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Diffstat (limited to 'arch/x86/mm/physaddr.c')
-rw-r--r--arch/x86/mm/physaddr.c60
1 files changed, 44 insertions, 16 deletions
diff --git a/arch/x86/mm/physaddr.c b/arch/x86/mm/physaddr.c
index d2e2735327b4..e666cbbb9261 100644
--- a/arch/x86/mm/physaddr.c
+++ b/arch/x86/mm/physaddr.c
@@ -1,3 +1,4 @@
+#include <linux/bootmem.h>
#include <linux/mmdebug.h>
#include <linux/module.h>
#include <linux/mm.h>
@@ -8,33 +9,54 @@
#ifdef CONFIG_X86_64
+#ifdef CONFIG_DEBUG_VIRTUAL
unsigned long __phys_addr(unsigned long x)
{
- if (x >= __START_KERNEL_map) {
- x -= __START_KERNEL_map;
- VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
- x += phys_base;
+ unsigned long y = x - __START_KERNEL_map;
+
+ /* use the carry flag to determine if x was < __START_KERNEL_map */
+ if (unlikely(x > y)) {
+ x = y + phys_base;
+
+ VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
} else {
- VIRTUAL_BUG_ON(x < PAGE_OFFSET);
- x -= PAGE_OFFSET;
- VIRTUAL_BUG_ON(!phys_addr_valid(x));
+ x = y + (__START_KERNEL_map - PAGE_OFFSET);
+
+ /* carry flag will be set if starting x was >= PAGE_OFFSET */
+ VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
}
+
return x;
}
EXPORT_SYMBOL(__phys_addr);
+unsigned long __phys_addr_symbol(unsigned long x)
+{
+ unsigned long y = x - __START_KERNEL_map;
+
+ /* only check upper bounds since lower bounds will trigger carry */
+ VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
+
+ return y + phys_base;
+}
+EXPORT_SYMBOL(__phys_addr_symbol);
+#endif
+
bool __virt_addr_valid(unsigned long x)
{
- if (x >= __START_KERNEL_map) {
- x -= __START_KERNEL_map;
- if (x >= KERNEL_IMAGE_SIZE)
+ unsigned long y = x - __START_KERNEL_map;
+
+ /* use the carry flag to determine if x was < __START_KERNEL_map */
+ if (unlikely(x > y)) {
+ x = y + phys_base;
+
+ if (y >= KERNEL_IMAGE_SIZE)
return false;
- x += phys_base;
} else {
- if (x < PAGE_OFFSET)
- return false;
- x -= PAGE_OFFSET;
- if (!phys_addr_valid(x))
+ x = y + (__START_KERNEL_map - PAGE_OFFSET);
+
+ /* carry flag will be set if starting x was >= PAGE_OFFSET */
+ if ((x > y) || !phys_addr_valid(x))
return false;
}
@@ -47,10 +69,16 @@ EXPORT_SYMBOL(__virt_addr_valid);
#ifdef CONFIG_DEBUG_VIRTUAL
unsigned long __phys_addr(unsigned long x)
{
+ unsigned long phys_addr = x - PAGE_OFFSET;
/* VMALLOC_* aren't constants */
VIRTUAL_BUG_ON(x < PAGE_OFFSET);
VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
- return x - PAGE_OFFSET;
+ /* max_low_pfn is set early, but not _that_ early */
+ if (max_low_pfn) {
+ VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
+ BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
+ }
+ return phys_addr;
}
EXPORT_SYMBOL(__phys_addr);
#endif