x86/efistub: Give up if memory attribute protocol returns an error

[platform/kernel/linux-rpi.git] / drivers / firmware / efi / libstub / x86-stub.c

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 9d5df68..5d0934a 100644 (file)
--- 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);
 }
 
 /*
@@ -799,11 +808,25 @@ 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;
+               }
        }
 
        status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
@@ -820,9 +843,7 @@ 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,