linux-toradex.git/arch/x86/include/asm/setup.h, branch v4.4.7

x86: kaslr: fix build due to missing ALIGN definition

2015-04-29T19:54:54+00:00

Fengguang's bot reported that 4545c898 ("x86: introduce kaslr_offset()") broke
randconfig build

   In file included from arch/x86/xen/vga.c:5:0:
   arch/x86/include/asm/setup.h: In function 'kaslr_offset':
>> arch/x86/include/asm/setup.h:77:2: error: implicit declaration of function 'ALIGN' [-Werror=implicit-function-declaration]
     return (unsigned long)&_text - __START_KERNEL;
     ^
Fix that by making setup.h self-sufficient by explicitly including
linux/kernel.h, which is needed for ALIGN() (which is what __START_KERNEL
contains in its expansion).

Reported-by: fengguang.wu@intel.com
Signed-off-by: Jiri Kosina

x86: introduce kaslr_offset()

2015-04-29T14:51:33+00:00

Offset that has been chosen for kaslr during kernel decompression can be
easily computed as a difference between _text and __START_KERNEL. We are
already making use of this in dump_kernel_offset() notifier and in
arch_crash_save_vmcoreinfo().

Introduce kaslr_offset() that makes this computation instead of hard-coding
it, so that other kernel code (such as live patching) can make use of it.
Also convert existing users to make use of it.

This patch is equivalent transofrmation without any effects on the resulting
code:

	$ diff -u vmlinux.old.asm vmlinux.new.asm
	--- vmlinux.old.asm     2015-04-28 17:55:19.520983368 +0200
	+++ vmlinux.new.asm     2015-04-28 17:55:24.141206072 +0200
	@@ -1,5 +1,5 @@

	-vmlinux.old:     file format elf64-x86-64
	+vmlinux.new:     file format elf64-x86-64

	Disassembly of section .text:
	$

Acked-by: Borislav Petkov 
Signed-off-by: Jiri Kosina

x86/mm/KASLR: Propagate KASLR status to kernel proper

2015-04-03T13:26:15+00:00

Commit:

  e2b32e678513 ("x86, kaslr: randomize module base load address")

made module base address randomization unconditional and didn't regard
disabled KKASLR due to CONFIG_HIBERNATION and command line option
"nokaslr". For more info see (now reverted) commit:

  f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation")

In order to propagate KASLR status to kernel proper, we need a single bit
in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
top-down allocated bits for bits supposed to be used by the bootloader.

Originally-From: Jiri Kosina 
Suggested-by: H. Peter Anvin 
Signed-off-by: Borislav Petkov 
Cc: Kees Cook 
Signed-off-by: Ingo Molnar

x86, espfix: Move espfix definitions into a separate header file

2014-05-01T21:16:15+00:00

Sparse warns that the percpu variables aren't declared before they are
defined.  Rather than hacking around it, move espfix definitions into
a proper header file.

Reported-by: Fengguang Wu 
Signed-off-by: H. Peter Anvin

x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack

2014-04-30T21:14:28+00:00

The IRET instruction, when returning to a 16-bit segment, only
restores the bottom 16 bits of the user space stack pointer.  This
causes some 16-bit software to break, but it also leaks kernel state
to user space.  We have a software workaround for that ("espfix") for
the 32-bit kernel, but it relies on a nonzero stack segment base which
is not available in 64-bit mode.

In checkin:

    b3b42ac2cbae x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels

we "solved" this by forbidding 16-bit segments on 64-bit kernels, with
the logic that 16-bit support is crippled on 64-bit kernels anyway (no
V86 support), but it turns out that people are doing stuff like
running old Win16 binaries under Wine and expect it to work.

This works around this by creating percpu "ministacks", each of which
is mapped 2^16 times 64K apart.  When we detect that the return SS is
on the LDT, we copy the IRET frame to the ministack and use the
relevant alias to return to userspace.  The ministacks are mapped
readonly, so if IRET faults we promote #GP to #DF which is an IST
vector and thus has its own stack; we then do the fixup in the #DF
handler.

(Making #GP an IST exception would make the msr_safe functions unsafe
in NMI/MC context, and quite possibly have other effects.)

Special thanks to:

- Andy Lutomirski, for the suggestion of using very small stack slots
  and copy (as opposed to map) the IRET frame there, and for the
  suggestion to mark them readonly and let the fault promote to #DF.
- Konrad Wilk for paravirt fixup and testing.
- Borislav Petkov for testing help and useful comments.

Reported-by: Brian Gerst 
Signed-off-by: H. Peter Anvin 
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Cc: Konrad Rzeszutek Wilk 
Cc: Borislav Petkov 
Cc: Andrew Lutomriski 
Cc: Linus Torvalds 
Cc: Dirk Hohndel 
Cc: Arjan van de Ven 
Cc: comex 
Cc: Alexander van Heukelum 
Cc: Boris Ostrovsky 
Cc:  # consider after upstream merge

x86, platforms: Remove SGI Visual Workstation

2014-02-27T16:07:39+00:00

The SGI Visual Workstation seems to be dead; remove support so we
don't have to continue maintaining it.

Cc: Andrey Panin 
Cc: Michael Reed 
Link: http://lkml.kernel.org/r/530CFD6C.7040705@zytor.com
Signed-off-by: H. Peter Anvin

x86, ramdisk: Export relocated ramdisk VA

2014-01-13T18:56:25+00:00

The ramdisk can possibly get relocated if the whole image is not mapped.
And since we're going over it in the microcode loader and fishing out
the relevant microcode patches, we want access it at its new location.
Thus, export it.

Signed-off-by: Borislav Petkov 
Tested-by: Aravind Gopalakrishnan

intel_mid: Renamed mrst to intel_mid

2013-10-17T23:40:47+00:00

mrst is used as common name to represent all intel_mid type
soc's. But moorsetwon is just one of the intel_mid soc. So
renamed them to use intel_mid.

This patch mainly renames the variables and related
functions that uses *mrst* prefix with *intel_mid*.

To ensure that there are no functional changes, I have compared
the objdump of related files before and after rename and found
the only difference is symbol and name changes.

Signed-off-by: Kuppuswamy Sathyanarayanan 
Link: http://lkml.kernel.org/r/1382049336-21316-6-git-send-email-david.a.cohen@linux.intel.com
Signed-off-by: David Cohen 
Signed-off-by: H. Peter Anvin

x86, asmlinkage: Make _*_start_kernel visible

2013-08-06T21:18:26+00:00

Obviously these functions have to be visible, otherwise
the whole kernel could be optimized away.

Signed-off-by: Andi Kleen 
Link: http://lkml.kernel.org/r/1375740170-7446-5-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin

UAPI: (Scripted) Disintegrate arch/x86/include/asm

2012-12-14T22:37:13+00:00

Signed-off-by: David Howells 
Acked-by: Arnd Bergmann 
Acked-by: Thomas Gleixner 
Acked-by: Michael Kerrisk 
Acked-by: Paul E. McKenney 
Acked-by: Dave Jones