/*
* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
* these modifications are Copyright 2004-2010 Analog Devices Inc.
*
* Licensed under the GPL-2
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/regset.h>
#include <linux/signal.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/asm-offsets.h>
#include <asm/dma.h>
#include <asm/fixed_code.h>
#include <asm/cacheflush.h>
#include <asm/mem_map.h>
#include <asm/mmu_context.h>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* Get contents of register REGNO in task TASK.
*/
static inline long
get_reg(struct task_struct *task, unsigned long regno,
unsigned long __user *datap)
{
long tmp;
struct pt_regs *regs = task_pt_regs(task);
if (regno & 3 || regno > PT_LAST_PSEUDO)
return -EIO;
switch (regno) {
case PT_TEXT_ADDR:
tmp = task->mm->start_code;
break;
case PT_TEXT_END_ADDR:
tmp = task->mm->end_code;
break;
case PT_DATA_ADDR:
tmp = task->mm->start_data;
break;
case PT_USP:
tmp = task->thread.usp;
break;
default:
if (regno < sizeof(*regs)) {
void *reg_ptr = regs;
tmp = *(long *)(reg_ptr + regno);
} else
return -EIO;
}
return put_user(tmp, datap);
}
/*
* Write contents of register REGNO in task TASK.
*/
static inline int
put_reg(struct task_struct *task, unsigned long regno, unsigned long data)
{
struct pt_regs *regs = task_pt_regs(task);
if (regno & 3 || regno > PT_LAST_PSEUDO)
return -EIO;
switch (regno) {
case PT_PC:
/*********************************************************************/
/* At this point the kernel is most likely in exception. */
/* The RETX register will be used to populate the pc of the process. */
/*********************************************************************/
regs->retx = data;
regs->pc = data;
break;
case PT_RETX:
break; /* regs->retx = data; break; */
case PT_USP:
regs->usp = data;
task->thread.usp = data;
break;
case PT_SYSCFG: /* don't let userspace screw with this */
if ((data & ~1) != 0x6)
pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
break; /* regs->syscfg = data; break; */
default:
if (regno < sizeof(*regs)) {
void *reg_offset = regs;
*(long *)(reg_offset + regno) = data;
}
/* Ignore writes to pseudo registers */
}
return 0;
}
/*
* check that an address falls within the bounds of the target process's memory mappings
*/
int
is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len)
{
bool valid;
struct vm_area_struct *vma;
struct sram_list_struct *sraml;
/* overflow */
if (start + len < start)
return -EIO;
down_read(&child->mm->mmap_sem);
vma = find_vma(child->mm, start);
valid = vma && start >= vma->vm_start && start + len <= vma->vm_end;
up_read(&child->mm->mmap_sem);
if (valid)
return 0;
for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
if (start >= (unsigned long)sraml->addr
&& start + len < (unsigned long)sraml->addr + sraml->length)
return 0;
if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
return 0;
#ifdef CONFIG_APP_STACK_L1
if (child->mm->context.l1_stack_save)
if (start >= (unsigned long)l1_stack_base &&
start + len < (unsigned long)l1_stack_base + l1_stack_len)
return 0;
#endif
return -EIO;
}
/*
* retrieve the contents of Blackfin userspace general registers
*/
static int genregs_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 = task_pt_regs(target);
int ret;
/* This sucks ... */
regs->usp = target->thread.usp;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
regs, 0, sizeof(*regs));
if (ret < 0)
return ret;
return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
sizeof(*regs), -1);
}
/*
* update the contents of the Blackfin userspace general registers
*/
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)
{
struct pt_regs *regs = task_pt_regs(target);
int ret;
/* Don't let people set SYSCFG (it's at the end of pt_regs) */
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
regs, 0, PT_SYSCFG);
if (ret < 0)
return ret;
/* This sucks ... */
target->thread.usp = regs->usp;
/* regs->retx = regs->pc; */
return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
PT_SYSCFG, -1);
}
/*
* Define the register sets available on the Blackfin under Linux
*/
enum bfin_regset {
