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

Pull EFI fixes from Ingo Molnar:
 "Various fixes all over the map: prevent boot crashes on HyperV,
  classify UEFI randomness as bootloader randomness, fix EFI boot for
  the Raspberry Pi2, fix efi_test permissions, etc"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/efi_test: Lock down /dev/efi_test and require CAP_SYS_ADMIN
  x86, efi: Never relocate kernel below lowest acceptable address
  efi: libstub/arm: Account for firmware reserved memory at the base of RAM
  efi/random: Treat EFI_RNG_PROTOCOL output as bootloader randomness
  efi/tpm: Return -EINVAL when determining tpm final events log size fails
  efi: Make CONFIG_EFI_RCI2_TABLE selectable on x86 only

Author: torvalds

arch/x86/boot/compressed/eboot.c

@@ -13,6 +13,7 @@
 #include <asm/e820/types.h>
 #include <asm/setup.h>
 #include <asm/desc.h>
+#include <asm/boot.h>
 
 #include "../string.h"
 #include "eboot.h"
@@ -813,7 +814,8 @@ efi_main(struct efi_config *c, struct boot_params *boot_params)
 		status = efi_relocate_kernel(sys_table, &bzimage_addr,
 					     hdr->init_size, hdr->init_size,
 					     hdr->pref_address,
-					     hdr->kernel_alignment);
+					     hdr->kernel_alignment,
+					     LOAD_PHYSICAL_ADDR);
 		if (status != EFI_SUCCESS) {
 			efi_printk(sys_table, "efi_relocate_kernel() failed!\n");
 			goto fail;

drivers/firmware/efi/Kconfig

@@ -182,6 +182,7 @@ config RESET_ATTACK_MITIGATION
 
 config EFI_RCI2_TABLE
 	bool "EFI Runtime Configuration Interface Table Version 2 Support"
+	depends on X86 || COMPILE_TEST
 	help
 	  Displays the content of the Runtime Configuration Interface
 	  Table version 2 on Dell EMC PowerEdge systems as a binary

drivers/firmware/efi/efi.c

@@ -554,7 +554,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 					      sizeof(*seed) + size);
 			if (seed != NULL) {
 				pr_notice("seeding entropy pool\n");
-				add_device_randomness(seed->bits, seed->size);
+				add_bootloader_randomness(seed->bits, seed->size);
 				early_memunmap(seed, sizeof(*seed) + size);
 			} else {
 				pr_err("Could not map UEFI random seed!\n");

drivers/firmware/efi/libstub/Makefile

@@ -52,6 +52,7 @@ lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o string.o random.o \
 
 lib-$(CONFIG_ARM)		+= arm32-stub.o
 lib-$(CONFIG_ARM64)		+= arm64-stub.o
+CFLAGS_arm32-stub.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
 CFLAGS_arm64-stub.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
 
 #

drivers/firmware/efi/libstub/arm32-stub.c

@@ -195,6 +195,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
 				 unsigned long dram_base,
 				 efi_loaded_image_t *image)
 {
+	unsigned long kernel_base;
 	efi_status_t status;
 
 	/*
@@ -204,9 +205,18 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
 	 * loaded. These assumptions are made by the decompressor,
 	 * before any memory map is available.
 	 */
-	dram_base = round_up(dram_base, SZ_128M);
+	kernel_base = round_up(dram_base, SZ_128M);
 
-	status = reserve_kernel_base(sys_table, dram_base, reserve_addr,
+	/*
+	 * Note that some platforms (notably, the Raspberry Pi 2) put
+	 * spin-tables and other pieces of firmware at the base of RAM,
+	 * abusing the fact that the window of TEXT_OFFSET bytes at the
+	 * base of the kernel image is only partially used at the moment.
+	 * (Up to 5 pages are used for the swapper page tables)
+	 */
+	kernel_base += TEXT_OFFSET - 5 * PAGE_SIZE;
+
+	status = reserve_kernel_base(sys_table, kernel_base, reserve_addr,
 				     reserve_size);
 	if (status != EFI_SUCCESS) {
 		pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n");
@@ -220,7 +230,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
 	*image_size = image->image_size;
 	status = efi_relocate_kernel(sys_table, image_addr, *image_size,
 				     *image_size,
-				     dram_base + MAX_UNCOMP_KERNEL_SIZE, 0);
+				     kernel_base + MAX_UNCOMP_KERNEL_SIZE, 0, 0);
 	if (status != EFI_SUCCESS) {
 		pr_efi_err(sys_table, "Failed to relocate kernel.\n");
 		efi_free(sys_table, *reserve_size, *reserve_addr);

drivers/firmware/efi/libstub/efi-stub-helper.c

@@ -260,11 +260,11 @@ efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
 }
 
 /*
- * Allocate at the lowest possible address.
+ * Allocate at the lowest possible address that is not below 'min'.
  */
-efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
-			   unsigned long size, unsigned long align,
-			   unsigned long *addr)
+efi_status_t efi_low_alloc_above(efi_system_table_t *sys_table_arg,
+				 unsigned long size, unsigned long align,
+				 unsigned long *addr, unsigned long min)
 {
 	unsigned long map_size, desc_size, buff_size;
 	efi_memory_desc_t *map;
@@ -311,13 +311,8 @@ efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
 		start = desc->phys_addr;
 		end = start + desc->num_pages * EFI_PAGE_SIZE;
 
-		/*
-		 * Don't allocate at 0x0. It will confuse code that
-		 * checks pointers against NULL. Skip the first 8
-		 * bytes so we start at a nice even number.
-		 */
-		if (start == 0x0)
-			start += 8;
+		if (start < min)
+			start = min;
 
 		start = round_up(start, align);
 		if ((start + size) > end)
@@ -698,7 +693,8 @@ efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
 				 unsigned long image_size,
 				 unsigned long alloc_size,
 				 unsigned long preferred_addr,
-				 unsigned long alignment)
+				 unsigned long alignment,
+				 unsigned long min_addr)
 {
 	unsigned long cur_image_addr;
 	unsigned long new_addr = 0;
@@ -731,8 +727,8 @@ efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
 	 * possible.
 	 */
 	if (status != EFI_SUCCESS) {
-		status = efi_low_alloc(sys_table_arg, alloc_size, alignment,
-				       &new_addr);
+		status = efi_low_alloc_above(sys_table_arg, alloc_size,
+					     alignment, &new_addr, min_addr);
 	}
 	if (status != EFI_SUCCESS) {
 		pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n");

drivers/firmware/efi/test/efi_test.c

@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 #include <linux/efi.h>
+#include <linux/security.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 
@@ -717,6 +718,13 @@ static long efi_test_ioctl(struct file *file, unsigned int cmd,
 
 static int efi_test_open(struct inode *inode, struct file *file)
 {
+	int ret = security_locked_down(LOCKDOWN_EFI_TEST);
+
+	if (ret)
+		return ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
 	/*
 	 * nothing special to do here
 	 * We do accept multiple open files at the same time as we

drivers/firmware/efi/tpm.c

@@ -88,6 +88,7 @@ int __init efi_tpm_eventlog_init(void)
 
 	if (tbl_size < 0) {
 		pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n");
+		ret = -EINVAL;
 		goto out_calc;
 	}
 

include/linux/efi.h

@@ -1579,9 +1579,22 @@ char *efi_convert_cmdline(efi_system_table_t *sys_table_arg,
 efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
 				struct efi_boot_memmap *map);
 
+efi_status_t efi_low_alloc_above(efi_system_table_t *sys_table_arg,
+				 unsigned long size, unsigned long align,
+				 unsigned long *addr, unsigned long min);
+
+static inline
 efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
 			   unsigned long size, unsigned long align,
-			   unsigned long *addr);
+			   unsigned long *addr)
+{
+	/*
+	 * Don't allocate at 0x0. It will confuse code that
+	 * checks pointers against NULL. Skip the first 8
+	 * bytes so we start at a nice even number.
+	 */
+	return efi_low_alloc_above(sys_table_arg, size, align, addr, 0x8);
+}
 
 efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
 			    unsigned long size, unsigned long align,
@@ -1592,7 +1605,8 @@ efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
 				 unsigned long image_size,
 				 unsigned long alloc_size,
 				 unsigned long preferred_addr,
-				 unsigned long alignment);
+				 unsigned long alignment,
+				 unsigned long min_addr);
 
 efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 				  efi_loaded_image_t *image,

include/linux/security.h

@@ -105,6 +105,7 @@ enum lockdown_reason {
 	LOCKDOWN_NONE,
 	LOCKDOWN_MODULE_SIGNATURE,
 	LOCKDOWN_DEV_MEM,
+	LOCKDOWN_EFI_TEST,
 	LOCKDOWN_KEXEC,
 	LOCKDOWN_HIBERNATION,
 	LOCKDOWN_PCI_ACCESS,

security/lockdown/lockdown.c

@@ -20,6 +20,7 @@ static const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
 	[LOCKDOWN_NONE] = "none",
 	[LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading",
 	[LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port",
+	[LOCKDOWN_EFI_TEST] = "/dev/efi_test access",
 	[LOCKDOWN_KEXEC] = "kexec of unsigned images",
 	[LOCKDOWN_HIBERNATION] = "hibernation",
 	[LOCKDOWN_PCI_ACCESS] = "direct PCI access",