sh: Add kprobes support. (d39f5450) · Commits · e / devices / android_kernel_oneplus_sm7250

arch/sh/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,8 @@ config SUPERH

		config SUPERH32
		def_bool !SUPERH64
		select HAVE_KPROBES
		select HAVE_KRETPROBES

		config SUPERH64
		def_bool y if CPU_SH5

arch/sh/include/asm/kprobes.h

0 → 100644

+59 −0

Original line number	Diff line number	Diff line
		#ifndef __ASM_SH_KPROBES_H
		#define __ASM_SH_KPROBES_H

		#ifdef CONFIG_KPROBES

		#include <linux/types.h>
		#include <linux/ptrace.h>

		struct pt_regs;

		typedef u16 kprobe_opcode_t;
		#define BREAKPOINT_INSTRUCTION 0xc3ff

		#define MAX_INSN_SIZE 16
		#define MAX_STACK_SIZE 64
		#define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
		(((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
		? (MAX_STACK_SIZE) \
		: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))

		#define regs_return_value(regs) ((regs)->regs[0])
		#define flush_insn_slot(p) do { } while (0)
		#define kretprobe_blacklist_size 0

		struct kprobe;

		void arch_remove_kprobe(struct kprobe *);
		void kretprobe_trampoline(void);
		void jprobe_return_end(void);

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

		struct prev_kprobe {
		struct kprobe *kp;
		unsigned long status;
		};

		/* per-cpu kprobe control block */
		struct kprobe_ctlblk {
		unsigned long kprobe_status;
		unsigned long jprobe_saved_r15;
		struct pt_regs jprobe_saved_regs;
		kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
		struct prev_kprobe prev_kprobe;
		};

		extern int kprobe_exceptions_notify(struct notifier_block *self,
		unsigned long val, void *data);
		extern int kprobe_handle_illslot(unsigned long pc);
		#else

		#define kprobe_handle_illslot(pc) (-1)

		#endif /* CONFIG_KPROBES */
		#endif /* __ASM_SH_KPROBES_H */

arch/sh/kernel/Makefile_32

+1 −0

Original line number	Diff line number	Diff line
		@@ -23,5 +23,6 @@ obj-$(CONFIG_PM) += pm.o
		obj-$(CONFIG_STACKTRACE) += stacktrace.o
		obj-$(CONFIG_ELF_CORE) += dump_task.o
		obj-$(CONFIG_IO_TRAPPED) += io_trapped.o
		obj-$(CONFIG_KPROBES) += kprobes.o

		EXTRA_CFLAGS += -Werror

arch/sh/kernel/kprobes.c

0 → 100644

+568 −0

Original line number	Diff line number	Diff line
		/*
		* Kernel probes (kprobes) for SuperH
		*
		* Copyright (C) 2007 Chris Smith <chris.smith@st.com>
		* Copyright (C) 2006 Lineo Solutions, Inc.
		*
		* This file is subject to the terms and conditions of the GNU General Public
		* License. See the file "COPYING" in the main directory of this archive
		* for more details.
		*/
		#include <linux/kprobes.h>
		#include <linux/module.h>
		#include <linux/ptrace.h>
		#include <linux/preempt.h>
		#include <linux/kdebug.h>
		#include <asm/cacheflush.h>
		#include <asm/uaccess.h>

		DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
		DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);

		static struct kprobe saved_current_opcode;
		static struct kprobe saved_next_opcode;
		static struct kprobe saved_next_opcode2;

		#define OPCODE_JMP(x) (((x) & 0xF0FF) == 0x402b)
		#define OPCODE_JSR(x) (((x) & 0xF0FF) == 0x400b)
		#define OPCODE_BRA(x) (((x) & 0xF000) == 0xa000)
		#define OPCODE_BRAF(x) (((x) & 0xF0FF) == 0x0023)
		#define OPCODE_BSR(x) (((x) & 0xF000) == 0xb000)
		#define OPCODE_BSRF(x) (((x) & 0xF0FF) == 0x0003)

