Similar to zboot architectures, implement support for embedding SBAT data
for x86. Put '.sbat' section in between '.data' and '.text' as the former
also covers '.bss' and '.pgtable' and thus must be the last one in the
file.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/20250603091951.57775-1-vkuznets@redhat.com
simplifies the act of creating a pte which addresses the first page in a
folio and reduces the amount of plumbing which architecture must
implement to provide this.
- The 8 patch series "Misc folio patches for 6.16" from Matthew Wilcox
is a shower of largely unrelated folio infrastructure changes which
clean things up and better prepare us for future work.
- The 3 patch series "memory,x86,acpi: hotplug memory alignment
advisement" from Gregory Price adds early-init code to prevent x86 from
leaving physical memory unused when physical address regions are not
aligned to memory block size.
- The 2 patch series "mm/compaction: allow more aggressive proactive
compaction" from Michal Clapinski provides some tuning of the (sadly,
hard-coded (more sadly, not auto-tuned)) thresholds for our invokation
of proactive compaction. In a simple test case, the reduction of a guest
VM's memory consumption was dramatic.
- The 8 patch series "Minor cleanups and improvements to swap freeing
code" from Kemeng Shi provides some code cleaups and a small efficiency
improvement to this part of our swap handling code.
- The 6 patch series "ptrace: introduce PTRACE_SET_SYSCALL_INFO API"
from Dmitry Levin adds the ability for a ptracer to modify syscalls
arguments. At this time we can alter only "system call information that
are used by strace system call tampering, namely, syscall number,
syscall arguments, and syscall return value.
This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.
- The 3 patch series "fs/proc: extend the PAGEMAP_SCAN ioctl to report
guard regions" from Andrei Vagin extends the info returned by the
PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more
efficiently get at the info about guard regions.
- The 2 patch series "Fix parameter passed to page_mapcount_is_type()"
from Gavin Shan implements that fix. No runtime effect is expected
because validate_page_before_insert() happens to fix up this error.
- The 3 patch series "kernel/events/uprobes: uprobe_write_opcode()
rewrite" from David Hildenbrand basically brings uprobe text poking into
the current decade. Remove a bunch of hand-rolled implementation in
favor of using more current facilities.
- The 3 patch series "mm/ptdump: Drop assumption that pxd_val() is u64"
from Anshuman Khandual provides enhancements and generalizations to the
pte dumping code. This might be needed when 128-bit Page Table
Descriptors are enabled for ARM.
- The 12 patch series "Always call constructor for kernel page tables"
from Kevin Brodsky "ensures that the ctor/dtor is always called for
kernel pgtables, as it already is for user pgtables". This permits the
addition of more functionality such as "insert hooks to protect page
tables". This change does result in various architectures performing
unnecesary work, but this is fixed up where it is anticipated to occur.
- The 9 patch series "Rust support for mm_struct, vm_area_struct, and
mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM
structures.
- The 3 patch series "fix incorrectly disallowed anonymous VMA merges"
from Lorenzo Stoakes takes advantage of some VMA merging opportunities
which we've been missing for 15 years.
- The 4 patch series "mm/madvise: batch tlb flushes for MADV_DONTNEED
and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB
flushing. Instead of flushing each address range in the provided iovec,
we batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.
- The 6 patch series "Track node vacancy to reduce worst case allocation
counts" from Sidhartha Kumar makes the maple tree smarter about its node
preallocation. stress-ng mmap performance increased by single-digit
percentages and the amount of unnecessarily preallocated memory was
dramaticelly reduced.
- The 3 patch series "mm/gup: Minor fix, cleanup and improvements" from
Baoquan He removes a few unnecessary things which Baoquan noted when
reading the code.
- The 3 patch series ""Enhance sysfs handling for memory hotplug in
weighted interleave" from Rakie Kim "enhances the weighted interleave
policy in the memory management subsystem by improving sysfs handling,
fixing memory leaks, and introducing dynamic sysfs updates for memory
hotplug support". Fixes things on error paths which we are unlikely to
hit.
