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Commit 962ff380 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
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x86: x86-64 ptrace debugreg cleanup 



This cleans up the 64-bit ptrace code to separate the guts of the
debug register access from the implementation of PTRACE_PEEKUSR and
PTRACE_POKEUSR.  The new functions ptrace_[gs]et_debugreg are made
global so that the ia32 code can later be changed to call them too.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e4aed6cc

arch/x86/kernel/ptrace_64.c

+66 −74
Original line number Diff line number Diff line
@@ -183,9 +183,63 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) 


}



unsigned long ptrace_get_debugreg(struct task_struct *child, int n)

{

	switch (n) {

	case 0:		return child->thread.debugreg0;

	case 1:		return child->thread.debugreg1;

	case 2:		return child->thread.debugreg2;

	case 3:		return child->thread.debugreg3;

	case 6:		return child->thread.debugreg6;

	case 7:		return child->thread.debugreg7;

	}

	return 0;

}



int ptrace_set_debugreg(struct task_struct *child, int n, unsigned long data)

{

	int i;



	if (n < 4) {

		int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;

		if (unlikely(data >= TASK_SIZE_OF(child) - dsize))

			return -EIO;

	}



	switch (n) {

	case 0:		child->thread.debugreg0 = data; break;

	case 1:		child->thread.debugreg1 = data; break;

	case 2:		child->thread.debugreg2 = data; break;

	case 3:		child->thread.debugreg3 = data; break;



	case 6:

		if (data >> 32)

			return -EIO;

		child->thread.debugreg6 = data;

		break;



	case 7:

		/*

		 * See ptrace_32.c for an explanation of this awkward check.

		 */

		data &= ~DR_CONTROL_RESERVED;

		for (i = 0; i < 4; i++)

			if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)

				return -EIO;

		child->thread.debugreg7 = data;

		if (data)

			set_tsk_thread_flag(child, TIF_DEBUG);

		else

			clear_tsk_thread_flag(child, TIF_DEBUG);

		break;

	}



	return 0;

}



long arch_ptrace(struct task_struct *child, long request, long addr, long data)

{

	long i, ret;

	long ret;

	unsigned ui;



	switch (request) {
@@ -204,32 +258,14 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
		    addr > sizeof(struct user) - 7)

			break;



		switch (addr) { 

		case 0 ... sizeof(struct user_regs_struct) - sizeof(long):

			tmp = getreg(child, addr);

			break;

		case offsetof(struct user, u_debugreg[0]):

			tmp = child->thread.debugreg0;

			break;

		case offsetof(struct user, u_debugreg[1]):

			tmp = child->thread.debugreg1;

			break;

		case offsetof(struct user, u_debugreg[2]):

			tmp = child->thread.debugreg2;

			break;

		case offsetof(struct user, u_debugreg[3]):

			tmp = child->thread.debugreg3;

			break;

		case offsetof(struct user, u_debugreg[6]):

			tmp = child->thread.debugreg6;

			break;

		case offsetof(struct user, u_debugreg[7]):

			tmp = child->thread.debugreg7;

			break;

		default:

		tmp = 0;

			break;

		if (addr < sizeof(struct user_regs_struct))

			tmp = getreg(child, addr);

		else if (addr >= offsetof(struct user, u_debugreg[0])) {

			addr -= offsetof(struct user, u_debugreg[0]);

			tmp = ptrace_get_debugreg(child, addr / sizeof(long));

		}



		ret = put_user(tmp,(unsigned long __user *) data);

		break;

	}
@@ -241,63 +277,19 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
		break;



	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */

	{

		int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;

		ret = -EIO;

		if ((addr & 7) ||

		    addr > sizeof(struct user) - 7)

			break;



		switch (addr) { 

		case 0 ... sizeof(struct user_regs_struct) - sizeof(long):

		if (addr < sizeof(struct user_regs_struct))

			ret = putreg(child, addr, data);

			break;

		/* Disallows to set a breakpoint into the vsyscall */

		case offsetof(struct user, u_debugreg[0]):

			if (data >= TASK_SIZE_OF(child) - dsize) break;

			child->thread.debugreg0 = data;

			ret = 0;

			break;

		case offsetof(struct user, u_debugreg[1]):

			if (data >= TASK_SIZE_OF(child) - dsize) break;

			child->thread.debugreg1 = data;

			ret = 0;

			break;

		case offsetof(struct user, u_debugreg[2]):

			if (data >= TASK_SIZE_OF(child) - dsize) break;

			child->thread.debugreg2 = data;

			ret = 0;

			break;

		case offsetof(struct user, u_debugreg[3]):

			if (data >= TASK_SIZE_OF(child) - dsize) break;

			child->thread.debugreg3 = data;

			ret = 0;

			break;

		case offsetof(struct user, u_debugreg[6]):

				  if (data >> 32)

				break; 

			child->thread.debugreg6 = data;

			ret = 0;

			break;

		case offsetof(struct user, u_debugreg[7]):

			/* See arch/i386/kernel/ptrace.c for an explanation of

			 * this awkward check.*/

			data &= ~DR_CONTROL_RESERVED;

			for(i=0; i<4; i++)

				if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)

					break;

			if (i == 4) {

			  child->thread.debugreg7 = data;

			  if (data)

			  	set_tsk_thread_flag(child, TIF_DEBUG);

			  else

			  	clear_tsk_thread_flag(child, TIF_DEBUG);

			  ret = 0;

		  	}

		  break;

		else if (addr >= offsetof(struct user, u_debugreg[0])) {

			addr -= offsetof(struct user, u_debugreg[0]);

			ret = ptrace_set_debugreg(child,

						  addr / sizeof(long), data);

		}

		break;

	}



#ifdef CONFIG_IA32_EMULATION

		/* This makes only sense with 32bit programs. Allow a

include/asm-x86/ptrace.h

+3 −0
Original line number Diff line number Diff line
@@ -110,6 +110,9 @@ void signal_fault(struct pt_regs *regs, void __user *frame, char *where); 


struct task_struct;



extern unsigned long ptrace_get_debugreg(struct task_struct *child, int n);

extern int ptrace_set_debugreg(struct task_struct *child, int n, unsigned long);



extern unsigned long

convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs);