Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes from Ingo Molnar:
 "This contains:

   - EFI fixes
   - a boot printout fix
   - ASLR/kASLR fixes
   - intel microcode driver fixes
   - other misc fixes

  Most of the linecount comes from an EFI revert"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch
  x86/microcode/intel: Handle truncated microcode images more robustly
  x86/microcode/intel: Guard against stack overflow in the loader
  x86, mm/ASLR: Fix stack randomization on 64-bit systems
  x86/mm/init: Fix incorrect page size in init_memory_mapping() printks
  x86/mm/ASLR: Propagate base load address calculation
  Documentation/x86: Fix path in zero-page.txt
  x86/apic: Fix the devicetree build in certain configs
  Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes"
  x86/efi: Avoid triple faults during EFI mixed mode calls

4 files changed, 29 insertions, 14 deletions

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index c6826d1e8082..746e7fd08aad 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -196,6 +196,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
 		struct microcode_header_intel mc_header;
 		unsigned int mc_size;
 
+		if (leftover < sizeof(mc_header)) {
+			pr_err("error! Truncated header in microcode data file\n");
+			break;
+		}
+
 		if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header)))
 			break;
 
diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c
index ec9df6f9cd47..420eb933189c 100644
--- a/arch/x86/kernel/cpu/microcode/intel_early.c
+++ b/arch/x86/kernel/cpu/microcode/intel_early.c
@@ -321,7 +321,11 @@ get_matching_model_microcode(int cpu, unsigned long start,
 	unsigned int mc_saved_count = mc_saved_data->mc_saved_count;
 	int i;
 
-	while (leftover) {
+	while (leftover && mc_saved_count < ARRAY_SIZE(mc_saved_tmp)) {
+
+		if (leftover < sizeof(mc_header))
+			break;
+
 		mc_header = (struct microcode_header_intel *)ucode_ptr;
 
 		mc_size = get_totalsize(mc_header);
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index d1ac80b72c72..9bbb9b35c144 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -47,21 +47,13 @@ do {							\
 
 #ifdef CONFIG_RANDOMIZE_BASE
 static unsigned long module_load_offset;
-static int randomize_modules = 1;
 
 /* Mutex protects the module_load_offset. */
 static DEFINE_MUTEX(module_kaslr_mutex);
 
-static int __init parse_nokaslr(char *p)
-{
-	randomize_modules = 0;
-	return 0;
-}
-early_param("nokaslr", parse_nokaslr);
-
 static unsigned long int get_module_load_offset(void)
 {
-	if (randomize_modules) {
+	if (kaslr_enabled) {
 		mutex_lock(&module_kaslr_mutex);
 		/*
 		 * Calculate the module_load_offset the first time this
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0a2421cca01f..98dc9317286e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -122,6 +122,8 @@
 unsigned long max_low_pfn_mapped;
 unsigned long max_pfn_mapped;
 
+bool __read_mostly kaslr_enabled = false;
+
 #ifdef CONFIG_DMI
 RESERVE_BRK(dmi_alloc, 65536);
 #endif
@@ -425,6 +427,11 @@ static void __init reserve_initrd(void)
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
 
+static void __init parse_kaslr_setup(u64 pa_data, u32 data_len)
+{
+	kaslr_enabled = (bool)(pa_data + sizeof(struct setup_data));
+}
+
 static void __init parse_setup_data(void)
 {
 	struct setup_data *data;
@@ -450,6 +457,9 @@ static void __init parse_setup_data(void)
 		case SETUP_EFI:
 			parse_efi_setup(pa_data, data_len);
 			break;
+		case SETUP_KASLR:
+			parse_kaslr_setup(pa_data, data_len);
+			break;
 		default:
 			break;
 		}
@@ -832,10 +842,14 @@ static void __init trim_low_memory_range(void)
 static int
 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
 {
-	pr_emerg("Kernel Offset: 0x%lx from 0x%lx "
-		 "(relocation range: 0x%lx-0x%lx)\n",
-		 (unsigned long)&_text - __START_KERNEL, __START_KERNEL,
-		 __START_KERNEL_map, MODULES_VADDR-1);
+	if (kaslr_enabled)
+		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
+			 (unsigned long)&_text - __START_KERNEL,
+			 __START_KERNEL,
+			 __START_KERNEL_map,
+			 MODULES_VADDR-1);
+	else
+		pr_emerg("Kernel Offset: disabled\n");
 
 	return 0;
 }