| From 53aab43adbe82706ac06595dfde6da9af94eb5e9 Mon Sep 17 00:00:00 2001 |
| From: Jari Ruusu <jari.ruusu@gmail.com> |
| Date: Sun, 12 Jan 2020 15:00:53 +0200 |
| Subject: [PATCH] Fix built-in early-load Intel microcode alignment |
| |
| commit f5ae2ea6347a308cfe91f53b53682ce635497d0d upstream. |
| |
| Intel Software Developer's Manual, volume 3, chapter 9.11.6 says: |
| |
| "Note that the microcode update must be aligned on a 16-byte boundary |
| and the size of the microcode update must be 1-KByte granular" |
| |
| When early-load Intel microcode is loaded from initramfs, userspace tool |
| 'iucode_tool' has already 16-byte aligned those microcode bits in that |
| initramfs image. Image that was created something like this: |
| |
| iucode_tool --write-earlyfw=FOO.cpio microcode-files... |
| |
| However, when early-load Intel microcode is loaded from built-in |
| firmware BLOB using CONFIG_EXTRA_FIRMWARE= kernel config option, that |
| 16-byte alignment is not guaranteed. |
| |
| Fix this by forcing all built-in firmware BLOBs to 16-byte alignment. |
| |
| [ If we end up having other firmware with much bigger alignment |
| requirements, we might need to introduce some method for the firmware |
| to specify it, this is the minimal "just increase the alignment a bit |
| to account for this one special case" patch - Linus ] |
| |
| Signed-off-by: Jari Ruusu <jari.ruusu@gmail.com> |
| Cc: Borislav Petkov <bp@alien8.de> |
| Cc: Fenghua Yu <fenghua.yu@intel.com> |
| Cc: Luis Chamberlain <mcgrof@kernel.org> |
| Cc: stable@kernel.org |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/base/firmware_loader/builtin/Makefile b/drivers/base/firmware_loader/builtin/Makefile |
| index 4a66888e7253..5fa7ce3745a0 100644 |
| --- a/drivers/base/firmware_loader/builtin/Makefile |
| +++ b/drivers/base/firmware_loader/builtin/Makefile |
| @@ -17,7 +17,7 @@ PROGBITS = $(if $(CONFIG_ARM),%,@)progbits |
| filechk_fwbin = \ |
| echo "/* Generated by $(src)/Makefile */" ;\ |
| echo " .section .rodata" ;\ |
| - echo " .p2align $(ASM_ALIGN)" ;\ |
| + echo " .p2align 4" ;\ |
| echo "_fw_$(FWSTR)_bin:" ;\ |
| echo " .incbin \"$(fwdir)/$(FWNAME)\"" ;\ |
| echo "_fw_end:" ;\ |
| -- |
| 2.7.4 |
| |