- The 7 patch series "mm/damon: auto-tune DAMOS for NUMA setups
including tiered memory" from SeongJae Park introduces new DAMOS quota
goal metrics which eliminate the manual tuning which is required when
utilizing DAMON for memory tiering.
- The 5 patch series "mm/vmalloc.c: code cleanup and improvements" from
Baoquan He provides cleanups and small efficiency improvements which
Baoquan found via code inspection.
- The 2 patch series "vmscan: enforce mems_effective during demotion"
from Gregory Price "changes reclaim to respect cpuset.mems_effective
during demotion when possible". because "presently, reclaim explicitly
ignores cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated." "This is useful for isolating workloads on a
multi-tenant system from certain classes of memory more consistently."
- The 2 patch series ""Clean up split_huge_pmd_locked() and remove
unnecessary folio pointers" from Gavin Guo provides minor cleanups and
efficiency gains in in the huge page splitting and migrating code.
- The 3 patch series "Use kmem_cache for memcg alloc" from Huan Yang
creates a slab cache for `struct mem_cgroup', yielding improved memory
utilization.
- The 4 patch series "add max arg to swappiness in memory.reclaim and
lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness="
argument for memory.reclaim MGLRU's lru_gen. This directs proactive
reclaim to reclaim from only anon folios rather than file-backed folios.
- The 17 patch series "kexec: introduce Kexec HandOver (KHO)" from Mike
Rapoport is the first step on the path to permitting the kernel to
maintain existing VMs while replacing the host kernel via file-based
kexec. At this time only memblock's reserve_mem is preserved.
- The 7 patch series "mm: Introduce for_each_valid_pfn()" from David
Woodhouse provides and uses a smarter way of looping over a pfn range.
By skipping ranges of invalid pfns.
- The 2 patch series "sched/numa: Skip VMA scanning on memory pinned to
one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless
VMA scanning when a task is pinned a single NUMA mode. Dramatic
performance benefits were seen in some real world cases.
- The 2 patch series "JFS: Implement migrate_folio for
jfs_metapage_aops" from Shivank Garg addresses a warning which occurs
during memory compaction when using JFS.
- The 4 patch series "move all VMA allocation, freeing and duplication
logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c
into the more appropriate mm/vma.c.
- The 6 patch series "mm, swap: clean up swap cache mapping helper" from
Kairui Song provides code consolidation and cleanups related to the
folio_index() function.
- The 2 patch series "mm/gup: Cleanup memfd_pin_folios()" from Vishal
Moola does that.
- The 8 patch series "memcg: Fix test_memcg_min/low test failures" from
Waiman Long addresses some bogus failures which are being reported by
the test_memcontrol selftest.
- The 3 patch series "eliminate mmap() retry merge, add .mmap_prepare
hook" from Lorenzo Stoakes commences the deprecation of
file_operations.mmap() in favor of the new
file_operations.mmap_prepare(). The latter is more restrictive and
prevents drivers from messing with things in ways which, amongst other
problems, may defeat VMA merging.
- The 4 patch series "memcg: decouple memcg and objcg stocks"" from
Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's
one. This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.
- The 6 patch series "mm/damon: minor fixups and improvements for code,
tests, and documents" from SeongJae Park is "yet another batch of
miscellaneous DAMON changes. Fix and improve minor problems in code,
tests and documents."
- The 7 patch series "memcg: make memcg stats irq safe" from Shakeel
Butt converts memcg stats to be irq safe. Another step along the way to
making memcg charging and stats updates NMI-safe, a BPF requirement.
- The 4 patch series "Let unmap_hugepage_range() and several related
functions take folio instead of page" from Fan Ni provides folio
conversions in the hugetlb code.
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Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
creating a pte which addresses the first page in a folio and reduces
the amount of plumbing which architecture must implement to provide
this.
- "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
largely unrelated folio infrastructure changes which clean things up
and better prepare us for future work.
- "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
Price adds early-init code to prevent x86 from leaving physical
memory unused when physical address regions are not aligned to memory
block size.
- "mm/compaction: allow more aggressive proactive compaction" from
Michal Clapinski provides some tuning of the (sadly, hard-coded (more
sadly, not auto-tuned)) thresholds for our invokation of proactive
compaction. In a simple test case, the reduction of a guest VM's
memory consumption was dramatic.
- "Minor cleanups and improvements to swap freeing code" from Kemeng
Shi provides some code cleaups and a small efficiency improvement to
this part of our swap handling code.
- "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
adds the ability for a ptracer to modify syscalls arguments. At this
time we can alter only "system call information that are used by
strace system call tampering, namely, syscall number, syscall
arguments, and syscall return value.
This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.
- "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
against /proc/pid/pagemap. This permits CRIU to more efficiently get
at the info about guard regions.
- "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
implements that fix. No runtime effect is expected because
validate_page_before_insert() happens to fix up this error.
- "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
Hildenbrand basically brings uprobe text poking into the current
decade. Remove a bunch of hand-rolled implementation in favor of
using more current facilities.
- "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
Khandual provides enhancements and generalizations to the pte dumping
code. This might be needed when 128-bit Page Table Descriptors are
enabled for ARM.
- "Always call constructor for kernel page tables" from Kevin Brodsky
ensures that the ctor/dtor is always called for kernel pgtables, as
it already is for user pgtables.
This permits the addition of more functionality such as "insert hooks
to protect page tables". This change does result in various
architectures performing unnecesary work, but this is fixed up where
it is anticipated to occur.
- "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
Ryhl adds plumbing to permit Rust access to core MM structures.
- "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
Stoakes takes advantage of some VMA merging opportunities which we've
been missing for 15 years.
- "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
SeongJae Park optimizes process_madvise()'s TLB flushing.
Instead of flushing each address range in the provided iovec, we
batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.
- "Track node vacancy to reduce worst case allocation counts" from
Sidhartha Kumar makes the maple tree smarter about its node
preallocation.
stress-ng mmap performance increased by single-digit percentages and
the amount of unnecessarily preallocated memory was dramaticelly
reduced.
- "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
a few unnecessary things which Baoquan noted when reading the code.
- ""Enhance sysfs handling for memory hotplug in weighted interleave"
from Rakie Kim "enhances the weighted interleave policy in the memory
management subsystem by improving sysfs handling, fixing memory
leaks, and introducing dynamic sysfs updates for memory hotplug
support". Fixes things on error paths which we are unlikely to hit.
- "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
from SeongJae Park introduces new DAMOS quota goal metrics which
eliminate the manual tuning which is required when utilizing DAMON
for memory tiering.
- "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
provides cleanups and small efficiency improvements which Baoquan
found via code inspection.
- "vmscan: enforce mems_effective during demotion" from Gregory Price
changes reclaim to respect cpuset.mems_effective during demotion when
possible. because presently, reclaim explicitly ignores
cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated.
This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently.
- "Clean up split_huge_pmd_locked() and remove unnecessary folio
pointers" from Gavin Guo provides minor cleanups and efficiency gains
in in the huge page splitting and migrating code.
- "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
for `struct mem_cgroup', yielding improved memory utilization.
- "add max arg to swappiness in memory.reclaim and lru_gen" from
Zhongkun He adds a new "max" argument to the "swappiness=" argument
for memory.reclaim MGLRU's lru_gen.
This directs proactive reclaim to reclaim from only anon folios
rather than file-backed folios.
- "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
first step on the path to permitting the kernel to maintain existing
VMs while replacing the host kernel via file-based kexec. At this
time only memblock's reserve_mem is preserved.
- "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
and uses a smarter way of looping over a pfn range. By skipping
ranges of invalid pfns.
- "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
when a task is pinned a single NUMA mode.
Dramatic performance benefits were seen in some real world cases.
- "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
Garg addresses a warning which occurs during memory compaction when
using JFS.
- "move all VMA allocation, freeing and duplication logic to mm" from
Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
appropriate mm/vma.c.
- "mm, swap: clean up swap cache mapping helper" from Kairui Song
provides code consolidation and cleanups related to the folio_index()
function.
- "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.
- "memcg: Fix test_memcg_min/low test failures" from Waiman Long
addresses some bogus failures which are being reported by the
test_memcontrol selftest.
- "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
Stoakes commences the deprecation of file_operations.mmap() in favor
of the new file_operations.mmap_prepare().
The latter is more restrictive and prevents drivers from messing with
things in ways which, amongst other problems, may defeat VMA merging.
- "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
the per-cpu memcg charge cache from the objcg's one.
This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.
- "mm/damon: minor fixups and improvements for code, tests, and
documents" from SeongJae Park is yet another batch of miscellaneous
DAMON changes. Fix and improve minor problems in code, tests and
documents.
- "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
stats to be irq safe. Another step along the way to making memcg
charging and stats updates NMI-safe, a BPF requirement.
- "Let unmap_hugepage_range() and several related functions take folio
instead of page" from Fan Ni provides folio conversions in the
hugetlb code.
* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
mm: pcp: increase pcp->free_count threshold to trigger free_high
mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
mm/hugetlb: pass folio instead of page to unmap_ref_private()
memcg: objcg stock trylock without irq disabling
memcg: no stock lock for cpu hot-unplug
memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
memcg: make count_memcg_events re-entrant safe against irqs
memcg: make mod_memcg_state re-entrant safe against irqs
memcg: move preempt disable to callers of memcg_rstat_updated
memcg: memcg_rstat_updated re-entrant safe against irqs
mm: khugepaged: decouple SHMEM and file folios' collapse
selftests/eventfd: correct test name and improve messages
alloc_tag: check mem_profiling_support in alloc_tag_init
Docs/damon: update titles and brief introductions to explain DAMOS
selftests/damon/_damon_sysfs: read tried regions directories in order
mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
...
- Add support for emitting a .sbat section into the EFI zboot image, so
that downstreams can easily include revocation metadata in the signed
EFI images
- Align PE symbolic constant names with other projects
- Bug fix for the efi_test module
- Log the physical address and size of the EFI memory map when failing
to map it
- A kerneldoc fix for the EFI stub code
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Merge tag 'efi-next-for-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel:
"Not a lot going on in the EFI tree this cycle. The only thing that
stands out is the new support for SBAT metadata, which was a bit
contentious when it was first proposed, because in the initial
incarnation, it would have required us to maintain a revocation index,
and bump it each time a vulnerability affecting UEFI secure boot got
fixed. This was shot down for obvious reasons.
This time, only the changes needed to emit the SBAT section into the
PE/COFF image are being carried upstream, and it is up to the distros
to decide what to put in there when creating and signing the build.
This only has the EFI zboot bits (which the distros will be using for
arm64); the x86 bzImage changes should be arriving next cycle,
presumably via the -tip tree.
Summary:
- Add support for emitting a .sbat section into the EFI zboot image,
so that downstreams can easily include revocation metadata in the
signed EFI images
- Align PE symbolic constant names with other projects
- Bug fix for the efi_test module
- Log the physical address and size of the EFI memory map when
failing to map it
- A kerneldoc fix for the EFI stub code"
* tag 'efi-next-for-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
include: pe.h: Fix PE definitions
efi/efi_test: Fix missing pending status update in getwakeuptime
efi: zboot specific mechanism for embedding SBAT section
efi/libstub: Describe missing 'out' parameter in efi_load_initrd
efi: Improve logging around memmap init
Both Intel and AMD CPUs support 5-level paging, which is expected to
become more widely adopted in the future. All major x86 Linux
distributions have the feature enabled.
Remove CONFIG_X86_5LEVEL and related #ifdeffery for it to make it more readable.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250516123306.3812286-4-kirill.shutemov@linux.intel.com
The main CPUID header <asm/cpuid.h> was originally a storefront for the
headers:
<asm/cpuid/api.h>
<asm/cpuid/leaf_0x2_api.h>
Now that the latter CPUID(0x2) header has been merged into the former,
there is no practical difference between <asm/cpuid.h> and
<asm/cpuid/api.h>.
Migrate all users to the <asm/cpuid/api.h> header, in preparation of
the removal of <asm/cpuid.h>.
