Commit:
d54d610243 ("x86/boot/sev: Avoid shared GHCB page for early memory acceptance")
provided a fix for SEV-SNP memory acceptance from the EFI stub when
running at VMPL #0. However, that fix was insufficient for SVSM SEV-SNP
guests running at VMPL >0, as those rely on a SVSM calling area, which
is a shared buffer whose address is programmed into a SEV-SNP MSR, and
the SEV init code that sets up this calling area executes much later
during the boot.
Given that booting via the EFI stub at VMPL >0 implies that the firmware
has configured this calling area already, reuse it for performing memory
acceptance in the EFI stub.
Fixes: fcd042e864 ("x86/sev: Perform PVALIDATE using the SVSM when not at VMPL0")
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Co-developed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250428174322.2780170-2-ardb+git@google.com
Pull Kbuild updates from Masahiro Yamada:
- Improve performance in gendwarfksyms
- Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS
- Support CONFIG_HEADERS_INSTALL for ARCH=um
- Use more relative paths to sources files for better reproducibility
- Support the loong64 Debian architecture
- Add Kbuild bash completion
- Introduce intermediate vmlinux.unstripped for architectures that need
static relocations to be stripped from the final vmlinux
- Fix versioning in Debian packages for -rc releases
- Treat missing MODULE_DESCRIPTION() as an error
- Convert Nios2 Makefiles to use the generic rule for built-in DTB
- Add debuginfo support to the RPM package
* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
kbuild: rpm-pkg: build a debuginfo RPM
kconfig: merge_config: use an empty file as initfile
nios2: migrate to the generic rule for built-in DTB
rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
kbuild: pacman-pkg: hardcode module installation path
kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
modpost: require a MODULE_DESCRIPTION()
kbuild: make all file references relative to source root
x86: drop unnecessary prefix map configuration
kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
kbuild: Add a help message for "headers"
kbuild: deb-pkg: remove "version" variable in mkdebian
kbuild: deb-pkg: fix versioning for -rc releases
Documentation/kbuild: Fix indentation in modules.rst example
x86: Get rid of Makefile.postlink
kbuild: Create intermediate vmlinux build with relocations preserved
kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
kbuild: link-vmlinux.sh: Make output file name configurable
kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
Revert "kheaders: Ignore silly-rename files"
...
Pull EFI updates from Ard Biesheuvel:
- Decouple mixed mode startup code from the traditional x86
decompressor
- Revert zero-length file hack in efivarfs
- Prevent EFI zboot from using the CopyMem/SetMem boot services after
ExitBootServices()
- Update EFI zboot to use the ZLIB/ZSTD library interfaces directly
* tag 'efi-next-for-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi/libstub: Avoid legacy decompressor zlib/zstd wrappers
efi/libstub: Avoid CopyMem/SetMem EFI services after ExitBootServices
efi: efibc: change kmalloc(size * count, ...) to kmalloc_array()
efivarfs: Revert "allow creation of zero length files"
x86/efi/mixed: Move mixed mode startup code into libstub
x86/efi/mixed: Simplify and document thunking logic
x86/efi/mixed: Remove dependency on legacy startup_32 code
x86/efi/mixed: Set up 1:1 mapping of lower 4GiB in the stub
x86/efi/mixed: Factor out and clean up long mode entry
x86/efi/mixed: Check CPU compatibility without relying on verify_cpu()
x86/efistub: Merge PE and handover entrypoints
Pull x86 boot code updates from Ingo Molnar:
- Memblock setup and other early boot code cleanups (Mike Rapoport)
- Export e820_table_kexec[] to sysfs (Dave Young)
- Baby steps of adding relocate_kernel() debugging support (David
Woodhouse)
- Replace open-coded parity calculation with parity8() (Kuan-Wei Chiu)
- Move the LA57 trampoline to separate source file (Ard Biesheuvel)
- Misc micro-optimizations (Uros Bizjak)
- Drop obsolete E820_TYPE_RESERVED_KERN and related code (Mike
Rapoport)
* tag 'x86-boot-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kexec: Add relocate_kernel() debugging support: Load a GDT
x86/boot: Move the LA57 trampoline to separate source file
x86/boot: Do not test if AC and ID eflags are changeable on x86_64
