1 files changed, 153 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/uprobes.c b/arch/loongarch/kernel/uprobes.c
new file mode 100644
index 000000000000..87abc7137b73
--- /dev/null
+++ b/arch/loongarch/kernel/uprobes.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/uprobes.h>
+#include <asm/cacheflush.h>
+
+#define UPROBE_TRAP_NR	UINT_MAX
+
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
+			     struct mm_struct *mm, unsigned long addr)
+{
+	int idx;
+	union loongarch_instruction insn;
+
+	if (addr & 0x3)
+		return -EILSEQ;
+
+	for (idx = ARRAY_SIZE(auprobe->insn) - 1; idx >= 0; idx--) {
+		insn.word = auprobe->insn[idx];
+		if (insns_not_supported(insn))
+			return -EINVAL;
+	}
+
+	if (insns_need_simulation(insn)) {
+		auprobe->ixol[0] = larch_insn_gen_nop();
+		auprobe->simulate = true;
+	} else {
+		auprobe->ixol[0] = auprobe->insn[0];
+		auprobe->simulate = false;
+	}
+
+	auprobe->ixol[1] = UPROBE_XOLBP_INSN;
+
+	return 0;
+}
+
+int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	struct uprobe_task *utask = current->utask;
+
+	utask->autask.saved_trap_nr = current->thread.trap_nr;
+	current->thread.trap_nr = UPROBE_TRAP_NR;
+	instruction_pointer_set(regs, utask->xol_vaddr);
+	user_enable_single_step(current);
+
+	return 0;
+}
+
+int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	struct uprobe_task *utask = current->utask;
+
+	WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR);
+	current->thread.trap_nr = utask->autask.saved_trap_nr;
+
+	if (auprobe->simulate)
+		instruction_pointer_set(regs, auprobe->resume_era);
+	else
+		instruction_pointer_set(regs, utask->vaddr + LOONGARCH_INSN_SIZE);
+
+	user_disable_single_step(current);
+
+	return 0;
+}
+
+void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	struct uprobe_task *utask = current->utask;
+
+	current->thread.trap_nr = utask->autask.saved_trap_nr;
+	instruction_pointer_set(regs, utask->vaddr);
+	user_disable_single_step(current);
+}
+
+bool arch_uprobe_xol_was_trapped(struct task_struct *t)
+{
+	if (t->thread.trap_nr != UPROBE_TRAP_NR)
+		return true;
+
+	return false;
+}
+
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	union loongarch_instruction insn;
+
+	if (!auprobe->simulate)
+		return false;
+
+	insn.word = auprobe->insn[0];
+	arch_simulate_insn(insn, regs);
+	auprobe->resume_era = regs->csr_era;
+
+	return true;
+}
+
+unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
+						struct pt_regs *regs)
+{
+	unsigned long ra = regs->regs[1];
+
+	regs->regs[1] = trampoline_vaddr;
+
+	return ra;
+}
+
+bool arch_uretprobe_is_alive(struct return_instance *ret,
+			     enum rp_check ctx, struct pt_regs *regs)
+{
+	if (ctx == RP_CHECK_CHAIN_CALL)
+		return regs->regs[3] <= ret->stack;
+	else
+		return regs->regs[3] < ret->stack;
+}
+
+int arch_uprobe_exception_notify(struct notifier_block *self,
+				 unsigned long val, void *data)
+{
+	return NOTIFY_DONE;
+}
+
+bool uprobe_breakpoint_handler(struct pt_regs *regs)
+{
+	if (uprobe_pre_sstep_notifier(regs))
+		return true;
+
+	return false;
+}
+
+bool uprobe_singlestep_handler(struct pt_regs *regs)
+{
+	if (uprobe_post_sstep_notifier(regs))
+		return true;
+
+	return false;
+}
+
+unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+	return instruction_pointer(regs);
+}
+
+void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
+			   void *src, unsigned long len)
+{
+	void *kaddr = kmap_local_page(page);
+	void *dst = kaddr + (vaddr & ~PAGE_MASK);
+
+	memcpy(dst, src, len);
+	flush_icache_range((unsigned long)dst, (unsigned long)dst + len);
+	kunmap_local(kaddr);
+}