		#define OPCODE_BF_S(x) (((x) & 0xFF00) == 0x8f00)
		#define OPCODE_BT_S(x) (((x) & 0xFF00) == 0x8d00)

		#define OPCODE_BF(x) (((x) & 0xFF00) == 0x8b00)
		#define OPCODE_BT(x) (((x) & 0xFF00) == 0x8900)

		#define OPCODE_RTS(x) (((x) & 0x000F) == 0x000b)
		#define OPCODE_RTE(x) (((x) & 0xFFFF) == 0x002b)

		int __kprobes arch_prepare_kprobe(struct kprobe *p)
		{
		kprobe_opcode_t opcode = (kprobe_opcode_t ) (p->addr);

		if (OPCODE_RTE(opcode))
		return -EFAULT; /* Bad breakpoint */

		p->opcode = opcode;

		return 0;
		}

		void __kprobes arch_copy_kprobe(struct kprobe *p)
		{
		memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
		p->opcode = *p->addr;
		}

		void __kprobes arch_arm_kprobe(struct kprobe *p)
		{
		*p->addr = BREAKPOINT_INSTRUCTION;
		flush_icache_range((unsigned long)p->addr,
		(unsigned long)p->addr + sizeof(kprobe_opcode_t));
		}

		void __kprobes arch_disarm_kprobe(struct kprobe *p)
		{
		*p->addr = p->opcode;
		flush_icache_range((unsigned long)p->addr,
		(unsigned long)p->addr + sizeof(kprobe_opcode_t));
		}

		int __kprobes arch_trampoline_kprobe(struct kprobe *p)
		{
		if (*p->addr == BREAKPOINT_INSTRUCTION)
		return 1;

		return 0;
		}

		/**
		* If an illegal slot instruction exception occurs for an address
		* containing a kprobe, remove the probe.
		*
		* Returns 0 if the exception was handled successfully, 1 otherwise.
		*/
		int __kprobes kprobe_handle_illslot(unsigned long pc)
		{
		struct kprobe p = get_kprobe((kprobe_opcode_t ) pc + 1);

		if (p != NULL) {
		printk("Warning: removing kprobe from delay slot: 0x%.8x\n",
		(unsigned int)pc + 2);
		unregister_kprobe(p);
		return 0;
		}

		return 1;
		}

		void __kprobes arch_remove_kprobe(struct kprobe *p)
		{
		if (saved_next_opcode.addr != 0x0) {
		arch_disarm_kprobe(p);
		arch_disarm_kprobe(&saved_next_opcode);
		saved_next_opcode.addr = 0x0;
		saved_next_opcode.opcode = 0x0;

		if (saved_next_opcode2.addr != 0x0) {
		arch_disarm_kprobe(&saved_next_opcode2);
		saved_next_opcode2.addr = 0x0;
		saved_next_opcode2.opcode = 0x0;
		}
		}
		}

		static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
		{
		kcb->prev_kprobe.kp = kprobe_running();
		kcb->prev_kprobe.status = kcb->kprobe_status;
		}

		static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
		{
		__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
		kcb->kprobe_status = kcb->prev_kprobe.status;
		}

		static inline void set_current_kprobe(struct kprobe p, struct pt_regs regs,
		struct kprobe_ctlblk *kcb)
		{
		__get_cpu_var(current_kprobe) = p;
		}