x86/bootflag: Replace open-coded parity calculation with parity8()
x86/bootflag: Micro-optimize sbf_write()
x86/boot: Add missing has_cpuflag() prototype
x86/kexec: Export e820_table_kexec[] to sysfs
x86/boot: Change some static bootflag functions to bool
x86/e820: Drop obsolete E820_TYPE_RESERVED_KERN and related code
x86/boot: Split parsing of boot_params into the parse_boot_params() helper function
x86/boot: Split kernel resources setup into the setup_kernel_resources() helper function
x86/boot: Move setting of memblock parameters to e820__memblock_setup()
Pull x86 build updates from Ingo Molnar:
- Drop CRC-32 checksum and the build tool that generates it (Ard
Biesheuvel)
- Fix broken copy command in genimage.sh when making isoimage (Nir
Lichtman)
* tag 'x86-build-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Add back some padding for the CRC-32 checksum
x86/boot: Drop CRC-32 checksum and the build tool that generates it
x86/build: Fix broken copy command in genimage.sh when making isoimage
The toplevel Makefile already provides -fmacro-prefix-map as part of
KBUILD_CPPFLAGS. In contrast to the KBUILD_CFLAGS and KBUILD_AFLAGS
variables, KBUILD_CPPFLAGS is not redefined in the architecture specific
Makefiles. Therefore the toplevel KBUILD_CPPFLAGS do apply just fine, to
both C and ASM sources.
The custom configuration was necessary when it was added in
commit 9e2276fa6e ("arch/x86/boot: Use prefix map to avoid embedded
paths") but has since become unnecessary in commit a716bd7432
("kbuild: use -fmacro-prefix-map for .S sources").
Drop the now unnecessary custom prefix map configuration.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Instead of generating the vmlinux.relocs file (needed by the
decompressor build to construct the KASLR relocation tables) as a
vmlinux postlink step, which is dubious because it depends on data that
is stripped from vmlinux before the build completes, generate it from
vmlinux.unstripped, which has been introduced specifically for this
purpose.
This ensures that each artifact is rebuilt as needed, rather than as a
side effect of another build rule.
This effectively reverts commit
9d9173e9ce ("x86/build: Avoid relocation information in final vmlinux")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
To permit the EFI stub to call this code even when building the kernel
without the legacy decompressor, move the trampoline out of the latter's
startup code.
This is part of an ongoing WIP effort on my part to make the existing,
generic EFI zboot format work on x86 as well.
No functional change intended.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250313120324.1095968-2-ardb+git@google.com
Apart from some sanity checks on the size of setup.bin, the only
remaining task carried out by the arch/x86/boot/tools/build.c build tool
is generating the CRC-32 checksum of the bzImage. This feature was added
in commit
7d6e737c8d ("x86: add a crc32 checksum to the kernel image.")
without any motivation (or any commit log text, for that matter). This
checksum is not verified by any known bootloader, and given that
a) the checksum of the entire bzImage is reported by most tools (zlib,
rhash) as 0xffffffff and not 0x0 as documented,
b) the checksum is corrupted when the image is signed for secure boot,
which means that no distro ships x86 images with valid CRCs,
it seems quite unlikely that this checksum is being used, so let's just
drop it, along with the tool that generates it.
Instead, use simple file concatenation and truncation to combine the two
pieces into bzImage, and replace the checks on the size of the setup
block with a couple of ASSERT()s in the linker script.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250307164801.885261-2-ardb+git@google.com
The 5-level paging code parses the command line to look for the 'no5lvl'
string, and does so very early, before sanitize_boot_params() has been
called and has been given the opportunity to wipe bogus data from the
fields in boot_params that are not covered by struct setup_header, and
are therefore supposed to be initialized to zero by the bootloader.
This triggers an early boot crash when using syslinux-efi to boot a
recent kernel built with CONFIG_X86_5LEVEL=y and CONFIG_EFI_STUB=n, as
the 0xff padding that now fills the unused PE/COFF header is copied into
boot_params by the bootloader, and interpreted as the top half of the
command line pointer.
Fix this by sanitizing the boot_params before use. Note that there is no
harm in calling this more than once; subsequent invocations are able to
spot that the boot_params have already been cleaned up.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org> # v6.1+
Link: https://lore.kernel.org/r/20250306155915.342465-2-ardb+git@google.com
Closes: https://lore.kernel.org/all/202503041549.35913.ulrich.gemkow@ikr.uni-stuttgart.de
The EFI mixed mode code has been decoupled from the legacy decompressor,
in order to be able to reuse it with generic EFI zboot images for x86.
Move the source file into the libstub source directory to facilitate
this.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Now that the GDT/IDT and data segment selector preserve/restore logic
has been removed from the boot-time EFI mixed mode thunking routines,
the remaining logic to handle the function arguments can be simplified:
the setup of the arguments on the stack can be moved into the 32-bit
callee, which is able to use a more idiomatic sequence of PUSH
instructions.
This, in turn, allows the far call and far return to be issued using
plain LCALL and LRET instructions, removing the need to set up the
return explicitly.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The EFI mixed mode startup code calls into startup_32 in the legacy
decompressor with a mocked up boot_params struct, only to get it to set
up the 1:1 mapping of the lower 4 GiB of memory and switch to a GDT that
supports 64-bit mode.
In order to be able to reuse the EFI mixed mode startup code in EFI
zboot images, which do not incorporate the legacy decompressor code,
decouple it, by dealing with the GDT and IDT directly.
Doing so makes it possible to construct a GDT that is compatible with
the one the firmware uses, with one additional entry for a 64-bit mode
code segment appended. This removes the need entirely to switch between
GDTs and IDTs or data segment selector values and all of this code can
be removed.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
In preparation for dropping the dependency on startup_32 entirely in the
next patch, add the code that sets up the 1:1 mapping of the lower 4 GiB
of system RAM to the mixed mode stub.
The reload of CR3 after the long mode switch will be removed in a
subsequent patch, when it is no longer needed.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Entering long mode involves setting the EFER_LME and CR4.PAE bits before
enabling paging by setting CR0.PG bit.
It also involves disabling interrupts, given that the firmware's 32-bit
IDT becomes invalid as soon as the CPU transitions into long mode.
Reloading the CR3 register is not necessary at boot time, given that the
EFI firmware as well as the kernel's EFI stub use a 1:1 mapping of the
32-bit addressable memory in the system.
Break out this code into a separate helper for clarity, and so that it
can be reused in a subsequent patch.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
In order for the EFI mixed mode startup code to be reusable in a context
where the legacy decompressor is not used, replace the call to
verify_cpu() [which performs an elaborate set of checks] with a simple
check against the 'long mode' bit in the appropriate CPUID leaf.
This is reasonable, given that EFI support is implied when booting in
this manner, and so there is no need to consider very old CPUs when
performing this check.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The difference between the PE and handover entrypoints in the EFI stub
is that the former allocates a struct boot_params whereas the latter
expects one from the caller. Currently, these are two completely
separate entrypoints, duplicating some logic and both relying of
efi_exit() to return straight back to the firmware on an error.
Simplify this by making the PE entrypoint call the handover entrypoint
with NULL as the argument for the struct boot_params parameter. This
makes the code easier to follow, and removes the need to support two
different calling conventions in the mixed mode asm code.
While at it, move the assignment of boot_params_ptr into the function
that actually calls into the legacy decompressor, which is where its
value is required.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull x86 cleanups from Ingo Molnar:
"Miscellaneous x86 cleanups and typo fixes, and also the removal of
the 'disablelapic' boot parameter"
* tag 'x86-cleanups-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioapic: Remove a stray tab in the IO-APIC type string
x86/cpufeatures: Remove "AMD" from the comments to the AMD-specific leaf
Documentation/kernel-parameters: Fix a typo in kvm.enable_virt_at_load text
x86/cpu: Fix typo in x86_match_cpu()'s doc
x86/apic: Remove "disablelapic" cmdline option
Documentation: Merge x86-specific boot options doc into kernel-parameters.txt
x86/ioremap: Remove unused size parameter in remapping functions
x86/ioremap: Simplify setup_data mapping variants
x86/boot/compressed: Remove unused header includes from kaslr.c
Accessing guest video memory/RAM in the decompressor causes guest
termination as the boot stage2 #VC handler for SEV-ES/SNP systems does
not support MMIO handling.
This issue is observed during a SEV-ES/SNP guest kexec as kexec -c adds
screen_info to the boot parameters passed to the second kernel, which
causes console output to be dumped to both video and serial.
As the decompressor output gets cleared really fast, it is preferable to
get the console output only on serial, hence, skip accessing the video
RAM during decompressor stage to prevent guest termination.
Serial console output during decompressor stage works as boot stage2 #VC
handler already supports handling port I/O.
[ bp: Massage. ]
Suggested-by: Borislav Petkov (AMD) <bp@alien8.de>
Suggested-by: Thomas Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/8a55ea86524c686e575d273311acbe57ce8cee23.1722520012.git.ashish.kalra@amd.com
Pull EFI updates from Ard Biesheuvel:
"Note the removal of the EFI fake memory map support - this is believed
to be unused and no longer worth supporting. However, we could easily
bring it back if needed.
With recent developments regarding confidential VMs and unaccepted
memory, combined with kexec, creating a known inaccurate view of the
firmware's memory map and handing it to the OS is a feature we can
live without, hence the removal. Alternatively, I could imagine making
this feature mutually exclusive with those confidential VM related
features, but let's try simply removing it first.
Summary:
- Drop support for the 'fake' EFI memory map on x86
- Add an SMBIOS based tweak to the EFI stub instructing the firmware
on x86 Macbook Pros to keep both GPUs enabled
- Replace 0-sized array with flexible array in EFI memory attributes
table handling
- Drop redundant BSS clearing when booting via the native PE
entrypoint on x86
- Avoid returning EFI_SUCCESS when aborting on an out-of-memory
condition
- Cosmetic tweak for arm64 KASLR loading logic"
* tag 'efi-next-for-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array
efi: Rename efi_early_memdesc_ptr() to efi_memdesc_ptr()
arm64/efistub: Clean up KASLR logic
x86/efistub: Drop redundant clearing of BSS
x86/efistub: Avoid returning EFI_SUCCESS on error
x86/efistub: Call Apple set_os protocol on dual GPU Intel Macs
x86/efistub: Enable SMBIOS protocol handling for x86
efistub/smbios: Simplify SMBIOS enumeration API
x86/efi: Drop support for fake EFI memory maps
Pull x86 SEV updates from Borislav Petkov:
- Add support for running the kernel in a SEV-SNP guest, over a Secure
VM Service Module (SVSM).
When running over a SVSM, different services can run at different
protection levels, apart from the guest OS but still within the
secure SNP environment. They can provide services to the guest, like
a vTPM, for example.
This series adds the required facilities to interface with such a
SVSM module.
- The usual fixlets, refactoring and cleanups
[ And as always: "SEV" is AMD's "Secure Encrypted Virtualization".
I can't be the only one who gets all the newer x86 TLA's confused,
can I?
- Linus ]
* tag 'x86_sev_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation/ABI/configfs-tsm: Fix an unexpected indentation silly
x86/sev: Do RMP memory coverage check after max_pfn has been set
x86/sev: Move SEV compilation units
virt: sev-guest: Mark driver struct with __refdata to prevent section mismatch
x86/sev: Allow non-VMPL0 execution when an SVSM is present
x86/sev: Extend the config-fs attestation support for an SVSM
x86/sev: Take advantage of configfs visibility support in TSM
fs/configfs: Add a callback to determine attribute visibility
sev-guest: configfs-tsm: Allow the privlevel_floor attribute to be updated
virt: sev-guest: Choose the VMPCK key based on executing VMPL
x86/sev: Provide guest VMPL level to userspace
x86/sev: Provide SVSM discovery support
x86/sev: Use the SVSM to create a vCPU when not in VMPL0
x86/sev: Perform PVALIDATE using the SVSM when not at VMPL0
x86/sev: Use kernel provided SVSM Calling Areas
x86/sev: Check for the presence of an SVSM in the SNP secrets page
x86/irqflags: Provide native versions of the local_irq_save()/restore()
Pull x86 cleanups from Borislav Petkov:
- Remove an unused function and the documentation of an already removed
cmdline parameter
* tag 'x86_cleanups_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Remove unused function __fortify_panic()
Documentation: Remove "mfgpt_irq=" from the kernel-parameters.txt file
Between kexec and confidential VM support, handling the EFI memory maps
correctly on x86 is already proving to be rather difficult (as opposed
to other EFI architectures which manage to never modify the EFI memory
map to begin with)
EFI fake memory map support is essentially a development hack (for
testing new support for the 'special purpose' and 'more reliable' EFI
memory attributes) that leaked into production code. The regions marked
in this manner are not actually recognized as such by the firmware
itself or the EFI stub (and never have), and marking memory as 'more
reliable' seems rather futile if the underlying memory is just ordinary
RAM.
