[PATCH] Kprobes/IA64: arch specific handling (fd7b231f) · Commits · e / devices / android_kernel_xiaomi_markw

arch/ia64/Kconfig.debug

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		@@ -2,6 +2,17 @@ menu "Kernel hacking"

		source "lib/Kconfig.debug"

		config KPROBES
		bool "Kprobes"
		depends on DEBUG_KERNEL
		help
		Kprobes allows you to trap at almost any kernel address and
		execute a callback function. register_kprobe() establishes
		a probepoint and specifies the callback. Kprobes is useful
		for kernel debugging, non-intrusive instrumentation and testing.
		If in doubt, say "N".


		choice
		prompt "Physical memory granularity"
		default IA64_GRANULE_64MB

arch/ia64/kernel/Makefile

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		@@ -20,6 +20,7 @@ obj-$(CONFIG_SMP) += smp.o smpboot.o domain.o
		obj-$(CONFIG_PERFMON) += perfmon_default_smpl.o
		obj-$(CONFIG_IA64_CYCLONE) += cyclone.o
		obj-$(CONFIG_IA64_MCA_RECOVERY) += mca_recovery.o
		obj-$(CONFIG_KPROBES) += kprobes.o
		obj-$(CONFIG_IA64_UNCACHED_ALLOCATOR) += uncached.o
		mca_recovery-y += mca_drv.o mca_drv_asm.o

arch/ia64/kernel/kprobes.c

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		/*
		* Kernel Probes (KProbes)
		* arch/ia64/kernel/kprobes.c
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
		*
		* 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/config.h>
		#include <linux/kprobes.h>
		#include <linux/ptrace.h>
		#include <linux/spinlock.h>
		#include <linux/string.h>
		#include <linux/slab.h>
		#include <linux/preempt.h>
		#include <linux/moduleloader.h>

		#include <asm/pgtable.h>
		#include <asm/kdebug.h>

		/* kprobe_status settings */
		#define KPROBE_HIT_ACTIVE 0x00000001
		#define KPROBE_HIT_SS 0x00000002

		static struct kprobe *current_kprobe;
		static unsigned long kprobe_status;

		enum instruction_type {A, I, M, F, B, L, X, u};
		static enum instruction_type bundle_encoding[32][3] = {
		{ M, I, I }, /* 00 */
		{ M, I, I }, /* 01 */
		{ M, I, I }, /* 02 */
		{ M, I, I }, /* 03 */
		{ M, L, X }, /* 04 */
		{ M, L, X }, /* 05 */
		{ u, u, u }, /* 06 */
		{ u, u, u }, /* 07 */
		{ M, M, I }, /* 08 */
		{ M, M, I }, /* 09 */
		{ M, M, I }, /* 0A */
		{ M, M, I }, /* 0B */
		{ M, F, I }, /* 0C */
		{ M, F, I }, /* 0D */
		{ M, M, F }, /* 0E */
		{ M, M, F }, /* 0F */
		{ M, I, B }, /* 10 */
		{ M, I, B }, /* 11 */
		{ M, B, B }, /* 12 */
		{ M, B, B }, /* 13 */
		{ u, u, u }, /* 14 */
		{ u, u, u }, /* 15 */
		{ B, B, B }, /* 16 */
		{ B, B, B }, /* 17 */
		{ M, M, B }, /* 18 */
		{ M, M, B }, /* 19 */
		{ u, u, u }, /* 1A */
		{ u, u, u }, /* 1B */
		{ M, F, B }, /* 1C */
		{ M, F, B }, /* 1D */
		{ u, u, u }, /* 1E */
		{ u, u, u }, /* 1F */
		};

		int arch_prepare_kprobe(struct kprobe *p)
		{
		unsigned long addr = (unsigned long) p->addr;
		unsigned long bundle_addr = addr & ~0xFULL;
		unsigned long slot = addr & 0xf;
		bundle_t bundle;
		unsigned long template;

		/*
		* TODO: Verify that a probe is not being inserted
		* in sensitive regions of code
		* TODO: Verify that the memory holding the probe is rwx
		* TODO: verify this is a kernel address
		*/
		memcpy(&bundle, (unsigned long *)bundle_addr, sizeof(bundle_t));
		template = bundle.quad0.template;
		if (((bundle_encoding[template][1] == L) && slot > 1) \|\| (slot > 2)) {
		printk(KERN_WARNING "Attempting to insert unaligned kprobe at 0x%lx\n", addr);
		return -EINVAL;
		}
		return 0;
		}

		void arch_copy_kprobe(struct kprobe *p)
		{
		unsigned long addr = (unsigned long)p->addr;
		unsigned long bundle_addr = addr & ~0xFULL;

		memcpy(&p->ainsn.insn.bundle, (unsigned long *)bundle_addr,
		sizeof(bundle_t));
		memcpy(&p->opcode.bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
		}

		void arch_arm_kprobe(struct kprobe *p)
		{
		unsigned long addr = (unsigned long)p->addr;
		unsigned long arm_addr = addr & ~0xFULL;
		unsigned long slot = addr & 0xf;
		unsigned long template;
		bundle_t bundle;

		memcpy(&bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));

		template = bundle.quad0.template;
		if (slot == 1 && bundle_encoding[template][1] == L)
		slot = 2;
		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;
		}

		/* Flush icache for the instruction at the emulated address */
		flush_icache_range((unsigned long)&p->ainsn.insn.bundle,
		(unsigned long)&p->ainsn.insn.bundle +
		sizeof(bundle_t));
		/*
		* Patch the original instruction with the probe instruction
		* and flush the instruction cache
		*/
		memcpy((char ) arm_addr, (char ) &bundle, sizeof(bundle_t));
		flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
		}

		void arch_disarm_kprobe(struct kprobe *p)
		{
		unsigned long addr = (unsigned long)p->addr;
		unsigned long arm_addr = addr & ~0xFULL;