		/*
		* Singlestep is implemented by disabling the current kprobe and setting one
		* on the next instruction, following branches. Two probes are set if the
		* branch is conditional.
		*/
		static inline void prepare_singlestep(struct kprobe p, struct pt_regs regs)
		{
		kprobe_opcode_t *addr = NULL;
		saved_current_opcode.addr = (kprobe_opcode_t *) (regs->pc);
		addr = saved_current_opcode.addr;

		if (p != NULL) {
		arch_disarm_kprobe(p);

		if (OPCODE_JSR(p->opcode) \|\| OPCODE_JMP(p->opcode)) {
		unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
		saved_next_opcode.addr =
		(kprobe_opcode_t *) regs->regs[reg_nr];
		} else if (OPCODE_BRA(p->opcode) \|\| OPCODE_BSR(p->opcode)) {
		unsigned long disp = (p->opcode & 0x0FFF);
		saved_next_opcode.addr =
		(kprobe_opcode_t ) (regs->pc + 4 + disp 2);

		} else if (OPCODE_BRAF(p->opcode) \|\| OPCODE_BSRF(p->opcode)) {
		unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
		saved_next_opcode.addr =
		(kprobe_opcode_t *) (regs->pc + 4 +
		regs->regs[reg_nr]);

		} else if (OPCODE_RTS(p->opcode)) {
		saved_next_opcode.addr = (kprobe_opcode_t *) regs->pr;

		} else if (OPCODE_BF(p->opcode) \|\| OPCODE_BT(p->opcode)) {
		unsigned long disp = (p->opcode & 0x00FF);
		/* case 1 */
		saved_next_opcode.addr = p->addr + 1;
		/* case 2 */
		saved_next_opcode2.addr =
		(kprobe_opcode_t ) (regs->pc + 4 + disp 2);
		saved_next_opcode2.opcode = *(saved_next_opcode2.addr);
		arch_arm_kprobe(&saved_next_opcode2);

		} else if (OPCODE_BF_S(p->opcode) \|\| OPCODE_BT_S(p->opcode)) {
		unsigned long disp = (p->opcode & 0x00FF);
		/* case 1 */
		saved_next_opcode.addr = p->addr + 2;
		/* case 2 */
		saved_next_opcode2.addr =
		(kprobe_opcode_t ) (regs->pc + 4 + disp 2);
		saved_next_opcode2.opcode = *(saved_next_opcode2.addr);
		arch_arm_kprobe(&saved_next_opcode2);

		} else {
		saved_next_opcode.addr = p->addr + 1;
		}

		saved_next_opcode.opcode = *(saved_next_opcode.addr);
		arch_arm_kprobe(&saved_next_opcode);
		}
		}

		/* Called with kretprobe_lock held */
		void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
		struct pt_regs *regs)
		{
		ri->ret_addr = (kprobe_opcode_t *) regs->pr;

		/* Replace the return addr with trampoline addr */
		regs->pr = (unsigned long)kretprobe_trampoline;
		}

		static int __kprobes kprobe_handler(struct pt_regs *regs)
		{
		struct kprobe *p;
		int ret = 0;
		kprobe_opcode_t *addr = NULL;
		struct kprobe_ctlblk *kcb;

		/*
		* We don't want to be preempted for the entire
		* duration of kprobe processing
		*/
		preempt_disable();
		kcb = get_kprobe_ctlblk();

		addr = (kprobe_opcode_t *) (regs->pc);

		/* Check we're not actually recursing */
		if (kprobe_running()) {
		p = get_kprobe(addr);
		if (p) {
		if (kcb->kprobe_status == KPROBE_HIT_SS &&
		*p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
		goto no_kprobe;
		}
		/* We have reentered the 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, regs, kcb);
		kprobes_inc_nmissed_count(p);
		prepare_singlestep(p, regs);
		kcb->kprobe_status = KPROBE_REENTER;
		return 1;
		} else {
		p = __get_cpu_var(current_kprobe);
		if (p->break_handler && p->break_handler(p, regs)) {
		goto ss_probe;
		}
		}
		goto no_kprobe;
		}

		p = get_kprobe(addr);
		if (!p) {
		/* Not one of ours: let kernel handle it */
		goto no_kprobe;
		}

		set_current_kprobe(p, regs, kcb);
		kcb->kprobe_status = KPROBE_HIT_ACTIVE;

