Commit Graph

1279 Commits

Author SHA1 Message Date
8b766b0f8e sysfb: Enable boot time VESA graphic mode selection
Since switch to simplefb/simpledrm VESA graphic mode selection with vga=
kernel parameter is no longer available with legacy BIOS.

The x86 realmode boot code enables the VESA graphic modes when option
FB_BOOT_VESA_SUPPORT is enabled.

This option is selected by vesafb but not simplefb/simpledrm.

To enable use of VESA modes with simplefb in legacy BIOS boot mode drop
dependency of BOOT_VESA_SUPPORT on FB, also drop the FB_ prefix. Select
the option from sysfb rather than the drivers that depend on it.

The BOOT_VESA_SUPPORT is not specific to framebuffer but rather to x86
platform, move it from fbdev to x86 Kconfig.

Fixes: e3263ab389 ("x86: provide platform-devices for boot-framebuffers")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/948c39940a4e99f5b43bdbcbe537faae71a43e1d.1645822213.git.msuchanek@suse.de
2022-03-04 20:55:33 +01:00
7be2e31964 x86: clean up symbol aliasing
Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those
to simplify the definition of function aliases across arch/x86.

For clarity, where there are multiple annotations such as
EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For
example, where a function has a name and an alias which are both
exported, this is organised as:

	SYM_FUNC_START(func)
	    ... asm insns ...
	SYM_FUNC_END(func)
	EXPORT_SYMBOL(func)

	SYM_FUNC_ALIAS(alias, func)
	EXPORT_SYMBOL(alias)

Where there are only aliases and no exports or other annotations, I have
not bothered with line spacing, e.g.

	SYM_FUNC_START(func)
	    ... asm insns ...
	SYM_FUNC_END(func)
	SYM_FUNC_ALIAS(alias, func)

The tools/perf/ copies of memset_64.S and memset_64.S are updated
likewise to avoid the build system complaining these are mismatched:

| Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
| diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
| Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
| diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220216162229.1076788-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-02-22 16:21:34 +00:00
938a000e3f fortify: Detect struct member overflows in memmove() at compile-time
As done for memcpy(), also update memmove() to use the same tightened
compile-time checks under CONFIG_FORTIFY_SOURCE.

Signed-off-by: Kees Cook <keescook@chromium.org>
2022-02-13 16:50:06 -08:00
fd6f57bfda Merge tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add new kconfig target 'make mod2noconfig', which will be useful to
   speed up the build and test iteration.

 - Raise the minimum supported version of LLVM to 11.0.0

 - Refactor certs/Makefile

 - Change the format of include/config/auto.conf to stop double-quoting
   string type CONFIG options.

 - Fix ARCH=sh builds in dash

 - Separate compression macros for general purposes (cmd_bzip2 etc.) and
   the ones for decompressors (cmd_bzip2_with_size etc.)

 - Misc Makefile cleanups

* tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
  kbuild: add cmd_file_size
  arch: decompressor: remove useless vmlinux.bin.all-y
  kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}
  kbuild: drop $(size_append) from cmd_zstd
  sh: rename suffix-y to suffix_y
  doc: kbuild: fix default in `imply` table
  microblaze: use built-in function to get CPU_{MAJOR,MINOR,REV}
  certs: move scripts/extract-cert to certs/
  kbuild: do not quote string values in include/config/auto.conf
  kbuild: do not include include/config/auto.conf from shell scripts
  certs: simplify $(srctree)/ handling and remove config_filename macro
  kbuild: stop using config_filename in scripts/Makefile.modsign
  certs: remove misleading comments about GCC PR
  certs: refactor file cleaning
  certs: remove unneeded -I$(srctree) option for system_certificates.o
  certs: unify duplicated cmd_extract_certs and improve the log
  certs: use $< and $@ to simplify the key generation rule
  kbuild: remove headers_check stub
  kbuild: move headers_check.pl to usr/include/
  certs: use if_changed to re-generate the key when the key type is changed
  ...
2022-01-19 11:15:19 +02:00
7ce7e984ab kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}
GZIP-compressed files end with 4 byte data that represents the size
of the original input. The decompressors (the self-extracting kernel)
exploit it to know the vmlinux size beforehand. To mimic the GZIP's
trailer, Kbuild provides cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}.
Unfortunately these macros are used everywhere despite the appended
size data is only useful for the decompressors.

There is no guarantee that such hand-crafted trailers are safely ignored.
In fact, the kernel refuses compressed initramdfs with the garbage data.
That is why usr/Makefile overrides size_append to make it no-op.

