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Commit 4338774c authored by Dave Jones's avatar Dave Jones Committed by Ingo Molnar
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x86/debug: Only print out DR registers if they are not power-on defaults 



The DR registers are rarely useful when decoding oopses.
With screen real estate during oopses at a premium, we can save
two lines by only printing out these registers when they are set
to something other than they power-on state.

Signed-off-by: default avatarDave Jones <davej@redhat.com>
Acked-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130618160911.GA24487@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 17858ca6

arch/x86/kernel/process_32.c

+8 −3
Original line number Original line Diff line number Diff line
@@ -110,11 +110,16 @@ void __show_regs(struct pt_regs *regs, int all) 
	get_debugreg(d1, 1);

	get_debugreg(d1, 1);

	get_debugreg(d2, 2);

	get_debugreg(d2, 2);

	get_debugreg(d3, 3);

	get_debugreg(d3, 3);

	printk(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",

			d0, d1, d2, d3);



	get_debugreg(d6, 6);

	get_debugreg(d6, 6);

	get_debugreg(d7, 7);

	get_debugreg(d7, 7);



	/* Only print out debug registers if they are in their non-default state. */

	if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) &&

	    (d6 == DR6_RESERVED) && (d7 == 0x400))

		return;



	printk(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",

			d0, d1, d2, d3);

	printk(KERN_DEFAULT "DR6: %08lx DR7: %08lx\n",

	printk(KERN_DEFAULT "DR6: %08lx DR7: %08lx\n",

			d6, d7);

			d6, d7);

}

}

arch/x86/kernel/process_64.c

+8 −1
Original line number Original line Diff line number Diff line
@@ -105,11 +105,18 @@ void __show_regs(struct pt_regs *regs, int all) 
	get_debugreg(d0, 0);

	get_debugreg(d0, 0);

	get_debugreg(d1, 1);

	get_debugreg(d1, 1);

	get_debugreg(d2, 2);

	get_debugreg(d2, 2);

	printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);

	get_debugreg(d3, 3);

	get_debugreg(d3, 3);

	get_debugreg(d6, 6);

	get_debugreg(d6, 6);

	get_debugreg(d7, 7);

	get_debugreg(d7, 7);



	/* Only print out debug registers if they are in their non-default state. */

	if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) &&

	    (d6 == DR6_RESERVED) && (d7 == 0x400))

		return;



	printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);

	printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);

	printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);



}

}





void release_thread(struct task_struct *dead_task)

void release_thread(struct task_struct *dead_task)