Hello,

diff -Nur --exclude=setup.c --exclude=nmi.c --exclude='*.o' --exclude='*.s'
--exclude='*.swp' --exclude=compile.h --exclude=serial.c
xen-unstable.hg/xen/arch/x86/gdbstub.c
xen-unstable.hg.new/xen/arch/x86/gdbstub.c --- xen-unstable.hg/xen/arch/x86/gdbstub.c 2007-12-19 14:18:45.000000000 -0800 +++ xen-unstable.hg.new/xen/arch/x86/gdbstub.c 2007-12-19 09:21:29.000000000
-0800 ... @@ -107,13 +67,107 @@ void gdb_arch_enter(struct cpu_user_regs *regs) { - /* nothing */ + /* + * We must pause all other CPUs. + */ + gdb_smp_pause(); }

void gdb_arch_exit(struct cpu_user_regs *regs) { - /* nothing */ + /* + * Resume all CPUs. + */ + gdb_smp_resume(); +} + +static void gdb_pause_this_cpu(void *unused) +{ + unsigned long flags; + + local_irq_save(flags); + + atomic_set(&gdb_cpu[smp_processor_id()].ack, 1); + atomic_inc(&gdb_smp_paused_count); + + while (atomic_read(&gdb_cpu[smp_processor_id()].paused)) + mdelay(1); + + atomic_dec(&gdb_smp_paused_count); + atomic_set(&gdb_cpu[smp_processor_id()].ack, 0); + + /* Restore interrupts */ + local_irq_restore(flags); +} + +static void gdb_smp_pause(void) +{ + int timeout = 100; + int cpu; + + for_each_online_cpu(cpu) + { + atomic_set(&gdb_cpu[cpu].ack, 0); + atomic_set(&gdb_cpu[cpu].paused, 1); + } + + atomic_set(&gdb_smp_paused_count, 0); + + smp_call_function(gdb_pause_this_cpu, NULL, /* dont wait! */0, 0); + + /* Wait 100ms for all other CPUs to enter pause loop */ + while ( (atomic_read(&gdb_smp_paused_count) < (num_online_cpus() - 1)) + && (timeout-- > 0) ) + mdelay(1); + + if ( atomic_read(&gdb_smp_paused_count) < (num_online_cpus() - 1) ) + { + printk("GDB: Not all CPUs have paused, missing CPUs "); + for_each_online_cpu(cpu) + { + if ( cpu == smp_processor_id() ) + continue; + + if ( !atomic_read(&gdb_cpu[cpu].ack) ) + { + printk("%d ", cpu); + } + } + printk("\n"); + } +} + +static void gdb_smp_resume(void) +{ + int cpu; + int timeout = 100; + + for_each_online_cpu(cpu) + { + atomic_set(&gdb_cpu[cpu].paused, 0); + } + + /* Make sure all CPUs resume */ + while ( (atomic_read(&gdb_smp_paused_count) > 0) + && (timeout-- > 0) ) + mdelay(1); + + if ( atomic_read(&gdb_smp_paused_count) > 0 ) + { + printk("GDB: Not all CPUs have resumed execution, missing CPUs "); + for_each_online_cpu(cpu) + { + if ( cpu == smp_processor_id() ) + continue; + + if ( !atomic_read(&gdb_cpu[cpu].ack) ) + { + printk("%d ", cpu); + } + } + printk("\n"); + } }

diff -Nur --exclude=setup.c --exclude=nmi.c --exclude='*.o' --exclude='*.s'
--exclude='*.swp' --exclude=compile.h --exclude=serial.c
xen-unstable.hg/xen/common/keyhandler.c
xen-unstable.hg.new/xen/common/keyhandler.c --- xen-unstable.hg/xen/common/keyhandler.c 2007-12-19 14:18:45.000000000 -0800 +++ xen-unstable.hg.new/xen/common/keyhandler.c 2007-12-19 09:21:29.000000000
-0800 @@ -276,7 +276,7 @@ static void do_debug_key(unsigned char key, struct cpu_user_regs *regs) { printk("'%c' pressed -> trapping into debugger\n", key); - (void)debugger_trap_fatal(0xf001, regs); + (void)debugger_trap_fatal(TRAP_int3, regs); nop(); /* Prevent the compiler doing tail call optimisation, as that confuses xendbg a bit. */

diff -Nur --exclude=setup.c --exclude=nmi.c --exclude='*.o' --exclude='*.s'
--exclude='*.swp' --exclude=compile.h --exclude=serial.c
xen-unstable.hg/xen/include/xen/gdbstub.h
xen-unstable.hg.new/xen/include/xen/gdbstub.h --- xen-unstable.hg/xen/include/xen/gdbstub.h 2007-12-19 14:18:46.000000000
-0800 +++ xen-unstable.hg.new/xen/include/xen/gdbstub.h 2007-12-19 09:21:29.000000000
-0800 @@ -69,6 +69,9 @@ struct cpu_user_regs *regs, const char* buf, struct gdb_context *ctx); void gdb_arch_read_reg( unsigned long regnum, struct cpu_user_regs *regs, struct gdb_context *ctx); +void gdb_arch_write_reg( + unsigned long regnum, unsigned long val, struct cpu_user_regs *regs, + struct gdb_context *ctx); unsigned int gdb_arch_copy_from_user( void *dest, const void *src, unsigned len); unsigned int gdb_arch_copy_to_user(