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Commit 0f534093 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

x86: x86-32 thread_struct.debugreg 



This replaces the debugreg[7] member of thread_struct with individual
members debugreg0, etc.  This saves two words for the dummies 4 and 5,
and harmonizes the code between 32 and 64.

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 d277fb89

arch/x86/kernel/process_32.c

+20 −11
Original line number Diff line number Diff line
@@ -445,7 +445,12 @@ void flush_thread(void) 
{

	struct task_struct *tsk = current;



	memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);

	tsk->thread.debugreg0 = 0;

	tsk->thread.debugreg1 = 0;

	tsk->thread.debugreg2 = 0;

	tsk->thread.debugreg3 = 0;

	tsk->thread.debugreg6 = 0;

	tsk->thread.debugreg7 = 0;

	memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));	

	clear_tsk_thread_flag(tsk, TIF_DEBUG);

	/*
@@ -522,7 +527,6 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 
 */

void dump_thread(struct pt_regs * regs, struct user * dump)

{

	int i;

	u16 gs;



/* changed the size calculations - should hopefully work better. lbt */
@@ -533,8 +537,14 @@ void dump_thread(struct pt_regs * regs, struct user * dump) 
	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;

	dump->u_dsize -= dump->u_tsize;

	dump->u_ssize = 0;

	for (i = 0; i < 8; i++)

		dump->u_debugreg[i] = current->thread.debugreg[i];  

	dump->u_debugreg[0] = current->thread.debugreg0;

	dump->u_debugreg[1] = current->thread.debugreg1;

	dump->u_debugreg[2] = current->thread.debugreg2;

	dump->u_debugreg[3] = current->thread.debugreg3;

	dump->u_debugreg[4] = 0;

	dump->u_debugreg[5] = 0;

	dump->u_debugreg[6] = current->thread.debugreg6;

	dump->u_debugreg[7] = current->thread.debugreg7;



	if (dump->start_stack < TASK_SIZE)

		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
@@ -612,13 +622,13 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, 
		wrmsr(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr, 0);



	if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {

		set_debugreg(next->debugreg[0], 0);

		set_debugreg(next->debugreg[1], 1);

		set_debugreg(next->debugreg[2], 2);

		set_debugreg(next->debugreg[3], 3);

		set_debugreg(next->debugreg0, 0);

		set_debugreg(next->debugreg1, 1);

		set_debugreg(next->debugreg2, 2);

		set_debugreg(next->debugreg3, 3);

		/* no 4 and 5 */

		set_debugreg(next->debugreg[6], 6);

		set_debugreg(next->debugreg[7], 7);

		set_debugreg(next->debugreg6, 6);

		set_debugreg(next->debugreg7, 7);

	}



#ifdef CONFIG_SECCOMP
@@ -869,4 +879,3 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) 
	unsigned long range_end = mm->brk + 0x02000000;

	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;

}

arch/x86/kernel/ptrace_32.c

+24 −5
Original line number Diff line number Diff line
@@ -133,19 +133,39 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) 
 */

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

{

	return child->thread.debugreg[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;

}



static int ptrace_set_debugreg(struct task_struct *child,

			       int n, unsigned long data)

{

	int i;



	if (unlikely(n == 4 || n == 5))

		return -EIO;



	if (n < 4 && unlikely(data >= TASK_SIZE - 3))

		return -EIO;



	if (n == 7) {

	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:

		child->thread.debugreg6 = data;

		break;



	case 7:

		/*

		 * Sanity-check data. Take one half-byte at once with

		 * check = (val >> (16 + 4*i)) & 0xf. It contains the
@@ -176,19 +196,18 @@ static int ptrace_set_debugreg(struct task_struct *child, 
		 * 64-bit kernel), so the x86_64 mask value is 0x5454.

		 * See the AMD manual no. 24593 (AMD64 System Programming)

		 */

		int i;

		data &= ~DR_CONTROL_RESERVED;

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

			if ((0x5f54 >> ((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;

	}



	child->thread.debugreg[n] = data;



	return 0;

}

arch/x86/kernel/signal_32.c

+2 −2
Original line number Diff line number Diff line
@@ -605,8 +605,8 @@ static void fastcall do_signal(struct pt_regs *regs) 
		 * have been cleared if the watchpoint triggered

		 * inside the kernel.

		 */

		if (unlikely(current->thread.debugreg[7]))

			set_debugreg(current->thread.debugreg[7], 7);

		if (unlikely(current->thread.debugreg7))

			set_debugreg(current->thread.debugreg7, 7);



		/* Whee!  Actually deliver the signal.  */

		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {

arch/x86/kernel/traps_32.c

+2 −2
Original line number Diff line number Diff line
@@ -852,7 +852,7 @@ fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code) 


	/* Mask out spurious debug traps due to lazy DR7 setting */

	if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {

		if (!tsk->thread.debugreg[7])

		if (!tsk->thread.debugreg7)

			goto clear_dr7;

	}
@@ -860,7 +860,7 @@ fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code) 
		goto debug_vm86;



	/* Save debug status register where ptrace can see it */

	tsk->thread.debugreg[6] = condition;

	tsk->thread.debugreg6 = condition;



	/*

	 * Single-stepping through TF: make sure we ignore any events in

arch/x86/power/cpu.c

+7 −7
Original line number Diff line number Diff line
@@ -74,14 +74,14 @@ static void fix_processor_context(void) 
	/*

	 * Now maybe reload the debug registers

	 */

	if (current->thread.debugreg[7]){

		set_debugreg(current->thread.debugreg[0], 0);

		set_debugreg(current->thread.debugreg[1], 1);

		set_debugreg(current->thread.debugreg[2], 2);

		set_debugreg(current->thread.debugreg[3], 3);

	if (current->thread.debugreg7) {

		set_debugreg(current->thread.debugreg0, 0);

		set_debugreg(current->thread.debugreg1, 1);

		set_debugreg(current->thread.debugreg2, 2);

		set_debugreg(current->thread.debugreg3, 3);

		/* no 4 and 5 */

		set_debugreg(current->thread.debugreg[6], 6);

		set_debugreg(current->thread.debugreg[7], 7);

		set_debugreg(current->thread.debugreg6, 6);

		set_debugreg(current->thread.debugreg7, 7);

	}



}