600482c13d
On Blackfin systems, the hardware single step exception triggers before
the system call exception, so we need to save this info to process it
later on. Otherwise, single stepping in userspace misses a few insns
right after the system call.
This is based a bit on the SuperH code added in commit 4b505db9c4.
Reported-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
414 lines
10 KiB
C
414 lines
10 KiB
C
/*
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* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
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* these modifications are Copyright 2004-2010 Analog Devices Inc.
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*
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* Licensed under the GPL-2
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/elf.h>
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#include <linux/errno.h>
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#include <linux/ptrace.h>
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#include <linux/user.h>
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#include <linux/regset.h>
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#include <linux/signal.h>
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#include <linux/tracehook.h>
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#include <linux/uaccess.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/processor.h>
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#include <asm/asm-offsets.h>
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#include <asm/dma.h>
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#include <asm/fixed_code.h>
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#include <asm/cacheflush.h>
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#include <asm/mem_map.h>
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/*
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* does not yet catch signals sent when the child dies.
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* in exit.c or in signal.c.
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*/
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/*
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* Get contents of register REGNO in task TASK.
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*/
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static inline long
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get_reg(struct task_struct *task, long regno, unsigned long __user *datap)
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{
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long tmp;
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struct pt_regs *regs = task_pt_regs(task);
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if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
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return -EIO;
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switch (regno) {
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case PT_TEXT_ADDR:
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tmp = task->mm->start_code;
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break;
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case PT_TEXT_END_ADDR:
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tmp = task->mm->end_code;
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break;
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case PT_DATA_ADDR:
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tmp = task->mm->start_data;
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break;
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case PT_USP:
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tmp = task->thread.usp;
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break;
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default:
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if (regno < sizeof(*regs)) {
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void *reg_ptr = regs;
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tmp = *(long *)(reg_ptr + regno);
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} else
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return -EIO;
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}
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return put_user(tmp, datap);
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}
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/*
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* Write contents of register REGNO in task TASK.
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*/
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static inline int
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put_reg(struct task_struct *task, long regno, unsigned long data)
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{
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struct pt_regs *regs = task_pt_regs(task);
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if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
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return -EIO;
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switch (regno) {
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case PT_PC:
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/*********************************************************************/
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/* At this point the kernel is most likely in exception. */
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/* The RETX register will be used to populate the pc of the process. */
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/*********************************************************************/
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regs->retx = data;
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regs->pc = data;
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break;
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case PT_RETX:
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break; /* regs->retx = data; break; */
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case PT_USP:
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regs->usp = data;
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task->thread.usp = data;
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break;
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case PT_SYSCFG: /* don't let userspace screw with this */
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if ((data & ~1) != 0x6)
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pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
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break; /* regs->syscfg = data; break; */
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default:
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if (regno < sizeof(*regs)) {
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void *reg_offset = regs;
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*(long *)(reg_offset + regno) = data;
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}
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/* Ignore writes to pseudo registers */
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}
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return 0;
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}
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/*
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* check that an address falls within the bounds of the target process's memory mappings
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*/
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static inline int is_user_addr_valid(struct task_struct *child,
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unsigned long start, unsigned long len)
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{
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struct vm_area_struct *vma;
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struct sram_list_struct *sraml;
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/* overflow */
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if (start + len < start)
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return -EIO;
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vma = find_vma(child->mm, start);
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if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
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return 0;
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for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
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if (start >= (unsigned long)sraml->addr
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&& start + len < (unsigned long)sraml->addr + sraml->length)
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return 0;
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if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
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return 0;
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return -EIO;
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}
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/*
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* retrieve the contents of Blackfin userspace general registers
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*/
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static int genregs_get(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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struct pt_regs *regs = task_pt_regs(target);
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int ret;
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/* This sucks ... */
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regs->usp = target->thread.usp;
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ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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regs, 0, sizeof(*regs));
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if (ret < 0)
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return ret;
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return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
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sizeof(*regs), -1);
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}
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/*
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* update the contents of the Blackfin userspace general registers
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*/
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static int genregs_set(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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struct pt_regs *regs = task_pt_regs(target);
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int ret;
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/* Don't let people set SYSCFG (it's at the end of pt_regs) */
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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regs, 0, PT_SYSCFG);
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if (ret < 0)
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return ret;
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/* This sucks ... */
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target->thread.usp = regs->usp;
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/* regs->retx = regs->pc; */
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return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
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PT_SYSCFG, -1);
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}
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/*
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* Define the register sets available on the Blackfin under Linux
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*/
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enum bfin_regset {
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REGSET_GENERAL,
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};
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static const struct user_regset bfin_regsets[] = {
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[REGSET_GENERAL] = {
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.core_note_type = NT_PRSTATUS,
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.n = sizeof(struct pt_regs) / sizeof(long),
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.size = sizeof(long),
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.align = sizeof(long),
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.get = genregs_get,
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.set = genregs_set,
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},
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};
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static const struct user_regset_view user_bfin_native_view = {
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.name = "Blackfin",
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.e_machine = EM_BLACKFIN,
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.regsets = bfin_regsets,
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.n = ARRAY_SIZE(bfin_regsets),
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};
