linux-stable.git/arch/x86/kernel/verify_cpu.S, branch linux-rolling-stable

x86/cpufeatures: Generate the header based on build config

2025-03-19T10:15:11+00:00

Introduce an AWK script to auto-generate the  header
with required and disabled feature masks based on 
and the current build config.

Thus for any CPU feature with a build config, e.g., X86_FRED, simply add:

  config X86_DISABLED_FEATURE_FRED
	def_bool y
	depends on !X86_FRED

to arch/x86/Kconfig.cpufeatures, instead of adding a conditional CPU
feature disable flag, e.g., DISABLE_FRED.

Lastly, the generated required and disabled feature masks will be added to
their corresponding feature masks for this particular compile-time
configuration.

  [ Xin: build integration improvements ]
  [ mingo: Improved changelog and comments ]

Signed-off-by: H. Peter Anvin (Intel) 
Signed-off-by: Xin Li (Intel) 
Signed-off-by: Borislav Petkov (AMD) 
Signed-off-by: Ingo Molnar 
Reviewed-by: Nikolay Borisov 
Cc: Linus Torvalds 
Link: https://lore.kernel.org/r/20250305184725.3341760-3-xin@zytor.com

x86: Prepare asm files for straight-line-speculation

2021-12-08T11:25:37+00:00

Replace all ret/retq instructions with RET in preparation of making
RET a macro. Since AS is case insensitive it's a big no-op without
RET defined.

  find arch/x86/ -name \*.S | while read file
  do
	sed -i 's/\/RET/' $file
  done

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org

x86/asm: Annotate local pseudo-functions

2019-10-18T08:04:04+00:00

Use the newly added SYM_CODE_START_LOCAL* to annotate beginnings of
all pseudo-functions (those ending with END until now) which do not
have ".globl" annotation. This is needed to balance END for tools that
generate debuginfo. Note that ENDs are switched to SYM_CODE_END too so
that everybody can see the pairing.

C-like functions (which handle frame ptr etc.) are not annotated here,
hence SYM_CODE_* macros are used here, not SYM_FUNC_*. Note that the
32bit version of early_idt_handler_common already had ENDPROC -- switch
that to SYM_CODE_END for the same reason as above (and to be the same as
64bit).

While early_idt_handler_common is LOCAL, it's name is not prepended with
".L" as it happens to appear in call traces.

bad_get_user*, and bad_put_user are now aligned, as they are separate
functions. They do not mind to be aligned -- no need to be compact
there.

early_idt_handler_common is aligned now too, as it is after
early_idt_handler_array, so as well no need to be compact there.

verify_cpu is self-standing and included in other .S files, so align it
too.

The others have alignment preserved to what it used to be (using the
_NOALIGN variant of macros).

Signed-off-by: Jiri Slaby 
Signed-off-by: Borislav Petkov 
Cc: Alexios Zavras 
Cc: Allison Randal 
Cc: Andy Lutomirski 
Cc: Cao jin 
Cc: Enrico Weigelt 
Cc: Greg Kroah-Hartman 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: linux-arch@vger.kernel.org
Cc: Maran Wilson 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20191011115108.12392-6-jslaby@suse.cz

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230

2019-06-19T15:09:06+00:00

Based on 2 normalized pattern(s):

  this source code is licensed under the gnu general public license
  version 2 see the file copying for more details

  this source code is licensed under general public license version 2
  see

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 52 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Allison Randal 
Reviewed-by: Alexios Zavras 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.449021192@linutronix.de
Signed-off-by: Greg Kroah-Hartman

x86/boot: Annotate verify_cpu() as a callable function

2017-09-28T07:39:03+00:00

verify_cpu() is a callable function.  Annotate it as such.

Signed-off-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Jiri Slaby 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/293024b8a080832075312f38c07ccc970fc70292.1505764066.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar

x86/cpufeature: Carve out X86_FEATURE_*

2016-01-30T10:22:17+00:00

Move them to a separate header and have the following
dependency:

  x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h

This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.

Suggested-by: H. Peter Anvin 
Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/boot: Hide local labels in verify_cpu()

2016-01-12T10:54:32+00:00

... from the final ELF image's symbol table as they're not
really needed there.

Before:

$ readelf -a vmlinux | grep verify_cpu
    43: ffffffff810001a9     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu
    45: ffffffff8100028f     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_no_longmode
    46: ffffffff810001de     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_noamd
    47: ffffffff8100022b     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_check
    48: ffffffff8100021c     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_clear_xd
    49: ffffffff81000263     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_sse_test
    50: ffffffff81000296     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu_sse_ok

After:

$ readelf -a vmlinux | grep verify_cpu
    43: ffffffff810001a9     0 NOTYPE  LOCAL  DEFAULT    1 verify_cpu

No functionality change.

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1451860733-21163-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/cpu: Call verify_cpu() after having entered long mode too

2015-11-07T09:45:02+00:00

When we get loaded by a 64-bit bootloader, kernel entry point is
startup_64 in head_64.S. We don't trust any and all bootloaders because
some will fiddle with CPU configuration so we go ahead and massage each
CPU into sanity again.

For example, some dell BIOSes have this XD disable feature which set
IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround
for other OSes but Linux sure doesn't need it.

A similar thing is present in the Surface 3 firmware - see
https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit
only on the BSP:

  # rdmsr -a 0x1a0
  400850089
  850089
  850089
  850089

I know, right?!

There's not even an off switch in there.

So fix all those cases by sanitizing the 64-bit entry point too. For
that, make verify_cpu() callable in 64-bit mode also.

Requested-and-debugged-by: "H. Peter Anvin" 
Reported-and-tested-by: Bastien Nocera 
Signed-off-by: Borislav Petkov 
Cc: Matt Fleming 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner

x86: Fix common misspellings

2011-03-18T09:39:30+00:00

They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi 
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar

x86: Fix included-by file reference comments

2010-11-18T08:58:54+00:00

Adjust the paths for files that are including verify_cpu.S.

Reported-by: Yinghai Lu 
Signed-off-by: Kees Cook 
Acked-by: Pekka Enberg 
Cc: Alan Cox 
LKML-Reference: <1289931004-16066-1-git-send-email-kees.cook@canonical.com>
Signed-off-by: Ingo Molnar