To limit the use of such broken compressed files, this commit renames
the existing macros as follows:

  cmd_bzip2   --> cmd_bzip2_with_size
  cmd_lzma    --> cmd_lzma_with_size
  cmd_lzo     --> cmd_lzo_with_size
  cmd_lz4     --> cmd_lz4_with_size
  cmd_xzkern  --> cmd_xzkern_with_size
  cmd_zstd22  --> cmd_zstd22_with_size

To keep the decompressors working, I updated the following Makefiles
accordingly:

  arch/arm/boot/compressed/Makefile
  arch/h8300/boot/compressed/Makefile
  arch/mips/boot/compressed/Makefile
  arch/parisc/boot/compressed/Makefile
  arch/s390/boot/compressed/Makefile
  arch/sh/boot/compressed/Makefile
  arch/x86/boot/compressed/Makefile

I reused the current macro names for the normal usecases; they produce
the compressed data in the proper format.

I did not touch the following:

  arch/arc/boot/Makefile
  arch/arm64/boot/Makefile
  arch/csky/boot/Makefile
  arch/mips/boot/Makefile
  arch/riscv/boot/Makefile
  arch/sh/boot/Makefile
  kernel/Makefile

This means those Makefiles will stop appending the size data.

I dropped the 'override size_append' hack from usr/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-01-14 02:54:05 +09:00
64ad946152 Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov:

 - Get rid of all the .fixup sections because this generates
   misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
   LIVEPATCH as the backtrace misses the function which is being fixed
   up.

 - Add Straight Line Speculation mitigation support which uses a new
   compiler switch -mharden-sls= which sticks an INT3 after a RET or an
   indirect branch in order to block speculation after them. Reportedly,
   CPUs do speculate behind such insns.

 - The usual set of cleanups and improvements

* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/entry_32: Fix segment exceptions
  objtool: Remove .fixup handling
  x86: Remove .fixup section
  x86/word-at-a-time: Remove .fixup usage
  x86/usercopy: Remove .fixup usage
  x86/usercopy_32: Simplify __copy_user_intel_nocache()
  x86/sgx: Remove .fixup usage
  x86/checksum_32: Remove .fixup usage
  x86/vmx: Remove .fixup usage
  x86/kvm: Remove .fixup usage
  x86/segment: Remove .fixup usage
  x86/fpu: Remove .fixup usage
  x86/xen: Remove .fixup usage
  x86/uaccess: Remove .fixup usage
  x86/futex: Remove .fixup usage
  x86/msr: Remove .fixup usage
  x86/extable: Extend extable functionality
  x86/entry_32: Remove .fixup usage
  x86/entry_64: Remove .fixup usage
  x86/copy_mc_64: Remove .fixup usage
  ...
2022-01-12 16:31:19 -08:00
f12fc75ef7 Merge tag 'efi-next-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel:

 - support taking the measurement of the initrd when loaded via the
   LoadFile2 protocol

 - kobject API cleanup from Greg

 - some header file whitespace fixes

* tag 'efi-next-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: use default_groups in kobj_type
  efi/libstub: measure loaded initrd info into the TPM
  efi/libstub: consolidate initrd handling across architectures
  efi/libstub: x86/mixed: increase supported argument count
  efi/libstub: add prototype of efi_tcg2_protocol::hash_log_extend_event()
  include/linux/efi.h: Remove unneeded whitespaces before tabs
2022-01-11 15:36:30 -08:00
3c6d405666 Merge tag 'x86_build_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build fix from Borislav Petkov:
 "A fix for cross-compiling the compressed stub on arm64 with clang"

* tag 'x86_build_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/compressed: Move CLANG_FLAGS to beginning of KBUILD_CFLAGS
2022-01-10 10:18:58 -08:00
308319e990 Merge tag 'x86_cleanups_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:
 "The mandatory set of random minor cleanups all over tip"

* tag 'x86_cleanups_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/events/amd/iommu: Remove redundant assignment to variable shift
  x86/boot/string: Add missing function prototypes
  x86/fpu: Remove duplicate copy_fpstate_to_sigframe() prototype
  x86/uaccess: Move variable into switch case statement
2022-01-10 10:02:27 -08:00
5fe392ff9d x86/boot/compressed: Move CLANG_FLAGS to beginning of KBUILD_CFLAGS
When cross compiling i386_defconfig on an arm64 host with clang, there
are a few instances of '-Waddress-of-packed-member' and
'-Wgnu-variable-sized-type-not-at-end' in arch/x86/boot/compressed/,
which should both be disabled with the cc-disable-warning calls in that
directory's Makefile, which indicates that cc-disable-warning is failing
at the point of testing these flags.

The cc-disable-warning calls fail because at the point that the flags
are tested, KBUILD_CFLAGS has '-march=i386' without $(CLANG_FLAGS),
which has the '--target=' flag to tell clang what architecture it is
targeting. Without the '--target=' flag, the host architecture (arm64)
is used and i386 is not a valid value for '-march=' in that case. This
error can be seen by adding some logging to try-run:

  clang-14: error: the clang compiler does not support '-march=i386'

Invoking the compiler has to succeed prior to calling cc-option or
cc-disable-warning in order to accurately test whether or not the flag
is supported; if it doesn't, the requested flag can never be added to
the compiler flags. Move $(CLANG_FLAGS) to the beginning of KBUILD_FLAGS
so that any new flags that might be added in the future can be
accurately tested.

