[PATCH 25/56] microblaze_v2: ptrace support

monstr
2008-05-04T16:44:39Z

From: Michal Simek <monstr@monstr.eu>

Signed-off-by: Michal Simek <monstr@monstr.eu>
---
arch/microblaze/kernel/ptrace.c | 206 +++++++++++++++++++++++++++++++++++++++
include/asm-microblaze/ptrace.h | 70 +++++++++++++
2 files changed, 276 insertions(+), 0 deletions(-)
create mode 100644 arch/microblaze/kernel/ptrace.c
create mode 100644 include/asm-microblaze/ptrace.h

diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
new file mode 100644
index 0000000..958f076
--- /dev/null
+++ b/arch/microblaze/kernel/ptrace.c
@@ -0,0 +1,206 @@
+/*
+ * arch/microblaze/kernel/ptrace.c -- `ptrace' system call
+ *
+ * Copyright (C) 2008 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2007 PetaLogix
+ * Copyright (C) 2004-07 John Williams <john.williams@petalogix.com>
+ *
+ * derived from arch/v850/kernel/ptrace.c
+ *
+ * Copyright (C) 2002,03 NEC Electronics Corporation
+ * Copyright (C) 2002,03 Miles Bader <miles@gnu.org>
+ *
+ * Derived from arch/mips/kernel/ptrace.c:
+ *
+ * Copyright (C) 1992 Ross Biro
+ * Copyright (C) Linus Torvalds
+ * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
+ * Copyright (C) 1996 David S. Miller
+ * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999 MIPS Technologies, Inc.
+ *
+ * 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/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/ptrace.h>
+#include <linux/signal.h>
+
+#include <asm/errno.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+#include <asm/asm-offsets.h>
+
+/* Returns the address where the register at REG_OFFS in P is stashed away. */
+static microblaze_reg_t *reg_save_addr(unsigned reg_offs,
+ struct task_struct *t)
+{
+ struct pt_regs *regs;
+
+ /*
+ * Three basic cases:
+ *
+ * (1) A register normally saved before calling the scheduler, is
+ * available in the kernel entry pt_regs structure at the top
+ * of the kernel stack. The kernel trap/irq exit path takes
+ * care to save/restore almost all registers for ptrace'd
+ * processes.
+ *
+ * (2) A call-clobbered register, where the process P entered the
+ * kernel via [syscall] trap, is not stored anywhere; that's
+ * OK, because such registers are not expected to be preserved
+ * when the trap returns anyway (so we don't actually bother to
+ * test for this case).
+ *
+ * (3) A few registers not used at all by the kernel, and so
+ * normally never saved except by context-switches, are in the
+ * context switch state.
+ */
+
+ /* Register saved during kernel entry (or not available). */
+ regs = task_pt_regs(t);
+
+ return (microblaze_reg_t *)((char *)regs + reg_offs);
+}
+
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+ int rval;
+
+ switch (request) {
+ unsigned long val, copied;
+
+ case PTRACE_PEEKTEXT: /* read word at location addr. */
+ case PTRACE_PEEKDATA:
+ pr_debug("PEEKTEXT/PEEKDATA at %08lX\n", addr);
+ copied = access_process_vm(child, addr, &val, sizeof(val), 0);
+ rval = -EIO;
+ if (copied != sizeof(val))
+ break;
+ rval = put_user(val, (unsigned long *)data);
+ goto out;
+
+ case PTRACE_POKETEXT: /* write the word at location addr. */
+ case PTRACE_POKEDATA:
+ pr_debug("POKETEXT/POKEDATA to %08lX\n", addr);
+ rval = 0;
+ if (access_process_vm(child, addr, &data, sizeof(data), 1)
+ == sizeof(data))
+ break;
+ rval = -EIO;
+ goto out;
+
+ /* Read/write the word at location ADDR in the registers. */
+ case PTRACE_PEEKUSR:
+ case PTRACE_POKEUSR:
+ pr_debug("PEEKUSR/POKEUSR : 0x%08lx\n", addr);
+ rval = 0;
+ if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) {
+ /* Special requests that don't actually correspond
+ to offsets in struct pt_regs. */
+ if (addr == PT_TEXT_ADDR) {
+ val = child->mm->start_code;
+ } else if (addr == PT_DATA_ADDR) {
+ val = child->mm->start_data;
+ } else if (addr == PT_TEXT_LEN) {
+ val = child->mm->end_code
+ - child->mm->start_code;
+ } else {
+ rval = -EIO;
+ }
+ } else if (addr >= 0 && addr < PT_SIZE && (addr & 0x3) == 0) {
+ microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
+ if (request == PTRACE_PEEKUSR)
+ val = *reg_addr;
+ else
+ *reg_addr = data;
+ } else
+ rval = -EIO;
+
+ if (rval == 0 && request == PTRACE_PEEKUSR)
+ rval = put_user(val, (unsigned long *)data);
+ goto out;
+
+ /* Continue and stop at next (return from) syscall */
+ case PTRACE_SYSCALL:
+ pr_debug("PTRACE_SYSCALL\n");
+ case PTRACE_SINGLESTEP:
+ pr_debug("PTRACE_SINGLESTEP\n");
+ /* Restart after a signal. */
+ case PTRACE_CONT:
+ pr_debug("PTRACE_CONT\n");
+ rval = -EIO;
+ if (!valid_signal(data))
+ break;
+
+ if (request == PTRACE_SYSCALL)
+ set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ else
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+ child->exit_code = data;
+ pr_debug("wakeup_process\n");
+ wake_up_process(child);
+ rval = 0;
+ break;
+
+ /*
+ * make the child exit. Best I can do is send it a sigkill.
+ * perhaps it should be put in the status that it wants to
+ * exit.
+ */
+ case PTRACE_KILL:
+ pr_debug("PTRACE_KILL\n");
+ rval = 0;
+ if (child->exit_state == EXIT_ZOMBIE) /* already dead */
+ break;
+ child->exit_code = SIGKILL;
+ wake_up_process(child);
+ break;
+
+ case PTRACE_DETACH: /* detach a process that was attached. */
+ pr_debug("PTRACE_DETACH\n");
+ rval = ptrace_detach(child, data);
+ break;
+
+ default:
+ rval = -EIO;
+ goto out;
+ }
+ out:
+ return rval;
+}
+
+#if 0
+static asmlinkage void syscall_trace(void)
+{
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return;
+ if (!(current->ptrace & PT_PTRACED))
+ return;
+ /* 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;
+ }
+}
+#endif
+
+void ptrace_disable(struct task_struct *child)
+{
+ /* nothing to do */
+}
diff --git a/include/asm-microblaze/ptrace.h b/include/asm-microblaze/ptrace.h
new file mode 100644
index 0000000..f7ba49c
--- /dev/null
+++ b/include/asm-microblaze/ptrace.h
@@ -0,0 +1,70 @@
+/*
+ * include/asm-microblaze/ptrace.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.
+ *
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ */
+
+#ifndef _ASM_MICROBLAZE_PTRACE_H
+#define _ASM_MICROBLAZE_PTRACE_H
+
+#ifndef __ASSEMBLY__
+#include <asm/types.h>
+
+typedef unsigned long microblaze_reg_t;
+
+struct pt_regs {
+ microblaze_reg_t r0;
+ microblaze_reg_t r1;
+ microblaze_reg_t r2;
+ microblaze_reg_t r3;
+ microblaze_reg_t r4;
+ microblaze_reg_t r5;
+ microblaze_reg_t r6;
+ microblaze_reg_t r7;
+ microblaze_reg_t r8;
+ microblaze_reg_t r9;
+ microblaze_reg_t r10;
+ microblaze_reg_t r11;
+ microblaze_reg_t r12;
+ microblaze_reg_t r13;
+ microblaze_reg_t r14;
+ microblaze_reg_t r15;
+ microblaze_reg_t r16;
+ microblaze_reg_t r17;
+ microblaze_reg_t r18;
+ microblaze_reg_t r19;
+ microblaze_reg_t r20;
+ microblaze_reg_t r21;
+ microblaze_reg_t r22;
+ microblaze_reg_t r23;
+ microblaze_reg_t r24;
+ microblaze_reg_t r25;
+ microblaze_reg_t r26;
+ microblaze_reg_t r27;
+ microblaze_reg_t r28;
+ microblaze_reg_t r29;
+ microblaze_reg_t r30;
+ microblaze_reg_t r31;
+ microblaze_reg_t pc;
+ microblaze_reg_t msr;
+ microblaze_reg_t ear;
+ microblaze_reg_t esr;
+ microblaze_reg_t fsr;
+ int kernel_mode;
+};
+
+#define kernel_mode(regs) ((regs)->kernel_mode)
+#define user_mode(regs) (!kernel_mode(regs))
+
+#define instruction_pointer(regs) ((regs)->pc)
+#define profile_pc(regs) instruction_pointer(regs)
+
+extern void show_regs(struct pt_regs *);
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_MICROBLAZE_PTRACE_H */
--
1.5.4.GIT