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Diffstat (limited to 'arch/microblaze/kernel/ptrace.c')
| -rw-r--r-- | arch/microblaze/kernel/ptrace.c | 169 |
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 */ +} |