lwn.git/arch/loongarch/net, branch docs-mw

Merge tag 'loongarch-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

2026-04-24T16:54:45+00:00

Pull LoongArch updates from Huacai Chen: - Adjust build infrastructure for 32BIT/64BIT - Add HIGHMEM (PKMAP and FIX_KMAP) support - Show and handle CPU vulnerabilites correctly - Batch the icache maintenance for jump_label - Add more atomic instructions support for BPF JIT - Add more features (e.g. fsession) support for BPF trampoline - Some bug fixes and other small changes * tag 'loongarch-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (21 commits) selftests/bpf: Enable CAN_USE_LOAD_ACQ_STORE_REL for LoongArch LoongArch: BPF: Add fsession support for trampolines LoongArch: BPF: Introduce emit_store_stack_imm64() helper LoongArch: BPF: Support up to 12 function arguments for trampoline LoongArch: BPF: Support small struct arguments for trampoline LoongArch: BPF: Open code and remove invoke_bpf_mod_ret() LoongArch: BPF: Support load-acquire and store-release instructions LoongArch: BPF: Support 8 and 16 bit read-modify-write instructions LoongArch: BPF: Add the default case in emit_atomic() and rename it LoongArch: Define instruction formats for AM{SWAP/ADD}.{B/H} and DBAR LoongArch: Batch the icache maintenance for jump_label LoongArch: Add flush_icache_all()/local_flush_icache_all() LoongArch: Add spectre boundry for syscall dispatch table LoongArch: Show CPU vulnerabilites correctly LoongArch: Make arch_irq_work_has_interrupt() true only if IPI HW exist LoongArch: Use get_random_canary() for stack canary init LoongArch: Improve the logging of disabling KASLR LoongArch: Align FPU register state to 32 bytes LoongArch: Handle CONFIG_32BIT in syscall_get_arch() LoongArch: Add HIGHMEM (PKMAP and FIX_KMAP) support ...

LoongArch: BPF: Add fsession support for trampolines

2026-04-23T04:49:36+00:00

Implement BPF_TRACE_FSESSION support in LoongArch BPF JIT. The logic here is almost identical to what has been done in RISC-V JIT. The key changes are: - Allocate stack space for function meta and session cookies - Introduce invoke_bpf() as a wrapper around invoke_bpf_prog() that populates session cookies before each invocation - Implement bpf_jit_supports_fsession() callback Tested-by: Vincent Li Reviewed-by: Menglong Dong Signed-off-by: Hengqi Chen Signed-off-by: Huacai Chen

LoongArch: BPF: Introduce emit_store_stack_imm64() helper

2026-04-23T04:49:36+00:00

Introduce a helper to store 64-bit immediate on the trampoline stack. The helper will be used in the next patch. Also refactor the existing code to use this helper. Tested-by: Vincent Li Reviewed-by: Menglong Dong Signed-off-by: Hengqi Chen Signed-off-by: Huacai Chen

LoongArch: BPF: Support up to 12 function arguments for trampoline

2026-04-22T07:45:34+00:00

Currently, LoongArch bpf trampoline supports up to 8 function arguments. According to the statistics from commit 473e3150e30a ("bpf, x86: allow function arguments up to 12 for TRACING"), there are over 200 functions accept 9 to 12 arguments, so add 12 arguments support for trampoline. With this patch, the following related testcases passed: sudo ./test_progs -a tracing_struct/struct_many_args sudo ./test_progs -a fentry_test/fentry_many_args sudo ./test_progs -a fexit_test/fexit_many_args Acked-by: Hengqi Chen Tested-by: Hengqi Chen Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: BPF: Support small struct arguments for trampoline

2026-04-22T07:45:34+00:00

In the current BPF code, the struct argument size is at most 16 bytes, enforced by the verifier. According to the Procedure Call Standard for LoongArch, the struct argument size below 16 bytes are provided as part of the 8 argument registers, that is to say, the struct argument may be passed in a pair of registers if its size is more than 8 bytes and no more than 16 bytes. Extend the BPF trampoline JIT to support attachment to functions that take small structures (up to 16 bytes) as argument, save and restore a number of "argument registers" rather than a number of arguments. With this patch, the following related testcases passed: sudo ./test_progs -a tracing_struct/struct_args sudo ./test_progs -a tracing_struct/union_args Link: https://github.com/loongson/la-abi-specs/blob/release/lapcs.adoc#structures Acked-by: Hengqi Chen Tested-by: Hengqi Chen Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: BPF: Open code and remove invoke_bpf_mod_ret()

2026-04-22T07:45:34+00:00

invoke_bpf_mod_ret() is a small wrapper over invoke_bpf_prog(), it should check the return value of invoke_bpf_prog() and then return immediately if invoke_bpf_prog() failed, just open code and remove it due to it is called only once. Acked-by: Hengqi Chen Tested-by: Hengqi Chen Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: BPF: Support load-acquire and store-release instructions

2026-04-22T07:45:34+00:00

Use the LoongArch common memory access instructions with the barrier 'dbar' to support the BPF load-acquire and store-release instructions. With this patch, the following testcases passed on LoongArch if the macro CAN_USE_LOAD_ACQ_STORE_REL is usable in bpf selftests: sudo ./test_progs -t verifier_load_acquire sudo ./test_progs -t verifier_store_release sudo ./test_progs -t verifier_precision/bpf_load_acquire sudo ./test_progs -t verifier_precision/bpf_store_release sudo ./test_progs -t compute_live_registers/atomic_load_acq_store_rel Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: BPF: Support 8 and 16 bit read-modify-write instructions

2026-04-22T07:45:34+00:00

The 8 and 16 bit read-modify-write instructions {amadd/amswap}.{b/h} were newly added in the latest LoongArch Reference Manual, use them to avoid the error of unknown opcode if possible. Acked-by: Hengqi Chen Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: BPF: Add the default case in emit_atomic() and rename it

2026-04-22T07:45:34+00:00

Like the other archs such as x86 and riscv, add the default case in emit_atomic() to print an error message for the invalid opcode and return -EINVAL, then make its return type as int. While at it, given that all of the instructions in emit_atomic() are only read-modify-write instructions, rename emit_atomic() to emit_atomic_rmw() to make it clear, because there will be a new function emit_atomic_ld_st() for load-acquire and store-release instructions in the later patch. Acked-by: Hengqi Chen Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

bpf: Pass bpf_verifier_env to JIT

2026-04-16T14:03:40+00:00

Pass bpf_verifier_env to bpf_int_jit_compile(). The follow-up patch will use env->insn_aux_data in the JIT stage to detect indirect jump targets. Since bpf_prog_select_runtime() can be called by cbpf and lib/test_bpf.c code without verifier, introduce helper __bpf_prog_select_runtime() to accept the env parameter. Remove the call to bpf_prog_select_runtime() in bpf_prog_load(), and switch to call __bpf_prog_select_runtime() in the verifier, with env variable passed. The original bpf_prog_select_runtime() is preserved for cbpf and lib/test_bpf.c, where env is NULL. Now all constants blinding calls are moved into the verifier, except the cbpf and lib/test_bpf.c cases. The instructions arrays are adjusted by bpf_patch_insn_data() function for normal cases, so there is no need to call adjust_insn_arrays() in bpf_jit_blind_constants(). Remove it. Reviewed-by: Anton Protopopov # v8 Reviewed-by: Emil Tsalapatis # v12 Acked-by: Hengqi Chen # v14 Signed-off-by: Xu Kuohai Link: https://lore.kernel.org/r/20260416064341.151802-3-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov