| From: Jari Ruusu <jari.ruusu@gmail.com> |
| Date: Sun, 12 Jan 2020 15:00:53 +0200 |
| Subject: 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> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| [bwh: Backported to 3.16: adjust filename, context, indentation] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| firmware/Makefile | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/firmware/Makefile |
| +++ b/firmware/Makefile |
| @@ -156,7 +156,7 @@ quiet_cmd_fwbin = MK_FW $@ |
| PROGBITS=$(if $(CONFIG_ARM),%,@)progbits; \ |
| echo "/* Generated by firmware/Makefile */" > $@;\ |
| echo " .section .rodata" >>$@;\ |
| - echo " .p2align $${ASM_ALIGN}" >>$@;\ |
| + echo " .p2align 4" >>$@;\ |
| echo "_fw_$${FWSTR}_bin:" >>$@;\ |
| echo " .incbin \"$(2)\"" >>$@;\ |
| echo "_fw_end:" >>$@;\ |
