PATCH mm/slab.c against 2.5.15 (was: slab cache broken on sparc64

[Holzrichter, Bruce]

> 
> Do it like this instead.
> 
> 	int fault;
> 	mm_segment_t old_fs;
> 
> 	...
> 
> 	old_fs = get_fs();
> 	set_fs(KERNEL_DS);
> 	fault = __get_user(tmp, pc->name);
> 	set_fs(old_fs);
> 
> 	if (fault) {
> 	...
> 

Dave/Andi 

I've redone my patch against mm/slab.c for 2.5.15, although I can't test on
my Sparc ad I don't have a working kernel 2.5.15 yet for other reasons, but
it does compile.  I have tested against 2.5.13 with this, and it works fine,
with your changes, mentioned above, so there's no reason it shouldn't.

This will make sure the __get_user is called correctly.

Thanks,
Bruce H.

--- linus-2.5/mm/slab.c	Wed May  8 15:51:33 2002
+++ sparctest/mm/slab.c	Wed May  8 15:43:04 2002
@@ -843,10 +843,19 @@
 		list_for_each(p, &cache_chain) {
 			kmem_cache_t *pc = list_entry(p, kmem_cache_t,
next);
 			char tmp;
+			int fault;
+			mm_segment_t old_fs;
+
 			/* This happens when the module gets unloaded and
doesn't
 			   destroy its slab cache and noone else reuses the
vmalloc
 			   area of the module. Print a warning. */
-			if (__get_user(tmp,pc->name)) { 
+
+			old_fs = get_fs();
+			set_fs(KERNEL_DS);
+			fault = __get_user(tmp, pc->name);
+			set_fs(old_fs);
+
+			if (fault) { 
 				printk("SLAB: cache with size %d has lost
its name\n", 
 					pc->objsize); 
 				continue; 
@@ -1912,13 +1921,16 @@
 static int s_show(struct seq_file *m, void *p)
 {
 	kmem_cache_t *cachep = p;
+	mm_segment_t old_fs;
 	struct list_head *q;
 	slab_t		*slabp;
 	unsigned long	active_objs;
 	unsigned long	num_objs;
 	unsigned long	active_slabs = 0;
 	unsigned long	num_slabs;
-	const char *name; 
+	const char *name;
+	char tmp;
+	int fault; 
 
 	if (p == (void*)1) {
 		/*
@@ -1963,11 +1975,13 @@
 	num_objs = num_slabs*cachep->num;
 
 	name = cachep->name; 
-	{
-	char tmp; 
-	if (__get_user(tmp, name)) 
-		name = "broken"; 
-	} 	
+
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+	fault = __get_user(tmp, name);
+	set_fs(old_fs);
+
+	if (fault) name = "broken";
 
 	seq_printf(m, "%-17s %6lu %6lu %6u %4lu %4lu %4u",
 		name, active_objs, num_objs, cachep->objsize,