Jan Beulich
2007-Apr-04 15:49 UTC
[Xen-devel] [PATCH] linux/x86: fix amd64-agp aperture validation
Under Xen, pfn_valid() on a machine address makes no sense. But even on
native, under CONFIG_DISCONTIGMEM, assuming that a !pfn_valid() implies
all subsequent pfn-s are also invalid is wrong. Thus replace this by
explicitly checking against the E820 map.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Index: sle10sp1-2007-03-28/arch/i386/kernel/setup-xen.c
==================================================================---
sle10sp1-2007-03-28.orig/arch/i386/kernel/setup-xen.c 2007-04-04
17:07:13.000000000 +0200
+++ sle10sp1-2007-03-28/arch/i386/kernel/setup-xen.c 2007-04-04
16:45:36.000000000 +0200
@@ -1022,6 +1022,35 @@ efi_memory_present_wrapper(unsigned long
return 0;
}
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int
+e820_any_mapped(u64 start, u64 end, unsigned type)
+{
+ int i;
+
+#ifndef CONFIG_XEN
+ for (i = 0; i < e820.nr_map; i++) {
+ const struct e820entry *ei = &e820.map[i];
+#else
+ if (!is_initial_xendomain())
+ return 0;
+ for (i = 0; i < machine_e820.nr_map; ++i) {
+ const struct e820entry *ei = &machine_e820.map[i];
+#endif
+
+ if (type && ei->type != type)
+ continue;
+ if (ei->addr >= end || ei->addr + ei->size <= start)
+ continue;
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(e820_any_mapped);
+
/*
* This function checks if the entire range <start,end> is mapped with
type.
*
Index: sle10sp1-2007-03-28/arch/x86_64/kernel/e820-xen.c
==================================================================---
sle10sp1-2007-03-28.orig/arch/x86_64/kernel/e820-xen.c 2007-04-04
17:07:13.000000000 +0200
+++ sle10sp1-2007-03-28/arch/x86_64/kernel/e820-xen.c 2007-04-04
17:07:28.000000000 +0200
@@ -97,17 +97,27 @@ static inline int bad_addr(unsigned long
return 0;
}
-#ifndef CONFIG_XEN
/*
* This function checks if any part of the range <start,end> is mapped
* with type.
*/
-int __meminit
+int
e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
{
int i;
+
+#ifndef CONFIG_XEN
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
+#else
+ extern struct e820map machine_e820;
+
+ if (!is_initial_xendomain())
+ return 0;
+ for (i = 0; i < machine_e820.nr_map; i++) {
+ const struct e820entry *ei = &machine_e820.map[i];
+#endif
+
if (type && ei->type != type)
continue;
if (ei->addr >= end || ei->addr + ei->size <= start)
@@ -116,7 +126,7 @@ int __meminit e820_any_mapped(unsigned l
}
return 0;
}
-#endif
+EXPORT_SYMBOL_GPL(e820_any_mapped);
/*
* This function checks if the entire range <start,end> is mapped with
type.
Index: sle10sp1-2007-03-28/drivers/char/agp/amd64-agp.c
==================================================================---
sle10sp1-2007-03-28.orig/drivers/char/agp/amd64-agp.c 2007-04-04
17:07:13.000000000 +0200
+++ sle10sp1-2007-03-28/drivers/char/agp/amd64-agp.c 2007-04-04
16:45:36.000000000 +0200
@@ -14,6 +14,7 @@
#include <linux/agp_backend.h>
#include <linux/mmzone.h>
#include <asm/page.h> /* PAGE_SIZE */
+#include <asm/e820.h>
#include <asm/k8.h>
#include "agp.h"
@@ -252,7 +253,9 @@ static struct agp_bridge_driver amd_8151
/* Some basic sanity checks for the aperture. */
static int __devinit aperture_valid(u64 aper, u32 size)
{
+#ifndef CONFIG_XEN
u32 pfn, c;
+#endif
if (aper == 0) {
printk(KERN_ERR PFX "No aperture\n");
return 0;
@@ -265,6 +268,7 @@ static int __devinit aperture_valid(u64
printk(KERN_ERR PFX "Aperture out of bounds\n");
return 0;
}
+#ifndef CONFIG_XEN
pfn = aper >> PAGE_SHIFT;
for (c = 0; c < size/PAGE_SIZE; c++) {
if (!pfn_valid(pfn + c))
@@ -273,6 +277,11 @@ static int __devinit aperture_valid(u64
printk(KERN_ERR PFX "Aperture pointing to RAM\n");
return 0;
}
+#else
+ if (e820_any_mapped(aper, aper + size, E820_RAM)) {
+ printk(KERN_ERR PFX "Aperture pointing to RAM\n");
+ return 0;
+#endif
}
/* Request the Aperture. This catches cases when someone else
Index: sle10sp1-2007-03-28/include/asm-i386/e820.h
==================================================================---
sle10sp1-2007-03-28.orig/include/asm-i386/e820.h 2007-04-04 17:07:13.000000000
+0200
+++ sle10sp1-2007-03-28/include/asm-i386/e820.h 2007-04-04 16:45:36.000000000
+0200
@@ -38,6 +38,7 @@ extern struct e820map e820;
extern int e820_all_mapped(unsigned long start, unsigned long end,
unsigned type);
+extern int e820_any_mapped(u64 start, u64 end, unsigned type);
#endif/*!__ASSEMBLY__*/
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