x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data
efi_mem_reserve() allows us to permanently mark EFI boot services
regions as reserved, which means we no longer need to copy the image
data out and into a separate buffer.
Leaving the data in the original boot services region has the added
benefit that BGRT images can now be passed across kexec reboot.
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Môshe van der Sterre <me@moshe.nl>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c
index 6a2f569..6aad870 100644
--- a/arch/x86/platform/efi/efi-bgrt.c
+++ b/arch/x86/platform/efi/efi-bgrt.c
@@ -82,21 +82,12 @@
}
bgrt_image_size = bmp_header.size;
- bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL | __GFP_NOWARN);
+ bgrt_image = memremap(bgrt_tab->image_address, bmp_header.size, MEMREMAP_WB);
if (!bgrt_image) {
- pr_notice("Ignoring BGRT: failed to allocate memory for image (wanted %zu bytes)\n",
- bgrt_image_size);
- return;
- }
-
- image = memremap(bgrt_tab->image_address, bmp_header.size, MEMREMAP_WB);
- if (!image) {
pr_notice("Ignoring BGRT: failed to map image memory\n");
- kfree(bgrt_image);
bgrt_image = NULL;
return;
}
- memcpy(bgrt_image, image, bgrt_image_size);
- memunmap(image);
+ efi_mem_reserve(bgrt_tab->image_address, bgrt_image_size);
}