diff options
| author | Dave Jones <davej@redhat.com> | 2013-06-18 18:09:11 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-06-19 14:33:59 +0200 |
| commit | 4338774cd41a6abf72aa76585ce2184cea8ff8a2 (patch) | |
| tree | 8fe5dbff300e905f0578b8c937865c31a12d65c9 | |
| parent | Merge tag 'please-pull-fixia64' of git://git.kernel.org/pub/scm/linux/kernel/... (diff) | |
| download | linux-4338774cd41a6abf72aa76585ce2184cea8ff8a2.tar.xz linux-4338774cd41a6abf72aa76585ce2184cea8ff8a2.zip | |
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: Dave Jones <davej@redhat.com>
Acked-by: Borislav 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: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/process_32.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 9 |
2 files changed, 16 insertions, 4 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 7305f7dfc7ab..f84cfd1b0c0b 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -110,11 +110,16 @@ void __show_regs(struct pt_regs *regs, int all) get_debugreg(d1, 1); get_debugreg(d2, 2); 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(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", d6, d7); } diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 355ae06dbf94..a8b9abc5459a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -105,11 +105,18 @@ void __show_regs(struct pt_regs *regs, int all) get_debugreg(d0, 0); get_debugreg(d1, 1); get_debugreg(d2, 2); - printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); get_debugreg(d3, 3); get_debugreg(d6, 6); 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); + } void release_thread(struct task_struct *dead_task) |