void NORET_TYPE die(const char *str, struct pt_regs *regs, long err)
{
static int die_counter;
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n",
str, err, ++die_counter);
printk(KERN_EMERG);
#ifdef CONFIG_PREEMPT
printk(KERN_CONT "PREEMPT ");
#endif
#ifdef CONFIG_FRAME_POINTER
printk(KERN_CONT "FRAME_POINTER ");
#endif
if (current_cpu_data.features & AVR32_FEATURE_OCD) {
unsigned long did = ocd_read(DID);
printk(KERN_CONT "chip: 0x%03lx:0x%04lx rev %lu\n",
(did >> 1) & 0x7ff,
(did >> 12) & 0x7fff,
(did >> 28) & 0xf);
} else {
static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
{
unsigned long dc;
pr_debug("resuming execution at PC=%08lx\n", regs->pc);
dc = ocd_read(DC);
dc &= ~(1 << OCD_DC_SS_BIT);
ocd_write(DC, dc);
*p->addr = BREAKPOINT_INSTRUCTION;
flush_icache_range((unsigned long)p->addr,
(unsigned long)p->addr + sizeof(kprobe_opcode_t));
}
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
unsigned long dc;
pr_debug("preparing to singlestep over %p (PC=%08lx)\n",
p->addr, regs->pc);
BUG_ON(!(sysreg_read(SR) & SYSREG_BIT(SR_D)));
dc = ocd_read(DC);
dc |= 1 << OCD_DC_SS_BIT;
ocd_write(DC, dc);
*p->addr = p->opcode;
flush_icache_range((unsigned long)p->addr,
(unsigned long)p->addr + sizeof(kprobe_opcode_t));
}
void ocd_enable(struct task_struct *child)
{
u32 dc;
if (child)
pr_debug("ocd_enable: child=%s [%u]\n",
child->comm, child->pid);
else
pr_debug("ocd_enable (no child)\n");
if (!child || !test_and_set_tsk_thread_flag(child, TIF_DEBUG)) {
spin_lock(&ocd_lock);
ocd_count++;
dc = ocd_read(DC);
dc |= (1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT);
ocd_write(DC, dc);
spin_unlock(&ocd_lock);
}
}
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
unsigned long dc;
pr_debug("preparing to singlestep over %p (PC=%08lx)\n",
p->addr, regs->pc);
BUG_ON(!(sysreg_read(SR) & SYSREG_BIT(SR_D)));
dc = ocd_read(DC);
dc |= 1 << OCD_DC_SS_BIT;
ocd_write(DC, dc);
/*
* We must run the instruction from its original location
* since it may actually reference PC.
*
* TODO: Do the instruction replacement directly in icache.
*/
*p->addr = p->opcode;
flush_icache_range((unsigned long)p->addr,
(unsigned long)p->addr + sizeof(kprobe_opcode_t));
}
void ocd_disable(struct task_struct *child)
{
u32 dc;
if (!child)
pr_debug("ocd_disable (no child)\n");
else if (test_tsk_thread_flag(child, TIF_DEBUG))
pr_debug("ocd_disable: child=%s [%u]\n",
child->comm, child->pid);
if (!child || test_and_clear_tsk_thread_flag(child, TIF_DEBUG)) {
spin_lock(&ocd_lock);
ocd_count--;
WARN_ON(ocd_count < 0);
if (ocd_count <= 0) {
dc = ocd_read(DC);
dc &= ~((1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT));
ocd_write(DC, dc);
}
spin_unlock(&ocd_lock);
}
}
asmlinkage struct pt_regs *do_debug(struct pt_regs *regs)
{
struct thread_info *ti;
unsigned long trampoline_addr;
u32 status;
u32 ctrl;
int code;
status = ocd_read(DS);
ti = current_thread_info();
code = TRAP_BRKPT;
pr_debug("do_debug: status=0x%08x PC=0x%08lx SR=0x%08lx tif=0x%08lx\n",
status, regs->pc, regs->sr, ti->flags);
if (!user_mode(regs)) {
unsigned long die_val = DIE_BREAKPOINT;
if (status & (1 << OCD_DS_SSS_BIT))
die_val = DIE_SSTEP;
if (notify_die(die_val, "ptrace", regs, 0, 0, SIGTRAP)
== NOTIFY_STOP)
return regs;
if ((status & (1 << OCD_DS_SWB_BIT))
&& test_and_clear_ti_thread_flag(
ti, TIF_BREAKPOINT)) {
/*
* Explicit breakpoint from trampoline or
* exception/syscall/interrupt handler.
*
* The real saved regs are on the stack right
* after the ones we saved on entry.
*/
regs++;
pr_debug(" -> TIF_BREAKPOINT done, adjusted regs:"
"PC=0x%08lx SR=0x%08lx\n",
regs->pc, regs->sr);
BUG_ON(!user_mode(regs));
if (test_thread_flag(TIF_SINGLE_STEP)) {
pr_debug("Going to do single step...\n");
return regs;
}
/*
* No TIF_SINGLE_STEP means we're done
* stepping over a syscall. Do the trap now.
*/
code = TRAP_TRACE;
} else if ((status & (1 << OCD_DS_SSS_BIT))
&& test_ti_thread_flag(ti, TIF_SINGLE_STEP)) {
pr_debug("Stepped into something, "
"setting TIF_BREAKPOINT...\n");
set_ti_thread_flag(ti, TIF_BREAKPOINT);
/*
* We stepped into an exception, interrupt or
* syscall handler. Some exception handlers
* don't check for pending work, so we need to
* set up a trampoline just in case.
*
* The exception entry code will undo the
* trampoline stuff if it does a full context
* save (which also means that it'll check for
* pending work later.)
*/
if ((regs->sr & MODE_MASK) == MODE_EXCEPTION) {
trampoline_addr
= (unsigned long)&debug_trampoline;
pr_debug("Setting up trampoline...\n");
ti->rar_saved = sysreg_read(RAR_EX);
ti->rsr_saved = sysreg_read(RSR_EX);
sysreg_write(RAR_EX, trampoline_addr);
sysreg_write(RSR_EX, (MODE_EXCEPTION
| SR_EM | SR_GM));
BUG_ON(ti->rsr_saved & MODE_MASK);
}
/*
* If we stepped into a system call, we
* shouldn't do a single step after we return
* since the return address is right after the
* "scall" instruction we were told to step
* over.
*/
if ((regs->sr & MODE_MASK) == MODE_SUPERVISOR) {
pr_debug("Supervisor; no single step\n");
clear_ti_thread_flag(ti, TIF_SINGLE_STEP);
}
ctrl = ocd_read(DC);
ctrl &= ~(1 << OCD_DC_SS_BIT);
ocd_write(DC, ctrl);
return regs;
} else {
printk(KERN_ERR "Unexpected OCD_DS value: 0x%08x\n",
status);
printk(KERN_ERR "Thread flags: 0x%08lx\n", ti->flags);
die("Unhandled debug trap in kernel mode",
regs, SIGTRAP);
}
} else if (status & (1 << OCD_DS_SSS_BIT)) {
/* Single step in user mode */
code = TRAP_TRACE;
ctrl = ocd_read(DC);
ctrl &= ~(1 << OCD_DC_SS_BIT);
ocd_write(DC, ctrl);
}
pr_debug("Sending SIGTRAP: code=%d PC=0x%08lx SR=0x%08lx\n",
code, regs->pc, regs->sr);
clear_thread_flag(TIF_SINGLE_STEP);
_exception(SIGTRAP, regs, code, instruction_pointer(regs));
return regs;
}
static int ocd_DS_get(void *data, u64 *val)
{
*val = ocd_read(DS);
return 0;
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
int ret;
pr_debug("ptrace: Enabling monitor mode...\n");
ocd_write(DC, ocd_read(DC) | (1 << OCD_DC_MM_BIT)
| (1 << OCD_DC_DBE_BIT));
switch (request) {
/* Read the word at location addr in the child process */
case PTRACE_PEEKTEXT:
case PTRACE_PEEKDATA:
ret = generic_ptrace_peekdata(child, addr, data);
break;
case PTRACE_PEEKUSR:
ret = ptrace_read_user(child, addr,
(unsigned long __user *)data);
break;
/* Write the word in data at location addr */
case PTRACE_POKETEXT:
case PTRACE_POKEDATA:
ret = generic_ptrace_pokedata(child, addr, data);
break;
case PTRACE_POKEUSR:
ret = ptrace_write_user(child, addr, data);
break;
/* continue and stop at next (return from) syscall */
case PTRACE_SYSCALL:
/* restart after signal */
case PTRACE_CONT:
ret = -EIO;
if (!valid_signal(data))
break;
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;
/* XXX: Are we sure no breakpoints are active here? */
wake_up_process(child);
ret = 0;
break;
/*
* 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.
*/
case PTRACE_KILL:
ret = 0;
if (child->exit_state == EXIT_ZOMBIE)
break;
child->exit_code = SIGKILL;
wake_up_process(child);
break;
/*
* execute single instruction.
*/
case PTRACE_SINGLESTEP:
ret = -EIO;
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
ptrace_single_step(child);
child->exit_code = data;
wake_up_process(child);
ret = 0;
break;
case PTRACE_GETREGS:
ret = ptrace_getregs(child, (void __user *)data);
break;
case PTRACE_SETREGS:
ret = ptrace_setregs(child, (const void __user *)data);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}