1 files changed, 41 insertions, 17 deletions

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 1bfdae34df39..99429bc4b0c7 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -223,8 +223,8 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
 	}
 }
 
-void efi_adjust_memory_range_protection(unsigned long start,
-					unsigned long size)
+efi_status_t efi_adjust_memory_range_protection(unsigned long start,
+						unsigned long size)
 {
 	efi_status_t status;
 	efi_gcd_memory_space_desc_t desc;
@@ -236,13 +236,17 @@ void efi_adjust_memory_range_protection(unsigned long start,
 	rounded_end = roundup(start + size, EFI_PAGE_SIZE);
 
 	if (memattr != NULL) {
-		efi_call_proto(memattr, clear_memory_attributes, rounded_start,
-			       rounded_end - rounded_start, EFI_MEMORY_XP);
-		return;
+		status = efi_call_proto(memattr, clear_memory_attributes,
+					rounded_start,
+					rounded_end - rounded_start,
+					EFI_MEMORY_XP);
+		if (status != EFI_SUCCESS)
+			efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
+		return status;
 	}
 
 	if (efi_dxe_table == NULL)
-		return;
+		return EFI_SUCCESS;
 
 	/*
 	 * Don't modify memory region attributes, they are
@@ -255,7 +259,7 @@ void efi_adjust_memory_range_protection(unsigned long start,
 		status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
 
 		if (status != EFI_SUCCESS)
-			return;
+			break;
 
 		next = desc.base_address + desc.length;
 
@@ -280,8 +284,10 @@ void efi_adjust_memory_range_protection(unsigned long start,
 				 unprotect_start,
 				 unprotect_start + unprotect_size,
 				 status);
+			break;
 		}
 	}
+	return EFI_SUCCESS;
 }
 
 static void setup_unaccepted_memory(void)
@@ -307,17 +313,20 @@ static void setup_unaccepted_memory(void)
 		efi_err("Memory acceptance protocol failed\n");
 }
 
+static efi_char16_t *efistub_fw_vendor(void)
+{
+	unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
+
+	return (efi_char16_t *)vendor;
+}
+
 static const efi_char16_t apple[] = L"Apple";
 
 static void setup_quirks(struct boot_params *boot_params)
 {
-	efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
-		efi_table_attr(efi_system_table, fw_vendor);
-
-	if (!memcmp(fw_vendor, apple, sizeof(apple))) {
-		if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
-			retrieve_apple_device_properties(boot_params);
-	}
+	if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
+	    !memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
+		retrieve_apple_device_properties(boot_params);
 }
 
 /*
@@ -765,15 +774,32 @@ static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
 
 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
 		u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
+		static const efi_char16_t ami[] = L"American Megatrends";
 
 		efi_get_seed(seed, sizeof(seed));
 
 		virt_addr += (range * seed[1]) >> 32;
 		virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
+
+		/*
+		 * Older Dell systems with AMI UEFI firmware v2.0 may hang
+		 * while decompressing the kernel if physical address
+		 * randomization is enabled.
+		 *
+		 * https://bugzilla.kernel.org/show_bug.cgi?id=218173
+		 */
+		if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
+		    !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
+			efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
+			seed[0] = 0;
+		}
+
+		boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
 	}
 
 	status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
 				  seed[0], EFI_LOADER_CODE,
+				  LOAD_PHYSICAL_ADDR,
 				  EFI_X86_KERNEL_ALLOC_LIMIT);
 	if (status != EFI_SUCCESS)
 		return status;
@@ -786,9 +812,7 @@ static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
 
 	*kernel_entry = addr + entry;
 
-	efi_adjust_memory_range_protection(addr, kernel_total_size);
-
-	return EFI_SUCCESS;
+	return efi_adjust_memory_range_protection(addr, kernel_total_size);
 }
 
 static void __noreturn enter_kernel(unsigned long kernel_addr,