x86: check physical address range in ioremap
Roland Dreier reported in http://lkml.org/lkml/2008/2/27/194
[ 8425.915139] BUG: unable to handle kernel paging request at ffffc20001a0a000
[ 8425.919087] IP: [<ffffffff8021dacc>] clflush_cache_range+0xc/0x25
[ 8425.919087] PGD 1bf80e067 PUD 1bf80f067 PMD 1bb497067 PTE 80000047000ee17b
This is on a Intel machine with 36bit physical address space. The PTE
entry references 47000ee000, which is outside of it.
Add a check for the physical address space and warn/printk about the
stupid caller.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 868bbde..17f5188 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -35,6 +35,18 @@
}
EXPORT_SYMBOL(__phys_addr);
+static inline int phys_addr_valid(unsigned long addr)
+{
+ return addr < (1UL << boot_cpu_data.x86_phys_bits);
+}
+
+#else
+
+static inline int phys_addr_valid(unsigned long addr)
+{
+ return 1;
+}
+
#endif
int page_is_ram(unsigned long pagenr)
@@ -118,6 +130,13 @@
if (!size || last_addr < phys_addr)
return NULL;
+ if (!phys_addr_valid(phys_addr)) {
+ printk(KERN_WARNING "ioremap: invalid physical address %lx\n",
+ phys_addr);
+ WARN_ON_ONCE(1);
+ return NULL;
+ }
+
/*
* Don't remap the low PCI/ISA area, it's always mapped..
*/