x86: Make Alt-SysRq-p display the debug register contents

This patch (as921) adds code to the show_regs() routine in i386 and x86_64
to print the contents of the debug registers along with all the others.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 6c49acb96982..84664710b784 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -300,6 +300,7 @@ early_param("idle", idle_setup);
 void show_regs(struct pt_regs * regs)
 {
         unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
+        unsigned long d0, d1, d2, d3, d6, d7;
 
         printk("\n");
         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
@@ -324,6 +325,17 @@ void show_regs(struct pt_regs * regs)
         cr3 = read_cr3();
         cr4 = read_cr4_safe();
         printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
+
+        get_debugreg(d0, 0);
+        get_debugreg(d1, 1);
+        get_debugreg(d2, 2);
+        get_debugreg(d3, 3);
+        printk("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
+                        d0, d1, d2, d3);
+        get_debugreg(d6, 6);
+        get_debugreg(d7, 7);
+        printk("DR6: %08lx DR7: %08lx\n", d6, d7);
+
         show_trace(NULL, regs, &regs->esp);
 }