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Diffstat (limited to 'arch/microblaze/kernel/ptrace.c')
| -rw-r--r-- | arch/microblaze/kernel/ptrace.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c new file mode 100644 index 000000000000..b86aa623e36d --- /dev/null +++ b/arch/microblaze/kernel/ptrace.c @@ -0,0 +1,181 @@ +/* + * `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/smp_lock.h> +#include <linux/ptrace.h> +#include <linux/signal.h> + +#include <linux/errno.h> +#include <asm/processor.h> +#include <linux/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; + unsigned long val = 0; + unsigned long copied; + + switch (request) { + 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); + break; + + 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; + break; + + /* 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); + break; + /* 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 = ptrace_request(child, request, addr, data); noMMU */ + rval = -EIO; + } + return rval; +} + +void ptrace_disable(struct task_struct *child) +{ + /* nothing to do */ +} |