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const struct user_regset_view *task_user_regset_view(struct task_struct *task)
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{
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return &user_bfin_native_view;
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}
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void user_enable_single_step(struct task_struct *child)
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{
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struct pt_regs *regs = task_pt_regs(child);
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regs->syscfg |= SYSCFG_SSSTEP;
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set_tsk_thread_flag(child, TIF_SINGLESTEP);
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}
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void user_disable_single_step(struct task_struct *child)
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{
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struct pt_regs *regs = task_pt_regs(child);
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regs->syscfg &= ~SYSCFG_SSSTEP;
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clear_tsk_thread_flag(child, TIF_SINGLESTEP);
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}
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long arch_ptrace(struct task_struct *child, long request, long addr, long data)
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{
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int ret;
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unsigned long __user *datap = (unsigned long __user *)data;
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void *paddr = (void *)addr;
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switch (request) {
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/* when I and D space are separate, these will need to be fixed. */
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case PTRACE_PEEKDATA:
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pr_debug("ptrace: PEEKDATA\n");
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/* fall through */
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case PTRACE_PEEKTEXT: /* read word at location addr. */
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{
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unsigned long tmp = 0;
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int copied = 0, to_copy = sizeof(tmp);
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ret = -EIO;
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pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
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if (is_user_addr_valid(child, addr, to_copy) < 0)
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break;
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pr_debug("ptrace: user address is valid\n");
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switch (bfin_mem_access_type(addr, to_copy)) {
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case BFIN_MEM_ACCESS_CORE:
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case BFIN_MEM_ACCESS_CORE_ONLY:
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copied = access_process_vm(child, addr, &tmp,
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to_copy, 0);
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if (copied)
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break;
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/* hrm, why didn't that work ... maybe no mapping */
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if (addr >= FIXED_CODE_START &&
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addr + to_copy <= FIXED_CODE_END) {
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copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
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copied = to_copy;
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} else if (addr >= BOOT_ROM_START) {
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memcpy(&tmp, paddr, to_copy);
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copied = to_copy;
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}
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break;
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case BFIN_MEM_ACCESS_DMA:
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if (safe_dma_memcpy(&tmp, paddr, to_copy))
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copied = to_copy;
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break;
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case BFIN_MEM_ACCESS_ITEST:
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if (isram_memcpy(&tmp, paddr, to_copy))
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copied = to_copy;
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break;
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default:
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copied = 0;
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break;
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}
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pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
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if (copied == to_copy)
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ret = put_user(tmp, datap);
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break;
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}
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#ifdef CONFIG_BINFMT_ELF_FDPIC
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case PTRACE_GETFDPIC: {
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unsigned long tmp = 0;
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switch (addr) {
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case_PTRACE_GETFDPIC_EXEC:
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case PTRACE_GETFDPIC_EXEC:
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tmp = child->mm->context.exec_fdpic_loadmap;
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break;
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case_PTRACE_GETFDPIC_INTERP:
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case PTRACE_GETFDPIC_INTERP:
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tmp = child->mm->context.interp_fdpic_loadmap;
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break;
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default:
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break;
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}
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ret = put_user(tmp, datap);
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break;
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}
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#endif
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/* when I and D space are separate, this will have to be fixed. */
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case PTRACE_POKEDATA:
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pr_debug("ptrace: PTRACE_PEEKDATA\n");
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/* fall through */
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case PTRACE_POKETEXT: /* write the word at location addr. */
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{
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int copied = 0, to_copy = sizeof(data);
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ret = -EIO;
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pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
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addr, to_copy, data);
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if (is_user_addr_valid(child, addr, to_copy) < 0)
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break;
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pr_debug("ptrace: user address is valid\n");
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switch (bfin_mem_access_type(addr, to_copy)) {
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case BFIN_MEM_ACCESS_CORE:
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case BFIN_MEM_ACCESS_CORE_ONLY:
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copied = access_process_vm(child, addr, &data,
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to_copy, 1);
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break;
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case BFIN_MEM_ACCESS_DMA:
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if (safe_dma_memcpy(paddr, &data, to_copy))
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copied = to_copy;
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break;
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case BFIN_MEM_ACCESS_ITEST:
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if (isram_memcpy(paddr, &data, to_copy))
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copied = to_copy;
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break;
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default:
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copied = 0;
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break;
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}
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pr_debug("ptrace: copied size %d\n", copied);
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if (copied == to_copy)
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ret = 0;
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break;
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}
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case PTRACE_PEEKUSR:
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switch (addr) {
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#ifdef CONFIG_BINFMT_ELF_FDPIC /* backwards compat */
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case PT_FDPIC_EXEC: goto case_PTRACE_GETFDPIC_EXEC;
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case PT_FDPIC_INTERP: goto case_PTRACE_GETFDPIC_INTERP;
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#endif
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default:
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ret = get_reg(child, addr, datap);
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}
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pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
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break;
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case PTRACE_POKEUSR:
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ret = put_reg(child, addr, data);
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pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
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break;
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case PTRACE_GETREGS:
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pr_debug("ptrace: PTRACE_GETREGS\n");
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return copy_regset_to_user(child, &user_bfin_native_view,
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REGSET_GENERAL,
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0, sizeof(struct pt_regs),
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(void __user *)data);
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case PTRACE_SETREGS:
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pr_debug("ptrace: PTRACE_SETREGS\n");
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return copy_regset_from_user(child, &user_bfin_native_view,
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REGSET_GENERAL,
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0, sizeof(struct pt_regs),
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(const void __user *)data);
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default:
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ret = ptrace_request(child, request, addr, data);
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break;
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}
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return ret;
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}
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asmlinkage int syscall_trace_enter(struct pt_regs *regs)
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{
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int ret = 0;
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if (test_thread_flag(TIF_SYSCALL_TRACE))
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ret = tracehook_report_syscall_entry(regs);
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return ret;
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}
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asmlinkage void syscall_trace_leave(struct pt_regs *regs)
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{
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int step;
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step = test_thread_flag(TIF_SINGLESTEP);
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if (step || test_thread_flag(TIF_SYSCALL_TRACE))
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tracehook_report_syscall_exit(regs, step);
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}
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