Marking memory as 'special purpose' in this way is also dubious, but may
be in use in production code nonetheless. However, the same should be
achievable by using the memmap= command line option with the ! operator.
EFI fake memmap support is not enabled by any of the major distros
(Debian, Fedora, SUSE, Ubuntu) and does not exist on other
architectures, so let's drop support for it.
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The PVALIDATE instruction can only be performed at VMPL0. If an SVSM is
present, it will be running at VMPL0 while the guest itself is then
running at VMPL1 or a lower privilege level.
In that case, use the SVSM_CORE_PVALIDATE call to perform memory
validation instead of issuing the PVALIDATE instruction directly.
The validation of a single 4K page is now explicitly identified as such
in the function name, pvalidate_4k_page(). The pvalidate_pages()
function is used for validating 1 or more pages at either 4K or 2M in
size. Each function, however, determines whether it can issue the
PVALIDATE directly or whether the SVSM needs to be invoked.
[ bp: Touchups. ]
[ Tom: fold in a fix for Coconut SVSM:
https://lore.kernel.org/r/234bb23c-d295-76e5-a690-7ea68dc1118b@amd.com ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/4c4017d8b94512d565de9ccb555b1a9f8983c69c.1717600736.git.thomas.lendacky@amd.com
That function is only used when the kernel is compiled with FORTIFY_SOURCE and
when the kernel proper string.h header is used. The decompressor code doesn't
use the kernel proper header but has local copy which doesn't contain any
fortified implementations of the various string functions. As such
__fortify_panic() can never be called from the decompressor so remove it.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240613110837.300273-1-nik.borisov@suse.com
This is a re-commit of
da05b143a3 ("x86/boot: Don't add the EFI stub to targets")
after the tagged patch incorrectly reverted it.
vmlinux-objs-y is added to targets, with an assumption that they are all
relative to $(obj); adding a $(objtree)/drivers/... path causes the
build to incorrectly create a useless
arch/x86/boot/compressed/drivers/... directory tree.
Fix this just by using a different make variable for the EFI stub.
Fixes: cb8bda8ad4 ("x86/boot/compressed: Rename efi_thunk_64.S to efi-mixed.S")
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: stable@vger.kernel.org # v6.1+
Link: https://lore.kernel.org/r/xm267ceukksz.fsf@bsegall.svl.corp.google.com
During early boot phases, check for the presence of an SVSM when running
as an SEV-SNP guest.
An SVSM is present if not running at VMPL0 and the 64-bit value at offset
0x148 into the secrets page is non-zero. If an SVSM is present, save the
SVSM Calling Area address (CAA), located at offset 0x150 into the secrets
page, and set the VMPL level of the guest, which should be non-zero, to
indicate the presence of an SVSM.
[ bp: Touchups. ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/9d3fe161be93d4ea60f43c2a3f2c311fe708b63b.1717600736.git.thomas.lendacky@amd.com
Pull Kbuild updates from Masahiro Yamada:
- Avoid 'constexpr', which is a keyword in C23
- Allow 'dtbs_check' and 'dt_compatible_check' run independently of
'dt_binding_check'
- Fix weak references to avoid GOT entries in position-independent code
generation
- Convert the last use of 'optional' property in arch/sh/Kconfig
- Remove support for the 'optional' property in Kconfig
- Remove support for Clang's ThinLTO caching, which does not work with
the .incbin directive
- Change the semantics of $(src) so it always points to the source
directory, which fixes Makefile inconsistencies between upstream and
downstream
- Fix 'make tar-pkg' for RISC-V to produce a consistent package
- Provide reasonable default coverage for objtool, sanitizers, and
profilers
- Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc.
