linux/arch/tile/kernel/ptrace.c
Simon Marchi 9af6254767 arch/tile: implement arch_ptrace using user_regset on tile
This patch changes arch_ptrace on tile so that it uses user_regset
to implement the PTRACE_GETREGS and PTRACE_SETREGS operations.

Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-12-18 14:53:14 -05:00

291 lines
7.2 KiB
C

/*
* Copyright 2010 Tilera Corporation. 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
* as published by the Free Software Foundation, version 2.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* Copied from i386: Ross Biro 1/23/92
*/
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/kprobes.h>
#include <linux/compat.h>
#include <linux/uaccess.h>
#include <linux/regset.h>
#include <linux/elf.h>
#include <asm/traps.h>
#include <arch/chip.h>
void user_enable_single_step(struct task_struct *child)
{
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
/*
* These two are currently unused, but will be set by arch_ptrace()
* and used in the syscall assembly when we do support them.
*/
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}
/*
* Get registers from task and ready the result for userspace.
* Note that we localize the API issues to getregs() and putregs() at
* some cost in performance, e.g. we need a full pt_regs copy for
* PEEKUSR, and two copies for POKEUSR. But in general we expect
* GETREGS/PUTREGS to be the API of choice anyway.
*/
static char *getregs(struct task_struct *child, struct pt_regs *uregs)
{
*uregs = *task_pt_regs(child);
/* Set up flags ABI bits. */
uregs->flags = 0;
#ifdef CONFIG_COMPAT
if (task_thread_info(child)->status & TS_COMPAT)
uregs->flags |= PT_FLAGS_COMPAT;
#endif
return (char *)uregs;
}
/* Put registers back to task. */
static void putregs(struct task_struct *child, struct pt_regs *uregs)
{
struct pt_regs *regs = task_pt_regs(child);
/* Don't allow overwriting the kernel-internal flags word. */
uregs->flags = regs->flags;
/* Only allow setting the ICS bit in the ex1 word. */
uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));
*regs = *uregs;
}
enum tile_regset {
REGSET_GPR,
};
static int tile_gpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct pt_regs regs;
getregs(target, &regs);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs, 0,
sizeof(regs));
}
static int tile_gpr_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;
struct pt_regs regs;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
sizeof(regs));
if (ret)
return ret;
putregs(target, &regs);
return 0;
}
static const struct user_regset tile_user_regset[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(elf_greg_t),
.align = sizeof(elf_greg_t),
.get = tile_gpr_get,
.set = tile_gpr_set,
},
};
static const struct user_regset_view tile_user_regset_view = {
.name = CHIP_ARCH_NAME,
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = tile_user_regset,
.n = ARRAY_SIZE(tile_user_regset),
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &tile_user_regset_view;
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
unsigned long __user *datap = (long __user __force *)data;
unsigned long tmp;
long ret = -EIO;
char *childreg;
struct pt_regs copyregs;
switch (request) {
case PTRACE_PEEKUSR: /* Read register from pt_regs. */
if (addr >= PTREGS_SIZE)
break;
childreg = getregs(child, &copyregs) + addr;
#ifdef CONFIG_COMPAT
if (is_compat_task()) {
if (addr & (sizeof(compat_long_t)-1))
break;
ret = put_user(*(compat_long_t *)childreg,
(compat_long_t __user *)datap);
} else
#endif
{
if (addr & (sizeof(long)-1))
break;
ret = put_user(*(long *)childreg, datap);
}
break;
case PTRACE_POKEUSR: /* Write register in pt_regs. */
if (addr >= PTREGS_SIZE)
break;
childreg = getregs(child, &copyregs) + addr;
#ifdef CONFIG_COMPAT
if (is_compat_task()) {
if (addr & (sizeof(compat_long_t)-1))
break;
*(compat_long_t *)childreg = data;
} else
#endif
{
if (addr & (sizeof(long)-1))
break;
*(long *)childreg = data;
}
putregs(child, &copyregs);
ret = 0;
break;
case PTRACE_GETREGS: /* Get all registers from the child. */
ret = copy_regset_to_user(child, &tile_user_regset_view,
REGSET_GPR, 0,
sizeof(struct pt_regs), datap);
break;
case PTRACE_SETREGS: /* Set all registers in the child. */
ret = copy_regset_from_user(child, &tile_user_regset_view,
REGSET_GPR, 0,
sizeof(struct pt_regs), datap);
break;
case PTRACE_GETFPREGS: /* Get the child FPU state. */
case PTRACE_SETFPREGS: /* Set the child FPU state. */
break;
case PTRACE_SETOPTIONS:
/* Support TILE-specific ptrace options. */
BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
tmp = data & PTRACE_O_MASK_TILE;
data &= ~PTRACE_O_MASK_TILE;
ret = ptrace_request(child, request, addr, data);
if (ret == 0) {
unsigned int flags = child->ptrace;
flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
flags |= (tmp << PT_OPT_FLAG_SHIFT);
child->ptrace = flags;
}
break;
default:
#ifdef CONFIG_COMPAT
if (task_thread_info(current)->status & TS_COMPAT) {
ret = compat_ptrace_request(child, request,
addr, data);
break;
}
#endif
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
#ifdef CONFIG_COMPAT
/* Not used; we handle compat issues in arch_ptrace() directly. */
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
compat_ulong_t addr, compat_ulong_t data)
{
BUG();
}
#endif
void do_syscall_trace(void)
{
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return;
if (!(current->ptrace & PT_PTRACED))
return;
/*
* The 0x80 provides a way for the tracing parent to distinguish
* between a syscall stop and SIGTRAP delivery
*/
ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
/*
* this isn't the same as continuing with a signal, but it will do
* for normal use. strace only continues with a signal if the
* stopping signal is not SIGTRAP. -brl
*/
if (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
}
void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
{
struct siginfo info;
memset(&info, 0, sizeof(info));
info.si_signo = SIGTRAP;
info.si_code = TRAP_BRKPT;
info.si_addr = (void __user *) regs->pc;
/* Send us the fakey SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
}
/* Handle synthetic interrupt delivered only by the simulator. */
void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
{
send_sigtrap(current, regs, fault_num);
}