1.1 --- a/xen/common/keyhandler.c	Thu Feb 11 19:51:15 2010 +0000
     1.2 +++ b/xen/common/keyhandler.c	Thu Feb 11 21:08:06 2010 +0000
     1.3 @@ -20,19 +20,18 @@
     1.4  static struct keyhandler *key_table[256];
     1.5  static unsigned char keypress_key;
     1.6  
     1.7 +char keyhandler_scratch[100];
     1.8 +
     1.9  static void keypress_action(unsigned long unused)
    1.10  {
    1.11 -    unsigned char key = keypress_key;
    1.12 -    console_start_log_everything();
    1.13 -    if ( key_table[key] != NULL )
    1.14 -        (*key_table[key]->u.fn)(key);
    1.15 -    console_end_log_everything();
    1.16 +    handle_keypress(keypress_key, NULL);
    1.17  }
    1.18  
    1.19  static DECLARE_TASKLET(keypress_tasklet, keypress_action, 0);
    1.20  
    1.21  void handle_keypress(unsigned char key, struct cpu_user_regs *regs)
    1.22  {
    1.23 +    static bool_t executing_handler;
    1.24      struct keyhandler *h;
    1.25  
    1.26      if ( (h = key_table[key]) == NULL )
    1.27 @@ -40,9 +39,18 @@ void handle_keypress(unsigned char key, 
    1.28  
    1.29      if ( !in_irq() || h->irq_callback )
    1.30      {
    1.31 +        /*
    1.32 +         * No concurrent handler execution: prevents garbled console and
    1.33 +         * protects keyhandler_scratch[].
    1.34 +         */
    1.35 +        if ( test_and_set_bool(executing_handler) )
    1.36 +            return;
    1.37 +        wmb();
    1.38          console_start_log_everything();
    1.39 -        (*h->u.irq_fn)(key, regs);
    1.40 +        h->irq_callback ? (*h->u.irq_fn)(key, regs) : (*h->u.fn)(key);
    1.41          console_end_log_everything();
    1.42 +        wmb();
    1.43 +        executing_handler = 0;
    1.44      }
    1.45      else
    1.46      {
    1.47 @@ -174,7 +182,7 @@ static void dump_domains(unsigned char k
    1.48      struct domain *d;
    1.49      struct vcpu   *v;
    1.50      s_time_t       now = NOW();
    1.51 -    char           tmpstr[100];
    1.52 +#define tmpstr keyhandler_scratch
    1.53  
    1.54      printk("'%c' pressed -> dumping domain info (now=0x%X:%08X)\n", key,
    1.55             (u32)(now>>32), (u32)now);
    1.56 @@ -234,6 +242,7 @@ static void dump_domains(unsigned char k
    1.57      }
    1.58  
    1.59      rcu_read_unlock(&domlist_read_lock);
    1.60 +#undef tmpstr
    1.61  }
    1.62  
    1.63  static struct keyhandler dump_domains_keyhandler = {

     2.1 --- a/xen/common/sched_credit.c	Thu Feb 11 19:51:15 2010 +0000
     2.2 +++ b/xen/common/sched_credit.c	Thu Feb 11 21:08:06 2010 +0000
     2.3 @@ -21,6 +21,7 @@
     2.4  #include <xen/softirq.h>
     2.5  #include <asm/atomic.h>
     2.6  #include <xen/errno.h>
     2.7 +#include <xen/keyhandler.h>
     2.8  
     2.9  /*
    2.10   * CSCHED_STATS
    2.11 @@ -1241,7 +1242,7 @@ csched_dump_pcpu(int cpu)
    2.12      struct csched_pcpu *spc;
    2.13      struct csched_vcpu *svc;
    2.14      int loop;
    2.15 -    char cpustr[100];
    2.16 +#define cpustr keyhandler_scratch
    2.17  
    2.18      spc = CSCHED_PCPU(cpu);
    2.19      runq = &spc->runq;
    2.20 @@ -1269,6 +1270,7 @@ csched_dump_pcpu(int cpu)
    2.21              csched_dump_vcpu(svc);
    2.22          }
    2.23      }
    2.24 +#undef cpustr
    2.25  }
    2.26  
    2.27  static void
    2.28 @@ -1276,7 +1278,7 @@ csched_dump(void)
    2.29  {
    2.30      struct list_head *iter_sdom, *iter_svc;
    2.31      int loop;
    2.32 -    char idlers_buf[100];
    2.33 +#define idlers_buf keyhandler_scratch
    2.34  
    2.35      printk("info:\n"
    2.36             "\tncpus              = %u\n"
    2.37 @@ -1323,6 +1325,7 @@ csched_dump(void)
    2.38              csched_dump_vcpu(svc);
    2.39          }
    2.40      }
    2.41 +#undef idlers_buf
    2.42  }
    2.43  
    2.44  static void

     3.1 --- a/xen/include/xen/keyhandler.h	Thu Feb 11 19:51:15 2010 +0000
     3.2 +++ b/xen/include/xen/keyhandler.h	Thu Feb 11 21:08:06 2010 +0000
     3.3 @@ -52,4 +52,7 @@ extern void register_keyhandler(unsigned
     3.4  /* Inject a keypress into the key-handling subsystem. */
     3.5  extern void handle_keypress(unsigned char key, struct cpu_user_regs *regs);
     3.6  
     3.7 +/* Scratch space is available for use of any keyhandler. */
     3.8 +extern char keyhandler_scratch[100];
     3.9 +
    3.10  #endif /* __XEN_KEYHANDLER_H__ */