- Remove the last use of tristate choice in drivers/rapidio/Kconfig
- Various cleanups and fixes in Kconfig
* tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits)
kconfig: use sym_get_choice_menu() in sym_check_prop()
rapidio: remove choice for enumeration
kconfig: lxdialog: remove initialization with A_NORMAL
kconfig: m/nconf: merge two item_add_str() calls
kconfig: m/nconf: remove dead code to display value of bool choice
kconfig: m/nconf: remove dead code to display children of choice members
kconfig: gconf: show checkbox for choice correctly
kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal
Makefile: remove redundant tool coverage variables
kbuild: provide reasonable defaults for tool coverage
modules: Drop the .export_symbol section from the final modules
kconfig: use menu_list_for_each_sym() in sym_check_choice_deps()
kconfig: use sym_get_choice_menu() in conf_write_defconfig()
kconfig: add sym_get_choice_menu() helper
kconfig: turn defaults and additional prompt for choice members into error
kconfig: turn missing prompt for choice members into error
kconfig: turn conf_choice() into void function
kconfig: use linked list in sym_set_changed()
kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED
kconfig: gconf: remove debug code
...
Pull x86 SEV updates from Borislav Petkov:
- Small cleanups and improvements
* tag 'x86_sev_for_v6.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Make the VMPL0 checking more straight forward
x86/sev: Rename snp_init() in boot/compressed/sev.c
x86/sev: Shorten struct name snp_secrets_page_layout to snp_secrets_page
Now Kbuild provides reasonable defaults for objtool, sanitizers, and
profilers.
Remove redundant variables.
Note:
This commit changes the coverage for some objects:
- include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV
- include arch/sparc/vdso/vdso-image-*.o into UBSAN
- include arch/sparc/vdso/vma.o into UBSAN
- include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
- include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
- include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
- include arch/x86/entry/vdso/vma.o into GCOV, KCOV
- include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV
I believe these are positive effects because all of them are kernel
space objects.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
The snp_init() function in boot/compressed/sev.c is local to that file, is
not called from outside of the file and is independent of the snp_init()
function in kernel/sev.c. Change the name to better differentiate when
each function is used.
Move the renamed snp_init() and related functions up in the file to avoid
having to add a forward declaration and make the function static.
No functional change.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/afda29585c2724b9698003f24cefa77eb35f4ffb.1713974291.git.thomas.lendacky@amd.com
The early 64-bit boot code must be entered with a 1:1 mapping of the
bootable image, but it cannot operate without a 1:1 mapping of all the
assets in memory that it accesses, and therefore, it creates such
mappings for all known assets upfront, and additional ones on demand
when a page fault happens on a memory address.
These mappings are created with the global bit G set, as the flags used
to create page table descriptors are based on __PAGE_KERNEL_LARGE_EXEC
defined by the core kernel, even though the context where these mappings
are used is very different.
This means that the TLB maintenance carried out by the decompressor is
not sufficient if it is entered with CR4.PGE enabled, which has been
observed to happen with the stage0 bootloader of project Oak. While this
is a dubious practice if no global mappings are being used to begin
with, the decompressor is clearly at fault here for creating global
mappings and not performing the appropriate TLB maintenance.
Since commit:
f97b67a773 ("x86/decompressor: Only call the trampoline when changing paging levels")
CR4 is no longer modified by the decompressor if no change in the number
of paging levels is needed. Before that, CR4 would always be set to a
consistent value with PGE cleared.
So let's reinstate a simplified version of the original logic to put CR4
into a known state, and preserve the PAE, MCE and LA57 bits, none of
which can be modified freely at this point (PAE and LA57 cannot be
changed while running in long mode, and MCE cannot be cleared when
running under some hypervisors).
This effectively clears PGE and works around the project Oak bug.
