arch/powerpc/kernel/ptrace/ptrace-noadv.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later

 #include <linux/regset.h>
 #include <linux/hw_breakpoint.h>

 #include <asm/debug.h>

 #include "ptrace-decl.h"

 void user_enable_single_step(struct task_struct *task)
 {
 	struct pt_regs *regs = task->thread.regs;

 	if (regs != NULL) {
 		regs->msr &= ~MSR_BE;
 		regs->msr |= MSR_SE;
 	}
 	set_tsk_thread_flag(task, TIF_SINGLESTEP);
 }

 void user_enable_block_step(struct task_struct *task)
 {
 	struct pt_regs *regs = task->thread.regs;

 	if (regs != NULL) {
 		regs->msr &= ~MSR_SE;
 		regs->msr |= MSR_BE;
 	}
 	set_tsk_thread_flag(task, TIF_SINGLESTEP);
 }

 void user_disable_single_step(struct task_struct *task)
 {
 	struct pt_regs *regs = task->thread.regs;

 	if (regs != NULL)
 		regs->msr &= ~(MSR_SE | MSR_BE);

 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 }

 void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
 {
 	dbginfo->version = 1;
 	dbginfo->num_instruction_bps = 0;
 	if (ppc_breakpoint_available())
 		dbginfo->num_data_bps = nr_wp_slots();
 	else
 		dbginfo->num_data_bps = 0;
 	dbginfo->num_condition_regs = 0;
 	dbginfo->data_bp_alignment = sizeof(long);
 	dbginfo->sizeof_condition = 0;
 	if (IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT)) {
 		dbginfo->features = PPC_DEBUG_FEATURE_DATA_BP_RANGE;
 		if (dawr_enabled())
 			dbginfo->features |= PPC_DEBUG_FEATURE_DATA_BP_DAWR;
 	} else {
 		dbginfo->features = 0;
 	}
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
 		dbginfo->features |= PPC_DEBUG_FEATURE_DATA_BP_ARCH_31;
 }

 int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
 			unsigned long __user *datalp)
 {
 	unsigned long dabr_fake;

 	/* We only support one DABR and no IABRS at the moment */
 	if (addr > 0)
 		return -EINVAL;
 	dabr_fake = ((child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) |
 		     (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR));
 	return put_user(dabr_fake, datalp);
 }

 /*
  * ptrace_set_debugreg() fakes DABR and DABR is only one. So even if
  * internal hw supports more than one watchpoint, we support only one
  * watchpoint with this interface.
  */
 int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	int ret;
 	struct thread_struct *thread = &task->thread;
 	struct perf_event *bp;
 	struct perf_event_attr attr;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	bool set_bp = true;
 	struct arch_hw_breakpoint hw_brk;

 	/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
 	 *  For embedded processors we support one DAC and no IAC's at the
 	 *  moment.
 	 */
 	if (addr > 0)
 		return -EINVAL;

 	/* The bottom 3 bits in dabr are flags */
 	if ((data & ~0x7UL) >= TASK_SIZE)
 		return -EIO;

 	/* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
 	 *  It was assumed, on previous implementations, that 3 bits were
 	 *  passed together with the data address, fitting the design of the
 	 *  DABR register, as follows:
 	 *
 	 *  bit 0: Read flag
 	 *  bit 1: Write flag
 	 *  bit 2: Breakpoint translation
 	 *
 	 *  Thus, we use them here as so.
 	 */

 	/* Ensure breakpoint translation bit is set */
 	if (data && !(data & HW_BRK_TYPE_TRANSLATE))
 		return -EIO;
 	hw_brk.address = data & (~HW_BRK_TYPE_DABR);
 	hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
 	hw_brk.len = DABR_MAX_LEN;
 	hw_brk.hw_len = DABR_MAX_LEN;
 	set_bp = (data) && (hw_brk.type & HW_BRK_TYPE_RDWR);
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	bp = thread->ptrace_bps[0];
 	if (!set_bp) {
 		if (bp) {
 			unregister_hw_breakpoint(bp);
 			thread->ptrace_bps[0] = NULL;
 		}
 		return 0;
 	}
 	if (bp) {
 		attr = bp->attr;
 		attr.bp_addr = hw_brk.address;
 		attr.bp_len = DABR_MAX_LEN;
 		arch_bp_generic_fields(hw_brk.type, &attr.bp_type);

 		/* Enable breakpoint */
 		attr.disabled = false;

 		ret =  modify_user_hw_breakpoint(bp, &attr);
 		if (ret)
 			return ret;

 		thread->ptrace_bps[0] = bp;
 		thread->hw_brk[0] = hw_brk;
 		return 0;
 	}

 	/* Create a new breakpoint request if one doesn't exist already */
 	hw_breakpoint_init(&attr);
 	attr.bp_addr = hw_brk.address;
 	attr.bp_len = DABR_MAX_LEN;
 	arch_bp_generic_fields(hw_brk.type,
 			       &attr.bp_type);

 	thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
 					       ptrace_triggered, NULL, task);
 	if (IS_ERR(bp)) {
 		thread->ptrace_bps[0] = NULL;
 		return PTR_ERR(bp);
 	}

 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
 	if (set_bp && (!ppc_breakpoint_available()))
 		return -ENODEV;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	task->thread.hw_brk[0] = hw_brk;
 	return 0;
 }

 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 static int find_empty_ptrace_bp(struct thread_struct *thread)
 {
 	int i;

 	for (i = 0; i < nr_wp_slots(); i++) {
 		if (!thread->ptrace_bps[i])
 			return i;
 	}
 	return -1;
 }
 #endif

 static int find_empty_hw_brk(struct thread_struct *thread)
 {
 	int i;

 	for (i = 0; i < nr_wp_slots(); i++) {
 		if (!thread->hw_brk[i].address)
 			return i;
 	}
 	return -1;
 }

 long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
 {
 	int i;
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	int len = 0;
 	struct thread_struct *thread = &child->thread;
 	struct perf_event *bp;
 	struct perf_event_attr attr;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	struct arch_hw_breakpoint brk;

 	if (bp_info->version != 1)
 		return -ENOTSUPP;
 	/*
 	 * We only support one data breakpoint
 	 */
 	if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
 	    (bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
 	    bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
 		return -EINVAL;

 	if ((unsigned long)bp_info->addr >= TASK_SIZE)
 		return -EIO;

 	brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE);
 	brk.type = HW_BRK_TYPE_TRANSLATE | HW_BRK_TYPE_PRIV_ALL;
 	brk.len = DABR_MAX_LEN;
 	brk.hw_len = DABR_MAX_LEN;
 	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
 		brk.type |= HW_BRK_TYPE_READ;
 	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
 		brk.type |= HW_BRK_TYPE_WRITE;
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
 		len = bp_info->addr2 - bp_info->addr;
 	else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
 		len = 1;
 	else
 		return -EINVAL;

 	i = find_empty_ptrace_bp(thread);
 	if (i < 0)
 		return -ENOSPC;

 	/* Create a new breakpoint request if one doesn't exist already */
 	hw_breakpoint_init(&attr);
 	attr.bp_addr = (unsigned long)bp_info->addr;
 	attr.bp_len = len;
 	arch_bp_generic_fields(brk.type, &attr.bp_type);

 	bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
 	thread->ptrace_bps[i] = bp;
 	if (IS_ERR(bp)) {
 		thread->ptrace_bps[i] = NULL;
 		return PTR_ERR(bp);
 	}

 	return i + 1;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */

 	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
 		return -EINVAL;

 	i = find_empty_hw_brk(&child->thread);
 	if (i < 0)
 		return -ENOSPC;

 	if (!ppc_breakpoint_available())
 		return -ENODEV;

 	child->thread.hw_brk[i] = brk;

 	return i + 1;
 }

 long ppc_del_hwdebug(struct task_struct *child, long data)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	int ret = 0;
 	struct thread_struct *thread = &child->thread;
 	struct perf_event *bp;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	if (data < 1 || data > nr_wp_slots())
 		return -EINVAL;

 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	bp = thread->ptrace_bps[data - 1];
 	if (bp) {
 		unregister_hw_breakpoint(bp);
 		thread->ptrace_bps[data - 1] = NULL;
 	} else {
 		ret = -ENOENT;
 	}
 	return ret;
 #else /* CONFIG_HAVE_HW_BREAKPOINT */
 	if (!(child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED) &&
 	    child->thread.hw_brk[data - 1].address == 0)
 		return -ENOENT;

 	child->thread.hw_brk[data - 1].address = 0;
 	child->thread.hw_brk[data - 1].type = 0;
 	child->thread.hw_brk[data - 1].flags = 0;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later

	#include <linux/regset.h>
	#include <linux/hw_breakpoint.h>

	#include <asm/debug.h>

	#include "ptrace-decl.h"

	void user_enable_single_step(struct task_struct *task)
	{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
	regs->msr &= ~MSR_BE;
	regs->msr \|= MSR_SE;
	}
	set_tsk_thread_flag(task, TIF_SINGLESTEP);
	}

	void user_enable_block_step(struct task_struct *task)
	{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
	regs->msr &= ~MSR_SE;
	regs->msr \|= MSR_BE;
	}
	set_tsk_thread_flag(task, TIF_SINGLESTEP);
	}

	void user_disable_single_step(struct task_struct *task)
	{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL)
	regs->msr &= ~(MSR_SE \| MSR_BE);

	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
	}

	void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
	{
	dbginfo->version = 1;
	dbginfo->num_instruction_bps = 0;
	if (ppc_breakpoint_available())
	dbginfo->num_data_bps = nr_wp_slots();
	else
	dbginfo->num_data_bps = 0;
	dbginfo->num_condition_regs = 0;
	dbginfo->data_bp_alignment = sizeof(long);
	dbginfo->sizeof_condition = 0;
	if (IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT)) {
	dbginfo->features = PPC_DEBUG_FEATURE_DATA_BP_RANGE;
	if (dawr_enabled())
	dbginfo->features \|= PPC_DEBUG_FEATURE_DATA_BP_DAWR;
	} else {
	dbginfo->features = 0;
	}
	if (cpu_has_feature(CPU_FTR_ARCH_31))
	dbginfo->features \|= PPC_DEBUG_FEATURE_DATA_BP_ARCH_31;
	}

	int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
	unsigned long __user *datalp)
	{
	unsigned long dabr_fake;

	/* We only support one DABR and no IABRS at the moment */
	if (addr > 0)
	return -EINVAL;
	dabr_fake = ((child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) \|
	(child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR));
	return put_user(dabr_fake, datalp);
	}

	/*
	* ptrace_set_debugreg() fakes DABR and DABR is only one. So even if
	* internal hw supports more than one watchpoint, we support only one
	* watchpoint with this interface.
	*/
	int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
	{
	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	int ret;
	struct thread_struct *thread = &task->thread;
	struct perf_event *bp;
	struct perf_event_attr attr;
	#endif /* CONFIG_HAVE_HW_BREAKPOINT */
	bool set_bp = true;
	struct arch_hw_breakpoint hw_brk;

	/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
	* For embedded processors we support one DAC and no IAC's at the
	* moment.
	*/
	if (addr > 0)
	return -EINVAL;

	/* The bottom 3 bits in dabr are flags */
	if ((data & ~0x7UL) >= TASK_SIZE)
	return -EIO;

	/* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
	* It was assumed, on previous implementations, that 3 bits were
	* passed together with the data address, fitting the design of the
	* DABR register, as follows:
	*
	* bit 0: Read flag
	* bit 1: Write flag
	* bit 2: Breakpoint translation
	*
	* Thus, we use them here as so.
	*/

	/* Ensure breakpoint translation bit is set */
	if (data && !(data & HW_BRK_TYPE_TRANSLATE))
	return -EIO;
	hw_brk.address = data & (~HW_BRK_TYPE_DABR);
	hw_brk.type = (data & HW_BRK_TYPE_DABR) \| HW_BRK_TYPE_PRIV_ALL;
	hw_brk.len = DABR_MAX_LEN;
	hw_brk.hw_len = DABR_MAX_LEN;
	set_bp = (data) && (hw_brk.type & HW_BRK_TYPE_RDWR);
	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	bp = thread->ptrace_bps[0];
	if (!set_bp) {
	if (bp) {
	unregister_hw_breakpoint(bp);
	thread->ptrace_bps[0] = NULL;
	}
	return 0;
	}
	if (bp) {
	attr = bp->attr;
	attr.bp_addr = hw_brk.address;
	attr.bp_len = DABR_MAX_LEN;
	arch_bp_generic_fields(hw_brk.type, &attr.bp_type);

	/* Enable breakpoint */
	attr.disabled = false;

	ret = modify_user_hw_breakpoint(bp, &attr);
	if (ret)
	return ret;

	thread->ptrace_bps[0] = bp;
	thread->hw_brk[0] = hw_brk;
	return 0;
	}

	/* Create a new breakpoint request if one doesn't exist already */
	hw_breakpoint_init(&attr);
	attr.bp_addr = hw_brk.address;
	attr.bp_len = DABR_MAX_LEN;
	arch_bp_generic_fields(hw_brk.type,
	&attr.bp_type);

	thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
	ptrace_triggered, NULL, task);
	if (IS_ERR(bp)) {
	thread->ptrace_bps[0] = NULL;
	return PTR_ERR(bp);
	}

	#else /* !CONFIG_HAVE_HW_BREAKPOINT */
	if (set_bp && (!ppc_breakpoint_available()))
	return -ENODEV;
	#endif /* CONFIG_HAVE_HW_BREAKPOINT */
	task->thread.hw_brk[0] = hw_brk;
	return 0;
	}

	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	static int find_empty_ptrace_bp(struct thread_struct *thread)
	{
	int i;

	for (i = 0; i < nr_wp_slots(); i++) {
	if (!thread->ptrace_bps[i])
	return i;
	}
	return -1;
	}
	#endif

	static int find_empty_hw_brk(struct thread_struct *thread)
	{
	int i;

	for (i = 0; i < nr_wp_slots(); i++) {
	if (!thread->hw_brk[i].address)
	return i;
	}
	return -1;
	}

	long ppc_set_hwdebug(struct task_struct child, struct ppc_hw_breakpoint bp_info)
	{
	int i;
	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	int len = 0;
	struct thread_struct *thread = &child->thread;
	struct perf_event *bp;
	struct perf_event_attr attr;
	#endif /* CONFIG_HAVE_HW_BREAKPOINT */
	struct arch_hw_breakpoint brk;

	if (bp_info->version != 1)
	return -ENOTSUPP;
	/*
	* We only support one data breakpoint
	*/
	if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 \|\|
	(bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 \|\|
	bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
	return -EINVAL;

	if ((unsigned long)bp_info->addr >= TASK_SIZE)
	return -EIO;

	brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE);
	brk.type = HW_BRK_TYPE_TRANSLATE \| HW_BRK_TYPE_PRIV_ALL;
	brk.len = DABR_MAX_LEN;
	brk.hw_len = DABR_MAX_LEN;
	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
	brk.type \|= HW_BRK_TYPE_READ;
	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
	brk.type \|= HW_BRK_TYPE_WRITE;
	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
	len = bp_info->addr2 - bp_info->addr;
	else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
	len = 1;
	else
	return -EINVAL;

	i = find_empty_ptrace_bp(thread);
	if (i < 0)
	return -ENOSPC;

	/* Create a new breakpoint request if one doesn't exist already */
	hw_breakpoint_init(&attr);
	attr.bp_addr = (unsigned long)bp_info->addr;
	attr.bp_len = len;
	arch_bp_generic_fields(brk.type, &attr.bp_type);

	bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
	thread->ptrace_bps[i] = bp;
	if (IS_ERR(bp)) {
	thread->ptrace_bps[i] = NULL;
	return PTR_ERR(bp);
	}

	return i + 1;
	#endif /* CONFIG_HAVE_HW_BREAKPOINT */

	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
	return -EINVAL;

	i = find_empty_hw_brk(&child->thread);
	if (i < 0)
	return -ENOSPC;

	if (!ppc_breakpoint_available())
	return -ENODEV;

	child->thread.hw_brk[i] = brk;

	return i + 1;
	}

	long ppc_del_hwdebug(struct task_struct *child, long data)
	{
	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	int ret = 0;
	struct thread_struct *thread = &child->thread;
	struct perf_event *bp;
	#endif /* CONFIG_HAVE_HW_BREAKPOINT */
	if (data < 1 \|\| data > nr_wp_slots())
	return -EINVAL;

	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	bp = thread->ptrace_bps[data - 1];
	if (bp) {
	unregister_hw_breakpoint(bp);
	thread->ptrace_bps[data - 1] = NULL;
	} else {
	ret = -ENOENT;
	}
	return ret;
	#else /* CONFIG_HAVE_HW_BREAKPOINT */
	if (!(child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED) &&
	child->thread.hw_brk[data - 1].address == 0)
	return -ENOENT;

	child->thread.hw_brk[data - 1].address = 0;
	child->thread.hw_brk[data - 1].type = 0;
	child->thread.hw_brk[data - 1].flags = 0;
	#endif /* CONFIG_HAVE_HW_BREAKPOINT */

	return 0;
	}