summaryrefslogtreecommitdiffstats
path: root/arch/microblaze/kernel/ptrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/microblaze/kernel/ptrace.c')
-rw-r--r--arch/microblaze/kernel/ptrace.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
new file mode 100644
index 0000000000..5234d0c1dc
--- /dev/null
+++ b/arch/microblaze/kernel/ptrace.c
@@ -0,0 +1,169 @@
+/*
+ * `ptrace' system call
+ *
+ * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2004-2007 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/sched/task_stack.h>
+#include <linux/ptrace.h>
+#include <linux/signal.h>
+#include <linux/elf.h>
+#include <linux/audit.h>
+#include <linux/seccomp.h>
+
+#include <linux/errno.h>
+#include <asm/processor.h>
+#include <linux/uaccess.h>
+#include <asm/asm-offsets.h>
+#include <asm/cacheflush.h>
+#include <asm/syscall.h>
+#include <linux/io.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,
+ unsigned long addr, unsigned long data)
+{
+ int rval;
+ unsigned long val = 0;
+
+ switch (request) {
+ /* 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 < PT_SIZE && (addr & 0x3) == 0) {
+ microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
+ if (request == PTRACE_PEEKUSR)
+ val = *reg_addr;
+ else {
+#if 1
+ *reg_addr = data;
+#else
+ /* MS potential problem on WB system
+ * Be aware that reg_addr is virtual address
+ * virt_to_phys conversion is necessary.
+ * This could be sensible solution.
+ */
+ u32 paddr = virt_to_phys((u32)reg_addr);
+ invalidate_icache_range(paddr, paddr + 4);
+ *reg_addr = data;
+ flush_dcache_range(paddr, paddr + 4);
+#endif
+ }
+ } else
+ rval = -EIO;
+
+ if (rval == 0 && request == PTRACE_PEEKUSR)
+ rval = put_user(val, (unsigned long __user *)data);
+ break;
+ default:
+ rval = ptrace_request(child, request, addr, data);
+ }
+ return rval;
+}
+
+asmlinkage unsigned long do_syscall_trace_enter(struct pt_regs *regs)
+{
+ unsigned long ret = 0;
+
+ secure_computing_strict(regs->r12);
+
+ if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+ ptrace_report_syscall_entry(regs))
+ /*
+ * Tracing decided this syscall should not happen.
+ * We'll return a bogus call number to get an ENOSYS
+ * error, but leave the original number in regs->regs[0].
+ */
+ ret = -1L;
+
+ audit_syscall_entry(regs->r12, regs->r5, regs->r6, regs->r7, regs->r8);
+
+ return ret ?: regs->r12;
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+ int step;
+
+ audit_syscall_exit(regs);
+
+ step = test_thread_flag(TIF_SINGLESTEP);
+ if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+ ptrace_report_syscall_exit(regs, step);
+}
+
+void ptrace_disable(struct task_struct *child)
+{
+ /* nothing to do */
+}