// SPDX-License-Identifier: GPL-2.0-only
/*
* Ptrace support for Hexagon
*
* Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.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,
struct membuf to)
{
struct pt_regs *regs = task_pt_regs(target);
/* 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.
*/
membuf_write(&to, ®s->r00, 32*sizeof(unsigned long));
/* Must be exactly same sequence as struct user_regs_struct */
membuf_store(&to, regs->sa0);
membuf_store(&to, regs->lc0);
membuf_store(&to, regs->sa1);
membuf_store(&to, regs->lc1);
membuf_store(&to, regs->m0);
membuf_store(&to, regs->m1);
membuf_store(&to, regs->usr);
membuf_store(&to, regs->preds);
membuf_store(&to, regs->gp);
membuf_store(&to, regs->ugp);
membuf_store(&to, pt_elr(regs)); // pc
membuf_store(&to, (unsigned long)pt_cause(regs)); // cause
membuf_store(&to, pt_badva(regs)); // badva
#if CONFIG_HEXAGON_ARCH_VERSION >=4
membuf_store(&to, regs->cs0);
membuf_store(&to, regs->cs1);
return membuf_zero(&to, sizeof(unsigned long));
#else
return membuf_zero(&to, 3 * sizeof(unsigned long));
#endif
}
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)
user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
offsetof(struct user_regs_struct, pad1), -1);
else
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),
.regset_get = genregs_get,
.set = genregs_set,
},
};
static const struct user_regset_view hexagon_user_view = {
.name = "hexagon",
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = hexagon_regsets,
.e_flags = ELF_CORE_EFLAGS,
.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);
}