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-rw-r--r--arch/unicore32/kernel/ptrace.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/ptrace.c b/arch/unicore32/kernel/ptrace.c
new file mode 100644
index 000000000000..9f07c08da050
--- /dev/null
+++ b/arch/unicore32/kernel/ptrace.c
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+/*
+ * linux/arch/unicore32/kernel/ptrace.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * By Ross Biro 1/23/92
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/signal.h>
+#include <linux/uaccess.h>
+
+/*
+ * this routine will get a word off of the processes privileged stack.
+ * the offset is how far from the base addr as stored in the THREAD.
+ * this routine assumes that all the privileged stacks are in our
+ * data space.
+ */
+static inline long get_user_reg(struct task_struct *task, int offset)
+{
+ return task_pt_regs(task)->uregs[offset];
+}
+
+/*
+ * this routine will put a word on the processes privileged stack.
+ * the offset is how far from the base addr as stored in the THREAD.
+ * this routine assumes that all the privileged stacks are in our
+ * data space.
+ */
+static inline int
+put_user_reg(struct task_struct *task, int offset, long data)
+{
+ struct pt_regs newregs, *regs = task_pt_regs(task);
+ int ret = -EINVAL;
+
+ newregs = *regs;
+ newregs.uregs[offset] = data;
+
+ if (valid_user_regs(&newregs)) {
+ regs->uregs[offset] = data;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ */
+void ptrace_disable(struct task_struct *child)
+{
+}
+
+/*
+ * We actually access the pt_regs stored on the kernel stack.
+ */
+static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
+ unsigned long __user *ret)
+{
+ unsigned long tmp;
+
+ tmp = 0;
+ if (off < sizeof(struct pt_regs))
+ tmp = get_user_reg(tsk, off >> 2);
+
+ return put_user(tmp, ret);
+}
+
+/*
+ * We actually access the pt_regs stored on the kernel stack.
+ */
+static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
+ unsigned long val)
+{
+ if (off >= sizeof(struct pt_regs))
+ return 0;
+
+ return put_user_reg(tsk, off >> 2, val);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret;
+ unsigned long __user *datap = (unsigned long __user *) data;
+
+ switch (request) {
+ case PTRACE_PEEKUSR:
+ ret = ptrace_read_user(child, addr, datap);
+ break;
+
+ case PTRACE_POKEUSR:
+ ret = ptrace_write_user(child, addr, data);
+ break;
+
+ case PTRACE_GET_THREAD_AREA:
+ ret = put_user(task_pt_regs(child)->UCreg_16,
+ datap);
+ break;
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
+{
+ unsigned long ip;
+
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return scno;
+ if (!(current->ptrace & PT_PTRACED))
+ return scno;
+
+ /*
+ * Save IP. IP is used to denote syscall entry/exit:
+ * IP = 0 -> entry, = 1 -> exit
+ */
+ ip = regs->UCreg_ip;
+ regs->UCreg_ip = why;
+
+ current_thread_info()->syscall = scno;
+
+ /* the 0x80 provides a way for the tracing parent to distinguish
+ between a syscall stop and SIGTRAP delivery */
+ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+ ? 0x80 : 0));
+ /*
+ * this isn't the same as continuing with a signal, but it will do
+ * for normal use. strace only continues with a signal if the
+ * stopping signal is not SIGTRAP. -brl
+ */
+ if (current->exit_code) {
+ send_sig(current->exit_code, current, 1);
+ current->exit_code = 0;
+ }
+ regs->UCreg_ip = ip;
+
+ return current_thread_info()->syscall;
+}