		if (p->pre_handler && p->pre_handler(p, regs))
		/* handler has already set things up, so skip ss setup */
		return 1;

		ss_probe:
		prepare_singlestep(p, regs);
		kcb->kprobe_status = KPROBE_HIT_SS;
		return 1;

		no_kprobe:
		preempt_enable_no_resched();
		return ret;
		}

		/*
		* For function-return probes, init_kprobes() establishes a probepoint
		* here. When a retprobed function returns, this probe is hit and
		* trampoline_probe_handler() runs, calling the kretprobe's handler.
		*/
		void kretprobe_trampoline_holder(void)
		{
		asm volatile ("kretprobe_trampoline: \n" "nop\n");
		}

		/*
		* Called when we hit the probe point at kretprobe_trampoline
		*/
		int __kprobes trampoline_probe_handler(struct kprobe p, struct pt_regs regs)
		{
		struct kretprobe_instance *ri = NULL;
		struct hlist_head *head, empty_rp;
		struct hlist_node node, tmp;
		unsigned long flags, orig_ret_address = 0;
		unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;

		INIT_HLIST_HEAD(&empty_rp);
		kretprobe_hash_lock(current, &head, &flags);

		/*
		* It is possible to have multiple instances associated with a given
		* task either because an multiple functions in the call path
		* have a return probe installed on them, and/or more then one return
		* return probe was registered for a target function.
		*
		* We can handle this because:
		* - instances are always inserted at the head of the list
		* - when multiple return probes are registered for the same
		* function, the first instance's ret_addr will point to the
		* real return address, and all the rest will point to
		* kretprobe_trampoline
		*/
		hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
		if (ri->task != current)
		/* another task is sharing our hash bucket */
		continue;

		if (ri->rp && ri->rp->handler) {
		__get_cpu_var(current_kprobe) = &ri->rp->kp;
		ri->rp->handler(ri, regs);
		__get_cpu_var(current_kprobe) = NULL;
		}

		orig_ret_address = (unsigned long)ri->ret_addr;
		recycle_rp_inst(ri, &empty_rp);

		if (orig_ret_address != trampoline_address)
		/*
		* This is the real return address. Any other
		* instances associated with this task are for
		* other calls deeper on the call stack
		*/
		break;
		}

		kretprobe_assert(ri, orig_ret_address, trampoline_address);

		regs->pc = orig_ret_address;
		kretprobe_hash_unlock(current, &flags);

		preempt_enable_no_resched();

		hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
		hlist_del(&ri->hlist);
		kfree(ri);
		}

		return orig_ret_address;
		}

		static inline int post_kprobe_handler(struct pt_regs *regs)
		{
		struct kprobe *cur = kprobe_running();
		struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
		kprobe_opcode_t *addr = NULL;
		struct kprobe *p = NULL;

		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);
		}

		if (saved_next_opcode.addr != 0x0) {
		arch_disarm_kprobe(&saved_next_opcode);
		saved_next_opcode.addr = 0x0;
		saved_next_opcode.opcode = 0x0;

		addr = saved_current_opcode.addr;
		saved_current_opcode.addr = 0x0;

		p = get_kprobe(addr);
		arch_arm_kprobe(p);

		if (saved_next_opcode2.addr != 0x0) {
		arch_disarm_kprobe(&saved_next_opcode2);
		saved_next_opcode2.addr = 0x0;
		saved_next_opcode2.opcode = 0x0;
		}
		}

		/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;
		}

		static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
		{
		struct kprobe *cur = kprobe_running();
		struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
		const struct exception_table_entry *entry;

		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, point the pc back to the probe address
		* and allow the page fault handler to continue as a
		* normal page fault.
		*/
		regs->pc = (unsigned long)cur->addr;
		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 accounting
		* 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 ((entry = search_exception_tables(regs->pc)) != NULL) {
		regs->pc = entry->fixup;
		return 1;
		}

		/*
		* fixup_exception() could not handle it,
		* Let do_page_fault() fix it.
		*/
		break;
		default:
		break;
		}
		return 0;
		}

		/*
		* Wrapper routine to for handling exceptions.
		*/
		int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
		unsigned long val, void *data)
		{
		struct kprobe *p = NULL;
		struct die_args args = (struct die_args )data;
		int ret = NOTIFY_DONE;
		kprobe_opcode_t *addr = NULL;
		struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

		addr = (kprobe_opcode_t *) (args->regs->pc);
		if (val == DIE_TRAP) {
		if (!kprobe_running()) {
		if (kprobe_handler(args->regs)) {
		ret = NOTIFY_STOP;
		} else {
		/* Not a kprobe trap */
		force_sig(SIGTRAP, current);
		}
		} else {
		p = get_kprobe(addr);
		if ((kcb->kprobe_status == KPROBE_HIT_SS) \|\|
		(kcb->kprobe_status == KPROBE_REENTER)) {
		if (post_kprobe_handler(args->regs))
		ret = NOTIFY_STOP;
		} else {
		if (kprobe_handler(args->regs)) {
		ret = NOTIFY_STOP;
		} else {
		p = __get_cpu_var(current_kprobe);
		if (p->break_handler
		&& p->break_handler(p, args->regs))
		ret = NOTIFY_STOP;
		}
		}
		}
		}

		return ret;
		}

		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 kprobe_ctlblk *kcb = get_kprobe_ctlblk();

		kcb->jprobe_saved_regs = *regs;
		kcb->jprobe_saved_r15 = regs->regs[15];
		addr = kcb->jprobe_saved_r15;

		/*
		* TBD: As Linus pointed out, gcc assumes that the callee
		* owns the argument space and could overwrite it, e.g.
		* tailcall optimization. So, to be absolutely safe
		* we also save and restore enough stack bytes to cover
		* the argument area.
		*/
		memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr,
		MIN_STACK_SIZE(addr));

		regs->pc = (unsigned long)(jp->entry);

		return 1;
		}

		void __kprobes jprobe_return(void)
		{
		__asm("trapa #-1\n\t" "jprobe_return_end:\n\t" "nop\n\t");

		}

		int __kprobes longjmp_break_handler(struct kprobe p, struct pt_regs regs)
		{
		struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
		u8 addr = (u8 ) regs->pc;
		unsigned long stack_addr = kcb->jprobe_saved_r15;

		if ((addr >= (u8 *) jprobe_return)
		&& (addr <= (u8 *) jprobe_return_end)) {
		*regs = kcb->jprobe_saved_regs;

		memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
		MIN_STACK_SIZE(stack_addr));

		kcb->kprobe_status = KPROBE_HIT_SS;
		return 1;
		}
		return 0;
		}

		static struct kprobe trampoline_p = {
		.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
		.pre_handler = trampoline_probe_handler
		};

		int __init arch_init_kprobes(void)
		{
		saved_next_opcode.addr = 0x0;
		saved_next_opcode.opcode = 0x0;

		saved_current_opcode.addr = 0x0;
		saved_current_opcode.opcode = 0x0;

		saved_next_opcode2.addr = 0x0;
		saved_next_opcode2.opcode = 0x0;

		return register_kprobe(&trampoline_p);
		}

arch/sh/kernel/traps_32.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <asm/system.h>
		#include <asm/uaccess.h>
		#include <asm/fpu.h>
		#include <asm/kprobes.h>

		#ifdef CONFIG_SH_KGDB
		#include <asm/kgdb.h>
		@@ -743,6 +744,10 @@ asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
		struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
		unsigned long error_code;
		struct task_struct *tsk = current;

		if (kprobe_handle_illslot(regs->pc) == 0)
		return;

		#ifdef CONFIG_SH_FPU_EMU
		unsigned short inst = 0;