[patch] Fix some problem between kdb and kdump

Hi,

kdb has some problem to use with kdump.
This patch fixes some of them.

1) We can't use kdb when machine panicked.

crash_kexec() is called before notifier_call_chain(&panic_notifier_chain).
This patch makes KDB_ENTER() is called before crash_kexec().

2) We can't take a kdump when KDB_FLAG is set CATASTROPHIC.

kdb_do_dump() does not support kdump.
This patch makes machine_kexec() is called from kdb_do_dump().


diff -uprN linux-2.6.22-rc3.orig/kdb/kdbmain.c linux-2.6.22-rc3/kdb/kdbmain.c
--- linux-2.6.22-rc3.orig/kdb/kdbmain.c	2007-05-31 15:08:40.296000000 +0900
+++ linux-2.6.22-rc3/kdb/kdbmain.c	2007-05-31 15:18:52.172000000 +0900
@@ -36,6 +36,9 @@
 #include <linux/nmi.h>
 #include <linux/ptrace.h>
 #include <linux/sysctl.h>
+#ifdef CONFIG_KEXEC
+#include <linux/kexec.h>
+#endif
 #if defined(CONFIG_LKCD_DUMP) || defined(CONFIG_LKCD_DUMP_MODULE)
 #include <linux/dump.h>
 #endif
@@ -1089,6 +1092,21 @@ handle_ctrl_cmd(char *cmd)
 static void
 kdb_do_dump(void)
 {
+#ifdef CONFIG_KEXEC
+#ifdef CONFIG_IA64
+	if (ia64_kimage) {
+		kexec_disable_iosapic();
+		machine_kexec(ia64_kimage);
+	}
+#else
+	if (kexec_crash_image) {
+#ifdef CONFIG_X86_IO_APIC
+		disable_IO_APIC();
+#endif /* CONFIG_X86_IO_APIC */
+		machine_kexec(kexec_crash_image);
+	}
+#endif /* CONFIG_IA64 */
+#endif /* CONFIG_KEXEC */
 #if defined(CONFIG_LKCD_DUMP) || defined(CONFIG_LKCD_DUMP_MODULE)
 	kdb_printf("Forcing dump (if configured)\n");
 	console_loglevel = 8;	/* to see the dump messages */
@@ -3868,35 +3886,6 @@ kdb_cmd_init(void)
 	}
 }

-/*
- * kdb_panic
- *
- *	Invoked via the panic_notifier_list.
- *
- * Inputs:
- *	None.
- * Outputs:
- *	None.
- * Returns:
- *	Zero.
- * Locking:
- *	None.
- * Remarks:
- *	When this function is called from panic(), the other cpus have already
- *	been stopped.
- *
- */
-
-static int
-kdb_panic(struct notifier_block *self, unsigned long command, void *ptr)
-{
-	KDB_FLAG_SET(CATASTROPHIC);	/* kernel state is dubious now */
-	KDB_ENTER();
-	return 0;
-}
-
-static struct notifier_block kdb_block = { kdb_panic, NULL, 0 };
-
 #ifdef	CONFIG_SYSCTL
 static int proc_do_kdb(ctl_table *table, int write, struct file *filp,
 		       void __user *buffer, size_t *lenp, loff_t *ppos)
@@ -3989,7 +3978,6 @@ kdb_init(void)
 	kdb_initial_cpu = -1;	/* Avoid recursion problems */
 	kdb(KDB_REASON_CPU_UP, 0, NULL);	/* do kdb setup on boot cpu */
 	kdb_initial_cpu = smp_processor_id();
-	atomic_notifier_chain_register(&panic_notifier_list, &kdb_block);
 	register_cpu_notifier(&kdb_cpu_nfb);

 #ifdef kdba_setjmp
diff -uprN linux-2.6.22-rc3.orig/kernel/panic.c linux-2.6.22-rc3/kernel/panic.c
--- linux-2.6.22-rc3.orig/kernel/panic.c	2007-05-26 11:55:14.000000000 +0900
+++ linux-2.6.22-rc3/kernel/panic.c	2007-05-31 15:20:41.712000000 +0900
@@ -19,6 +19,10 @@
 #include <linux/nmi.h>
 #include <linux/kexec.h>
 #include <linux/debug_locks.h>
+#ifdef CONFIG_KDB
+#include <linux/kdb.h>
+#include <linux/kdbprivate.h>
+#endif

 int panic_on_oops;
 int tainted;
@@ -80,6 +84,11 @@ NORET_TYPE void panic(const char * fmt,
 	printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
 	bust_spinlocks(0);

+#ifdef CONFIG_KDB
+	KDB_FLAG_SET(CATASTROPHIC);
+	KDB_ENTER()
+#endif
+
 	/*
 	 * If we have crashed and we have a crash kernel loaded let it handle
 	 * everything else.
---------------------------
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