linux.git/arch/x86/kernel/Makefile, branch v5.6

x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y

2019-12-23T11:58:41+00:00

On x86 kernels configured with CONFIG_PROC_KCORE=y and
CONFIG_KEXEC_CORE=n, the vmcoreinfo note in /proc/kcore is incomplete.

Specifically, it is missing arch-specific information like the KASLR
offset and whether 5-level page tables are enabled. This breaks
applications like drgn [1] and crash [2], which need this information
for live debugging via /proc/kcore.

This happens because:

1. CONFIG_PROC_KCORE selects CONFIG_CRASH_CORE.
2. kernel/crash_core.c (compiled if CONFIG_CRASH_CORE=y) calls
   arch_crash_save_vmcoreinfo() to get the arch-specific parts of
   vmcoreinfo. If it is not defined, then it uses a no-op fallback.
3. x86 defines arch_crash_save_vmcoreinfo() in
   arch/x86/kernel/machine_kexec_*.c, which is only compiled if
   CONFIG_KEXEC_CORE=y.

Therefore, an x86 kernel with CONFIG_CRASH_CORE=y and
CONFIG_KEXEC_CORE=n uses the no-op fallback and gets incomplete
vmcoreinfo data. This isn't relevant to kdump, which requires
CONFIG_KEXEC_CORE. It only affects applications which read vmcoreinfo at
runtime, like the ones mentioned above.

Fix it by moving arch_crash_save_vmcoreinfo() into two new
arch/x86/kernel/crash_core_*.c files, which are gated behind
CONFIG_CRASH_CORE.

1: https://github.com/osandov/drgn/blob/73dd7def1217e24cc83d8ca95c995decbd9ba24c/libdrgn/program.c#L385
2: https://github.com/crash-utility/crash/commit/60a42d709280cdf38ab06327a5b4fa9d9208ef86

Signed-off-by: Omar Sandoval 
Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Greg Kroah-Hartman 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Kairui Song 
Cc: Lianbo Jiang 
Cc: Masahiro Yamada 
Cc: "Peter Zijlstra (Intel)" 
Cc: Thomas Gleixner 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/0589961254102cca23e3618b96541b89f2b249e2.1576858905.git.osandov@fb.com

x86/doublefault/32: Rename doublefault.c to doublefault_32.c

2019-11-26T20:53:34+00:00

doublefault.c now only contains 32-bit code.  Rename it to
doublefault_32.c.

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Linus Torvalds 
Signed-off-by: Ingo Molnar

Merge branches 'x86-cpu-for-linus' and 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-11-26T16:58:08+00:00

Pull x86 cpu and fpu updates from Ingo Molnar:

 - math-emu fixes

 - CPUID updates

 - sanity-check RDRAND output to see whether the CPU at least pretends
   to produce random data

 - various unaligned-access across cachelines fixes in preparation of
   hardware level split-lock detection

 - fix MAXSMP constraints to not allow !CPUMASK_OFFSTACK kernels with
   larger than 512 NR_CPUS

 - misc FPU related cleanups

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Align the x86_capability array to size of unsigned long
  x86/cpu: Align cpu_caps_cleared and cpu_caps_set to unsigned long
  x86/umip: Make the comments vendor-agnostic
  x86/Kconfig: Rename UMIP config parameter
  x86/Kconfig: Enforce limit of 512 CPUs with MAXSMP and no CPUMASK_OFFSTACK
  x86/cpufeatures: Add feature bit RDPRU on AMD
  x86/math-emu: Limit MATH_EMULATION to 486SX compatibles
  x86/math-emu: Check __copy_from_user() result
  x86/rdrand: Sanity-check RDRAND output

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Use XFEATURE_FP/SSE enum values instead of hardcoded numbers
  x86/fpu: Shrink space allocated for xstate_comp_offsets
  x86/fpu: Update stale variable name in comment

x86: Remove the calgary IOMMU driver

2019-11-15T09:36:59+00:00

The calgary IOMMU was only used on high-end IBM systems in the early
x86_64 age and has no known users left.  Remove it to avoid having to
touch it for pending changes to the DMA API.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20191113071836.21041-2-hch@lst.de

x86/Kconfig: Rename UMIP config parameter

2019-11-07T10:07:29+00:00

AMD 2nd generation EPYC processors support the UMIP (User-Mode
Instruction Prevention) feature. So, rename X86_INTEL_UMIP to
generic X86_UMIP and modify the text to cover both Intel and AMD.

 [ bp: take of the disabled-features.h copy in tools/ too. ]

Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Ricardo Neri 
Cc: Thomas Gleixner 
Cc: "x86@kernel.org" 
Link: https://lkml.kernel.org/r/157298912544.17462.2018334793891409521.stgit@naples-babu.amd.com

Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-07-09T00:34:44+00:00

Pull x86 paravirt updates from Ingo Molnar:
 "A handful of paravirt patching code enhancements to make it more
  robust against patching failures, and related cleanups and not so
  related cleanups - by Thomas Gleixner and myself"

* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/paravirt: Rename paravirt_patch_site::instrtype to paravirt_patch_site::type
  x86/paravirt: Standardize 'insn_buff' variable names
  x86/paravirt: Match paravirt patchlet field definition ordering to initialization ordering
  x86/paravirt: Replace the paravirt patch asm magic
  x86/paravirt: Unify the 32/64 bit paravirt patching code
  x86/paravirt: Detect over-sized patching bugs in paravirt_patch_call()
  x86/paravirt: Detect over-sized patching bugs in paravirt_patch_insns()
  x86/paravirt: Remove bogus extern declarations

treewide: prefix header search paths with $(srctree)/

2019-05-18T02:49:57+00:00

Currently, the Kbuild core manipulates header search paths in a crazy
way [1].

To fix this mess, I want all Makefiles to add explicit $(srctree)/ to
the search paths in the srctree. Some Makefiles are already written in
that way, but not all. The goal of this work is to make the notation
consistent, and finally get rid of the gross hacks.

Having whitespaces after -I does not matter since commit 48f6e3cf5bc6
("kbuild: do not drop -I without parameter").

[1]: https://patchwork.kernel.org/patch/9632347/

Signed-off-by: Masahiro Yamada

x86/paravirt: Unify the 32/64 bit paravirt patching code

2019-04-25T10:00:44+00:00

Large parts of these two files are identical. Merge them together.

Signed-off-by: Thomas Gleixner 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Link: http://lkml.kernel.org/r/20190424134223.603491680@linutronix.de
Signed-off-by: Ingo Molnar

jump_label: move 'asm goto' support test to Kconfig

2019-01-06T00:46:51+00:00

Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Sedat Dilek

x86/ima: retry detecting secure boot mode

2018-12-11T12:19:45+00:00

The secure boot mode may not be detected on boot for some reason (eg.
buggy firmware).  This patch attempts one more time to detect the
secure boot mode.

Signed-off-by: Mimi Zohar