Fixes: d5cbd80e30 ("x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211222163040.1961481-1-nathan@kernel.org
2021-12-23 11:03:28 +01:00
bc7aaf52f9 x86/boot/string: Add missing function prototypes
Silence "warning: no previous prototype for ... [-Wmissing-prototypes]"
warnings from string.h when building under W=1.

 [ bp: Clarify commit message. ]

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211119175325.3668419-1-keescook@chromium.org
2021-12-10 19:49:06 +01:00
f94909ceb1 x86: Prepare asm files for straight-line-speculation
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[q]*\>/RET/' $file
  done

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org
2021-12-08 12:25:37 +01:00
44f155b4b0 efi/libstub: x86/mixed: increase supported argument count
Increase the number of arguments supported by mixed mode calls, so that
we will be able to call into the TCG2 protocol to measure the initrd
and extend the associated PCR. This involves the TCG2 protocol's
hash_log_extend_event() method, which takes five arguments, three of
which are u64 and need to be split, producing a total of 8 outgoing

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Link: https://lore.kernel.org/r/20211119114745.1560453-3-ilias.apalodimas@linaro.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-11-21 17:08:10 +01:00
18c3933c19 x86/sev: Shorten GHCB terminate macro names
Shorten macro names for improved readability.

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Link: https://lkml.kernel.org/r/20211110220731.2396491-5-brijesh.singh@amd.com
2021-11-15 20:31:16 +01:00
cc0356d6a0 Merge tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov:

 - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to
   keep old userspace from breaking. Adjust the corresponding iopl
   selftest to that.

 - Improve stack overflow warnings to say which stack got overflowed and
   raise the exception stack sizes to 2 pages since overflowing the
   single page of exception stack is very easy to do nowadays with all
   the tracing machinery enabled. With that, rip out the custom mapping
   of AMD SEV's too.

 - A bunch of changes in preparation for FGKASLR like supporting more
   than 64K section headers in the relocs tool, correct ORC lookup table
   size to cover the whole kernel .text and other adjustments.

* tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage
  vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext
  x86/boot/compressed: Avoid duplicate malloc() implementations
  x86/boot: Allow a "silent" kaslr random byte fetch
  x86/tools/relocs: Support >64K section headers
  x86/sev: Make the #VC exception stacks part of the default stacks storage
  x86: Increase exception stack sizes
  x86/mm/64: Improve stack overflow warnings
  x86/iopl: Fake iopl(3) CLI/STI usage
2021-11-02 07:56:47 -07:00
2dc26d98cf Merge tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull overflow updates from Kees Cook:
 "The end goal of the current buffer overflow detection work[0] is to
  gain full compile-time and run-time coverage of all detectable buffer
  overflows seen via array indexing or memcpy(), memmove(), and
  memset(). The str*() family of functions already have full coverage.

  While much of the work for these changes have been on-going for many
  releases (i.e. 0-element and 1-element array replacements, as well as
  avoiding false positives and fixing discovered overflows[1]), this
  series contains the foundational elements of several related buffer
  overflow detection improvements by providing new common helpers and
  FORTIFY_SOURCE changes needed to gain the introspection required for
  compiler visibility into array sizes. Also included are a handful of
  already Acked instances using the helpers (or related clean-ups), with
  many more waiting at the ready to be taken via subsystem-specific
  trees[2].

  The new helpers are:

   - struct_group() for gaining struct member range introspection

   - memset_after() and memset_startat() for clearing to the end of
     structures

   - DECLARE_FLEX_ARRAY() for using flex arrays in unions or alone in
     structs

  Also included is the beginning of the refactoring of FORTIFY_SOURCE to
  support memcpy() introspection, fix missing and regressed coverage
  under GCC, and to prepare to fix the currently broken Clang support.
  Finishing this work is part of the larger series[0], but depends on
  all the false positives and buffer overflow bug fixes to have landed
  already and those that depend on this series to land.

  As part of the FORTIFY_SOURCE refactoring, a set of both a
  compile-time and run-time tests are added for FORTIFY_SOURCE and the
  mem*()-family functions respectively. The compile time tests have
  found a legitimate (though corner-case) bug[6] already.

  Please note that the appearance of "panic" and "BUG" in the
  FORTIFY_SOURCE refactoring are the result of relocating existing code,
  and no new use of those code-paths are expected nor desired.

  Finally, there are two tree-wide conversions for 0-element arrays and
  flexible array unions to gain sane compiler introspection coverage
  that result in no known object code differences.

  After this series (and the changes that have now landed via netdev and
  usb), we are very close to finally being able to build with
  -Warray-bounds and -Wzero-length-bounds.

