"IVT functions at 0x%lx\n", addr);
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return -EINVAL;
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}
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return 0;
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}
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static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
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{
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unsigned int i;
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i = atomic_add_return(1, &kcb->prev_kprobe_index);
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kcb->prev_kprobe[i-1].kp = kprobe_running();
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kcb->prev_kprobe[i-1].status = kcb->kprobe_status;
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}
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static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
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{
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unsigned int i;
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i = atomic_sub_return(1, &kcb->prev_kprobe_index);
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__get_cpu_var(current_kprobe) = kcb->prev_kprobe[i].kp;
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kcb->kprobe_status = kcb->prev_kprobe[i].status;
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}
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static void __kprobes set_current_kprobe(struct kprobe *p,
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struct kprobe_ctlblk *kcb)
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{
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__get_cpu_var(current_kprobe) = p;
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}
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static void kretprobe_trampoline(void)
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{
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}
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/*
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* At this point the target function has been tricked into
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* returning into our trampoline. Lookup the associated instance
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* and then:
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* - call the handler function
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* - cleanup by marking the instance as unused
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* - long jump back to the original return address
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*/
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int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
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{
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struct kretprobe_instance *ri = NULL;
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struct hlist_head *head, empty_rp;
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struct hlist_node *node, *tmp;
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unsigned long flags, orig_ret_address = 0;
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unsigned long trampoline_address =
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((struct fnptr *)kretprobe_trampoline)->ip;
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INIT_HLIST_HEAD(&empty_rp);
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spin_lock_irqsave(&kretprobe_lock, flags);
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head = kretprobe_inst_table_head(current);
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/*
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* It is possible to have multiple instances associated with a given
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* task either because an multiple functions in the call path
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* have a return probe installed on them, and/or more then one return
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* return probe was registered for a target function.
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*
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* We can handle this because:
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* - instances are always inserted at the head of the list
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* - when multiple return probes are registered for the same
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* function, the first instance's ret_addr will point to the
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* real return address, and all the rest will point to
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* kretprobe_trampoline
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*/
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hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
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if (ri->task != current)
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/* another task is sharing our hash bucket */
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continue;
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if (ri->rp && ri->rp->handler)
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ri->rp->handler(ri, regs);
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orig_ret_address = (unsigned long)ri->ret_addr;
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recycle_rp_inst(ri, &empty_rp);
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if (orig_ret_address != trampoline_address)
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/*
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* This is the real return address. Any other
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* instances associated with this task are for
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* other calls deeper on the call stack
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*/
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break;
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}
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kretprobe_assert(ri, orig_ret_address, trampoline_address);
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regs->cr_iip = orig_ret_address;
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reset_current_kprobe();
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spin_unlock_irqrestore(&kretprobe_lock, flags);
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preempt_enable_no_resched();
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hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
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hlist_del(&ri->hlist);
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kfree(ri);
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}
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/*
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* By returning a non-zero value, we are telling
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* kprobe_handler() that we don't want the post_handler
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* to run (and have re-enabled preemption)
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*/
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return 1;
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}
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/* Called with kretprobe_lock held */
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void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
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struct pt_regs *regs)
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{
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ri->ret_addr = (kprobe_opcode_t *)regs->b0;
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/* Replace the return addr with trampoline addr */
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regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
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}
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int __kprobes arch_prepare_kprobe(struct kprobe *p)
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{
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unsigned long addr = (unsigned long) p->addr;
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unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
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unsigned long kprobe_inst=0;
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unsigned int slot = addr & 0xf, template, major_opcode = 0;
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bundle_t *bundle;
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int qp;
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bundle = &((kprobe_opcode_t *)kprobe_addr)->bundle;
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template = bundle->quad0.template;
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if(valid_kprobe_addr(template, slot, addr))
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return -EINVAL;
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/* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
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if (slot == 1 && bundle_encoding[template][1] == L)
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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);
|
|
|
|
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));
|
|
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)
|
|
{
|
|
mutex_lock(&kprobe_mutex);
|
|
free_insn_slot(p->ainsn.insn, 0);
|
|
mutex_unlock(&kprobe_mutex);
|
|
}
|
|
/*
|
|
* 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) {
|
|
|
|
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 int template, major_opcode;
|
|
unsigned long kprobe_inst;
|
|
unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip;
|
|
bundle_t bundle;
|
|
|
|
memcpy(&bundle, kprobe_addr, sizeof(bundle_t));
|
|
template = bundle.quad0.template;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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 (args->err == __IA64_BREAK_JPROBE) {
|
|
/*
|
|
* jprobe instrumented function just completed
|
|
*/
|
|
p = __get_cpu_var(current_kprobe);
|
|
if (p->break_handler && p->break_handler(p, regs)) {
|
|
goto ss_probe;
|
|
}
|
|
} 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))
|
|
/*
|
|
* Our pre-handler is specifically requesting that we just
|
|
* do a return. This is used for both the jprobe pre-handler
|
|
* and the kretprobe trampoline
|
|
*/
|
|
return 1;
|
|
|
|
ss_probe:
|
|
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 kprobes_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:
|
|
/*
|
|
* We increment the nmissed count for accounting,
|
|
* we can also use npre/npostfault count for accouting
|
|
* these specific fault cases.
