[PATCH v2 25/29] nios2: ptrace support

From: Ley Foon Tan
Date: Tue Jul 15 2014 - 04:52:12 EST

Add ptrace support for nios2.

Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx>
---
arch/nios2/include/asm/ptrace.h | 33 +++++++
arch/nios2/include/uapi/asm/ptrace.h | 120 +++++++++++++++++++++++
arch/nios2/kernel/ptrace.c | 180 +++++++++++++++++++++++++++++++++++
3 files changed, 333 insertions(+)
create mode 100644 arch/nios2/include/asm/ptrace.h
create mode 100644 arch/nios2/include/uapi/asm/ptrace.h
create mode 100644 arch/nios2/kernel/ptrace.c

diff --git a/arch/nios2/include/asm/ptrace.h b/arch/nios2/include/asm/ptrace.h
new file mode 100644
index 0000000..20fb1cf
--- /dev/null
+++ b/arch/nios2/include/asm/ptrace.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Copyright (C) 2010 Tobias Klauser <tklauser@xxxxxxxxxx>
+ * Copyright (C) 2004 Microtronix Datacom Ltd
+ *
+ * based on m68k asm/processor.h
+ *
+ * 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.
+ */
+
+#ifndef _ASM_NIOS2_PTRACE_H
+#define _ASM_NIOS2_PTRACE_H
+
+#include <uapi/asm/ptrace.h>
+
+#ifndef __ASSEMBLY__
+#define user_mode(regs) (((regs)->estatus & ESTATUS_EU))
+
+#define instruction_pointer(regs) ((regs)->ra)
+#define profile_pc(regs) instruction_pointer(regs)
+#define user_stack_pointer(regs) ((regs)->sp)
+extern void show_regs(struct pt_regs *);
+
+#define current_pt_regs() \
+ ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE)\
+ - 1)
+
+int do_syscall_trace_enter(void);
+void do_syscall_trace_exit(void);
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_NIOS2_PTRACE_H */
diff --git a/arch/nios2/include/uapi/asm/ptrace.h b/arch/nios2/include/uapi/asm/ptrace.h
new file mode 100644
index 0000000..e83a7c9
--- /dev/null
+++ b/arch/nios2/include/uapi/asm/ptrace.h
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2010 Tobias Klauser <tklauser@xxxxxxxxxx>
+ * Copyright (C) 2004 Microtronix Datacom Ltd
+ *
+ * based on m68k asm/processor.h
+ *
+ * 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.
+ */
+
+#ifndef _UAPI_ASM_NIOS2_PTRACE_H
+#define _UAPI_ASM_NIOS2_PTRACE_H
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Register numbers used by 'ptrace' system call interface.
+ */
+
+/* GP registers */
+#define PTR_R0 0
+#define PTR_R1 1
+#define PTR_R2 2
+#define PTR_R3 3
+#define PTR_R4 4
+#define PTR_R5 5
+#define PTR_R6 6
+#define PTR_R7 7
+#define PTR_R8 8
+#define PTR_R9 9
+#define PTR_R10 10
+#define PTR_R11 11
+#define PTR_R12 12
+#define PTR_R13 13
+#define PTR_R14 14
+#define PTR_R15 15
+#define PTR_R16 16
+#define PTR_R17 17
+#define PTR_R18 18
+#define PTR_R19 19
+#define PTR_R20 20
+#define PTR_R21 21
+#define PTR_R22 22
+#define PTR_R23 23
+#define PTR_R24 24
+#define PTR_R25 25
+#define PTR_GP 26
+#define PTR_SP 27
+#define PTR_FP 28
+#define PTR_EA 29
+#define PTR_BA 30
+#define PTR_RA 31
+/* Control registers */
+#define PTR_PC 32
+#define PTR_STATUS 33
+#define PTR_ESTATUS 34
+#define PTR_BSTATUS 35
+#define PTR_IENABLE 36
+#define PTR_IPENDING 37
+#define PTR_CPUID 38
+#define PTR_CTL6 39
+#define PTR_CTL7 40
+#define PTR_PTEADDR 41
+#define PTR_TLBACC 42
+#define PTR_TLBMISC 43
+
+#define NUM_PTRACE_REG (PTR_TLBMISC + 1)
+
+/* this struct defines the way the registers are stored on the
+ stack during a system call.
+
+ There is a fake_regs in setup.c that has to match pt_regs.*/
+
+struct pt_regs {
+ unsigned long r8; /* r8-r15 Caller-saved GP registers */
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+ unsigned long r12;
+ unsigned long r13;
+ unsigned long r14;
+ unsigned long r15;
+ unsigned long r1; /* Assembler temporary */
+ unsigned long r2; /* Retval LS 32bits */
+ unsigned long r3; /* Retval MS 32bits */
+ unsigned long r4; /* r4-r7 Register arguments */
+ unsigned long r5;
+ unsigned long r6;
+ unsigned long r7;
+ unsigned long orig_r2; /* Copy of r2 ?? */
+ unsigned long ra; /* Return address */
+ unsigned long fp; /* Frame pointer */
+ unsigned long sp; /* Stack pointer */
+ unsigned long gp; /* Global pointer */
+ unsigned long estatus;
+ unsigned long ea; /* Exception return address (pc) */
+ unsigned long orig_r7;
+};
+
+/*
+ * This is the extended stack used by signal handlers and the context
+ * switcher: it's pushed after the normal "struct pt_regs".
+ */
+struct switch_stack {
+ unsigned long r16; /* r16-r23 Callee-saved GP registers */
+ unsigned long r17;
+ unsigned long r18;
+ unsigned long r19;
+ unsigned long r20;
+ unsigned long r21;
+ unsigned long r22;
+ unsigned long r23;
+ unsigned long fp;
+ unsigned long gp;
+ unsigned long ra;
+};
+
+#endif /* __ASSEMBLY__ */
+#endif /* _UAPI_ASM_NIOS2_PTRACE_H */
diff --git a/arch/nios2/kernel/ptrace.c b/arch/nios2/kernel/ptrace.c
new file mode 100644
index 0000000..152b31c
--- /dev/null
+++ b/arch/nios2/kernel/ptrace.c
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2014 Altera Corporation
+ * Copyright (C) 2010 Tobias Klauser <tklauser@xxxxxxxxxx>
+ *
+ * based on arch/m68knommu/kernel/ptrace.c
+ *
+ * Copyright (C) 1994 by Hamish Macdonald
+ *
+ * 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)
+{
+ int ret = -EIO;
+
+ pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
+
+ switch (request) {
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+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);
+}
--
1.8.2.1

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