[S390] Make vmalloc area start at address > 4GB.
Prevent that modules get loaded at addresses below 4GB to
prevent exchanging system call table entries.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h
index 3208dc6..39bb519 100644
--- a/include/asm-s390/pgtable.h
+++ b/include/asm-s390/pgtable.h
@@ -107,11 +107,18 @@
* any out-of-bounds memory accesses will hopefully be caught.
* The vmalloc() routines leaves a hole of 4kB between each vmalloced
* area for the same reason. ;)
+ * vmalloc area starts at 4GB to prevent syscall table entry exchanging
+ * from modules.
*/
extern unsigned long vmalloc_end;
-#define VMALLOC_OFFSET (8*1024*1024)
-#define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) \
- & ~(VMALLOC_OFFSET-1))
+
+#ifdef CONFIG_64BIT
+#define VMALLOC_ADDR (max(0x100000000UL, (unsigned long) high_memory))
+#else
+#define VMALLOC_ADDR ((unsigned long) high_memory)
+#endif
+#define VMALLOC_OFFSET (8*1024*1024)
+#define VMALLOC_START ((VMALLOC_ADDR + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
#define VMALLOC_END vmalloc_end
/*