|
|
*/
|
|
kprobes_inc_nmissed_count(cur);
|
|
|
|
/*
|
|
* We come here because instructions in the pre/post
|
|
* handler caused the page_fault, this could happen
|
|
* if handler tries to access user space by
|
|
* copy_from_user(), get_user() etc. Let the
|
|
* user-specified handler try to fix it first.
|
|
*/
|
|
if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
|
|
return 1;
|
|
/*
|
|
* 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 == __IA64_BREAK_JPROBE
|
|
|| 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;
|
|
}
|
|
|
|
struct param_bsp_cfm {
|
|
unsigned long ip;
|
|
unsigned long *bsp;
|
|
unsigned long cfm;
|
|
};
|
|
|
|
static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg)
|
|
{
|
|
unsigned long ip;
|
|
struct param_bsp_cfm *lp = arg;
|
|
|
|
do {
|
|
unw_get_ip(info, &ip);
|
|
if (ip == 0)
|
|
break;
|
|
if (ip == lp->ip) {
|
|
unw_get_bsp(info, (unsigned long*)&lp->bsp);
|
|
unw_get_cfm(info, (unsigned long*)&lp->cfm);
|
|
return;
|
|
}
|
|
} while (unw_unwind(info) >= 0);
|
|
lp->bsp = NULL;
|
|
lp->cfm = 0;
|
|
return;
|
|
}
|
|
|
|
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
|
|
{
|
|
struct jprobe *jp = container_of(p, struct jprobe, kp);
|
|
unsigned long addr = ((struct fnptr *)(jp->entry))->ip;
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
struct param_bsp_cfm pa;
|
|
int bytes;
|
|
|
|
/*
|
|
* Callee owns the argument space and could overwrite it, eg
|
|
* tail call optimization. So to be absolutely safe
|
|
* we save the argument space before transferring the control
|
|
* to instrumented jprobe function which runs in
|
|
* the process context
|
|
*/
|
|
pa.ip = regs->cr_iip;
|
|
unw_init_running(ia64_get_bsp_cfm, &pa);
|
|
bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f)
|
|
- (char *)pa.bsp;
|
|
memcpy( kcb->jprobes_saved_stacked_regs,
|
|
pa.bsp,
|
|
bytes );
|
|
kcb->bsp = pa.bsp;
|
|
kcb->cfm = pa.cfm;
|
|
|
|
/* save architectural state */
|
|
kcb->jprobe_saved_regs = *regs;
|
|
|
|
/* after rfi, execute the jprobe instrumented function */
|
|
regs->cr_iip = addr & ~0xFULL;
|
|
ia64_psr(regs)->ri = addr & 0xf;
|
|
regs->r1 = ((struct fnptr *)(jp->entry))->gp;
|
|
|
|
/*
|
|
* fix the return address to our jprobe_inst_return() function
|
|
* in the jprobes.S file
|
|
*/
|
|
regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
|
|
{
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
int bytes;
|
|
|
|
/* restoring architectural state */
|
|
*regs = kcb->jprobe_saved_regs;
|
|
|
|
/* restoring the original argument space */
|
|
flush_register_stack();
|
|
bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f)
|
|
- (char *)kcb->bsp;
|
|
memcpy( kcb->bsp,
|
|
kcb->jprobes_saved_stacked_regs,
|
|
bytes );
|
|
invalidate_stacked_regs();
|
|
|
|
preempt_enable_no_resched();
|
|
return 1;
|
|
}
|
|
|
|
static struct kprobe trampoline_p = {
|
|
.pre_handler = trampoline_probe_handler
|
|
};
|
|
|
|
int __init arch_init_kprobes(void)
|
|
{
|
|
trampoline_p.addr =
|
|
(kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip;
|
|
return register_kprobe(&trampoline_p);
|
|
}
|
|
|
|
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
|
|
{
|
|
if (p->addr ==
|
|
(kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|