efi/libstub/x86: Permit cmdline data to be allocated above 4 GB

We now support cmdline data that is located in memory that is not
32-bit addressable, so relax the allocation limit on systems where
this feature is enabled.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch/x86/include/asm/efi.h

@@ -34,8 +34,6 @@ static inline bool efi_have_uv1_memmap(void)
 #define EFI32_LOADER_SIGNATURE	"EL32"
 #define EFI64_LOADER_SIGNATURE	"EL64"
 
-#define MAX_CMDLINE_ADDRESS	UINT_MAX
-
 #define ARCH_EFI_IRQ_FLAGS_MASK	X86_EFLAGS_IF
 
 /*

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

@@ -169,7 +169,7 @@ efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
 	 * protocol. We are going to copy the command line into the
 	 * device tree, so this can be allocated anywhere.
 	 */
-	cmdline_ptr = efi_convert_cmdline(image, &cmdline_size);
+	cmdline_ptr = efi_convert_cmdline(image, &cmdline_size, ULONG_MAX);
 	if (!cmdline_ptr) {
 		pr_efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
 		status = EFI_OUT_OF_RESOURCES;

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

@@ -497,17 +497,13 @@ static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n)
 	return dst;
 }
 
-#ifndef MAX_CMDLINE_ADDRESS
-#define MAX_CMDLINE_ADDRESS	ULONG_MAX
-#endif
-
 /*
  * Convert the unicode UEFI command line to ASCII to pass to kernel.
  * Size of memory allocated return in *cmd_line_len.
  * Returns NULL on error.
  */
 char *efi_convert_cmdline(efi_loaded_image_t *image,
-			  int *cmd_line_len)
+			  int *cmd_line_len, unsigned long max_addr)
 {
 	const u16 *s2;
 	u8 *s1 = NULL;
@@ -535,8 +531,7 @@ char *efi_convert_cmdline(efi_loaded_image_t *image,
 
 	options_bytes++;	/* NUL termination */
 
-	status = efi_allocate_pages(options_bytes, &cmdline_addr,
-				MAX_CMDLINE_ADDRESS);
+	status = efi_allocate_pages(options_bytes, &cmdline_addr, max_addr);
 	if (status != EFI_SUCCESS)
 		return NULL;
 

drivers/firmware/efi/libstub/efistub.h

@@ -578,7 +578,8 @@ void efi_printk(char *str);
 
 void efi_free(unsigned long size, unsigned long addr);
 
-char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len);
+char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len,
+			  unsigned long max_addr);
 
 efi_status_t efi_get_memory_map(struct efi_boot_memmap *map);
 

drivers/firmware/efi/libstub/x86-stub.c

@@ -405,7 +405,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	hdr->type_of_loader = 0x21;
 
 	/* Convert unicode cmdline to ascii */
-	cmdline_ptr = efi_convert_cmdline(image, &options_size);
+	cmdline_ptr = efi_convert_cmdline(image, &options_size,
+					  above4g ? ULONG_MAX : UINT_MAX);
 	if (!cmdline_ptr)
 		goto fail;
 
@@ -445,7 +446,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	/* not reached */
 
 fail2:
-	efi_free(options_size, hdr->cmd_line_ptr);
+	efi_free(options_size, (unsigned long)cmdline_ptr);
 fail:
 	efi_free(0x4000, (unsigned long)boot_params);