		/* p->opcode contains the original unaltered bundle */
		memcpy((char ) arm_addr, (char ) &p->opcode.bundle, sizeof(bundle_t));
		flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
		}

		void arch_remove_kprobe(struct kprobe *p)
		{
		}

		/*
		* 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, and if we see that
		* the slot has incremented back to zero, then we need to point to the next
		* slot location.
		*/
		static void resume_execution(struct kprobe p, struct pt_regs regs)
		{
		unsigned long bundle = (unsigned long)p->addr & ~0xFULL;

		/*
		* TODO: Handle cases where kprobe was inserted on a branch instruction
		*/

		if (!ia64_psr(regs)->ri)
		regs->cr_iip = bundle + 0x10;
		else
		regs->cr_iip = bundle;

		ia64_psr(regs)->ss = 0;
		}

		static void 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;

		/* Update instruction pointer (IIP) and slot number (IPSR.ri) */
		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 pre_kprobes_handler(struct pt_regs *regs)
		{
		struct kprobe *p;
		int ret = 0;
		kprobe_opcode_t addr = (kprobe_opcode_t )instruction_pointer(regs);

		preempt_disable();

		/* Handle recursion cases */
		if (kprobe_running()) {
		p = get_kprobe(addr);
		if (p) {
		if (kprobe_status == KPROBE_HIT_SS) {
		unlock_kprobes();
		goto no_kprobe;
		}
		arch_disarm_kprobe(p);
		ret = 1;
		} else {
		/*
		* jprobe instrumented function just completed
		*/
		p = current_kprobe;
		if (p->break_handler && p->break_handler(p, regs)) {
		goto ss_probe;
		}
		}
		}

		lock_kprobes();
		p = get_kprobe(addr);
		if (!p) {
		unlock_kprobes();
		goto no_kprobe;
		}

		kprobe_status = KPROBE_HIT_ACTIVE;
		current_kprobe = p;

		if (p->pre_handler && p->pre_handler(p, regs))
		/*
		* Our pre-handler is specifically requesting that we just
		* do a return. This is handling the case where the
		* pre-handler is really our special jprobe pre-handler.
		*/
		return 1;

		ss_probe:
		prepare_ss(p, regs);
		kprobe_status = KPROBE_HIT_SS;
		return 1;

		no_kprobe:
		preempt_enable_no_resched();
		return ret;
		}

		static int post_kprobes_handler(struct pt_regs *regs)
		{
		if (!kprobe_running())
		return 0;

		if (current_kprobe->post_handler)
		current_kprobe->post_handler(current_kprobe, regs, 0);

		resume_execution(current_kprobe, regs);

		unlock_kprobes();
		preempt_enable_no_resched();
		return 1;
		}

		static int kprobes_fault_handler(struct pt_regs *regs, int trapnr)
		{
		if (!kprobe_running())
		return 0;

		if (current_kprobe->fault_handler &&
		current_kprobe->fault_handler(current_kprobe, regs, trapnr))
		return 1;

		if (kprobe_status & KPROBE_HIT_SS) {
		resume_execution(current_kprobe, regs);
		unlock_kprobes();
		preempt_enable_no_resched();
		}

		return 0;
		}

		int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
		void *data)
		{
		struct die_args args = (struct die_args )data;
		switch(val) {
		case DIE_BREAK:
		if (pre_kprobes_handler(args->regs))
		return NOTIFY_STOP;
		break;
		case DIE_SS:
		if (post_kprobes_handler(args->regs))
		return NOTIFY_STOP;
		break;
		case DIE_PAGE_FAULT:
		if (kprobes_fault_handler(args->regs, args->trapnr))
		return NOTIFY_STOP;
		default:
		break;
		}
		return NOTIFY_DONE;
		}

		int setjmp_pre_handler(struct kprobe p, struct pt_regs regs)
		{
		printk(KERN_WARNING "Jprobes is not supported\n");
		return 0;
		}

		void jprobe_return(void)
		{
		}

		int longjmp_break_handler(struct kprobe p, struct pt_regs regs)
		{
		return 0;
		}

include/asm-ia64/kprobes.h

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		#ifndef _ASM_KPROBES_H
		#define _ASM_KPROBES_H
		/*
		* Kernel Probes (KProbes)
		* include/asm-ia64/kprobes.h
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
		*
		* 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/types.h>
		#include <linux/ptrace.h>
		#include <asm/break.h>

		#define BREAK_INST (long)(__IA64_BREAK_KPROBE << 6)

		typedef struct _bundle {
		struct {
		unsigned long long template : 5;
		unsigned long long slot0 : 41;
		unsigned long long slot1_p0 : 64-46;
		} quad0;
		struct {
		unsigned long long slot1_p1 : 41 - (64-46);
		unsigned long long slot2 : 41;
		} quad1;
		} __attribute__((__aligned__(16))) bundle_t;

		#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)pentry

		typedef struct kprobe_opcode {
		bundle_t bundle;
		} kprobe_opcode_t;

		struct fnptr {
		unsigned long ip;
		unsigned long gp;
		};

		/* Architecture specific copy of original instruction*/
		struct arch_specific_insn {
		/* copy of the original instruction */
		kprobe_opcode_t insn;
		};

		#ifdef CONFIG_KPROBES
		extern int kprobe_exceptions_notify(struct notifier_block *self,
		unsigned long val, void *data);
		#else /* !CONFIG_KPROBES */
		static inline int kprobe_exceptions_notify(struct notifier_block *self,
		unsigned long val, void *data)
		{
		return 0;
		}
		#endif
		#endif /* _ASM_KPROBES_H */