2.4.2-ac18 fix for Alpha machines

2.4.2-ac18 fix for Alpha machines

[Matti Aarnio]

The linkage of vmlinux fails with lacking code for  bust_spinlocks(),
thus I cloned the i386 one as is -- which apparently is not really
processor specific...


--- arch/alpha/mm/fault.c~	Sun Mar 11 11:49:23 2001
+++ arch/alpha/mm/fault.c	Sun Mar 11 14:46:39 2001
@@ -231,3 +231,39 @@
 	}
 #endif
 }
+
+extern spinlock_t timerlist_lock;
+
+/*
+ * Unlock any spinlocks which will prevent us from getting the
+ * message out (timerlist_lock is acquired through the
+ * console unblank code)
+ */
+void bust_spinlocks(int yes)
+{
+	spin_lock_init(&timerlist_lock);
+	if (yes) {
+		oops_in_progress = 1;
+#ifdef CONFIG_SMP
+		global_irq_lock = 0;	/* Many serial drivers do __global_cli() */
+#endif
+	} else {
+		int loglevel_save = console_loglevel;
+		unblank_screen();
+		oops_in_progress = 0;
+		/*
+		 * OK, the message is on the console.  Now we call printk()
+		 * without oops_in_progress set so that printk will give klogd
+		 * a poke.  Hold onto your hats...
+		 */
+		console_loglevel = 15;		/* NMI oopser may have shut the console up */
+		printk(" ");
+		console_loglevel = loglevel_save;
+	}
+}
+
+void do_BUG(const char *file, int line)
+{
+	bust_spinlocks(1);
+	printk("kernel BUG at %s:%d!\n", file, line);
+}

Re: 2.4.2-ac18 fix for Alpha machines

[Jeff Garzik]

[-- Attachment #1: Type: text/plain, Size: 1775 bytes --]

Matti Aarnio wrote:
> 
> The linkage of vmlinux fails with lacking code for  bust_spinlocks(),
> thus I cloned the i386 one as is -- which apparently is not really
> processor specific...
> 
> --- arch/alpha/mm/fault.c~      Sun Mar 11 11:49:23 2001
> +++ arch/alpha/mm/fault.c       Sun Mar 11 14:46:39 2001
> @@ -231,3 +231,39 @@
>         }
>  #endif
>  }
> +
> +extern spinlock_t timerlist_lock;
> +
> +/*
> + * Unlock any spinlocks which will prevent us from getting the
> + * message out (timerlist_lock is acquired through the
> + * console unblank code)
> + */
> +void bust_spinlocks(int yes)
> +{
> +       spin_lock_init(&timerlist_lock);
> +       if (yes) {
> +               oops_in_progress = 1;
> +#ifdef CONFIG_SMP
> +               global_irq_lock = 0;    /* Many serial drivers do __global_cli() */

can you say untested-on-smp :)
global_irq_lock is a spinlock.

> +#endif
> +       } else {
> +               int loglevel_save = console_loglevel;
> +               unblank_screen();

need to include vt_kern.h for unblank_screen proto

> +void do_BUG(const char *file, int line)
> +{
> +       bust_spinlocks(1);
> +       printk("kernel BUG at %s:%d!\n", file, line);
> +}

hmm, is this necessary?  The patch I sent to Alan is missing this.

Don't forget to CC Richard Henderson, the Alpha maintainer, on
patches... Attached are the two patches I sent to Alan and Richard
earlier today.  The first is my version of the bust_spinlock fix.  The
second is an unrelated fix which was needed for our build, and may be
helpful to some seeing "get_wchan_stack" warnings or errors.

-- 
Jeff Garzik       | May you have warm words on a cold evening,
Building 1024     | a full mooon on a dark night,
MandrakeSoft      | and a smooth road all the way to your door.

[-- Attachment #2: fault.patch --]
[-- Type: text/plain, Size: 1254 bytes --]

--- linux/arch/alpha/mm/fault.c.orig	Sun Mar 11 22:44:41 2001
+++ linux/arch/alpha/mm/fault.c	Sun Mar 11 22:51:04 2001
@@ -24,9 +24,36 @@
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
 #include <linux/interrupt.h>
+#include <linux/vt_kern.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
+
+extern spinlock_t timerlist_lock;
+void bust_spinlocks(int yes)
+{
+        spin_lock_init(&timerlist_lock);
+        if (yes) {
+                oops_in_progress = 1;
+#ifdef CONFIG_SMP
+		spin_lock_init(&global_irq_lock);    /* Many serial drivers do __global_cli() */
+#endif
+        } else {
+                int loglevel_save = console_loglevel;
+                unblank_screen();
+                oops_in_progress = 0;
+                /*
+                 * OK, the message is on the console.  Now we call printk()
+                 * without oops_in_progress set so that printk will give klogd
+                 * a poke.  Hold onto your hats...
+                 */
+                console_loglevel = 15;          /* NMI oopser may have shut the console up */
+                printk(" ");
+                console_loglevel = loglevel_save;
+        }
+}
+
+
 
 extern void die_if_kernel(char *,struct pt_regs *,long, unsigned long *);
 

[-- Attachment #3: array.patch --]
[-- Type: text/plain, Size: 497 bytes --]

--- linux/fs/proc/array.c.orig	Sun Mar 11 22:42:37 2001
+++ linux/fs/proc/array.c	Sun Mar 11 22:43:26 2001
@@ -271,6 +271,7 @@
 extern int get_wchan_stack(struct task_struct *p, unsigned long *stack, int max);
 inline char *task_stack(struct task_struct *p, char *buffer)
 {
+#ifdef CONFIG_X86
 	unsigned long stack[64];
 	int i;
 	int cnt = get_wchan_stack(p, stack, 64);
@@ -278,6 +279,7 @@
 		buffer += sprintf(buffer, "Stack[%d]: %lx\n",
 				  i, stack[i]);
 	}
+#endif
 	return buffer;
 }