Don't remove <asm/cpuid.h> just yet, in case some new code in -next
started using it.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: x86-cpuid@lists.linux.dev
Link: https://lore.kernel.org/r/20250508150240.172915-3-darwi@linutronix.de
The global pseudo-constants 'page_offset_base', 'vmalloc_base' and
'vmemmap_base' are not used extremely early during the boot, and cannot be
used safely until after the KASLR memory randomization code in
kernel_randomize_memory() executes, which may update their values.
So there is no point in setting these variables extremely early, and it
can wait until after the kernel itself is mapped and running from its
permanent virtual mapping.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250513111157.717727-9-ardb+git@google.com
Prepare to resolve conflicts with an upstream series of fixes that conflict
with pending x86 changes:
6f5bf947ba Merge tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Prepare to resolve conflicts with an upstream series of fixes that conflict
with pending x86 changes:
6f5bf947ba Merge tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Signed-off-by: Ingo Molnar <mingo@kernel.org>
During kexec handover (KHO) memory contains data that should be preserved
and this data would be consumed by kexec'ed kernel.
To make sure that the preserved memory is not overwritten, KHO uses
"scratch regions" to bootstrap kexec'ed kernel. These regions are
guaranteed to not have any memory that KHO would preserve and are used as
the only memory the kernel sees during the early boot.
The scratch regions are passed in the setup_data by the first kernel with
other KHO parameters. If the setup_data contains the KHO parameters,
limit randomization to scratch areas only to make sure preserved memory
won't get overwritten.
Since all the pointers in setup_data are represented by u64, they require
double casting (first to unsigned long and then to the actual pointer
type) to compile on 32-bits. This looks goofy out of context, but it is
unfortunately the way that this is handled across the tree. There are at
least a dozen instances of casting like this.
Link: https://lkml.kernel.org/r/20250509074635.3187114-14-changyuanl@google.com
Signed-off-by: Alexander Graf <graf@amazon.com>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Co-developed-by: Changyuan Lyu <changyuanl@google.com>
Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Gowans <jgowans@amazon.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Most of the SEV support code used to reside in a single C source file
that was included in two places: the core kernel, and the decompressor.
The code that is actually shared with the decompressor was moved into a
separate, shared source file under startup/, on the basis that the
decompressor also executes from the early 1:1 mapping of memory.
However, while the elaborate #VC handling and instruction decoding that
it involves is also performed by the decompressor, it does not actually
occur in the core kernel at early boot, and therefore, does not need to
be part of the confined early startup code.
So split off the #VC handling code and move it back into arch/x86/coco
where it came from, into another C source file that is included from
both the decompressor and the core kernel.
Code movement only - no functional change intended.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-31-ardb+git@google.com
The SME encryption startup code populates page tables using the ordinary
set_pXX() helpers, and in a PTI build, these will call out to
__pti_set_user_pgtbl() to manipulate the shadow copy of the page tables
for user space.
This is unneeded for the startup code, which only manipulates the
swapper page tables, and so this call could be avoided in this
particular case. So instead of exposing the ordinary
__pti_set_user_pgtblt() to the startup code after its gets confined into
its own symbol space, provide an alternative which just returns pgd,
which is always correct in the startup context.
Annotate it as __weak for now, this will be dropped in a subsequent
patch.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-40-ardb+git@google.com
As a first step towards disentangling the SEV #VC handling code -which
is shared between the decompressor and the core kernel- from the SEV
startup code, move the decompressor's copy of the instruction decoder
into a separate source file.
Code movement only - no functional change intended.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-30-ardb+git@google.com
sev_snp_enabled() is no longer used outside of the source file that
defines it, so make it static and drop the extern declarations.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-29-ardb+git@google.com
__supported_pte_mask is statically initialized to U64_MAX and never
assigned until long after the startup code executes that creates the
initial page tables. So applying the mask is unnecessary, and can be
avoided.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-27-ardb+git@google.com
Move early_setup_gdt() out of the startup code that is callable from the
1:1 mapping - this is not needed, and instead, it is better to expose
the helper that does reside in __head directly.
This reduces the amount of code that needs special checks for 1:1
execution suitability. In particular, it avoids dealing with the GHCB
page (and its physical address) in startup code, which runs from the
1:1 mapping, making physical to virtual translations ambiguous.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-26-ardb+git@google.com
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
The GNU coreutils version of truncate, which is the original, accepts a
% prefix for the -s size argument which means the file in question
should be padded to a multiple of the given size. This is currently used
to pad the setup block of bzImage to a multiple of 4k before appending
the decompressor.
busybox reimplements truncate but does not support this idiom, and
therefore fails the build since commit
9c54baab44 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")
Since very little build code within the kernel depends on the 'truncate'
utility, work around this incompatibility by avoiding truncate altogether,
and relying on dd to perform the padding.
Fixes: 9c54baab44 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")
Reported-by: <phasta@kernel.org>
Tested-by: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250424101917.1552527-2-ardb+git@google.com
This commits breaks SNP guests:
234cf67fc3 ("x86/sev: Split off startup code from core code")
The SNP guest boots, but no longer has access to the VMPCK keys needed
to communicate with the ASP, which is used, for example, to obtain an
attestation report.
The secrets_pa value is defined as static in both startup.c and
core.c. It is set by a function in startup.c and so when used in
core.c its value will be 0.
Share it again and add the sev_ prefix to put it into the global
SEV symbols namespace.
[ mingo: Renamed to sev_secrets_pa ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Link: https://lore.kernel.org/r/cf878810-81ed-3017-52c6-ce6aa41b5f01@amd.com
objtool already struggles to identify jump tables correctly in non-PIC
code, where the idiom is something like
jmpq *table(,%idx,8)
and the table is a list of absolute addresses of jump targets.
When using -fPIC, both the table reference as well as the jump targets
are emitted in a RIP-relative manner, resulting in something like
leaq table(%rip), %tbl
movslq (%tbl,%idx,4), %offset
addq %offset, %tbl
jmpq *%tbl
and the table is a list of offsets of the jump targets relative to the
start of the entire table.
Considering that this sequence of instructions can be interleaved with
other instructions that have nothing to do with the jump table in
question, it is extremely difficult to infer the control flow by
deriving the jump targets from the indirect jump, the location of the
table and the relative offsets it contains.
So let's not bother and disable jump tables for code built with -fPIC
under arch/x86/boot/startup.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250422210510.600354-2-ardb+git@google.com
Now that the early SEV code is built with -fPIC, RIP_REL_REF() has no
effect and can be dropped.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250418141253.2601348-13-ardb+git@google.com
Move the SEV startup code into arch/x86/boot/startup/, where it will
reside along with other code that executes extremely early, and
therefore needs to be built in a special manner.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250418141253.2601348-12-ardb+git@google.com
Disentangle the SEV core code and the SEV code that is called during
early boot. The latter piece will be moved into startup/ in a subsequent
patch.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250418141253.2601348-11-ardb+git@google.com
In particular we need this fix before applying subsequent changes:
d54d610243 ("x86/boot/sev: Avoid shared GHCB page for early memory acceptance")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Communicating with the hypervisor using the shared GHCB page requires
clearing the C bit in the mapping of that page. When executing in the
context of the EFI boot services, the page tables are owned by the
firmware, and this manipulation is not possible.
So switch to a different API for accepting memory in SEV-SNP guests, one
which is actually supported at the point during boot where the EFI stub
may need to accept memory, but the SEV-SNP init code has not executed
yet.
For simplicity, also switch the memory acceptance carried out by the
decompressor when not booting via EFI - this only involves the
allocation for the decompressed kernel, and is generally only called
after kexec, as normal boot will jump straight into the kernel from the
EFI stub.
Fixes: 6c32117963 ("x86/sev: Add SNP-specific unaccepted memory support")
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: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250404082921.2767593-8-ardb+git@google.com # discussion thread #1
Link: https://lore.kernel.org/r/20250410132850.3708703-2-ardb+git@google.com # discussion thread #2
Link: https://lore.kernel.org/r/20250417202120.1002102-2-ardb+git@google.com # final submission
Current minimum required version of binutils is 2.25,
which supports PAUSE instruction mnemonic.