  However, due corner cases in GCC[3] and Clang[4], I have not included
  the last two patches that turn on these options, as I don't want to
  introduce any known warnings to the build. Hopefully these can be
  solved soon"

Link: https://lore.kernel.org/lkml/20210818060533.3569517-1-keescook@chromium.org/ [0]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=FORTIFY_SOURCE [1]
Link: https://lore.kernel.org/lkml/202108220107.3E26FE6C9C@keescook/ [2]
Link: https://lore.kernel.org/lkml/3ab153ec-2798-da4c-f7b1-81b0ac8b0c5b@roeck-us.net/ [3]
Link: https://bugs.llvm.org/show_bug.cgi?id=51682 [4]
Link: https://lore.kernel.org/lkml/202109051257.29B29745C0@keescook/ [5]
Link: https://lore.kernel.org/lkml/20211020200039.170424-1-keescook@chromium.org/ [6]

* tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (30 commits)
  fortify: strlen: Avoid shadowing previous locals
  compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer
  treewide: Replace 0-element memcpy() destinations with flexible arrays
  treewide: Replace open-coded flex arrays in unions
  stddef: Introduce DECLARE_FLEX_ARRAY() helper
  btrfs: Use memset_startat() to clear end of struct
  string.h: Introduce memset_startat() for wiping trailing members and padding
  xfrm: Use memset_after() to clear padding
  string.h: Introduce memset_after() for wiping trailing members/padding
  lib: Introduce CONFIG_MEMCPY_KUNIT_TEST
  fortify: Add compile-time FORTIFY_SOURCE tests
  fortify: Allow strlen() and strnlen() to pass compile-time known lengths
  fortify: Prepare to improve strnlen() and strlen() warnings
  fortify: Fix dropped strcpy() compile-time write overflow check
  fortify: Explicitly disable Clang support
  fortify: Move remaining fortify helpers into fortify-string.h
  lib/string: Move helper functions out of string.c
  compiler_types.h: Remove __compiletime_object_size()
  cm4000_cs: Use struct_group() to zero struct cm4000_dev region
  can: flexcan: Use struct_group() to zero struct flexcan_regs regions
  ...
2021-11-01 17:12:56 -07:00
33f98a9798 x86/boot/compressed: Avoid duplicate malloc() implementations
The early malloc() and free() implementation in include/linux/decompress/mm.h
(which is also included by the static decompressors) is static. This is
fine when the only thing interested in using malloc() is the decompression
code, but the x86 early boot environment may use malloc() in a couple places,
leading to a potential collision when the static copies of the available
memory region ("malloc_ptr") gets reset to the global "free_mem_ptr" value.
As it happened, the existing usage pattern was accidentally safe because each
user did 1 malloc() and 1 free() before returning and were not nested:

extract_kernel() (misc.c)
	choose_random_location() (kaslr.c)
		mem_avoid_init()
			handle_mem_options()
				malloc()
				...
				free()
	...
	parse_elf() (misc.c)
		malloc()
		...
		free()

Once the future FGKASLR series is added, however, it will insert
additional malloc() calls local to fgkaslr.c in the middle of
parse_elf()'s malloc()/free() pair:

	parse_elf() (misc.c)
		malloc()
		if (...) {
			layout_randomized_image(output, &ehdr, phdrs);
				malloc() <- boom
				...
		else
			layout_image(output, &ehdr, phdrs);
		free()

To avoid collisions, there must be a single implementation of malloc().
Adjust include/linux/decompress/mm.h so that visibility can be
controlled, provide prototypes in misc.h, and implement the functions in
misc.c. This also results in a small size savings:

$ size vmlinux.before vmlinux.after
   text    data     bss     dec     hex filename
8842314     468  178320 9021102  89a6ae vmlinux.before
8842240     468  178320 9021028  89a664 vmlinux.after

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211013175742.1197608-4-keescook@chromium.org
2021-10-27 11:07:59 +02:00
067595d728 x86/boot: Fix make hdimage with older versions of mtools
Some versions of mtools (fixed somewhere between 4.0.31 and 4.0.35)
generate bad output for mformat when used with the partition= option.
Use the offset= option instead. An mtools.conf entry is *also* needed
with partition= to support mpartition; combining them in one entry does
not work either.

Don't specify the -t option to mpartition; it is unnecessary and seems
to confuse mpartition under some circumstances.

Also do a few minor optimizations:

Use a larger cluster size; there is no reason for the typical 4K
clusters when we are dealing mainly with comparatively huge files.

Start the partition at 32K. There is no reason to align it more than
that, since the internal FAT filesystem structures will at best be
cluster-aligned, and 32K is the maximum FAT cluster size.

 [ bp: Remove "we". ]

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210911003906.2700218-1-hpa@zytor.com
2021-09-29 11:06:47 +02:00
cfecea6ead lib/string: Move helper functions out of string.c
The core functions of string.c are those that may be implemented by
per-architecture functions, or overloaded by FORTIFY_SOURCE. As a
result, it needs to be built with __NO_FORTIFY. Without this, macros
will collide with function declarations. This was accidentally working
due to -ffreestanding (on some architectures). Make this deterministic
by explicitly setting __NO_FORTIFY and move all the helper functions
into string_helpers.c so that they gain the fortification coverage they
had been missing.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andy Lavr <andy.lavr@gmail.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2021-09-25 08:20:49 -07:00
b250e6d141 Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add <linux/stdarg.h> to the kernel source instead of borrowing
   <stdarg.h> from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
2021-09-03 15:33:47 -07:00
230bda0873 Merge tag 'x86_cleanups_for_v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:
 "The usual round of minor cleanups and fixes"

* tag 'x86_cleanups_for_v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kaslr: Have process_mem_region() return a boolean
  x86/power: Fix kernel-doc warnings in cpu.c
  x86/mce/inject: Replace deprecated CPU-hotplug functions.
  x86/microcode: Replace deprecated CPU-hotplug functions.
  x86/mtrr: Replace deprecated CPU-hotplug functions.
  x86/mmiotrace: Replace deprecated CPU-hotplug functions.
2021-08-30 13:35:36 -07:00
ced119b630 Merge tag 'x86_build_for_v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build updates from Borislav Petkov:

 - Remove cc-option checks which are old and already supported by the
   minimal compiler version the kernel uses and thus avoid the need to
   invoke the compiler unnecessarily.

 - Cleanups

* tag 'x86_build_for_v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Move the install rule to arch/x86/Makefile
  x86/build: Remove the left-over bzlilo target
  x86/tools/relocs: Mark die() with the printf function attr format
  x86/build: Remove stale cc-option checks
2021-08-30 13:27:16 -07:00
081551266d x86/build: Move the install rule to arch/x86/Makefile
Currently, the install target in arch/x86/Makefile descends into
arch/x86/boot/Makefile to invoke the shell script, but there is no
good reason to do so.

arch/x86/Makefile can run the shell script directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210729140023.442101-2-masahiroy@kernel.org
2021-08-25 11:57:38 +02:00
5b3fd8aa5d x86/kaslr: Have process_mem_region() return a boolean
Fix the following coccicheck warning:

  ./arch/x86/boot/compressed/kaslr.c:671:10-11:WARNING:return of 0/1
  in function 'process_mem_region' with return type bool

Generated by: scripts/coccinelle/misc/boolreturn.cocci

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Jing Yangyang <jing.yangyang@zte.com.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210824070515.61065-1-deng.changcheng@zte.com.cn
2021-08-24 10:54:15 +02:00
22aa45cb46 x86/efi: Restore Firmware IDT before calling ExitBootServices()
Commit

  79419e13e8 ("x86/boot/compressed/64: Setup IDT in startup_32 boot path")

introduced an IDT into the 32-bit boot path of the decompressor stub.
But the IDT is set up before ExitBootServices() is called, and some UEFI
firmwares rely on their own IDT.

Save the firmware IDT on boot and restore it before calling into EFI
functions to fix boot failures introduced by above commit.

Fixes: 79419e13e8 ("x86/boot/compressed/64: Setup IDT in startup_32 boot path")
Reported-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: stable@vger.kernel.org # 5.13+
Link: https://lkml.kernel.org/r/20210820125703.32410-1-joro@8bytes.org
2021-08-21 17:57:04 +02:00
c0891ac15f isystem: ship and use stdarg.h
Ship minimal stdarg.h (1 type, 4 macros) as <linux/stdarg.h>.
stdarg.h is the only userspace header commonly used in the kernel.

GPL 2 version of <stdarg.h> can be extracted from
http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-19 09:02:55 +09:00
1b98ed0e83 Merge tag 'x86-boot-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot update from Ingo Molnar:
 "Modernize the genimage.sh script, add a 'hdimage' target and EFI
  support"

* tag 'x86-boot-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Modernize genimage script; hdimage+EFI support
2021-06-28 13:05:09 -07:00
a554e740b6 x86/boot/compressed: Enable -Wundef
A discussion around -Wundef showed that there were still a few boolean
Kconfigs where #if was used rather than #ifdef to guard different code.
Kconfig doesn't define boolean configs, which can result in -Wundef
warnings.

arch/x86/boot/compressed/Makefile resets the CFLAGS used for this
directory, and doesn't re-enable -Wundef as the top level Makefile does.
If re-added, with RANDOMIZE_BASE and X86_NEED_RELOCS disabled, the
following warnings are visible.

  arch/x86/boot/compressed/misc.h:82:5: warning: 'CONFIG_RANDOMIZE_BASE'
  is not defined, evaluates to 0 [-Wundef]
      ^
  arch/x86/boot/compressed/misc.c:175:5: warning: 'CONFIG_X86_NEED_RELOCS'
  is not defined, evaluates to 0 [-Wundef]
      ^

Simply fix these and re-enable this warning for this directory.

Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210422190450.3903999-1-ndesaulniers@google.com
2021-05-12 21:39:56 +02:00
f279b49f13 x86/boot: Modernize genimage script; hdimage+EFI support
The image generation scripts in arch/x86/boot are pretty out of date,
except for the isoimage target. Update and clean up the
genimage.sh script, and make it support an arbitrary number of
initramfs files in the image.

Add a "hdimage" target, which can be booted by either BIOS or
EFI (if the kernel is compiled with the EFI stub.) For EFI to be able
to pass the command line to the kernel, we need the EFI shell, but the
firmware builtin EFI shell, if it even exists, is pretty much always
the last resort boot option, so search for OVMF or EDK2 and explicitly
include a copy of the EFI shell.

To make this all work, use bash features in the script.  Furthermore,
this version of the script makes use of some mtools features,
especially mpartition, that might not exist in very old version of
mtools, but given all the other dependencies on this script this
doesn't seem such a big deal.

Finally, put a volume label ("LINUX_BOOT") on all generated images.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210510082840.628372-1-hpa@zytor.com
2021-05-10 12:27:50 +02:00
e759959fe3 x86/sev-es: Rename sev-es.{ch} to sev.{ch}
SEV-SNP builds upon the SEV-ES functionality while adding new hardware
protection. Version 2 of the GHCB specification adds new NAE events that
are SEV-SNP specific. Rename the sev-es.{ch} to sev.{ch} so that all
SEV* functionality can be consolidated in one place.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-2-brijesh.singh@amd.com
2021-05-10 07:40:27 +02:00
c6536676c7 Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 updates from Borislav Petkov:

 - Turn the stack canary into a normal __percpu variable on 32-bit which
   gets rid of the LAZY_GS stuff and a lot of code.

 - Add an insn_decode() API which all users of the instruction decoder
   should preferrably use. Its goal is to keep the details of the
   instruction decoder away from its users and simplify and streamline
   how one decodes insns in the kernel. Convert its users to it.

 - kprobes improvements and fixes

 - Set the maximum DIE per package variable on Hygon

 - Rip out the dynamic NOP selection and simplify all the machinery
   around selecting NOPs. Use the simplified NOPs in objtool now too.

 - Add Xeon Sapphire Rapids to list of CPUs that support PPIN

 - Simplify the retpolines by folding the entire thing into an
   alternative now that objtool can handle alternatives with stack ops.
   Then, have objtool rewrite the call to the retpoline with the
   alternative which then will get patched at boot time.

 - Document Intel uarch per models in intel-family.h

 - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the
   exception on Intel.

* tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  x86, sched: Treat Intel SNC topology as default, COD as exception
  x86/cpu: Comment Skylake server stepping too
  x86/cpu: Resort and comment Intel models
  objtool/x86: Rewrite retpoline thunk calls
  objtool: Skip magical retpoline .altinstr_replacement
  objtool: Cache instruction relocs
  objtool: Keep track of retpoline call sites
  objtool: Add elf_create_undef_symbol()
  objtool: Extract elf_symbol_add()
  objtool: Extract elf_strtab_concat()
  objtool: Create reloc sections implicitly
  objtool: Add elf_create_reloc() helper
  objtool: Rework the elf_rebuild_reloc_section() logic
  objtool: Fix static_call list generation
  objtool: Handle per arch retpoline naming
  objtool: Correctly handle retpoline thunk calls
  x86/retpoline: Simplify retpolines
  x86/alternatives: Optimize optimize_nops()
  x86: Add insn_decode_kernel()
  x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration
  ...
2021-04-27 17:45:09 -07:00
ca53fb2c7c Merge tag 'x86_build_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build updates from Borislav Petkov:
 "A bunch of clang build fixes and a Kconfig highmem selection fix for
  486SX"

* tag 'x86_build_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Disable HIGHMEM64G selection for M486SX
  efi/libstub: Add $(CLANG_FLAGS) to x86 flags
  x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS
  x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)
2021-04-26 09:32:35 -07:00
ea5bc7b977 Merge tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 cleanups from Borislav Petkov:
 "Trivial cleanups and fixes all over the place"

* tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Remove me from IDE/ATAPI section
  x86/pat: Do not compile stubbed functions when X86_PAT is off
  x86/asm: Ensure asm/proto.h can be included stand-alone
  x86/platform/intel/quark: Fix incorrect kernel-doc comment syntax in files
  x86/msr: Make locally used functions static
  x86/cacheinfo: Remove unneeded dead-store initialization
  x86/process/64: Move cpu_current_top_of_stack out of TSS
  tools/turbostat: Unmark non-kernel-doc comment
  x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()
  x86/fpu/math-emu: Fix function cast warning
  x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypes
  x86: Fix various typos in comments, take #2
  x86: Remove unusual Unicode characters from comments
  x86/kaslr: Return boolean values from a function returning bool
  x86: Fix various typos in comments
  x86/setup: Remove unused RESERVE_BRK_ARRAY()
  stacktrace: Move documentation for arch_stack_walk_reliable() to header
  x86: Remove duplicate TSC DEADLINE MSR definitions
2021-04-26 09:25:47 -07:00
90e66ce9e8 Merge tag 'x86_boot_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Borislav Petkov:
 "Consolidation and cleanup of the early memory reservations, along with
  a couple of gcc11 warning fixes"

