[Xen-devel] [patch] common gdbstub issues

[Hollis Blanchard <hollisb@xxxxxxxxxx>]

This patch fixes up some issues I found when porting PPC to the new common gdb 
stub code:
- cosmetic changes in the messages printed
- 'flags' must always be unsigned long.
- explicitly calling initialize_gdb() is not difficult. For x86 and ia64 I 
placed this call immediately before do_initcalls(), since that's where it's 
being called from now so we know it's safe. Architecture people can move it 
earlier as appropriate.
- I don't understand all these ASSERT(!local_irq_is_enabled()) statements, 
sometimes bracketing a single call like receive_command(). How exactly would 
receive_command() manage to re-enable irqs? Also, a failing ASSERT would just 
call into the stub again anways...
- initialize_gdb() was overcomplicated. serial_parse_handle() already handles 
the parsing for us, and there's no need to panic there.

Please apply.

Signed-off-by: Hollis Blanchard <hollisb@xxxxxxxxxx>

diff -r 404fdd14c6d3 xen/arch/ia64/xen/xensetup.c
--- a/xen/arch/ia64/xen/xensetup.c      Tue Feb 28 20:57:06 2006
+++ b/xen/arch/ia64/xen/xensetup.c      Thu Mar  2 16:01:41 2006
@@ -333,6 +333,8 @@
     smp_cpus_done(max_cpus);
 #endif
 
+    initialize_gdb(); /* could be moved earlier */
+
     do_initcalls();
 printk("About to call sort_main_extable()\n");
     sort_main_extable();
diff -r 404fdd14c6d3 xen/arch/x86/setup.c
--- a/xen/arch/x86/setup.c      Tue Feb 28 20:57:06 2006
+++ b/xen/arch/x86/setup.c      Thu Mar  2 16:01:41 2006
@@ -479,6 +479,8 @@
     printk("Brought up %ld CPUs\n", (long)num_online_cpus());
     smp_cpus_done(max_cpus);
 
+    initialize_gdb(); /* could be moved earlier */
+
     do_initcalls();
 
     schedulers_start();
diff -r 404fdd14c6d3 xen/common/gdbstub.c
--- a/xen/common/gdbstub.c      Tue Feb 28 20:57:06 2006
+++ b/xen/common/gdbstub.c      Thu Mar  2 16:01:41 2006
@@ -376,7 +376,6 @@
         break;
     case 'g': /* Read registers */
         gdb_arch_read_reg_array(regs, ctx);
-        ASSERT(!local_irq_is_enabled());
         break;
     case 'G': /* Write registers */
         gdb_arch_write_reg_array(regs, ctx->in_buf + 1, ctx);
@@ -395,7 +394,6 @@
             return 0;
         }
         gdb_cmd_read_mem(addr, length, ctx);
-        ASSERT(!local_irq_is_enabled());
         break;
     case 'M': /* Write memory */
         addr = simple_strtoul(ctx->in_buf + 1, &ptr, 16);
@@ -477,7 +475,7 @@
 {
     int resume = 0;
     int r;
-    unsigned flags;
+    unsigned long flags;
 
     if ( gdb_ctx->serhnd < 0 )
     {
@@ -506,7 +504,7 @@
 
     if ( !gdb_ctx->connected )
     {
-        printk("GDB connection activated\n");
+        printk("GDB connection activated.\n");
         gdb_arch_print_state(regs);
         gdb_ctx->connected = 1;
     }
@@ -522,7 +520,7 @@
 
     /* Shouldn't really do this, but otherwise we stop for no
        obvious reason, which is Bad */
-    printk("Waiting for GDB to attach to Gdb\n");
+    printk("Waiting for GDB to attach...\n");
 
     gdb_arch_enter(regs);
     gdb_ctx->signum = gdb_arch_signal_num(regs, cookie);
@@ -535,9 +533,7 @@
 
     while ( resume == 0 )
     {
-        ASSERT(!local_irq_is_enabled());
         r = receive_command(gdb_ctx);
-        ASSERT(!local_irq_is_enabled());
         if ( r < 0 )
         {
             dbg_printk("GDB disappeared, trying to resume Xen...\n");
@@ -545,9 +541,7 @@
         }
         else
         {
-            ASSERT(!local_irq_is_enabled());
             resume = process_command(regs, gdb_ctx);
-            ASSERT(!local_irq_is_enabled());
         }
     }
 
@@ -561,27 +555,14 @@
     return 0;
 }
 
-/*
- * initialization
- * XXX TODO
- *     This should be an explicit call from architecture code.               
- *     initcall is far too late for some early debugging, and only the 
- *     architecture code knows when this call can be made.          
- */
-static int
+int
 initialize_gdb(void)
 {
-    if ( !strcmp(opt_gdb, "none") )
-        return 0;
     gdb_ctx->serhnd = serial_parse_handle(opt_gdb);
-    if ( gdb_ctx->serhnd == -1 )
-        panic("Can't parse %s as GDB serial info.\n", opt_gdb);
-
-    printk("Gdb initialised.\n");
+    if ( gdb_ctx->serhnd != -1 )
+        printk("GDB stub initialised.\n");
     return 0;
 }
-
-__initcall(initialize_gdb);
 
 /*
  * Local variables:

-- 
Hollis Blanchard
IBM Linux Technology Center

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