kernel/linux.git/arch/arm64/include/asm, branch v5.10.257

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

2026-04-18T08:31:00+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 [ added PTE_DIRTY to PAGE_KERNEL* macros directly instead of _PAGE_KERNEL* ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

arm64: cputype: Add Neoverse-V3AE definitions

2025-10-29T13:01:23+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()

2025-10-29T13:01:21+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

2025-08-28T14:22:39+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: proton-pack: Add new CPUs 'k' values for branch mitigation

2025-06-27T10:04:23+00:00

[ Upstream commit efe676a1a7554219eae0b0dcfe1e0cdcc9ef9aef ] Update the list of 'k' values for the branch mitigation from arm's website. Add the values for Cortex-X1C. The MIDR_EL1 value can be found here: https://developer.arm.com/documentation/101968/0002/Register-descriptions/AArch> Link: https://developer.arm.com/documentation/110280/2-0/?lang=en Signed-off-by: James Morse Reviewed-by: Catalin Marinas Signed-off-by: Pu Lehui Signed-off-by: Greg Kroah-Hartman

arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs

2025-06-27T10:04:23+00:00

[ Upstream commit 0dfefc2ea2f29ced2416017d7e5b1253a54c2735 ] A malicious BPF program may manipulate the branch history to influence what the hardware speculates will happen next. On exit from a BPF program, emit the BHB mititgation sequence. This is only applied for 'classic' cBPF programs that are loaded by seccomp. Signed-off-by: James Morse Reviewed-by: Catalin Marinas Acked-by: Daniel Borkmann Signed-off-by: Pu Lehui Signed-off-by: Greg Kroah-Hartman

arm64: proton-pack: Expose whether the branchy loop k value

2025-06-27T10:04:23+00:00

[ Upstream commit a1152be30a043d2d4dcb1683415f328bf3c51978 ] Add a helper to expose the k value of the branchy loop. This is needed by the BPF JIT to generate the mitigation sequence in BPF programs. Signed-off-by: James Morse Reviewed-by: Catalin Marinas Signed-off-by: Pu Lehui Signed-off-by: Greg Kroah-Hartman

arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB

2025-06-27T10:04:23+00:00

[ Upstream commit e403e8538359d8580cbee1976ff71813e947101e ] The code for detecting CPUs that are vulnerable to Spectre BHB was based on a hardcoded list of CPU IDs that were known to be affected. Unfortunately, the list mostly only contained the IDs of standard ARM cores. The IDs for many cores that are minor variants of the standard ARM cores (like many Qualcomm Kyro CPUs) weren't listed. This led the code to assume that those variants were not affected. Flip the code on its head and instead assume that a core is vulnerable if it doesn't have CSV2_3 but is unrecognized as being safe. This involves creating a "Spectre BHB safe" list. As of right now, the only CPU IDs added to the "Spectre BHB safe" list are ARM Cortex A35, A53, A55, A510, and A520. This list was created by looking for cores that weren't listed in ARM's list [1] as per review feedback on v2 of this patch [2]. Additionally Brahma A53 is added as per mailing list feedback [3]. NOTE: this patch will not actually _mitigate_ anyone, it will simply cause them to report themselves as vulnerable. If any cores in the system are reported as vulnerable but not mitigated then the whole system will be reported as vulnerable though the system will attempt to mitigate with the information it has about the known cores. [1] https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB [2] https://lore.kernel.org/r/20241219175128.GA25477@willie-the-truck [3] https://lore.kernel.org/r/18dbd7d1-a46c-4112-a425-320c99f67a8d@broadcom.com Fixes: 558c303c9734 ("arm64: Mitigate spectre style branch history side channels") Cc: stable@vger.kernel.org Reviewed-by: Julius Werner Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20250107120555.v4.2.I2040fa004dafe196243f67ebcc647cbedbb516e6@changeid Signed-off-by: Catalin Marinas [The conflicts were mainly due to LTS commit e192c8baa69a differ from mainline commit 558c303c9734] Signed-off-by: Pu Lehui Signed-off-by: Greg Kroah-Hartman

arm64: proton-pack: Expose whether the platform is mitigated by firmware

2025-06-27T10:04:23+00:00

[ Upstream commit e7956c92f396a44eeeb6eaf7a5b5e1ad24db6748 ] is_spectre_bhb_fw_affected() allows the caller to determine if the CPU is known to need a firmware mitigation. CPUs are either on the list of CPUs we know about, or firmware has been queried and reported that the platform is affected - and mitigated by firmware. This helper is not useful to determine if the platform is mitigated by firmware. A CPU could be on the know list, but the firmware may not be implemented. Its affected but not mitigated. spectre_bhb_enable_mitigation() handles this distinction by checking the firmware state before enabling the mitigation. Add a helper to expose this state. This will be used by the BPF JIT to determine if calling firmware for a mitigation is necessary and supported. Signed-off-by: James Morse Reviewed-by: Catalin Marinas [The conflicts were due to not include bitmap of mitigations] Signed-off-by: Pu Lehui Signed-off-by: Greg Kroah-Hartman

arm64: insn: Add support for encoding DSB

2025-06-27T10:04:23+00:00

[ Upstream commit 63de8abd97ddb9b758bd8f915ecbd18e1f1a87a0 ] To generate code in the eBPF epilogue that uses the DSB instruction, insn.c needs a heler to encode the type and domain. Re-use the crm encoding logic from the DMB instruction. Signed-off-by: James Morse Reviewed-by: Catalin Marinas Signed-off-by: Pu Lehui Signed-off-by: Greg Kroah-Hartman