efi/libstub/x86: Use ULONG_MAX as upper bound for all allocations

The header flag XLF_CAN_BE_LOADED_ABOVE_4G will inform us whether
allocations above 4 GiB for kernel, command line, etc are permitted,
so we take it into account when calling efi_allocate_pages() etc.

However, CONFIG_EFI_STUB implies CONFIG_RELOCATABLE, and so the flag
is guaranteed to be set on x86_64 builds, whereas i386 builds are
guaranteed to run under firmware that will not allocate above 4 GB
in the first place.

So drop the check, and just pass ULONG_MAX as the upper bound for
all allocations.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303225054.28741-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-27-ardb@kernel.org

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 4615d29dd66510022454048a60de7d66b9d72bf2..383f59d44fbea8d5ba3cf746d0d27a30ecf50028 100644 (file)
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -376,7 +376,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
        char *cmdline_ptr;
        unsigned long ramdisk_addr;
        unsigned long ramdisk_size;
-       bool above4g;
 
        sys_table = sys_table_arg;
 
@@ -394,10 +393,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
        image_offset = (void *)startup_32 - image_base;
 
        hdr = &((struct boot_params *)image_base)->hdr;
-       above4g = hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G;
 
-       status = efi_allocate_pages(0x4000, (unsigned long *)&boot_params,
-                                   above4g ? ULONG_MAX : UINT_MAX);
+       status = efi_allocate_pages(0x4000, (unsigned long *)&boot_params, ULONG_MAX);
        if (status != EFI_SUCCESS) {
                efi_printk("Failed to allocate lowmem for boot params\n");
                efi_exit(handle, status);
@@ -421,8 +418,7 @@ 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,
-                                         above4g ? ULONG_MAX : UINT_MAX);
+       cmdline_ptr = efi_convert_cmdline(image, &options_size, ULONG_MAX);
        if (!cmdline_ptr)
                goto fail;
 
@@ -442,8 +438,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
                        status = efi_load_initrd(image, &ramdisk_addr,
                                                 &ramdisk_size,
                                                 hdr->initrd_addr_max,
-                                                above4g ? ULONG_MAX
-                                                        : hdr->initrd_addr_max);
+                                                ULONG_MAX);
                        if (status != EFI_SUCCESS)
                                goto fail2;
                        hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
@@ -795,12 +790,8 @@ unsigned long efi_main(efi_handle_t handle,
         */
        if (!noinitrd()) {
                unsigned long addr, size;
-               unsigned long max_addr = hdr->initrd_addr_max;
 
-               if (hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)
-                       max_addr = ULONG_MAX;
-
-               status = efi_load_initrd_dev_path(&addr, &size, max_addr);
+               status = efi_load_initrd_dev_path(&addr, &size, ULONG_MAX);
                if (status == EFI_SUCCESS) {
                        hdr->ramdisk_image              = (u32)addr;
                        hdr->ramdisk_size               = (u32)size;