Fixes: f97b67a773 ("x86/decompressor: Only call the trampoline when ...")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240410151354.506098-2-ardb+git@google.com
The pure EFI stub entry point does not take a struct boot_params from
the boot loader, but creates it from scratch, and populates only the
fields that still have meaning in this context (command line, initrd
base and size, etc)
The original mixed mode implementation used the EFI handover protocol
instead, where the boot loader (i.e., GRUB) populates a boot_params
struct and passes it to a special Linux specific EFI entry point that
takes the boot_params pointer as its third argument.
When the new mixed mode implementation was introduced, using a special
32-bit PE entrypoint in the 64-bit kernel, it adopted the pure approach,
and relied on the EFI stub to create the struct boot_params. This is
preferred because it makes the bootloader side much easier to implement,
as it does not need any x86-specific knowledge on how struct boot_params
and struct setup_header are put together. This mixed mode implementation
was adopted by systemd-boot version 252 and later.
When commit
e2ab9eab32 ("x86/boot/compressed: Move 32-bit entrypoint code into .text section")
refactored this code and moved it out of head_64.S, the fact that ESI
was populated with the address of the base of the image was overlooked,
and to simplify the code flow, ESI is now zeroed and stored to memory
unconditionally in shared code, so that the NULL-ness of that variable
can still be used later to determine which mixed mode boot protocol is
in use.
With ESI pointing to the base of the image, it can serve as a struct
boot_params pointer for startup_32(), which only accesses the init_data
and kernel_alignment fields (and the scratch field as a temporary
stack). Zeroing ESI means that those accesses produce garbage now, even
though things appear to work if the first page of memory happens to be
zeroed, and the region right before LOAD_PHYSICAL_ADDR (== 16 MiB)
happens to be free.
The solution is to pass a special, temporary struct boot_params to
startup_32() via ESI, one that is sufficient for getting it to create
the page tables correctly and is discarded right after. This involves
setting a minimal alignment of 4k, only to get the statically allocated
page tables line up correctly, and setting init_size to the executable
image size (_end - startup_32). This ensures that the page tables are
covered by the static footprint of the PE image.
Given that EFI boot no longer calls the decompressor and no longer pads
the image to permit the decompressor to execute in place, the same
temporary struct boot_params should be used in the EFI handover protocol
based mixed mode implementation as well, to prevent the page tables from
being placed outside of allocated memory.
Fixes: e2ab9eab32 ("x86/boot/compressed: Move 32-bit entrypoint code into .text section")
Cc: <stable@kernel.org> # v6.1+
Closes: https://lore.kernel.org/all/20240321150510.GI8211@craftyguy.net/
Reported-by: Clayton Craft <clayton@craftyguy.net>
Tested-by: Clayton Craft <clayton@craftyguy.net>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull EFI fixes from Ard Biesheuvel:
- Fix logic that is supposed to prevent placement of the kernel image
below LOAD_PHYSICAL_ADDR
- Use the firmware stack in the EFI stub when running in mixed mode
- Clear BSS only once when using mixed mode
- Check efi.get_variable() function pointer for NULL before trying to
call it
* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: fix panic in kdump kernel
x86/efistub: Don't clear BSS twice in mixed mode
x86/efistub: Call mixed mode boot services on the firmware's stack
efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address
Normally, the EFI stub calls into the EFI boot services using the stack
that was live when the stub was entered. According to the UEFI spec,
this stack needs to be at least 128k in size - this might seem large but
all asynchronous processing and event handling in EFI runs from the same
stack and so quite a lot of space may be used in practice.
In mixed mode, the situation is a bit different: the bootloader calls
the 32-bit EFI stub entry point, which calls the decompressor's 32-bit
entry point, where the boot stack is set up, using a fixed allocation
of 16k. This stack is still in use when the EFI stub is started in
64-bit mode, and so all calls back into the EFI firmware will be using
the decompressor's limited boot stack.
Due to the placement of the boot stack right after the boot heap, any
stack overruns have gone unnoticed. However, commit
5c4feadb00 ("x86/decompressor: Move global symbol references to C code")
moved the definition of the boot heap into C code, and now the boot
stack is placed right at the base of BSS, where any overruns will
corrupt the end of the .data section.
