ptrace.c
/*
* Ptrace support for Hexagon
*
* Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include <generated/compile.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <asm/user.h>
#if arch_has_single_step()
/* Both called from ptrace_resume */
void user_enable_single_step(struct task_struct *child)
{
pt_set_singlestep(task_pt_regs(child));
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
pt_clr_singlestep(task_pt_regs(child));
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}
#endif
static int genregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret;
unsigned int dummy;
struct pt_regs *regs = task_pt_regs(target);
if (!regs)
return -EIO;
/* The general idea here is that the copyout must happen in
* exactly the same order in which the userspace expects these
* regs. Now, the sequence in userspace does not match the
* sequence in the kernel, so everything past the 32 gprs
* happens one at a time.
*/
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
®s->r00, 0, 32*sizeof(unsigned long));
#define ONEXT(KPT_REG, USR_REG) \
if (!ret) \
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, \
KPT_REG, offsetof(struct user_regs_struct, USR_REG), \
offsetof(struct user_regs_struct, USR_REG) + \
sizeof(unsigned long));
/* Must be exactly same sequence as struct user_regs_struct */
ONEXT(®s->sa0, sa0);
ONEXT(®s->lc0, lc0);
ONEXT(®s->sa1, sa1);
ONEXT(®s->lc1, lc1);
ONEXT(®s->m0, m0);
ONEXT(®s->m1, m1);
ONEXT(®s->usr, usr);
ONEXT(®s->preds, p3_0);
ONEXT(®s->gp, gp);
ONEXT(®s->ugp, ugp);
ONEXT(&pt_elr(regs), pc);
dummy = pt_cause(regs);
ONEXT(&dummy, cause);
ONEXT(&pt_badva(regs), badva);
#if CONFIG_HEXAGON_ARCH_VERSION >=4
ONEXT(®s->cs0, cs0);
ONEXT(®s->cs1, cs1);
#endif
/* Pad the rest with zeros, if needed */
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
offsetof(struct user_regs_struct, pad1), -1);
return ret;
}
static int genregs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret;
unsigned long bucket;
struct pt_regs *regs = task_pt_regs(target);
if (!regs)
return -EIO;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
®s->r00, 0, 32*sizeof(unsigned long));
#define INEXT(KPT_REG, USR_REG) \
if (!ret) \
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
KPT_REG, offsetof(struct user_regs_struct, USR_REG), \
offsetof(struct user_regs_struct, USR_REG) + \
sizeof(unsigned long));
/* Must be exactly same sequence as struct user_regs_struct */
INEXT(®s->sa0, sa0);
INEXT(®s->lc0, lc0);
INEXT(®s->sa1, sa1);
INEXT(®s->lc1, lc1);
INEXT(®s->m0, m0);
INEXT(®s->m1, m1);
INEXT(®s->usr, usr);
INEXT(®s->preds, p3_0);
INEXT(®s->gp, gp);
INEXT(®s->ugp, ugp);
INEXT(&pt_elr(regs), pc);
/* CAUSE and BADVA aren't writeable. */
INEXT(&bucket, cause);
INEXT(&bucket, badva);
#if CONFIG_HEXAGON_ARCH_VERSION >=4
INEXT(®s->cs0, cs0);
INEXT(®s->cs1, cs1);
#endif
/* Ignore the rest, if needed */
if (!ret)
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
offsetof(struct user_regs_struct, pad1), -1);
if (ret)
return ret;
/*
* This is special; SP is actually restored by the VM via the
* special event record which is set by the special trap.
*/
regs->hvmer.vmpsp = regs->r29;
return 0;
}
enum hexagon_regset {
REGSET_GENERAL,
};
static const struct user_regset hexagon_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(unsigned long),
.align = sizeof(unsigned long),
.get = genregs_get,
.set = genregs_set,
},
};
static const struct user_regset_view hexagon_user_view = {
.name = UTS_MACHINE,
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = hexagon_regsets,
.n = ARRAY_SIZE(hexagon_regsets)
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &hexagon_user_view;
}
void ptrace_disable(struct task_struct *child)
{
/* Boilerplate - resolves to null inline if no HW single-step */
user_disable_single_step(child);
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
return ptrace_request(child, request, addr, data);
}