MM: virtual address debug

Add some (configurable) expensive sanity checking to catch wrong address
translations on x86.

- create linux/mmdebug.h file to be able include this file in
  asm headers to not get unsolvable loops in header files
- __phys_addr on x86_32 became a function in ioremap.c since
  PAGE_OFFSET, is_vmalloc_addr and VMALLOC_* non-constasts are undefined
  if declared in page_32.h
- add __phys_addr_const for initializing doublefault_tss.__cr3

Tested on 386, 386pae, x86_64 and x86_64 numa=fake=2.

Contains Andi's enable numa virtual address debug patch.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 25 insertions, 8 deletions

diff --git a/arch/x86/kernel/doublefault_32.c b/arch/x86/kernel/doublefault_32.c
index a47798b59f07..395acb12b0d1 100644
--- a/arch/x86/kernel/doublefault_32.c
+++ b/arch/x86/kernel/doublefault_32.c
@@ -66,6 +66,6 @@ struct tss_struct doublefault_tss __cacheline_aligned = {
                 .ds             = __USER_DS,
                 .fs             = __KERNEL_PERCPU,
 
-                .__cr3          = __pa(swapper_pg_dir)
+                .__cr3          = __phys_addr_const((unsigned long)swapper_pg_dir)
         }
 };
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 2b2bb3f9b683..a78ffef62a2b 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -23,18 +23,26 @@
 
 #ifdef CONFIG_X86_64
 
-unsigned long __phys_addr(unsigned long x)
+static inline int phys_addr_valid(unsigned long addr)
 {
-        if (x >= __START_KERNEL_map)
-                return x - __START_KERNEL_map + phys_base;
-        return x - PAGE_OFFSET;
+        return addr < (1UL << boot_cpu_data.x86_phys_bits);
 }
-EXPORT_SYMBOL(__phys_addr);
 
-static inline int phys_addr_valid(unsigned long addr)
+unsigned long __phys_addr(unsigned long x)
 {
-        return addr < (1UL << boot_cpu_data.x86_phys_bits);
+        if (x >= __START_KERNEL_map) {
+                x -= __START_KERNEL_map;
+                VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
+                x += phys_base;
+        } else {
+                VIRTUAL_BUG_ON(x < PAGE_OFFSET);
+                x -= PAGE_OFFSET;
+                VIRTUAL_BUG_ON(system_state == SYSTEM_BOOTING ? x > MAXMEM :
+                                        !phys_addr_valid(x));
+        }
+        return x;
 }
+EXPORT_SYMBOL(__phys_addr);
 
 #else
 
@@ -43,6 +51,15 @@ static inline int phys_addr_valid(unsigned long addr)
         return 1;
 }
 
+unsigned long __phys_addr(unsigned long x)
+{
+        /* VMALLOC_* aren't constants; not available at the boot time */
+        VIRTUAL_BUG_ON(x < PAGE_OFFSET || (system_state != SYSTEM_BOOTING &&
+                                        is_vmalloc_addr((void *)x)));
+        return x - PAGE_OFFSET;
+}
+EXPORT_SYMBOL(__phys_addr);
+
 #endif
 
 int page_is_ram(unsigned long pagenr)