x86/boot/KASLR: Wrap e820 entries walking code into new function process_e820_entries()

The original function process_e820_entry() only takes care of each
e820 entry passed.

And move the E820_TYPE_RAM checking logic into process_e820_entries().

And remove the redundent local variable 'addr' definition in
find_random_phys_addr().

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fanc.fnst@cn.fujitsu.com
Cc: izumi.taku@jp.fujitsu.com
Cc: matt@codeblueprint.co.uk
Cc: thgarnie@google.com
Link: http://lkml.kernel.org/r/1499603862-11516-2-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 91f27ab970ef74347c1915e7ff6ac5f8a8803b8d..1485f48aeda18c03078e25606212b5d8724e3881 100644 (file)
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -488,10 +488,6 @@ static void process_e820_entry(struct boot_e820_entry *entry,
        unsigned long start_orig, end;
        struct boot_e820_entry cur_entry;
 
-       /* Skip non-RAM entries. */
-       if (entry->type != E820_TYPE_RAM)
-               return;
-
        /* On 32-bit, ignore entries entirely above our maximum. */
        if (IS_ENABLED(CONFIG_X86_32) && entry->addr >= KERNEL_IMAGE_SIZE)
                return;
@@ -562,12 +558,29 @@ static void process_e820_entry(struct boot_e820_entry *entry,
        }
 }
 
-static unsigned long find_random_phys_addr(unsigned long minimum,
-                                          unsigned long image_size)
+static void process_e820_entries(unsigned long minimum,
+                                unsigned long image_size)
 {
        int i;
-       unsigned long addr;
+       struct boot_e820_entry *entry;
+
+       /* Verify potential e820 positions, appending to slots list. */
+       for (i = 0; i < boot_params->e820_entries; i++) {
+               entry = &boot_params->e820_table[i];
+               /* Skip non-RAM entries. */
+               if (entry->type != E820_TYPE_RAM)
+                       continue;
+               process_e820_entry(entry, minimum, image_size);
+               if (slot_area_index == MAX_SLOT_AREA) {
+                       debug_putstr("Aborted e820 scan (slot_areas full)!\n");
+                       break;
+               }
+       }
+}
 
+static unsigned long find_random_phys_addr(unsigned long minimum,
+                                          unsigned long image_size)
+{
        /* Check if we had too many memmaps. */
        if (memmap_too_large) {
                debug_putstr("Aborted e820 scan (more than 4 memmap= args)!\n");
@@ -577,16 +590,7 @@ static unsigned long find_random_phys_addr(unsigned long minimum,
        /* Make sure minimum is aligned. */
        minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN);
 
-       /* Verify potential e820 positions, appending to slots list. */
-       for (i = 0; i < boot_params->e820_entries; i++) {
-               process_e820_entry(&boot_params->e820_table[i], minimum,
-                                  image_size);
-               if (slot_area_index == MAX_SLOT_AREA) {
-                       debug_putstr("Aborted e820 scan (slot_areas full)!\n");
-                       break;
-               }
-       }
-
+       process_e820_entries(minimum, image_size);
        return slots_fetch_random();
 }