nios2: ptrace support

Add ptrace support for nios2.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

1 files changed, 166 insertions, 0 deletions

diff --git a/arch/nios2/kernel/ptrace.c b/arch/nios2/kernel/ptrace.c
new file mode 100644
index 000000000000..681dda92eff1
--- /dev/null
+++ b/arch/nios2/kernel/ptrace.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2014 Altera Corporation
+ * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of this
+ * archive for more details.
+ */
+
+#include <linux/elf.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/ptrace.h>
+#include <linux/regset.h>
+#include <linux/sched.h>
+#include <linux/tracehook.h>
+#include <linux/uaccess.h>
+#include <linux/user.h>
+
+static int genregs_get(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       void *kbuf, void __user *ubuf)
+{
+	const struct pt_regs *regs = task_pt_regs(target);
+	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
+	int ret = 0;
+
+#define REG_O_ZERO_RANGE(START, END)		\
+	if (!ret)					\
+		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
+			START * 4, (END * 4) + 4);
+
+#define REG_O_ONE(PTR, LOC)	\
+	if (!ret)			\
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
+			LOC * 4, (LOC * 4) + 4);
+
+#define REG_O_RANGE(PTR, START, END)	\
+	if (!ret)				\
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
+			START * 4, (END * 4) + 4);
+
+	REG_O_ZERO_RANGE(PTR_R0, PTR_R0);
+	REG_O_RANGE(&regs->r1, PTR_R1, PTR_R7);
+	REG_O_RANGE(&regs->r8, PTR_R8, PTR_R15);
+	REG_O_RANGE(sw, PTR_R16, PTR_R23);
+	REG_O_ZERO_RANGE(PTR_R24, PTR_R25); /* et and bt */
+	REG_O_ONE(&regs->gp, PTR_GP);
+	REG_O_ONE(&regs->sp, PTR_SP);
+	REG_O_ONE(&regs->fp, PTR_FP);
+	REG_O_ONE(&regs->ea, PTR_EA);
+	REG_O_ZERO_RANGE(PTR_BA, PTR_BA);
+	REG_O_ONE(&regs->ra, PTR_RA);
+	REG_O_ONE(&regs->ea, PTR_PC); /* use ea for PC */
+	if (!ret)
+		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					 PTR_STATUS * 4, -1);
+
+	return ret;
+}
+
+/*
+ * Set the thread state from a regset passed in via ptrace
+ */
+static int genregs_set(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       const void *kbuf, const void __user *ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
+	int ret = 0;
+
+#define REG_IGNORE_RANGE(START, END)		\
+	if (!ret)					\
+		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
+			START * 4, (END * 4) + 4);
+
+#define REG_IN_ONE(PTR, LOC)	\
+	if (!ret)			\
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
+			(void *)(PTR), LOC * 4, (LOC * 4) + 4);
+
+#define REG_IN_RANGE(PTR, START, END)	\
+	if (!ret)				\
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
+			(void *)(PTR), START * 4, (END * 4) + 4);
+
+	REG_IGNORE_RANGE(PTR_R0, PTR_R0);
+	REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
+	REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
+	REG_IN_RANGE(sw, PTR_R16, PTR_R23);
+	REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
+	REG_IN_ONE(&regs->gp, PTR_GP);
+	REG_IN_ONE(&regs->sp, PTR_SP);
+	REG_IN_ONE(&regs->fp, PTR_FP);
+	REG_IN_ONE(&regs->ea, PTR_EA);
+	REG_IGNORE_RANGE(PTR_BA, PTR_BA);
+	REG_IN_ONE(&regs->ra, PTR_RA);
+	REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
+	if (!ret)
+		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					 PTR_STATUS * 4, -1);
+
+	return ret;
+}
+
+/*
+ * Define the register sets available on Nios2 under Linux
+ */
+enum nios2_regset {
+	REGSET_GENERAL,
+};
+
+static const struct user_regset nios2_regsets[] = {
+	[REGSET_GENERAL] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = NUM_PTRACE_REG,
+		.size = sizeof(unsigned long),
+		.align = sizeof(unsigned long),
+		.get = genregs_get,
+		.set = genregs_set,
+	}
+};
+
+static const struct user_regset_view nios2_user_view = {
+	.name = "nios2",
+	.e_machine = ELF_ARCH,
+	.ei_osabi = ELF_OSABI,
+	.regsets = nios2_regsets,
+	.n = ARRAY_SIZE(nios2_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &nios2_user_view;
+}
+
+void ptrace_disable(struct task_struct *child)
+{
+
+}
+
+long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
+		 unsigned long data)
+{
+	return ptrace_request(child, request, addr, data);
+}
+
+asmlinkage int do_syscall_trace_enter(void)
+{
+	int ret = 0;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		ret = tracehook_report_syscall_entry(task_pt_regs(current));
+
+	return ret;
+}
+
+asmlinkage void do_syscall_trace_exit(void)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(task_pt_regs(current), 0);
+}