While it would be possible to work around this by increasing the size of
the boot stack, doing so would affect all x86 systems, and mixed mode
systems are a tiny (and shrinking) fraction of the x86 installed base.
So instead, record the firmware stack pointer value when entering from
the 32-bit firmware, and switch to this stack every time a EFI boot
service call is made.
Cc: <stable@kernel.org> # v6.1+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull MM updates from Andrew Morton:
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...
Pull EFI updates from Ard Biesheuvel:
- Measure initrd and command line using the CC protocol if the ordinary
TCG2 protocol is not implemented, typically on TDX confidential VMs
- Avoid creating mappings that are both writable and executable while
running in the EFI boot services. This is a prerequisite for getting
the x86 shim loader signed by MicroSoft again, which allows the
distros to install on x86 PCs that ship with EFI secure boot enabled.
- API update for struct platform_driver::remove()
* tag 'efi-next-for-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
virt: efi_secret: Convert to platform remove callback returning void
x86/efistub: Remap kernel text read-only before dropping NX attribute
efi/libstub: Add get_event_log() support for CC platforms
efi/libstub: Measure into CC protocol if TCG2 protocol is absent
efi/libstub: Add Confidential Computing (CC) measurement typedefs
efi/tpm: Use symbolic GUID name from spec for final events table
efi/libstub: Use TPM event typedefs from the TCG PC Client spec
Pull hardening updates from Kees Cook:
"As is pretty normal for this tree, there are changes all over the
place, especially for small fixes, selftest improvements, and improved
macro usability.
Some header changes ended up landing via this tree as they depended on
the string header cleanups. Also, a notable set of changes is the work
for the reintroduction of the UBSAN signed integer overflow sanitizer
so that we can continue to make improvements on the compiler side to
make this sanitizer a more viable future security hardening option.
Summary:
- string.h and related header cleanups (Tanzir Hasan, Andy
Shevchenko)
- VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev,
Harshit Mogalapalli)
- selftests/powerpc: Fix load_unaligned_zeropad build failure
(Michael Ellerman)
- hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn)
- Handle tail call optimization better in LKDTM (Douglas Anderson)
- Use long form types in overflow.h (Andy Shevchenko)
- Add flags param to string_get_size() (Andy Shevchenko)
- Add Coccinelle script for potential struct_size() use (Jacob
Keller)
- Fix objtool corner case under KCFI (Josh Poimboeuf)
- Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng)
- Add str_plural() helper (Michal Wajdeczko, Kees Cook)
- Ignore relocations in .notes section
- Add comments to explain how __is_constexpr() works
- Fix m68k stack alignment expectations in stackinit Kunit test
- Convert string selftests to KUnit
- Add KUnit tests for fortified string functions
- Improve reporting during fortified string warnings
- Allow non-type arg to type_max() and type_min()
- Allow strscpy() to be called with only 2 arguments
- Add binary mode to leaking_addresses scanner
- Various small cleanups to leaking_addresses scanner
- Adding wrapping_*() arithmetic helper
- Annotate initial signed integer wrap-around in refcount_t
- Add explicit UBSAN section to MAINTAINERS
- Fix UBSAN self-test warnings
- Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL
- Reintroduce UBSAN's signed overflow sanitizer"
* tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits)
selftests/powerpc: Fix load_unaligned_zeropad build failure
string: Convert helpers selftest to KUnit
string: Convert selftest to KUnit
sh: Fix build with CONFIG_UBSAN=y
compiler.h: Explain how __is_constexpr() works
overflow: Allow non-type arg to type_max() and type_min()
VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()
lib/string_helpers: Add flags param to string_get_size()
x86, relocs: Ignore relocations in .notes section
objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks
overflow: Use POD in check_shl_overflow()
lib: stackinit: Adjust target string to 8 bytes for m68k
sparc: vdso: Disable UBSAN instrumentation
kernel.h: Move lib/cmdline.c prototypes to string.h
leaking_addresses: Provide mechanism to scan binary files
leaking_addresses: Ignore input device status lines
leaking_addresses: Use File::Temp for /tmp files
MAINTAINERS: Update LEAKING_ADDRESSES details
fortify: Improve buffer overflow reporting
fortify: Add KUnit tests for runtime overflows
...
