1 files changed, 196 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/ptrace.h b/arch/loongarch/include/asm/ptrace.h
new file mode 100644
index 0000000000..f3ddaed9ef
--- /dev/null
+++ b/arch/loongarch/include/asm/ptrace.h
@@ -0,0 +1,196 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_PTRACE_H
+#define _ASM_PTRACE_H
+
+#include <asm/page.h>
+#include <asm/irqflags.h>
+#include <asm/thread_info.h>
+#include <uapi/asm/ptrace.h>
+
+/*
+ * This struct defines the way the registers are stored on the stack during
+ * a system call/exception. If you add a register here, please also add it to
+ * regoffset_table[] in arch/loongarch/kernel/ptrace.c.
+ */
+struct pt_regs {
+	/* Main processor registers. */
+	unsigned long regs[32];
+
+	/* Original syscall arg0. */
+	unsigned long orig_a0;
+
+	/* Special CSR registers. */
+	unsigned long csr_era;
+	unsigned long csr_badvaddr;
+	unsigned long csr_crmd;
+	unsigned long csr_prmd;
+	unsigned long csr_euen;
+	unsigned long csr_ecfg;
+	unsigned long csr_estat;
+	unsigned long __last[];
+} __aligned(8);
+
+static inline int regs_irqs_disabled(struct pt_regs *regs)
+{
+	return arch_irqs_disabled_flags(regs->csr_prmd);
+}
+
+static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
+{
+	return regs->regs[3];
+}
+
+/*
+ * Don't use asm-generic/ptrace.h it defines FP accessors that don't make
+ * sense on LoongArch.  We rather want an error if they get invoked.
+ */
+
+static inline void instruction_pointer_set(struct pt_regs *regs, unsigned long val)
+{
+	regs->csr_era = val;
+}
+
+/* Query offset/name of register from its name/offset */
+extern int regs_query_register_offset(const char *name);
+#define MAX_REG_OFFSET (offsetof(struct pt_regs, __last))
+
+/**
+ * regs_get_register() - get register value from its offset
+ * @regs:       pt_regs from which register value is gotten.
+ * @offset:     offset number of the register.
+ *
+ * regs_get_register returns the value of a register. The @offset is the
+ * offset of the register in struct pt_regs address which specified by @regs.
+ * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
+ */
+static inline unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
+{
+	if (unlikely(offset > MAX_REG_OFFSET))
+		return 0;
+
+	return *(unsigned long *)((unsigned long)regs + offset);
+}
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs:       pt_regs which contains kernel stack pointer.
+ * @addr:       address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+static inline int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+	return ((addr & ~(THREAD_SIZE - 1))  ==
+		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:       pt_regs which contains kernel stack pointer.
+ * @n:          stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+	addr += n;
+	if (regs_within_kernel_stack(regs, (unsigned long)addr))
+		return *addr;
+	else
+		return 0;
+}
+
+struct task_struct;
+
+/**
+ * regs_get_kernel_argument() - get Nth function argument in kernel
+ * @regs:       pt_regs of that context
+ * @n:          function argument number (start from 0)
+ *
+ * regs_get_argument() returns @n th argument of the function call.
+ * Note that this chooses most probably assignment, in some case
+ * it can be incorrect.
+ * This is expected to be called from kprobes or ftrace with regs
+ * where the top of stack is the return address.
+ */
+static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
+						     unsigned int n)
+{
+#define NR_REG_ARGUMENTS 8
+	static const unsigned int args[] = {
+		offsetof(struct pt_regs, regs[4]),
+		offsetof(struct pt_regs, regs[5]),
+		offsetof(struct pt_regs, regs[6]),
+		offsetof(struct pt_regs, regs[7]),
+		offsetof(struct pt_regs, regs[8]),
+		offsetof(struct pt_regs, regs[9]),
+		offsetof(struct pt_regs, regs[10]),
+		offsetof(struct pt_regs, regs[11]),
+	};
+
+	if (n < NR_REG_ARGUMENTS)
+		return regs_get_register(regs, args[n]);
+	else {
+		n -= NR_REG_ARGUMENTS;
+		return regs_get_kernel_stack_nth(regs, n);
+	}
+}
+
+/*
+ * Does the process account for user or for system time?
+ */
+#define user_mode(regs) (((regs)->csr_prmd & PLV_MASK) == PLV_USER)
+
+static inline long regs_return_value(struct pt_regs *regs)
+{
+	return regs->regs[4];
+}
+
+static inline void regs_set_return_value(struct pt_regs *regs, unsigned long val)
+{
+	regs->regs[4] = val;
+}
+
+#define instruction_pointer(regs) ((regs)->csr_era)
+#define profile_pc(regs) instruction_pointer(regs)
+
+extern void die(const char *str, struct pt_regs *regs);
+
+static inline void die_if_kernel(const char *str, struct pt_regs *regs)
+{
+	if (unlikely(!user_mode(regs)))
+		die(str, regs);
+}
+
+#define current_pt_regs()						\
+({									\
+	unsigned long sp = (unsigned long)__builtin_frame_address(0);	\
+	(struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1) - 1;		\
+})
+
+/* Helpers for working with the user stack pointer */
+
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+	return regs->regs[3];
+}
+
+static inline void user_stack_pointer_set(struct pt_regs *regs,
+	unsigned long val)
+{
+	regs->regs[3] = val;
+}
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+#define arch_has_single_step()		(1)
+#endif
+
+#endif /* _ASM_PTRACE_H */