* tag 'x86_boot_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/setup: Move trim_snb_memory() later in setup_arch() to fix boot hangs
  x86/setup: Merge several reservations of start of memory
  x86/setup: Consolidate early memory reservations
  x86/boot/compressed: Avoid gcc-11 -Wstringop-overread warning
  x86/boot/tboot: Avoid Wstringop-overread-warning
2021-04-26 09:24:06 -07:00
d5cbd80e30 x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS
When cross compiling x86 on an ARM machine with clang, there are several
errors along the lines of:

  arch/x86/include/asm/string_64.h:27:10: error: invalid output constraint '=&c' in asm

This happens because the compressed boot Makefile reassigns KBUILD_CFLAGS
and drops the clang flags that set the target architecture ('--target=')
and the path to the GNU cross tools ('--prefix='), meaning that the host
architecture is targeted.

These flags are available as $(CLANG_FLAGS) from the main Makefile so
add them to the compressed boot folder's KBUILD_CFLAGS so that cross
compiling works as expected.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lkml.kernel.org/r/20210326000435.4785-3-nathan@kernel.org
2021-03-26 11:32:55 +01:00
e14cfb3bdd x86/boot/compressed: Avoid gcc-11 -Wstringop-overread warning
GCC gets confused by the comparison of a pointer to an integer literal,
with the assumption that this is an offset from a NULL pointer and that
dereferencing it is invalid:

  In file included from arch/x86/boot/compressed/misc.c:18:
  In function ‘parse_elf’,
      inlined from ‘extract_kernel’ at arch/x86/boot/compressed/misc.c:442:2:
  arch/x86/boot/compressed/../string.h:15:23: error: ‘__builtin_memcpy’ reading 64 bytes from a region of size 0 [-Werror=stringop-overread]
     15 | #define memcpy(d,s,l) __builtin_memcpy(d,s,l)
        |                       ^~~~~~~~~~~~~~~~~~~~~~~
  arch/x86/boot/compressed/misc.c:283:9: note: in expansion of macro ‘memcpy’
    283 |         memcpy(&ehdr, output, sizeof(ehdr));
        |         ^~~~~~

I could not find any good workaround for this, but as this is only
a warning for a failure during early boot, removing the line entirely
works around the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Sebor <msebor@gmail.com>
Link: https://lore.kernel.org/r/20210322160253.4032422-2-arnd@kernel.org
2021-03-23 00:16:25 +01:00
163b099146 x86: Fix various typos in comments, take #2
Fix another ~42 single-word typos in arch/x86/ code comments,
missed a few in the first pass, in particular in .S files.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-kernel@vger.kernel.org
2021-03-21 23:50:28 +01:00
21d6a7dcbf x86/kaslr: Return boolean values from a function returning bool
Fix the following coccicheck warnings:

  ./arch/x86/boot/compressed/kaslr.c:642:10-11: WARNING: return of 0/1 in
  function 'process_mem_region' with return type bool.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1615283963-67277-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-03-19 13:25:07 +01:00
f15a0a732a x86/sev-es: Replace open-coded hlt-loops with sev_es_terminate()
There are a few places left in the SEV-ES C code where hlt loops and/or
terminate requests are implemented. Replace them all with calls to
sev_es_terminate().

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-9-joro@8bytes.org
2021-03-18 23:04:12 +01:00
fef81c8626 x86/boot/compressed/64: Check SEV encryption in the 32-bit boot-path
Check whether the hypervisor reported the correct C-bit when running
as an SEV guest. Using a wrong C-bit position could be used to leak
sensitive data from the guest to the hypervisor.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-8-joro@8bytes.org
2021-03-18 23:04:12 +01:00
e927e62d8e x86/boot/compressed/64: Add CPUID sanity check to 32-bit boot-path
The 32-bit #VC handler has no GHCB and can only handle CPUID exit codes.
It is needed by the early boot code to handle #VC exceptions raised in
verify_cpu() and to get the position of the C-bit.

But the CPUID information comes from the hypervisor which is untrusted
and might return results which trick the guest into the no-SEV boot path
with no C-bit set in the page-tables. All data written to memory would
then be unencrypted and could leak sensitive data to the hypervisor.

Add sanity checks to the 32-bit boot #VC handler to make sure the
hypervisor does not pretend that SEV is not enabled.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-7-joro@8bytes.org
2021-03-18 23:04:12 +01:00
1ccdbf748d x86/boot/compressed/64: Add 32-bit boot #VC handler
Add a #VC exception handler which is used when the kernel still executes
in protected mode. This boot-path already uses CPUID, which will cause #VC
exceptions in an SEV-ES guest.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-6-joro@8bytes.org
2021-03-18 23:03:43 +01:00
79419e13e8 x86/boot/compressed/64: Setup IDT in startup_32 boot path
This boot path needs exception handling when it is used with SEV-ES.
Setup an IDT and provide a helper function to write IDT entries for
use in 32-bit protected mode.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-5-joro@8bytes.org
2021-03-18 16:44:46 +01:00
0c289ff81c x86/boot/compressed/64: Reload CS in startup_32
Exception handling in the startup_32 boot path requires the CS
selector to be correctly set up. Reload it from the current GDT.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-4-joro@8bytes.org
2021-03-18 16:44:43 +01:00
eab696d8e8 x86/sev: Do not require Hypervisor CPUID bit for SEV guests
A malicious hypervisor could disable the CPUID intercept for an SEV or
SEV-ES guest and trick it into the no-SEV boot path, where it could
potentially reveal secrets. This is not an issue for SEV-SNP guests,
as the CPUID intercept can't be disabled for those.

