linux-toradex.git/arch/riscv/include/asm, branch master Linux kernel for Apalis and Colibri modules riscv: cfi: clear CFI lock status in start_thread() 2026-04-05T00:40:58+00:00 Zong Li zong.li@sifive.com 2026-04-05T00:40:58+00:00 a6ede084c4b7cd6ecd0d31d5292336e556901bd7 When libc locks the CFI status through the following prctl: - PR_LOCK_SHADOW_STACK_STATUS - PR_LOCK_INDIR_BR_LP_STATUS A newly execd address space will inherit the lock status if it does not clear the lock bits. Since the lock bits remain set, libc will later fail to enable the landing pad and shadow stack. Signed-off-by: Zong Li <zong.li@sifive.com> Link: https://patch.msgid.link/20260323065640.4045713-1-zong.li@sifive.com [pjw@kernel.org: ensure we unlock before changing state; cleaned up subject line] Signed-off-by: Paul Walmsley <pjw@kernel.org> 
When libc locks the CFI status through the following prctl:
 - PR_LOCK_SHADOW_STACK_STATUS
 - PR_LOCK_INDIR_BR_LP_STATUS

A newly execd address space will inherit the lock status
if it does not clear the lock bits. Since the lock bits
remain set, libc will later fail to enable the landing
pad and shadow stack.

Signed-off-by: Zong Li <zong.li@sifive.com>
Link: https://patch.msgid.link/20260323065640.4045713-1-zong.li@sifive.com
[pjw@kernel.org: ensure we unlock before changing state; cleaned up subject line]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
riscv: make runtime const not usable by modules 2026-04-05T00:37:31+00:00 Jisheng Zhang jszhang@kernel.org 2026-02-21T02:37:31+00:00 57f0253bc1538446ee46a4550fe85d91235fb678 Similar as commit 284922f4c563 ("x86: uaccess: don't use runtime-const rewriting in modules") does, make riscv's runtime const not usable by modules too, to "make sure this doesn't get forgotten the next time somebody wants to do runtime constant optimizations". The reason is well explained in the above commit: "The runtime-const infrastructure was never designed to handle the modular case, because the constant fixup is only done at boot time for core kernel code." Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Link: https://patch.msgid.link/20260221023731.3476-1-jszhang@kernel.org Signed-off-by: Paul Walmsley <pjw@kernel.org> 
Similar as commit 284922f4c563 ("x86: uaccess: don't use runtime-const
rewriting in modules") does, make riscv's runtime const not usable by
modules too, to "make sure this doesn't get forgotten the next time
somebody wants to do runtime constant optimizations". The reason is
well explained in the above commit: "The runtime-const infrastructure
was never designed to handle the modular case, because the constant
fixup is only done at boot time for core kernel code."

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://patch.msgid.link/20260221023731.3476-1-jszhang@kernel.org
Signed-off-by: Paul Walmsley <pjw@kernel.org>
 Merge tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux 2026-02-13T03:17:44+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-02-13T03:17:44+00:00 cee73b1e840c154f64ace682cb477c1ae2e29cc4 Pull RISC-V updates from Paul Walmsley: - Add support for control flow integrity for userspace processes. This is based on the standard RISC-V ISA extensions Zicfiss and Zicfilp - Improve ptrace behavior regarding vector registers, and add some selftests - Optimize our strlen() assembly - Enable the ISO-8859-1 code page as built-in, similar to ARM64, for EFI volume mounting - Clean up some code slightly, including defining copy_user_page() as copy_page() rather than memcpy(), aligning us with other architectures; and using max3() to slightly simplify an expression in riscv_iommu_init_check() * tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits) riscv: lib: optimize strlen loop efficiency selftests: riscv: vstate_exec_nolibc: Use the regular prctl() function selftests: riscv: verify ptrace accepts valid vector csr values selftests: riscv: verify ptrace rejects invalid vector csr inputs selftests: riscv: verify syscalls discard vector context selftests: riscv: verify initial vector state with ptrace selftests: riscv: test ptrace vector interface riscv: ptrace: validate input vector csr registers riscv: csr: define vtype register elements riscv: vector: init vector context with proper vlenb riscv: ptrace: return ENODATA for inactive vector extension kselftest/riscv: add kselftest for user mode CFI riscv: add documentation for shadow stack riscv: add documentation for landing pad / indirect branch tracking riscv: create a Kconfig fragment for shadow stack and landing pad support arch/riscv: add dual vdso creation logic and select vdso based on hw arch/riscv: compile vdso with landing pad and shadow stack note riscv: enable kernel access to shadow stack memory via the FWFT SBI call riscv: add kernel command line option to opt out of user CFI riscv/hwprobe: add zicfilp / zicfiss enumeration in hwprobe ... 
Pull RISC-V updates from Paul Walmsley:

 - Add support for control flow integrity for userspace processes.

   This is based on the standard RISC-V ISA extensions Zicfiss and
   Zicfilp

 - Improve ptrace behavior regarding vector registers, and add some
   selftests

 - Optimize our strlen() assembly

 - Enable the ISO-8859-1 code page as built-in, similar to ARM64, for
   EFI volume mounting

 - Clean up some code slightly, including defining copy_user_page() as
   copy_page() rather than memcpy(), aligning us with other
   architectures; and using max3() to slightly simplify an expression
   in riscv_iommu_init_check()

* tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
  riscv: lib: optimize strlen loop efficiency
  selftests: riscv: vstate_exec_nolibc: Use the regular prctl() function
  selftests: riscv: verify ptrace accepts valid vector csr values
  selftests: riscv: verify ptrace rejects invalid vector csr inputs
  selftests: riscv: verify syscalls discard vector context
  selftests: riscv: verify initial vector state with ptrace
  selftests: riscv: test ptrace vector interface
  riscv: ptrace: validate input vector csr registers
  riscv: csr: define vtype register elements
  riscv: vector: init vector context with proper vlenb
  riscv: ptrace: return ENODATA for inactive vector extension
  kselftest/riscv: add kselftest for user mode CFI
  riscv: add documentation for shadow stack
  riscv: add documentation for landing pad / indirect branch tracking
  riscv: create a Kconfig fragment for shadow stack and landing pad support
  arch/riscv: add dual vdso creation logic and select vdso based on hw
  arch/riscv: compile vdso with landing pad and shadow stack note
  riscv: enable kernel access to shadow stack memory via the FWFT SBI call
  riscv: add kernel command line option to opt out of user CFI
  riscv/hwprobe: add zicfilp / zicfiss enumeration in hwprobe
  ...
Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2026-02-12T19:32:37+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-02-12T19:32:37+00:00 4cff5c05e076d2ee4e34122aa956b84a2eaac587 Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ... 
Pull MM updates from Andrew Morton:

 - "powerpc/64s: do not re-activate batched TLB flush" makes
   arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)

   It adds a generic enter/leave layer and switches architectures to use
   it. Various hacks were removed in the process.

 - "zram: introduce compressed data writeback" implements data
   compression for zram writeback (Richard Chang and Sergey Senozhatsky)

 - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
   page ranges for hugepages. Large improvements during demand faulting
   are demonstrated (David Hildenbrand)

 - "memcg cleanups" tidies up some memcg code (Chen Ridong)

 - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
   stats" improves DAMOS stat's provided information, deterministic
   control, and readability (SeongJae Park)

 - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
   issues in the hugetlb cgroup charging selftests (Li Wang)

 - "Fix va_high_addr_switch.sh test failure - again" addresses several
   issues in the va_high_addr_switch test (Chunyu Hu)

 - "mm/damon/tests/core-kunit: extend existing test scenarios" improves
   the KUnit test coverage for DAMON (Shu Anzai)

 - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
   glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
   transiently return -EAGAIN (Shivank Garg)

 - "arch, mm: consolidate hugetlb early reservation" reworks and
   consolidates a pile of straggly code related to reservation of
   hugetlb memory from bootmem and creation of CMA areas for hugetlb
   (Mike Rapoport)

 - "mm: clean up anon_vma implementation" cleans up the anon_vma
   implementation in various ways (Lorenzo Stoakes)

 - "tweaks for __alloc_pages_slowpath()" does a little streamlining of
   the page allocator's slowpath code (Vlastimil Babka)

 - "memcg: separate private and public ID namespaces" cleans up the
   memcg ID code and prevents the internal-only private IDs from being
   exposed to userspace (Shakeel Butt)

 - "mm: hugetlb: allocate frozen gigantic folio" cleans up the
   allocation of frozen folios and avoids some atomic refcount
   operations (Kefeng Wang)

 - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
   of memory betewwn the active and inactive LRUs and adds auto-tuning
   of the ratio-based quotas and of monitoring intervals (SeongJae Park)

 - "Support page table check on PowerPC" makes
   CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)

 - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
   nodes_and() and nodes_andnot() propagate the return values from the
   underlying bit operations, enabling some cleanup in calling code
   (Yury Norov)

 - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
   some DAMON internal interfaces (SeongJae Park)

 - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
   in khupaged and fixes a scan limit accounting issue (Shivank Garg)

 - "mm: balloon infrastructure cleanups" goes to town on the balloon
   infrastructure and its page migration function. Mainly cleanups, also
   some locking simplification (David Hildenbrand)

 - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
   additional tracepoints to the page reclaim code (Jiayuan Chen)

 - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
   part of Marco's kernel-wide migration from the legacy workqueue APIs
   over to the preferred unbound workqueues (Marco Crivellari)

 - "Various mm kselftests improvements/fixes" provides various unrelated
   improvements/fixes for the mm kselftests (Kevin Brodsky)

 - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
   folio allocation, mainly by avoiding unnecessary work in
   pfn_range_valid_contig() (Kefeng Wang)

 - "selftests/damon: improve leak detection and wss estimation
   reliability" improves the reliability of two of the DAMON selftests
   (SeongJae Park)

 - "mm/damon: cleanup kdamond, damon_call(), damos filter and
   DAMON_MIN_REGION" does some cleanup work in the core DAMON code
   (SeongJae Park)

 - "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
   performs maintenance work on the DAMON documentation (SeongJae Park)

 - "mm: add and use vma_assert_stabilised() helper" refactors and cleans
   up the core VMA code. The main aim here is to be able to use the mmap
   write lock's lockdep state to perform various assertions regarding
   the locking which the VMA code requires (Lorenzo Stoakes)

 - "mm, swap: swap table phase II: unify swapin use" removes some old
   swap code (swap cache bypassing and swap synchronization) which
   wasn't working very well. Various other cleanups and simplifications
   were made. The end result is a 20% speedup in one benchmark (Kairui
   Song)

 - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
   available on 64-bit alpha, loongarch, mips, parisc, and um. Various
   cleanups were performed along the way (Qi Zheng)

* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
  mm/memory: handle non-split locks correctly in zap_empty_pte_table()
  mm: move pte table reclaim code to memory.c
  mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
  mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
  um: mm: enable MMU_GATHER_RCU_TABLE_FREE
  parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
  LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
  alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
  mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
  zsmalloc: make common caches global
  mm: add SPDX id lines to some mm source files
  mm/zswap: use %pe to print error pointers
  mm/vmscan: use %pe to print error pointers
  mm/readahead: fix typo in comment
  mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
  mm: refactor vma_map_pages to use vm_insert_pages
  mm/damon: unify address range representation with damon_addr_range
  mm/cma: replace snprintf with strscpy in cma_new_area
  ...
Merge tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2026-02-11T03:01:45+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-02-11T03:01:45+00:00 57cb845067e0bf5d42af6bc570190bba3238660e Pull x86 paravirt updates from Borislav Petkov: - A nice cleanup to the paravirt code containing a unification of the paravirt clock interface, taming the include hell by splitting the pv_ops structure and removing of a bunch of obsolete code (Juergen Gross) * tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted() x86/paravirt: Remove trailing semicolons from alternative asm templates x86/pvlocks: Move paravirt spinlock functions into own header x86/paravirt: Specify pv_ops array in paravirt macros x86/paravirt: Allow pv-calls outside paravirt.h objtool: Allow multiple pv_ops arrays x86/xen: Drop xen_mmu_ops x86/xen: Drop xen_cpu_ops x86/xen: Drop xen_irq_ops x86/paravirt: Move pv_native_*() prototypes to paravirt.c x86/paravirt: Introduce new paravirt-base.h header x86/paravirt: Move paravirt_sched_clock() related code into tsc.c x86/paravirt: Use common code for paravirt_steal_clock() riscv/paravirt: Use common code for paravirt_steal_clock() loongarch/paravirt: Use common code for paravirt_steal_clock() arm64/paravirt: Use common code for paravirt_steal_clock() arm/paravirt: Use common code for paravirt_steal_clock() sched: Move clock related paravirt code to kernel/sched paravirt: Remove asm/paravirt_api_clock.h x86/paravirt: Move thunk macros to paravirt_types.h ... 
Pull x86 paravirt updates from Borislav Petkov:

 - A nice cleanup to the paravirt code containing a unification of the
   paravirt clock interface, taming the include hell by splitting the
   pv_ops structure and removing of a bunch of obsolete code (Juergen
   Gross)

* tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted()
  x86/paravirt: Remove trailing semicolons from alternative asm templates
  x86/pvlocks: Move paravirt spinlock functions into own header
  x86/paravirt: Specify pv_ops array in paravirt macros
  x86/paravirt: Allow pv-calls outside paravirt.h
  objtool: Allow multiple pv_ops arrays
  x86/xen: Drop xen_mmu_ops
  x86/xen: Drop xen_cpu_ops
  x86/xen: Drop xen_irq_ops
  x86/paravirt: Move pv_native_*() prototypes to paravirt.c
  x86/paravirt: Introduce new paravirt-base.h header
  x86/paravirt: Move paravirt_sched_clock() related code into tsc.c
  x86/paravirt: Use common code for paravirt_steal_clock()
  riscv/paravirt: Use common code for paravirt_steal_clock()
  loongarch/paravirt: Use common code for paravirt_steal_clock()
  arm64/paravirt: Use common code for paravirt_steal_clock()
  arm/paravirt: Use common code for paravirt_steal_clock()
  sched: Move clock related paravirt code to kernel/sched
  paravirt: Remove asm/paravirt_api_clock.h
  x86/paravirt: Move thunk macros to paravirt_types.h
  ...
riscv: csr: define vtype register elements 2026-02-09T22:27:33+00:00 Sergey Matyukevich geomatsi@gmail.com 2026-01-26T04:09:57+00:00 fd515e037efb3b6300eace247e14ab2bc7e38db5 Define masks and shifts for vtype CSR according to the vector specs: - v0.7.1 used in early T-Head cores, known as xtheadvector in the kernel - v1.0 Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com> Reviewed-by: Andy Chiu <andybnac@gmail.com> Tested-by: Andy Chiu <andybnac@gmail.com> Link: https://patch.msgid.link/20251214163537.1054292-4-geomatsi@gmail.com Signed-off-by: Paul Walmsley <pjw@kernel.org> 
Define masks and shifts for vtype CSR according to the vector specs:
- v0.7.1 used in early T-Head cores, known as xtheadvector in the kernel
- v1.0

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
Reviewed-by: Andy Chiu <andybnac@gmail.com>
Tested-by: Andy Chiu <andybnac@gmail.com>
Link: https://patch.msgid.link/20251214163537.1054292-4-geomatsi@gmail.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
arch/riscv: add dual vdso creation logic and select vdso based on hw 2026-01-29T09:38:40+00:00 Deepak Gupta debug@rivosinc.com 2026-01-26T04:09:56+00:00 ccad8c1336b6511e3c7ca5c02f797b1fd2cf67e1 Shadow stack instructions are taken from the Zimop ISA extension, which is mandated on RVA23. Any userspace with shadow stack instructions in it will fault on hardware that doesn't have support for Zimop. Thus, a shadow stack-enabled userspace can't be run on hardware that doesn't support Zimop. It's not known how Linux userspace providers will respond to this kind of binary fragmentation. In order to keep kernel portable across different hardware, 'arch/riscv/kernel/vdso_cfi' is created which has Makefile logic to compile 'arch/riscv/kernel/vdso' sources with CFI flags, and 'arch/riscv/kernel/vdso.c' is modified to select the appropriate vdso depending on whether the underlying CPU implements the Zimop extension. Since the offset of vdso symbols will change due to having two different vdso binaries, there is added logic to include a new generated vdso offset header and dynamically select the offset (like for rt_sigreturn). Signed-off-by: Deepak Gupta <debug@rivosinc.com> Acked-by: Charles Mirabile <cmirabil@redhat.com> Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6 Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com> Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-24-b55691eacf4f@rivosinc.com [pjw@kernel.org: cleaned up patch description] Signed-off-by: Paul Walmsley <pjw@kernel.org> 
Shadow stack instructions are taken from the Zimop ISA extension,
which is mandated on RVA23. Any userspace with shadow stack
instructions in it will fault on hardware that doesn't have support
for Zimop.  Thus, a shadow stack-enabled userspace can't be run on
hardware that doesn't support Zimop.

It's not known how Linux userspace providers will respond to this kind
of binary fragmentation.  In order to keep kernel portable across
different hardware, 'arch/riscv/kernel/vdso_cfi' is created which has
Makefile logic to compile 'arch/riscv/kernel/vdso' sources with CFI
flags, and 'arch/riscv/kernel/vdso.c' is modified to select the
appropriate vdso depending on whether the underlying CPU implements
the Zimop extension. Since the offset of vdso symbols will change due
to having two different vdso binaries, there is added logic to include
a new generated vdso offset header and dynamically select the offset
(like for rt_sigreturn).

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Acked-by: Charles Mirabile <cmirabil@redhat.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-24-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
arch/riscv: compile vdso with landing pad and shadow stack note 2026-01-29T09:38:40+00:00 Jim Shu jim.shu@sifive.com 2026-01-26T04:09:56+00:00 37f57bd3faeac92e898c3381355f4fd2b6a80901 User mode tasks compiled with Zicfilp may call indirectly into the vdso (like hwprobe indirect calls). Add support for compiling landing pads into the vdso. Landing pad instructions in the vdso will be no-ops for tasks which have not enabled landing pads. Furthermore, add support for the C sources of the vdso to be compiled with shadow stack and landing pads enabled as well. Landing pad and shadow stack instructions are emitted only when the VDSO_CFI cflags option is defined during compile. Signed-off-by: Jim Shu <jim.shu@sifive.com> Reviewed-by: Zong Li <zong.li@sifive.com> Signed-off-by: Deepak Gupta <debug@rivosinc.com> Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6 Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com> Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-23-b55691eacf4f@rivosinc.com [pjw@kernel.org: cleaned up patch description, issues reported by checkpatch] Signed-off-by: Paul Walmsley <pjw@kernel.org> 
User mode tasks compiled with Zicfilp may call indirectly into the
vdso (like hwprobe indirect calls). Add support for compiling landing
pads into the vdso. Landing pad instructions in the vdso will be
no-ops for tasks which have not enabled landing pads. Furthermore, add
support for the C sources of the vdso to be compiled with shadow stack
and landing pads enabled as well.

Landing pad and shadow stack instructions are emitted only when the
VDSO_CFI cflags option is defined during compile.

Signed-off-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-23-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description, issues reported by checkpatch]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
riscv: add kernel command line option to opt out of user CFI 2026-01-29T09:38:40+00:00 Deepak Gupta debug@rivosinc.com 2026-01-26T04:09:55+00:00 c9b859c4d8f56c014b3d5fbd1bcfb916c34955a1 Add a kernel command line option to disable part or all of user CFI. User backward CFI and forward CFI can be controlled independently. The kernel command line parameter "riscv_nousercfi" can take the following values: - "all" : Disable forward and backward cfi both - "bcfi" : Disable backward cfi - "fcfi" : Disable forward cfi Signed-off-by: Deepak Gupta <debug@rivosinc.com> Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6 Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com> Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-21-b55691eacf4f@rivosinc.com [pjw@kernel.org: fixed warnings from checkpatch; cleaned up patch description, doc, printk text] Signed-off-by: Paul Walmsley <pjw@kernel.org> 
Add a kernel command line option to disable part or all
of user CFI.  User backward CFI and forward CFI can be controlled
independently.  The kernel command line parameter "riscv_nousercfi" can
take the following values:
 - "all" : Disable forward and backward cfi both
 - "bcfi" : Disable backward cfi
 - "fcfi" : Disable forward cfi

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-21-b55691eacf4f@rivosinc.com
[pjw@kernel.org: fixed warnings from checkpatch; cleaned up patch description, doc, printk text]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
riscv: hwprobe: add support for RISCV_HWPROBE_KEY_IMA_EXT_1 2026-01-29T09:38:40+00:00 Paul Walmsley pjw@kernel.org 2026-01-26T04:09:55+00:00 462a94fb8ae8ba0d4d3901c7283b4af052ab8804 We've run out of bits to describe RISC-V ISA extensions in our initial hwprobe key, RISCV_HWPROBE_KEY_IMA_EXT_0. So, let's add RISCV_HWPROBE_KEY_IMA_EXT_1, along with the framework to set the appropriate hwprobe tuple, and add testing for it. Based on a suggestion from Andrew Jones <andrew.jones@oss.qualcomm.com>, also fix the documentation for RISCV_HWPROBE_KEY_IMA_EXT_0. Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com> Signed-off-by: Paul Walmsley <pjw@kernel.org> 
We've run out of bits to describe RISC-V ISA extensions in our initial
hwprobe key, RISCV_HWPROBE_KEY_IMA_EXT_0.  So, let's add
RISCV_HWPROBE_KEY_IMA_EXT_1, along with the framework to set the
appropriate hwprobe tuple, and add testing for it.

Based on a suggestion from Andrew Jones <andrew.jones@oss.qualcomm.com>,
also fix the documentation for RISCV_HWPROBE_KEY_IMA_EXT_0.

Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
Signed-off-by: Paul Walmsley <pjw@kernel.org>