Replace "REP; NOP" with this proper mnemonic.
No functional change intended.
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://lore.kernel.org/r/20250418080805.83679-2-ubizjak@gmail.com
Minimum version of binutils required to compile the kernel is 2.25.
This version correctly handles the "rep" prefixes, so it is possible
to remove the semicolon, which was used to support ancient versions
of GNU as.
Due to the semicolon, the compiler considers "rep; insn" (or its
alternate "rep\n\tinsn" form) as two separate instructions. Removing
the semicolon makes asm length calculations more accurate, consequently
making scheduling and inlining decisions of the compiler more accurate.
Removing the semicolon also enables assembler checks involving "rep"
prefixes. Trying to assemble e.g. "rep addl %eax, %ebx" results in:
Error: invalid instruction `add' after `rep'
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Mares <mj@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250418071437.4144391-1-ubizjak@gmail.com
When building with CONFIG_LTO_CLANG, there is an error in the x86 boot
startup code because it builds with a different code model than the rest
of the kernel:
ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 2' from vmlinux.a(head64.o at 1302448), and 'i32 1' from vmlinux.a(map_kernel.o at 1314208)
ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 2' from vmlinux.a(common.o at 1306108), and 'i32 1' from vmlinux.a(gdt_idt.o at 1314148)
As this directory is for code that only runs during early system
initialization, LTO is not very important, so filter out the LTO flags
from KBUILD_CFLAGS for arch/x86/boot/startup to resolve the build error.
Fixes: 4cecebf200 ("x86/boot: Move the early GDT/IDT setup code into startup/")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20250414-x86-boot-startup-lto-error-v1-1-7c8bed7c131c@kernel.org
Closes: https://lore.kernel.org/CA+G9fYvnun+bhYgtt425LWxzOmj+8Jf3ruKeYxQSx-F6U7aisg@mail.gmail.com/
Prepare for splitting off parts of the SEV core.c source file into a
file that carries code that must tolerate being called from the early
1:1 mapping. This will allow special build-time handling of thise code,
to ensure that it gets generated in a way that is compatible with the
early execution context.
So create a de-facto internal SEV API and put the definitions into
sev-internal.h. No attempt is made to allow this header file to be
included in arbitrary other sources - this is explicitly not the intent.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250410134117.3713574-20-ardb+git@google.com
RIP_REL_REF() has no effect on code residing in arch/x86/boot/startup,
as it is built with -fPIC. So remove any occurrences from the SME
startup code.
Note the SME is the only caller of cc_set_mask() that requires this, so
drop it from there as well.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250410134117.3713574-19-ardb+git@google.com
Move the SME initialization code, which runs from the 1:1 mapping of
memory as it operates on the kernel virtual mapping, into the new
sub-directory arch/x86/boot/startup/ where all startup code will reside
that needs to tolerate executing from the 1:1 mapping.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250410134117.3713574-18-ardb+git@google.com
Now that __startup_64() is built using -fPIC, RIP_REL_REF() has become a
NOP and can be removed. Only some occurrences of rip_rel_ptr() will
remain, to explicitly take the address of certain global structures in
the 1:1 mapping of memory.
While at it, update the code comment to describe why this is needed.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250410134117.3713574-17-ardb+git@google.com
The startup code that constructs the kernel virtual mapping runs from
the 1:1 mapping of memory itself, and therefore, cannot use absolute
symbol references. Before making changes in subsequent patches, move
this code into a separate source file under arch/x86/boot/startup/ where
all such code will be kept from now on.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250410134117.3713574-16-ardb+git@google.com
Move the early GDT/IDT setup code that runs long before the kernel
virtual mapping is up into arch/x86/boot/startup/, and build it in a way
that ensures that the code tolerates being called from the 1:1 mapping
of memory. The code itself is left unchanged by this patch.
Also tweak the sed symbol matching pattern in the decompressor to match
on lower case 't' or 'b', as these will be emitted by Clang for symbols
with hidden linkage.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250410134117.3713574-15-ardb+git@google.com
The library code built under arch/x86/boot/startup is not intended to be
linked into vmlinux but only into the decompressor and/or the EFI stub.
