fd7b231ff9
This is an IA64 arch specific handling of Kprobes Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
333 lines
8.3 KiB
C
333 lines
8.3 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/config.h>
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#include <linux/kprobes.h>
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#include <linux/ptrace.h>
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#include <linux/spinlock.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 <asm/pgtable.h>
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#include <asm/kdebug.h>
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/* kprobe_status settings */
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#define KPROBE_HIT_ACTIVE 0x00000001
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#define KPROBE_HIT_SS 0x00000002
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static struct kprobe *current_kprobe;
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static unsigned long kprobe_status;
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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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int 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 bundle_addr = addr & ~0xFULL;
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unsigned long slot = addr & 0xf;
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bundle_t bundle;
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unsigned long template;
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/*
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* TODO: Verify that a probe is not being inserted
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* in sensitive regions of code
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* TODO: Verify that the memory holding the probe is rwx
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* TODO: verify this is a kernel address
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*/
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memcpy(&bundle, (unsigned long *)bundle_addr, sizeof(bundle_t));
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template = bundle.quad0.template;
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if (((bundle_encoding[template][1] == L) && slot > 1) || (slot > 2)) {
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printk(KERN_WARNING "Attempting to insert unaligned kprobe 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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void arch_copy_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 bundle_addr = addr & ~0xFULL;
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memcpy(&p->ainsn.insn.bundle, (unsigned long *)bundle_addr,
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sizeof(bundle_t));
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memcpy(&p->opcode.bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
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}
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void arch_arm_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 arm_addr = addr & ~0xFULL;
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unsigned long slot = addr & 0xf;
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unsigned long template;
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bundle_t bundle;
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memcpy(&bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
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template = bundle.quad0.template;
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if (slot == 1 && bundle_encoding[template][1] == L)
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slot = 2;
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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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/* Flush icache for the instruction at the emulated address */
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flush_icache_range((unsigned long)&p->ainsn.insn.bundle,
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(unsigned long)&p->ainsn.insn.bundle +
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sizeof(bundle_t));
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/*
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* Patch the original instruction with the probe instruction
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* and flush the instruction cache
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*/
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memcpy((char *) arm_addr, (char *) &bundle, sizeof(bundle_t));
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flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
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}
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void arch_disarm_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 arm_addr = addr & ~0xFULL;
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/* p->opcode contains the original unaltered bundle */
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memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t));
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flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
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}
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void arch_remove_kprobe(struct kprobe *p)
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{
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}
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/*
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* We are resuming execution after a single step fault, so the pt_regs
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* structure reflects the register state after we executed the instruction
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* located in the kprobe (p->ainsn.insn.bundle). We still need to adjust
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* the ip to point back to the original stack address, and if we see that
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* the slot has incremented back to zero, then we need to point to the next
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* slot location.
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*/
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static void resume_execution(struct kprobe *p, struct pt_regs *regs)
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{
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unsigned long bundle = (unsigned long)p->addr & ~0xFULL;
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/*
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* TODO: Handle cases where kprobe was inserted on a branch instruction
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*/
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if (!ia64_psr(regs)->ri)
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regs->cr_iip = bundle + 0x10;
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else
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regs->cr_iip = bundle;
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ia64_psr(regs)->ss = 0;
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}
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static void prepare_ss(struct kprobe *p, struct pt_regs *regs)
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{
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unsigned long bundle_addr = (unsigned long) &p->ainsn.insn.bundle;
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unsigned long slot = (unsigned long)p->addr & 0xf;
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/* Update instruction pointer (IIP) and slot number (IPSR.ri) */
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regs->cr_iip = bundle_addr & ~0xFULL;
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if (slot > 2)
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slot = 0;
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ia64_psr(regs)->ri = slot;
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/* turn on single stepping */
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ia64_psr(regs)->ss = 1;
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}
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static int pre_kprobes_handler(struct pt_regs *regs)
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{
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struct kprobe *p;
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int ret = 0;
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kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
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preempt_disable();
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/* Handle recursion cases */
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if (kprobe_running()) {
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p = get_kprobe(addr);
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if (p) {
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if (kprobe_status == KPROBE_HIT_SS) {
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unlock_kprobes();
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goto no_kprobe;
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}
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arch_disarm_kprobe(p);
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ret = 1;
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} else {
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/*
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* jprobe instrumented function just completed
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*/
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p = current_kprobe;
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if (p->break_handler && p->break_handler(p, regs)) {
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goto ss_probe;
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}
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}
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}
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lock_kprobes();
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p = get_kprobe(addr);
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if (!p) {
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unlock_kprobes();
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goto no_kprobe;
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}
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kprobe_status = KPROBE_HIT_ACTIVE;
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current_kprobe = p;
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if (p->pre_handler && p->pre_handler(p, regs))
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/*
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* Our pre-handler is specifically requesting that we just
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* do a return. This is handling the case where the
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* pre-handler is really our special jprobe pre-handler.
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*/
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return 1;
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ss_probe:
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prepare_ss(p, regs);
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kprobe_status = KPROBE_HIT_SS;
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return 1;
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no_kprobe:
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preempt_enable_no_resched();
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return ret;
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}
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static int post_kprobes_handler(struct pt_regs *regs)
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{
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if (!kprobe_running())
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return 0;
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if (current_kprobe->post_handler)
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current_kprobe->post_handler(current_kprobe, regs, 0);
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resume_execution(current_kprobe, regs);
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unlock_kprobes();
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preempt_enable_no_resched();
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return 1;
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}
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static int kprobes_fault_handler(struct pt_regs *regs, int trapnr)
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{
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if (!kprobe_running())
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return 0;
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if (current_kprobe->fault_handler &&
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current_kprobe->fault_handler(current_kprobe, regs, trapnr))
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return 1;
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if (kprobe_status & KPROBE_HIT_SS) {
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resume_execution(current_kprobe, regs);
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unlock_kprobes();
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preempt_enable_no_resched();
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}
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return 0;
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}
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int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
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void *data)
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{
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struct die_args *args = (struct die_args *)data;
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switch(val) {
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case DIE_BREAK:
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if (pre_kprobes_handler(args->regs))
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return NOTIFY_STOP;
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break;
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case DIE_SS:
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if (post_kprobes_handler(args->regs))
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return NOTIFY_STOP;
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break;
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case DIE_PAGE_FAULT:
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if (kprobes_fault_handler(args->regs, args->trapnr))
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return NOTIFY_STOP;
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default:
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break;
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}
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return NOTIFY_DONE;
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}
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int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
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{
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printk(KERN_WARNING "Jprobes is not supported\n");
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return 0;
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}
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void jprobe_return(void)
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{
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}
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int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
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{
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return 0;
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}
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