Remove the Hypervisor CPUID bit check from the SEV detection code to
protect against this kind of attack and add a Hypervisor bit equals zero
check to the SME detection path to prevent non-encrypted guests from
trying to enable SME.

This handles the following cases:

	1) SEV(-ES) guest where CPUID intercept is disabled. The guest
	   will still see leaf 0x8000001f and the SEV bit. It can
	   retrieve the C-bit and boot normally.

	2) Non-encrypted guests with intercepted CPUID will check
	   the SEV_STATUS MSR and find it 0 and will try to enable SME.
	   This will fail when the guest finds MSR_K8_SYSCFG to be zero,
	   as it is emulated by KVM. But we can't rely on that, as there
	   might be other hypervisors which return this MSR with bit
	   23 set. The Hypervisor bit check will prevent that the guest
	   tries to enable SME in this case.

	3) Non-encrypted guests on SEV capable hosts with CPUID intercept
	   disabled (by a malicious hypervisor) will try to boot into
	   the SME path. This will fail, but it is also not considered
	   a problem because non-encrypted guests have no protection
	   against the hypervisor anyway.

 [ bp: s/non-SEV/non-encrypted/g ]

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20210312123824.306-3-joro@8bytes.org
2021-03-18 16:44:40 +01:00
b099155e2d x86/boot/compressed/64: Cleanup exception handling before booting kernel
Disable the exception handling before booting the kernel to make sure
any exceptions that happen during early kernel boot are not directed to
the pre-decompression code.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210312123824.306-2-joro@8bytes.org
2021-03-18 16:44:36 +01:00
514ef77607 x86/boot/compressed/sev-es: Convert to insn_decode()
Other than simplifying the code there should be no functional changes
resulting from this.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210304174237.31945-7-bp@alien8.de
2021-03-15 11:18:35 +01:00
4a1106afee Merge tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Borislav Petkov:
 "These got delayed due to a last minute ia64 build issue which got
  fixed in the meantime.

  EFI updates collected by Ard Biesheuvel:

   - Don't move BSS section around pointlessly in the x86 decompressor

   - Refactor helper for discovering the EFI secure boot mode

   - Wire up EFI secure boot to IMA for arm64

   - Some fixes for the capsule loader

   - Expose the RT_PROP table via the EFI test module

   - Relax DT and kernel placement restrictions on ARM

  with a few followup fixes:

   - fix the build breakage on IA64 caused by recent capsule loader
     changes

   - suppress a type mismatch build warning in the expansion of
     EFI_PHYS_ALIGN on ARM"

* tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: arm: force use of unsigned type for EFI_PHYS_ALIGN
  efi: ia64: disable the capsule loader
  efi: stub: get rid of efi_get_max_fdt_addr()
  efi/efi_test: read RuntimeServicesSupported
  efi: arm: reduce minimum alignment of uncompressed kernel
  efi: capsule: clean scatter-gather entries from the D-cache
  efi: capsule: use atomic kmap for transient sglist mappings
  efi: x86/xen: switch to efi_get_secureboot_mode helper
  arm64/ima: add ima_arch support
  ima: generalize x86/EFI arch glue for other EFI architectures
  efi: generalize efi_get_secureboot
  efi/libstub: EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER should not default to yes
  efi/x86: Only copy the compressed kernel image in efi_relocate_kernel()
  efi/libstub/x86: simplify efi_is_native()
2020-12-24 12:40:07 -08:00
8a494023b8 kasan, x86, s390: update undef CONFIG_KASAN
With the intoduction of hardware tag-based KASAN some kernel checks of
this kind:

  ifdef CONFIG_KASAN

will be updated to:

  if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code
that isn't linked with KASAN runtime and shouldn't have any KASAN
annotations.

Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN.

Link: https://lkml.kernel.org/r/9d84bfaaf8fabe0fc89f913c9e420a30bd31a260.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-22 12:55:08 -08:00
84292fffc2 Merge tag 'x86_build_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build updates from Borislav Petkov:
 "Two x86 build fixes:

   - Fix the vmlinux size check on 64-bit along with adding useful
     clarifications on the topic (Arvind Sankar)

   - Remove -m16 workaround now that the GCC versions that need it are
     unsupported (Nick Desaulniers)"

* tag 'x86_build_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Remove -m16 workaround for unsupported versions of GCC
  x86/build: Fix vmlinux size check on 64-bit
2020-12-14 13:54:50 -08:00