[PATCH v4 1/4] x86/boot/KASLR: Wrap e820 entries walking code into new function process_e820_entries()

From: Baoquan He
Date: Sun Jul 09 2017 - 08:38:19 EST


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@xxxxxxxxxx>
---
arch/x86/boot/compressed/kaslr.c | 38 +++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 91f27ab970ef..1485f48aeda1 100644
--- 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();
}

--
2.5.5