REGSET_GENERAL,
};
static const struct user_regset bfin_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct pt_regs) / sizeof(long),
.size = sizeof(long),
.align = sizeof(long),
.get = genregs_get,
.set = genregs_set,
},
};
static const struct user_regset_view user_bfin_native_view = {
.name = "Blackfin",
.e_machine = EM_BLACKFIN,
.regsets = bfin_regsets,
.n = ARRAY_SIZE(bfin_regsets),
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_bfin_native_view;
}
void user_enable_single_step(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
regs->syscfg |= SYSCFG_SSSTEP;
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
regs->syscfg &= ~SYSCFG_SSSTEP;
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret;
unsigned long __user *datap = (unsigned long __user *)data;
void *paddr = (void *)addr;
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKDATA:
pr_debug("ptrace: PEEKDATA\n");
/* fall through */
case PTRACE_PEEKTEXT: /* read word at location addr. */
{
unsigned long tmp = 0;
int copied = 0, to_copy = sizeof(tmp);
ret = -EIO;
pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
if (is_user_addr_valid(child, addr, to_copy) < 0)
break;
pr_debug("ptrace: user address is valid\n");
switch (bfin_mem_access_type(addr, to_copy)) {
case BFIN_MEM_ACCESS_CORE:
case BFIN_MEM_ACCESS_CORE_ONLY:
copied = access_process_vm(child, addr, &tmp,
to_copy, 0);
if (copied)
break;
/* hrm, why didn't that work ... maybe no mapping */
if (addr >= FIXED_CODE_START &&
addr + to_copy <= FIXED_CODE_END) {
copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
copied = to_copy;
} else if (addr >= BOOT_ROM_START) {
memcpy(&tmp, paddr, to_copy);
copied = to_copy;
}
break;
case BFIN_MEM_ACCESS_DMA:
if (safe_dma_memcpy(&tmp, paddr, to_copy))
copied = to_copy;
break;
case BFIN_MEM_ACCESS_ITEST:
if (isram_memcpy(&tmp, paddr, to_copy))
copied = to_copy;
break;
default:
copied = 0;
break;
}
pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
if (copied == to_copy)
ret = put_user(tmp, datap);
break;
}
/* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKEDATA:
pr_debug("ptrace: PTRACE_PEEKDATA\n");
/* fall through */
case PTRACE_POKETEXT: /* write the word at location addr. */
{
int copied = 0, to_copy = sizeof(data);
ret = -EIO;
pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
addr, to_copy, data);
if (is_user_addr_valid(child, addr, to_copy) < 0)
break;
pr_debug("ptrace: user address is valid\n");
switch (bfin_mem_access_type(addr, to_copy)) {
case BFIN_MEM_ACCESS_CORE:
case BFIN_MEM_ACCESS_CORE_ONLY:
copied = access_process_vm(child, addr, &data,
to_copy, 1);
break;
case BFIN_MEM_ACCESS_DMA:
if (safe_dma_memcpy(paddr, &data, to_copy))
copied = to_copy;
break;
case BFIN_MEM_ACCESS_ITEST:
if (isram_memcpy(paddr, &data, to_copy))
copied = to_copy;
break;
default:
copied = 0;
break;
}
pr_debug("ptrace: copied size %d\n", copied);
if (copied == to_copy)
ret = 0;
break;
}
case PTRACE_PEEKUSR:
switch (addr) {
#ifdef CONFIG_BINFMT_ELF_FDPIC /* backwards compat */
case PT_FDPIC_EXEC:
request = PTRACE_GETFDPIC;
addr = PTRACE_GETFDPIC_EXEC;
goto case_default;
case PT_FDPIC_INTERP:
request = PTRACE_GETFDPIC;
addr = PTRACE_GETFDPIC_INTERP;
goto case_default;
#endif
default:
ret = get_reg(child, addr, datap);
}
pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
break;
case PTRACE_POKEUSR:
ret = put_reg(child, addr, data);
pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
break;
case PTRACE_GETREGS:
pr_debug("ptrace: PTRACE_GETREGS\n");
return copy_regset_to_user(child, &user_bfin_native_view,
REGSET_GENERAL,
0, sizeof(struct pt_regs),
datap);
case PTRACE_SETREGS:
pr_debug("ptrace: PTRACE_SETREGS\n");
return copy_regset_from_user(child, &user_bfin_native_view,
REGSET_GENERAL,
0, sizeof(struct pt_regs),
datap);
case_default:
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
int ret = 0;
if (test_thread_flag(TIF_SYSCALL_TRACE))
ret = tracehook_report_syscall_entry(regs);
return ret;
}
asmlinkage void syscall_trace_leave(struct pt_regs *regs)
{
int step;
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
}