This means objtool validation is not needed here, and may result in
false positive errors for things like missing retpolines.
So disable it for all objects added to lib-y
Tested-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20250408085254.836788-10-ardb+git@google.com
Linus expressed a strong preference for arch-specific asm code (i.e.,
virtually all of it) to reside under arch/ rather than anywhere else.
So move the EFI mixed mode startup code back, and put it under
arch/x86/boot/startup/ where all shared x86 startup code is going to
live.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20250401133416.1436741-11-ardb+git@google.com
The 5-level paging trampoline is used by both the EFI stub and the
traditional decompressor. Move it out of the decompressor sources into
the newly minted arch/x86/boot/startup/ sub-directory which will hold
startup code that may be shared between the decompressor, the EFI stub
and the kernel proper, and needs to tolerate being called during early
boot, before the kernel virtual mapping has been created.
This will allow the 5-level paging trampoline to be used by EFI boot
images such as zboot that omit the traditional decompressor entirely.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250401133416.1436741-10-ardb+git@google.com
Merge the local include "pgtable.h" -which declares the API of the
5-level paging trampoline- into <asm/boot.h> so that its implementation
in la57toggle.S as well as the calling code can be decoupled from the
traditional decompressor.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250401133416.1436741-9-ardb+git@google.com
- 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
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Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
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"
...
- 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
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Merge tag 'efi-next-for-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
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
We've had this before: when we remove infrastructure to generate files,
the old stale build artifacts still remain in-tree. And when the
infrastructure to generate them is gone, so is the gitignore file for
those build artifacts.
End result: git will see the old generated files, and people will
mistakenly commit them. That's what happened with the 'genheaders' file
not that long ago (see commit 04a3389b35 "Remove stale generated
'genheaders' file").
This time it's commit 9c54baab44 ("x86/boot: Drop CRC-32 checksum and
the build tool that generates it") that removed the 'build' file from
the arch/x86/boot/tools/ subdirectory, and removed the .gitignore file
too (because the whole subdirectory is gone).
And as a result, if you don't do a 'git clean -dqfx' or similar to clean
up your tree, 'git status' will say
Untracked files:
(use "git add <file>..." to include in what will be committed)
arch/x86/boot/tools/
and some hapless sleep-deprived developer will inevitably decide that
that means that they need to 'git add' that directory. Which would
bring back some stale generated file that we most definitely do not want
in the tree.
So when removing directories that had special .gitignore patterns, make
sure to add a new gitignore entry in the parent directory for the no
longer existing subdirectory.
It will avoid mistakes.
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Fixes: 9c54baab44 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- 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)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-boot-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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()
- 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)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-build-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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>
While the GCC and Clang compilers already define __ASSEMBLER__
automatically when compiling assembly code, __ASSEMBLY__ is a
macro that only gets defined by the Makefiles in the kernel.
This can be very confusing when switching between userspace
and kernelspace coding, or when dealing with UAPI headers that
rather should use __ASSEMBLER__ instead. So let's standardize on
the __ASSEMBLER__ macro that is provided by the compilers now.
This is mostly a mechanical patch (done with a simple "sed -i"
statement), with some manual tweaks in <asm/frame.h>, <asm/hw_irq.h>
and <asm/setup.h> that mentioned this macro in comments with some
missing underscores.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250314071013.1575167-38-thuth@redhat.com
Introduce an AWK script to auto-generate the <asm/cpufeaturemasks.h> header
with required and disabled feature masks based on <asm/cpufeatures.h>
and the current build config.
Thus for any CPU feature with a build config, e.g., X86_FRED, simply add:
config X86_DISABLED_FEATURE_FRED
def_bool y
depends on !X86_FRED
to arch/x86/Kconfig.cpufeatures, instead of adding a conditional CPU
feature disable flag, e.g., DISABLE_FRED.
Lastly, the generated required and disabled feature masks will be added to
their corresponding feature masks for this particular compile-time
configuration.
[ Xin: build integration improvements ]
[ mingo: Improved changelog and comments ]
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250305184725.3341760-3-xin@zytor.com
