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-rw-r--r--arch/loongarch/kernel/uprobes.c153
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 0000000000..87abc7137b
--- /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);
+}