From 61cf49e44926fe5758699f2ff2eb0ceb3bfb8aa5 Mon Sep 17 00:00:00 2001 From: Chenghao Duan Date: Wed, 31 Dec 2025 15:19:20 +0800 Subject: [PATCH] LoongArch: Enable exception fixup for specific ADE subcode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch allows the LoongArch BPF JIT to handle recoverable memory access errors generated by BPF_PROBE_MEM* instructions. When a BPF program performs memory access operations, the instructions it executes may trigger ADEM exceptions. The kernel’s built-in BPF exception table mechanism (EX_TYPE_BPF) will generate corresponding exception fixup entries in the JIT compilation phase; however, the architecture-specific trap handling function needs to proactively call the common fixup routine to achieve exception recovery. do_ade(): fix EX_TYPE_BPF memory access exceptions for BPF programs, ensure safe execution. Relevant test cases: illegal address access tests in module_attach and subprogs_extable of selftests/bpf. Signed-off-by: Chenghao Duan Signed-off-by: Huacai Chen Signed-off-by: maoxiaochuan --- arch/loongarch/kernel/traps.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index da5926fea..8e51ce004 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -535,10 +535,15 @@ out: asmlinkage void noinstr do_ade(struct pt_regs *regs) { irqentry_state_t state = irqentry_enter(regs); + unsigned int esubcode = FIELD_GET(CSR_ESTAT_ESUBCODE, regs->csr_estat); + + if ((esubcode == EXSUBCODE_ADEM) && fixup_exception(regs)) + goto out; die_if_kernel("Kernel ade access", regs); force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr); +out: irqentry_exit(regs, state); }