1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
424 lines
11 KiB
C
424 lines
11 KiB
C
/*
|
|
* Kernel support for the ptrace() and syscall tracing interfaces.
|
|
*
|
|
* Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
|
|
* Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
|
|
* Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/user.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/security.h>
|
|
#include <linux/compat.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/system.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/offsets.h>
|
|
|
|
/* PSW bits we allow the debugger to modify */
|
|
#define USER_PSW_BITS (PSW_N | PSW_V | PSW_CB)
|
|
|
|
#undef DEBUG_PTRACE
|
|
|
|
#ifdef DEBUG_PTRACE
|
|
#define DBG(x...) printk(x)
|
|
#else
|
|
#define DBG(x...)
|
|
#endif
|
|
|
|
#ifdef __LP64__
|
|
|
|
/* This function is needed to translate 32 bit pt_regs offsets in to
|
|
* 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel
|
|
* will request offset 12 if it wants gr3, but the lower 32 bits of
|
|
* the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
|
|
* This code relies on a 32 bit pt_regs being comprised of 32 bit values
|
|
* except for the fp registers which (a) are 64 bits, and (b) follow
|
|
* the gr registers at the start of pt_regs. The 32 bit pt_regs should
|
|
* be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
|
|
* being 64 bit in both cases.
|
|
*/
|
|
|
|
static long translate_usr_offset(long offset)
|
|
{
|
|
if (offset < 0)
|
|
return -1;
|
|
else if (offset <= 32*4) /* gr[0..31] */
|
|
return offset * 2 + 4;
|
|
else if (offset <= 32*4+32*8) /* gr[0..31] + fr[0..31] */
|
|
return offset + 32*4;
|
|
else if (offset < sizeof(struct pt_regs)/2 + 32*4)
|
|
return offset * 2 + 4 - 32*8;
|
|
else
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Called by kernel/ptrace.c when detaching..
|
|
*
|
|
* Make sure single step bits etc are not set.
|
|
*/
|
|
void ptrace_disable(struct task_struct *child)
|
|
{
|
|
/* make sure the trap bits are not set */
|
|
pa_psw(child)->r = 0;
|
|
pa_psw(child)->t = 0;
|
|
pa_psw(child)->h = 0;
|
|
pa_psw(child)->l = 0;
|
|
}
|
|
|
|
long sys_ptrace(long request, pid_t pid, long addr, long data)
|
|
{
|
|
struct task_struct *child;
|
|
long ret;
|
|
#ifdef DEBUG_PTRACE
|
|
long oaddr=addr, odata=data;
|
|
#endif
|
|
|
|
lock_kernel();
|
|
ret = -EPERM;
|
|
if (request == PTRACE_TRACEME) {
|
|
/* are we already being traced? */
|
|
if (current->ptrace & PT_PTRACED)
|
|
goto out;
|
|
|
|
ret = security_ptrace(current->parent, current);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* set the ptrace bit in the process flags. */
|
|
current->ptrace |= PT_PTRACED;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = -ESRCH;
|
|
read_lock(&tasklist_lock);
|
|
child = find_task_by_pid(pid);
|
|
if (child)
|
|
get_task_struct(child);
|
|
read_unlock(&tasklist_lock);
|
|
if (!child)
|
|
goto out;
|
|
ret = -EPERM;
|
|
if (pid == 1) /* no messing around with init! */
|
|
goto out_tsk;
|
|
|
|
if (request == PTRACE_ATTACH) {
|
|
ret = ptrace_attach(child);
|
|
goto out_tsk;
|
|
}
|
|
|
|
ret = ptrace_check_attach(child, request == PTRACE_KILL);
|
|
if (ret < 0)
|
|
goto out_tsk;
|
|
|
|
switch (request) {
|
|
case PTRACE_PEEKTEXT: /* read word at location addr. */
|
|
case PTRACE_PEEKDATA: {
|
|
int copied;
|
|
|
|
#ifdef __LP64__
|
|
if (is_compat_task(child)) {
|
|
unsigned int tmp;
|
|
|
|
addr &= 0xffffffffL;
|
|
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
|
|
ret = -EIO;
|
|
if (copied != sizeof(tmp))
|
|
goto out_tsk;
|
|
ret = put_user(tmp,(unsigned int *) data);
|
|
DBG("sys_ptrace(PEEK%s, %d, %lx, %lx) returning %ld, data %x\n",
|
|
request == PTRACE_PEEKTEXT ? "TEXT" : "DATA",
|
|
pid, oaddr, odata, ret, tmp);
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
unsigned long tmp;
|
|
|
|
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
|
|
ret = -EIO;
|
|
if (copied != sizeof(tmp))
|
|
goto out_tsk;
|
|
ret = put_user(tmp,(unsigned long *) data);
|
|
}
|
|
goto out_tsk;
|
|
}
|
|
|
|
/* when I and D space are separate, this will have to be fixed. */
|
|
case PTRACE_POKETEXT: /* write the word at location addr. */
|
|
case PTRACE_POKEDATA:
|
|
ret = 0;
|
|
#ifdef __LP64__
|
|
if (is_compat_task(child)) {
|
|
unsigned int tmp = (unsigned int)data;
|
|
DBG("sys_ptrace(POKE%s, %d, %lx, %lx)\n",
|
|
request == PTRACE_POKETEXT ? "TEXT" : "DATA",
|
|
pid, oaddr, odata);
|
|
addr &= 0xffffffffL;
|
|
if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1) == sizeof(tmp))
|
|
goto out_tsk;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
|
|
goto out_tsk;
|
|
}
|
|
ret = -EIO;
|
|
goto out_tsk;
|
|
|
|
/* Read the word at location addr in the USER area. For ptraced
|
|
processes, the kernel saves all regs on a syscall. */
|
|
case PTRACE_PEEKUSR: {
|
|
ret = -EIO;
|
|
#ifdef __LP64__
|
|
if (is_compat_task(child)) {
|
|
unsigned int tmp;
|
|
|
|
if (addr & (sizeof(int)-1))
|
|
goto out_tsk;
|
|
if ((addr = translate_usr_offset(addr)) < 0)
|
|
goto out_tsk;
|
|
|
|
tmp = *(unsigned int *) ((char *) task_regs(child) + addr);
|
|
ret = put_user(tmp, (unsigned int *) data);
|
|
DBG("sys_ptrace(PEEKUSR, %d, %lx, %lx) returning %ld, addr %lx, data %x\n",
|
|
pid, oaddr, odata, ret, addr, tmp);
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
unsigned long tmp;
|
|
|
|
if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs))
|
|
goto out_tsk;
|
|
tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
|
|
ret = put_user(tmp, (unsigned long *) data);
|
|
}
|
|
goto out_tsk;
|
|
}
|
|
|
|
/* Write the word at location addr in the USER area. This will need
|
|
to change when the kernel no longer saves all regs on a syscall.
|
|
FIXME. There is a problem at the moment in that r3-r18 are only
|
|
saved if the process is ptraced on syscall entry, and even then
|
|
those values are overwritten by actual register values on syscall
|
|
exit. */
|
|
case PTRACE_POKEUSR:
|
|
ret = -EIO;
|
|
/* Some register values written here may be ignored in
|
|
* entry.S:syscall_restore_rfi; e.g. iaoq is written with
|
|
* r31/r31+4, and not with the values in pt_regs.
|
|
*/
|
|
/* PT_PSW=0, so this is valid for 32 bit processes under 64
|
|
* bit kernels.
|
|
*/
|
|
if (addr == PT_PSW) {
|
|
/* PT_PSW=0, so this is valid for 32 bit processes
|
|
* under 64 bit kernels.
|
|
*
|
|
* Allow writing to Nullify, Divide-step-correction,
|
|
* and carry/borrow bits.
|
|
* BEWARE, if you set N, and then single step, it won't
|
|
* stop on the nullified instruction.
|
|
*/
|
|
DBG("sys_ptrace(POKEUSR, %d, %lx, %lx)\n",
|
|
pid, oaddr, odata);
|
|
data &= USER_PSW_BITS;
|
|
task_regs(child)->gr[0] &= ~USER_PSW_BITS;
|
|
task_regs(child)->gr[0] |= data;
|
|
ret = 0;
|
|
goto out_tsk;
|
|
}
|
|
#ifdef __LP64__
|
|
if (is_compat_task(child)) {
|
|
if (addr & (sizeof(int)-1))
|
|
goto out_tsk;
|
|
if ((addr = translate_usr_offset(addr)) < 0)
|
|
goto out_tsk;
|
|
DBG("sys_ptrace(POKEUSR, %d, %lx, %lx) addr %lx\n",
|
|
pid, oaddr, odata, addr);
|
|
if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
|
|
/* Special case, fp regs are 64 bits anyway */
|
|
*(unsigned int *) ((char *) task_regs(child) + addr) = data;
|
|
ret = 0;
|
|
}
|
|
else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
|
|
addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
|
|
addr == PT_SAR+4) {
|
|
/* Zero the top 32 bits */
|
|
*(unsigned int *) ((char *) task_regs(child) + addr - 4) = 0;
|
|
*(unsigned int *) ((char *) task_regs(child) + addr) = data;
|
|
ret = 0;
|
|
}
|
|
goto out_tsk;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs))
|
|
goto out_tsk;
|
|
if ((addr >= PT_GR1 && addr <= PT_GR31) ||
|
|
addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
|
|
(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
|
|
addr == PT_SAR) {
|
|
*(unsigned long *) ((char *) task_regs(child) + addr) = data;
|
|
ret = 0;
|
|
}
|
|
goto out_tsk;
|
|
}
|
|
|
|
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
|
|
case PTRACE_CONT:
|
|
ret = -EIO;
|
|
DBG("sys_ptrace(%s)\n",
|
|
request == PTRACE_SYSCALL ? "SYSCALL" : "CONT");
|
|
if ((unsigned long) data > _NSIG)
|
|
goto out_tsk;
|
|
child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP);
|
|
if (request == PTRACE_SYSCALL) {
|
|
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
|
|
} else {
|
|
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
|
|
}
|
|
child->exit_code = data;
|
|
goto out_wake_notrap;
|
|
|
|
case PTRACE_KILL:
|
|
/*
|
|
* make the child exit. Best I can do is send it a
|
|
* sigkill. perhaps it should be put in the status
|
|
* that it wants to exit.
|
|
*/
|
|
DBG("sys_ptrace(KILL)\n");
|
|
if (child->exit_state == EXIT_ZOMBIE) /* already dead */
|
|
goto out_tsk;
|
|
child->exit_code = SIGKILL;
|
|
goto out_wake_notrap;
|
|
|
|
case PTRACE_SINGLEBLOCK:
|
|
DBG("sys_ptrace(SINGLEBLOCK)\n");
|
|
ret = -EIO;
|
|
if ((unsigned long) data > _NSIG)
|
|
goto out_tsk;
|
|
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
|
|
child->ptrace &= ~PT_SINGLESTEP;
|
|
child->ptrace |= PT_BLOCKSTEP;
|
|
child->exit_code = data;
|
|
|
|
/* Enable taken branch trap. */
|
|
pa_psw(child)->r = 0;
|
|
pa_psw(child)->t = 1;
|
|
pa_psw(child)->h = 0;
|
|
pa_psw(child)->l = 0;
|
|
goto out_wake;
|
|
|
|
case PTRACE_SINGLESTEP:
|
|
DBG("sys_ptrace(SINGLESTEP)\n");
|
|
ret = -EIO;
|
|
if ((unsigned long) data > _NSIG)
|
|
goto out_tsk;
|
|
|
|
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
|
|
child->ptrace &= ~PT_BLOCKSTEP;
|
|
child->ptrace |= PT_SINGLESTEP;
|
|
child->exit_code = data;
|
|
|
|
if (pa_psw(child)->n) {
|
|
struct siginfo si;
|
|
|
|
/* Nullified, just crank over the queue. */
|
|
task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1];
|
|
task_regs(child)->iasq[0] = task_regs(child)->iasq[1];
|
|
task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4;
|
|
pa_psw(child)->n = 0;
|
|
pa_psw(child)->x = 0;
|
|
pa_psw(child)->y = 0;
|
|
pa_psw(child)->z = 0;
|
|
pa_psw(child)->b = 0;
|
|
ptrace_disable(child);
|
|
/* Don't wake up the child, but let the
|
|
parent know something happened. */
|
|
si.si_code = TRAP_TRACE;
|
|
si.si_addr = (void __user *) (task_regs(child)->iaoq[0] & ~3);
|
|
si.si_signo = SIGTRAP;
|
|
si.si_errno = 0;
|
|
force_sig_info(SIGTRAP, &si, child);
|
|
//notify_parent(child, SIGCHLD);
|
|
//ret = 0;
|
|
goto out_wake;
|
|
}
|
|
|
|
/* Enable recovery counter traps. The recovery counter
|
|
* itself will be set to zero on a task switch. If the
|
|
* task is suspended on a syscall then the syscall return
|
|
* path will overwrite the recovery counter with a suitable
|
|
* value such that it traps once back in user space. We
|
|
* disable interrupts in the childs PSW here also, to avoid
|
|
* interrupts while the recovery counter is decrementing.
|
|
*/
|
|
pa_psw(child)->r = 1;
|
|
pa_psw(child)->t = 0;
|
|
pa_psw(child)->h = 0;
|
|
pa_psw(child)->l = 0;
|
|
/* give it a chance to run. */
|
|
goto out_wake;
|
|
|
|
case PTRACE_DETACH:
|
|
ret = ptrace_detach(child, data);
|
|
goto out_tsk;
|
|
|
|
case PTRACE_GETEVENTMSG:
|
|
ret = put_user(child->ptrace_message, (unsigned int __user *) data);
|
|
goto out_tsk;
|
|
|
|
default:
|
|
ret = ptrace_request(child, request, addr, data);
|
|
goto out_tsk;
|
|
}
|
|
|
|
out_wake_notrap:
|
|
ptrace_disable(child);
|
|
out_wake:
|
|
wake_up_process(child);
|
|
ret = 0;
|
|
out_tsk:
|
|
put_task_struct(child);
|
|
out:
|
|
unlock_kernel();
|
|
DBG("sys_ptrace(%ld, %d, %lx, %lx) returning %ld\n",
|
|
request, pid, oaddr, odata, ret);
|
|
return ret;
|
|
}
|
|
|
|
void syscall_trace(void)
|
|
{
|
|
if (!test_thread_flag(TIF_SYSCALL_TRACE))
|
|
return;
|
|
if (!(current->ptrace & PT_PTRACED))
|
|
return;
|
|
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;
|
|
}
|
|
}
|