linux/arch/blackfin/kernel/ptrace.c
Mike Frysinger f2ce48024a Blackfin: simplify PTRACE_{PEEK,POKE}USR in preperation for regset support
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-03-09 00:30:51 -05:00

372 lines
9.2 KiB
C

/*
* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
* these modifications are Copyright 2004-2009 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/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/signal.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.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>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/* Find the stack offset for a register, relative to thread.esp0. */
#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
/*
* Get the address of the live pt_regs for the specified task.
* These are saved onto the top kernel stack when the process
* is not running.
*
* Note: if a user thread is execve'd from kernel space, the
* kernel stack will not be empty on entry to the kernel, so
* ptracing these tasks will fail.
*/
static inline struct pt_regs *task_pt_regs(struct task_struct *task)
{
return (struct pt_regs *)
((unsigned long)task_stack_page(task) +
(THREAD_SIZE - sizeof(struct pt_regs)));
}
/*
* Get all user integer registers.
*/
static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
{
struct pt_regs regs;
memcpy(&regs, task_pt_regs(tsk), sizeof(regs));
regs.usp = tsk->thread.usp;
return copy_to_user(uregs, &regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
}
/* Mapping from PT_xxx to the stack offset at which the register is
* saved. Notice that usp has no stack-slot and needs to be treated
* specially (see get_reg/put_reg below).
*/
/*
* Get contents of register REGNO in task TASK.
*/
static inline long
get_reg(struct task_struct *task, long regno, unsigned long __user *datap)
{
long tmp;
struct pt_regs *regs = task_pt_regs(task);
if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
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, long regno, unsigned long data)
{
struct pt_regs *regs = task_pt_regs(task);
if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
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
*/
static inline int is_user_addr_valid(struct task_struct *child,
unsigned long start, unsigned long len)
{
struct vm_area_struct *vma;
struct sram_list_struct *sraml;
/* overflow */
if (start + len < start)
return -EIO;
vma = find_vma(child->mm, start);
if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
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;
return -EIO;
}
void ptrace_enable(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
regs->syscfg |= SYSCFG_SSSTEP;
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure the single step bit is not set.
*/
void ptrace_disable(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
regs->syscfg &= ~SYSCFG_SSSTEP;
}
long arch_ptrace(struct task_struct *child, long request, long addr, 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;
}
#ifdef CONFIG_BINFMT_ELF_FDPIC
case PTRACE_GETFDPIC: {
unsigned long tmp = 0;
switch (addr) {
case_PTRACE_GETFDPIC_EXEC:
case PTRACE_GETFDPIC_EXEC:
tmp = child->mm->context.exec_fdpic_loadmap;
break;
case_PTRACE_GETFDPIC_INTERP:
case PTRACE_GETFDPIC_INTERP:
tmp = child->mm->context.interp_fdpic_loadmap;
break;
default:
break;
}
ret = put_user(tmp, datap);
break;
}
#endif
/* 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: goto case_PTRACE_GETFDPIC_EXEC;
case PT_FDPIC_INTERP: goto case_PTRACE_GETFDPIC_INTERP;
#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:
/* Get all gp regs from the child. */
ret = ptrace_getregs(child, datap);
break;
case PTRACE_SETREGS:
printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
/* Set all gp regs in the child. */
ret = 0;
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
asmlinkage void 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;
}
}