kernel/linux.git/arch/arm64/include, branch v6.1.168

arm64: mm: Add PTE_DIRTY back to PAGE_KERNEL* to fix kexec/hibernation

2026-03-25T10:03:15+00:00

[ Upstream commit c25c4aa3f79a488cc270507935a29c07dc6bddfc ] Commit 143937ca51cc ("arm64, mm: avoid always making PTE dirty in pte_mkwrite()") changed pte_mkwrite_novma() to only clear PTE_RDONLY when PTE_DIRTY is set. This was to allow writable-clean PTEs for swap pages that haven't actually been written. However, this broke kexec and hibernation for some platforms. Both go through trans_pgd_create_copy() -> _copy_pte(), which calls pte_mkwrite_novma() to make the temporary linear-map copy fully writable. With the updated pte_mkwrite_novma(), read-only kernel pages (without PTE_DIRTY) remain read-only in the temporary mapping. While such behaviour is fine for user pages where hardware DBM or trapping will make them writeable, subsequent in-kernel writes by the kexec relocation code will fault. Add PTE_DIRTY back to all _PAGE_KERNEL* protection definitions. This was the case prior to 5.4, commit aa57157be69f ("arm64: Ensure VM_WRITE|VM_SHARED ptes are clean by default"). With the kernel linear-map PTEs always having PTE_DIRTY set, pte_mkwrite_novma() correctly clears PTE_RDONLY. Fixes: 143937ca51cc ("arm64, mm: avoid always making PTE dirty in pte_mkwrite()") Signed-off-by: Catalin Marinas Cc: stable@vger.kernel.org Reported-by: Jianpeng Chang Link: https://lore.kernel.org/r/20251204062722.3367201-1-jianpeng.chang.cn@windriver.com Cc: Will Deacon Cc: Huang, Ying Cc: Guenter Roeck Reviewed-by: Huang Ying Signed-off-by: Will Deacon Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

arm64: reorganise PAGE_/PROT_ macros

2026-03-25T10:03:15+00:00

[ Upstream commit fa4cdccaa58224a12591f2c045c24abc5251bb9d ] Make these macros available to assembly code, so they can be re-used by the PIE initialisation code. This involves adding some extra macros, prepended with _ that are the raw values not `pgprot` values. A dummy value for PTE_MAYBE_NG is also provided, for use in assembly. Signed-off-by: Joey Gouly Cc: Will Deacon Cc: Mark Rutland Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20230606145859.697944-14-joey.gouly@arm.com Signed-off-by: Catalin Marinas Stable-dep-of: c25c4aa3f79a ("arm64: mm: Add PTE_DIRTY back to PAGE_KERNEL* to fix kexec/hibernation") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

arm64: Fix non-atomic __READ_ONCE() with CONFIG_LTO=y

2026-03-04T12:20:51+00:00

[ Upstream commit bb0c99e08ab9aa6d04b40cb63c72db9950d51749 ] The implementation of __READ_ONCE() under CONFIG_LTO=y incorrectly qualified the fallback "once" access for types larger than 8 bytes, which are not atomic but should still happen "once" and suppress common compiler optimizations. The cast `volatile typeof(__x)` applied the volatile qualifier to the pointer type itself rather than the pointee. This created a volatile pointer to a non-volatile type, which violated __READ_ONCE() semantics. Fix this by casting to `volatile typeof(*__x) *`. With a defconfig + LTO + debug options build, we see the following functions to be affected: xen_manage_runstate_time (884 -> 944 bytes) xen_steal_clock (248 -> 340 bytes) ^-- use __READ_ONCE() to load vcpu_runstate_info structs Fixes: e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y") Cc: stable@vger.kernel.org Reviewed-by: Boqun Feng Signed-off-by: Marco Elver Tested-by: David Laight Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

asm-generic: partially revert "Unify uapi bitsperlong.h for arm64, riscv and loongarch"

2025-12-06T21:12:36+00:00

commit 6e8d96909a23c8078ee965bd48bb31cbef2de943 upstream. Unifying the asm-generic headers across 32-bit and 64-bit architectures based on the compiler provided macros was a good idea and appears to work with all user space, but it caused a regression when building old kernels on systems that have the new headers installed in /usr/include, as this combination trips an inconsistency in the kernel's own tools/include headers that are a mix of userspace and kernel-internal headers. This affects kernel builds on arm64, riscv64 and loongarch64 systems that might end up using the "#define __BITS_PER_LONG 32" default from the old tools headers. Backporting the commit into stable kernels would address this, but it would still break building kernels without that backport, and waste time for developers trying to understand the problem. arm64 build machines are rather common, and on riscv64 this can also happen in practice, but loongarch64 is probably new enough to not be used much for building old kernels, so only revert the bits for arm64 and riscv. Link: https://lore.kernel.org/all/20230731160402.GB1823389@dev-arch.thelio-3990X/ Reported-by: Nathan Chancellor Fixes: 8386f58f8deda ("asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch") Acked-by: Catalin Marinas Acked-by: Palmer Dabbelt Tested-by: Nathan Chancellor Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch

2025-12-06T21:12:34+00:00

[ Upstream commit 8386f58f8deda81110283798a387fb53ec21957c ] Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0 in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are usable, it is probably fine to unify the definition of __BITS_PER_LONG as (__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h. In order to keep safe and avoid regression, only unify uapi bitsperlong.h for some archs such as arm64, riscv and loongarch which are using newer toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__. Suggested-by: Xi Ruoyao Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/ Suggested-by: Arnd Bergmann Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/ Signed-off-by: Tiezhu Yang Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin

arm64: cputype: Add Neoverse-V3AE definitions

2025-10-29T13:04:43+00:00

commit 3bbf004c4808e2c3241e5c1ad6cc102f38a03c39 upstream. Add cputype definitions for Neoverse-V3AE. These will be used for errata detection in subsequent patches. These values can be found in the Neoverse-V3AE TRM: https://developer.arm.com/documentation/SDEN-2615521/9-0/ ... in section A.6.1 ("MIDR_EL1, Main ID Register"). Signed-off-by: Mark Rutland Cc: James Morse Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Ryan Roberts Signed-off-by: Will Deacon [ Ryan: Trivial backport ] Signed-off-by: Ryan Roberts Signed-off-by: Greg Kroah-Hartman

arm64, mm: avoid always making PTE dirty in pte_mkwrite()

2025-10-29T13:04:36+00:00

[ Upstream commit 143937ca51cc6ae2fccc61a1cb916abb24cd34f5 ] Current pte_mkwrite_novma() makes PTE dirty unconditionally. This may mark some pages that are never written dirty wrongly. For example, do_swap_page() may map the exclusive pages with writable and clean PTEs if the VMA is writable and the page fault is for read access. However, current pte_mkwrite_novma() implementation always dirties the PTE. This may cause unnecessary disk writing if the pages are never written before being reclaimed. So, change pte_mkwrite_novma() to clear the PTE_RDONLY bit only if the PTE_DIRTY bit is set to make it possible to make the PTE writable and clean. The current behavior was introduced in commit 73e86cb03cf2 ("arm64: Move PTE_RDONLY bit handling out of set_pte_at()"). Before that, pte_mkwrite() only sets the PTE_WRITE bit, while set_pte_at() only clears the PTE_RDONLY bit if both the PTE_WRITE and the PTE_DIRTY bits are set. To test the performance impact of the patch, on an arm64 server machine, run 16 redis-server processes on socket 1 and 16 memtier_benchmark processes on socket 0 with mostly get transactions (that is, redis-server will mostly read memory only). The memory footprint of redis-server is larger than the available memory, so swap out/in will be triggered. Test results show that the patch can avoid most swapping out because the pages are mostly clean. And the benchmark throughput improves ~23.9% in the test. Fixes: 73e86cb03cf2 ("arm64: Move PTE_RDONLY bit handling out of set_pte_at()") Signed-off-by: Huang Ying Cc: Will Deacon Cc: Anshuman Khandual Cc: Ryan Roberts Cc: Gavin Shan Cc: Ard Biesheuvel Cc: Matthew Wilcox (Oracle) Cc: Yicong Yang Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Catalin Marinas Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

arm64: Handle KCOV __init vs inline mismatches

2025-08-28T14:25:51+00:00

[ Upstream commit 65c430906efffee9bd7551d474f01a6b1197df90 ] GCC appears to have kind of fragile inlining heuristics, in the sense that it can change whether or not it inlines something based on optimizations. It looks like the kcov instrumentation being added (or in this case, removed) from a function changes the optimization results, and some functions marked "inline" are _not_ inlined. In that case, we end up with __init code calling a function not marked __init, and we get the build warnings I'm trying to eliminate in the coming patch that adds __no_sanitize_coverage to __init functions: WARNING: modpost: vmlinux: section mismatch in reference: acpi_get_enable_method+0x1c (section: .text.unlikely) -> acpi_psci_present (section: .init.text) This problem is somewhat fragile (though using either __always_inline or __init will deterministically solve it), but we've tripped over this before with GCC and the solution has usually been to just use __always_inline and move on. For arm64 this requires forcing one ACPI function to be inlined with __always_inline. Link: https://lore.kernel.org/r/20250724055029.3623499-1-kees@kernel.org Signed-off-by: Kees Cook Signed-off-by: Sasha Levin

arm64/mm: Check PUD_TYPE_TABLE in pud_bad()

2025-06-04T12:40:07+00:00

[ Upstream commit bfb1d2b9021c21891427acc86eb848ccedeb274e ] pud_bad() is currently defined in terms of pud_table(). Although for some configs, pud_table() is hard-coded to true i.e. when using 64K base pages or when page table levels are less than 3. pud_bad() is intended to check that the pud is configured correctly. Hence let's open-code the same check that the full version of pud_table() uses into pud_bad(). Then it always performs the check regardless of the config. Cc: Will Deacon Cc: Ard Biesheuvel Cc: Ryan Roberts Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ryan Roberts Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/20250221044227.1145393-7-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

arm64: Add support for HIP09 Spectre-BHB mitigation

2025-06-04T12:40:02+00:00

[ Upstream commit e18c09b204e81702ea63b9f1a81ab003b72e3174 ] The HIP09 processor is vulnerable to the Spectre-BHB (Branch History Buffer) attack, which can be exploited to leak information through branch prediction side channels. This commit adds the MIDR of HIP09 to the list for software mitigation. Signed-off-by: Jinqian Yang Link: https://lore.kernel.org/r/20250325141900.2057314-1-yangjinqian1@huawei.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin