kernel/linux.git/arch/loongarch, branch v7.1.6

mm/sparse-vmemmap: pass @pgmap argument to memory deactivation paths

2026-08-03T09:26:03+00:00

[ Upstream commit 3bbc54dd1b62f1a4b218c70aafbeceeba7c90c5d ] Currently, the memory hot-remove call chain -- arch_remove_memory(), __remove_pages(), sparse_remove_section() and section_deactivate() -- does not carry the struct dev_pagemap pointer. This prevents the lower levels from knowing whether the section was originally populated with vmemmap optimizations (e.g., DAX with vmemmap optimization enabled). Without this information, we cannot call vmemmap_can_optimize() to determine if the vmemmap pages were optimized. As a result, the vmemmap page accounting during teardown will mistakenly assume a non-optimized allocation, leading to incorrect memmap statistics. To lay the groundwork for fixing the vmemmap page accounting, we need to pass the @pgmap pointer down to the deactivation location. Plumb the @pgmap argument through the APIs of arch_remove_memory(), __remove_pages() and sparse_remove_section(), mirroring the corresponding *_activate() paths. Link: https://lore.kernel.org/20260428081855.1249045-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Mike Rapoport (Microsoft) Reviewed-by: Oscar Salvador Acked-by: David Hildenbrand (Arm) Acked-by: Liam R. Howlett Cc: "Aneesh Kumar K.V" Cc: Joao Martins Cc: Lorenzo Stoakes Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Nicholas Piggin Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton Stable-dep-of: 721a73e30c9e ("mm/sparse-vmemmap: fix DAX vmemmap accounting with optimization") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

LoongArch: Retrieve CPU package ID from PPTT when available

2026-08-03T09:25:52+00:00

commit 4e8f58620f6717f72f3d88a2c8f25c0c656d0ba7 upstream. Currently, the LoongArch CPU topology initialization code calculates each core's package ID by dividing its physical ID by loongson_sysconf. cores_per_package. This relies on the assumption that cores_per_package counts in the same domain as physical IDs. On Loongson-3B6000 (XB612B0V_1.2), cores_per_package matches the visible core count -- 24 in this case. However, the physical IDs range from 0 to 31 in a noncontinuous fashion: $ cat /proc/cpuinfo | grep -i -F 'global_id' global_id : 0 global_id : 1 global_id : 4 global_id : 5 global_id : 6 global_id : 7 global_id : 8 global_id : 9 global_id : 10 global_id : 11 global_id : 14 global_id : 15 global_id : 16 global_id : 17 global_id : 20 global_id : 21 global_id : 22 global_id : 23 global_id : 26 global_id : 27 global_id : 28 global_id : 29 global_id : 30 global_id : 31 Retrieve the exact package ID from ACPI PPTT when available, in the same style as retrieving the core ID and thread ID in parse_acpi_topology(). Use this information in loongson_init_secondary() when the PPTT readout is successful. The original division logic is kept as a fallback. Meanwhile, since some existing code paths like loongson3_cpufreq expect a continuous integer sequence of package IDs in [0, MAX_PACKAGES) when retrieving from cpu_data[], here we also canonicalize the package ID to be filled in parse_acpi_topology() to meet such an expectation. Cc: stable@vger.kernel.org Tested-by: Mingcong Bai Co-developed-by: Xi Ruoyao Signed-off-by: Xi Ruoyao Signed-off-by: Rong Bao Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Move jump_label_init() before parse_early_param()

2026-08-03T09:25:52+00:00

commit ea68d444a658783234a06f05414e41cf93a18fb2 upstream. When enabling both CONFIG_MEM_ALLOC_PROFILING=y and CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT=y, then diabling memory profiling by adding the boot parameter 'sysctl.vm.mem_profiling=0' will cause the kernel failed to boot. After analysis, this is because jump_label_init() must be called before parse_early_param(), the early param handlers may modify static keys by static_branch_enable/disable(). Fix this by moving jump_label_init() to before parse_early_param(). The solution is similar to other architectures. Cc: Signed-off-by: Kanglong Wang Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Increase TASK_STRUCT_OFFSET up to 2040 for 32BIT

2026-08-03T09:25:52+00:00

commit 7917d16d14fb512f8ffe3815b7940b6c93ff4fde upstream. THREAD_INFO_IN_TASK increase the size of task_struct, which casuses a build error for the 32BIT kernel if RANDSTRUCT is enabled. So increase TASK_STRUCT_OFFSET as big as possible (2040), but can still be aligned and be fit in the addi.w instruction. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Fix oops during single-step debugging

2026-08-03T09:25:52+00:00

commit 73555fdab5e1e4f24ca000c41a616b34edf4b55d upstream. When entering KDB via a breakpoint and then performing single-step debugging, an oops is triggered. Now during single-step debugging, kdb_local() expects the reason to be KDB_REASON_SSTEP, but it is actually KDB_REASON_OOPS. In kdb_stub(), when determining the reason, the ex_vector for single-step should be 0, as already implemented on other architectures such as arm64 and riscv. Before the patch: [112]kdb> ss Entering kdb (current=0x900020009f520000, pid 10661) on processor 112 Oops: (null) due to oops @ 0x90000000005b57a4 Cc: stable@vger.kernel.org Signed-off-by: Haoran Jiang Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Fix build errors due to wrong instructions for 32BIT

2026-08-03T09:25:52+00:00

commit 7ea74820edcb22ffa3fb068076d73c6821d7e6d2 upstream. In some assembly files there are some instructions that only valid for 64BIT, but those files can be compiled for 32BIT and cause build errors. So, replace those instructions with macros: li.d --> LONG_LI (li.w or li.d), addi.d --> PTR_ADDI (addi.w or addi.d). BTW, Re-tab the indention in the assembly files for alignment. Cc: stable@vger.kernel.org # 6.19+ Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Fix address space mismatch in kexec command line lookup

2026-08-03T09:25:52+00:00

commit 485ed44db5694d8d2e5027f63ad608e705286f30 upstream. When searching the loaded segments for the "kexec" command line marker, the kexec_load(2) path (file_mode == 0) passes the user-space segment buffer straight to strncmp() through a bogus (char __user *) cast. This dereferences a user pointer in kernel context, which is wrong and is flagged by sparse: arch/loongarch/kernel/machine_kexec.c:84:51: sparse: incorrect type in argument 2 (different address spaces) @@ expected char const * @@ got char [noderef] __user * Here copy the marker-sized prefix of each segment into a small on-stack buffer with copy_from_user() before comparing, and skip segments that fault. The subsequent copy_from_user() that stages the full command line into the safe area is left unchanged. Cc: stable@vger.kernel.org Fixes: 4a03b2ac06a5 ("LoongArch: Add kexec support") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202605051639.aEPioXdD-lkp@intel.com/ Co-developed-by: Kexin Liu Signed-off-by: Kexin Liu Signed-off-by: George Guo Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: BPF: Fix memory leak in bpf_jit_free()

2026-08-03T09:25:38+00:00

[ Upstream commit 47e20d4b3da97ef3881d1e55e43545c22424f3fc ] When bpf_int_jit_compile() is called for subprograms, it returns early during the first pass (!prog->is_func || extra_pass is false), keeping ctx->offset alive for the subsequent extra pass. If JIT compilation fails for a later subprogram, the BPF core aborts and calls bpf_jit_free() to clean up the first subprogram. However, bpf_jit_free() fails to free jit_data->ctx.offset, which causes a memory leak of the JIT context offsets array. So fix this by adding the missing kvfree(jit_data->ctx.offset) in bpf_jit_free(). Reported-by: Sashiko Fixes: 4ab17e762b34 ("LoongArch: BPF: Use BPF prog pack allocator") Acked-by: Tiezhu Yang Signed-off-by: Pu Lehui Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin

LoongArch: BPF: Zero-extend signed ALU32 div/mod results

2026-08-03T09:25:36+00:00

[ Upstream commit dacd348b8a993373576fe2ee2d8b114740ba57a6 ] ALU32 operations write a 32-bit result and leave the upper 32 bits of the BPF register zero. The LoongArch JIT sign-extends the result of signed ALU32 BPF_DIV and BPF_MOD (off=1), so a negative 32-bit quotient or remainder leaves bits 63:32 set in JITted code while the verifier and interpreter model those bits as zero. Keep sign-extension on the operands, which signed divide needs, and zero-extend the ALU32 result after the divide or modulo instruction, matching the unsigned ALU32 div/mod paths and every other ALU32 operation in this JIT. Fixes: 2425c9e002d2 ("LoongArch: BPF: Support signed div instructions") Fixes: 7b6b13d32965 ("LoongArch: BPF: Support signed mod instructions") Assisted-by: Claude:claude-opus-4-8 Acked-by: Tiezhu Yang Tested-by: Tiezhu Yang Signed-off-by: Nicholas Dudar Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin

LoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect()

2026-07-24T14:21:16+00:00

commit 018e9828eb523c638fa3d9bdf0fd4956b74555b2 upstream. When hardware page table walker (PTW) is enabled on LoongArch, the CPU may set _PAGE_DIRTY directly in the page table entry during a write TLB miss, without going through the software TLB store handler. The software TLB store handler (tlbex.S:254) sets both _PAGE_DIRTY and_PAGE_MODIFIED together: ori t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED) Since hardware PTW only sets _PAGE_DIRTY, the software-only bit, i.e. _PAGE_MODIFIED is left unchanged. This creates a window where a PTE has _PAGE_DIRTY set (hardware knows the page is dirty) but _PAGE_MODIFIED clear (software is unaware). When fork()/clone() triggers copy-on-write, __copy_present_ptes() calls pte_wrprotect(), which unconditionally clears both the _PAGE_WRITE and _PAGE_DIRTY bits: pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY); Since _PAGE_MODIFIED was never set, the dirtiness information is lost completely. Subsequently, when memory pressure triggers page reclaim, page_mkclean() / try_to_unmap() sees the page as clean (i.e. pte_dirty() returns false) and the page may be freed without writeback, causing data corruption. Fix this by propagating the _PAGE_DIRTY bit to the _PAGE_MODIFIED bit in both pte_wrprotect() and pmd_wrprotect() before clearing writeable bits: if (pte_val(pte) & _PAGE_DIRTY) pte_val(pte) |= _PAGE_MODIFIED; The pmd_wrprotect() fix handles the CONFIG_TRANSPARENT_HUGEPAGE case, where pmd entries need the same treatment. This ensures the software dirty tracking bit (checked by pte_dirty() and pmd_dirty(), which read both the _PAGE_DIRTY and _PAGE_MODIFIED bits) is preserved across fork COW write-protection. The issue was found by the LTP madvise09 test case, which exercises page reclaim after "madvise(MADV_FREE), write and fork" operation sequence on private anonymous mappings. Cc: stable@vger.kernel.org Fixes: 09cfefb7fa70 ("LoongArch: Add memory management") Co-developed-by: Tianyang Zhang Signed-off-by: Tianyang Zhang Signed-off-by: Hongchen Zhang Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman