int
show_stack()
{
unsigned long *sp = (unsigned long *)rdusp();
int i;
raw_printk("Stack dump [0x%08lx]:\n", (unsigned long)sp);
for(i = 0; i < 16; i++)
raw_printk("sp + %d: 0x%08lx\n", i*4, sp[i]);
return 0;
}
void show_trace(unsigned long * stack)
{
unsigned long addr, module_start, module_end;
extern char _stext, _etext;
int i;
raw_printk("\nCall Trace: ");
i = 1;
module_start = VMALLOC_START;
module_end = VMALLOC_END;
while (((long) stack & (THREAD_SIZE-1)) != 0) {
if (__get_user (addr, stack)) {
/* This message matches "failing address" marked
s390 in ksymoops, so lines containing it will
not be filtered out by ksymoops. */
raw_printk ("Failing address 0x%lx\n", (unsigned long)stack);
break;
}
stack++;
/*
* If the address is either in the text segment of the
* kernel, or in the region which contains vmalloc'ed
* memory, it *may* be the address of a calling
* routine; if so, print it so that someone tracing
* down the cause of the crash will be able to figure
* out the call path that was taken.
*/
if (((addr >= (unsigned long) &_stext) &&
(addr <= (unsigned long) &_etext)) ||
((addr >= module_start) && (addr <= module_end))) {
if (i && ((i % 8) == 0))
raw_printk("\n ");
raw_printk("[<%08lx>] ", addr);
i++;
}
}
}
void
show_stack(struct task_struct *task, unsigned long *sp)
{
unsigned long *stack, addr;
int i;
/*
* debugging aid: "show_stack(NULL);" prints a
* back trace.
*/
if(sp == NULL) {
if (task)
sp = (unsigned long*)task->thread.ksp;
else
sp = (unsigned long*)rdsp();
}
stack = sp;
raw_printk("\nStack from %08lx:\n ", (unsigned long)stack);
for(i = 0; i < kstack_depth_to_print; i++) {
if (((long) stack & (THREAD_SIZE-1)) == 0)
break;
if (i && ((i % 8) == 0))
raw_printk("\n ");
if (__get_user (addr, stack)) {
/* This message matches "failing address" marked
s390 in ksymoops, so lines containing it will
not be filtered out by ksymoops. */
raw_printk ("Failing address 0x%lx\n", (unsigned long)stack);
break;
}
stack++;
raw_printk("%08lx ", addr);
}
show_trace(sp);
}
void
handle_watchdog_bite(struct pt_regs* regs)
{
#if defined(CONFIG_ETRAX_WATCHDOG)
extern int cause_of_death;
raw_printk("Watchdog bite\n");
/* Check if forced restart or unexpected watchdog */
if (cause_of_death == 0xbedead) {
while(1);
}
/* Unexpected watchdog, stop the watchdog and dump registers*/
stop_watchdog();
raw_printk("Oops: bitten by watchdog\n");
show_registers(regs);
#ifndef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
reset_watchdog();
#endif
while(1) /* nothing */;
#endif
}
/* This is normally the 'Oops' routine */
void
die_if_kernel(const char * str, struct pt_regs * regs, long err)
{
if(user_mode(regs))
return;
#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
/* This printout might take too long and trigger the
* watchdog normally. If we're in the nice doggy
* development mode, stop the watchdog during printout.
*/
stop_watchdog();
#endif
raw_printk("%s: %04lx\n", str, err & 0xffff);
show_registers(regs);
#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
reset_watchdog();
#endif
do_exit(SIGSEGV);
}
void spinning_cpu(void* addr)
{
raw_printk("CPU %d spinning on %X\n", smp_processor_id(), addr);
dump_stack();
}
void oops_nmi_handler(struct pt_regs* regs)
{
stop_watchdog();
raw_printk("NMI!\n");
show_registers(regs);
}
asmlinkage void
do_page_fault(unsigned long address, struct pt_regs *regs,
int protection, int writeaccess)
{
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct * vma;
siginfo_t info;
D(printk("Page fault for %lX on %X at %lX, prot %d write %d\n",
address, smp_processor_id(), instruction_pointer(regs),
protection, writeaccess));
tsk = current;
/*
* We fault-in kernel-space virtual memory on-demand. The
* 'reference' page table is init_mm.pgd.
*
* NOTE! We MUST NOT take any locks for this case. We may
* be in an interrupt or a critical region, and should
* only copy the information from the master page table,
* nothing more.
*
* NOTE2: This is done so that, when updating the vmalloc
* mappings we don't have to walk all processes pgdirs and
* add the high mappings all at once. Instead we do it as they
* are used. However vmalloc'ed page entries have the PAGE_GLOBAL
* bit set so sometimes the TLB can use a lingering entry.
*
* This verifies that the fault happens in kernel space
* and that the fault was not a protection error (error_code & 1).
*/
if (address >= VMALLOC_START &&
!protection &&
!user_mode(regs))
goto vmalloc_fault;
/* When stack execution is not allowed we store the signal
* trampolines in the reserved cris_signal_return_page.
* Handle this in the exact same way as vmalloc (we know
* that the mapping is there and is valid so no need to
* call handle_mm_fault).
*/
if (cris_signal_return_page &&
address == cris_signal_return_page &&
!protection && user_mode(regs))
goto vmalloc_fault;
/* we can and should enable interrupts at this point */
local_irq_enable();
mm = tsk->mm;
info.si_code = SEGV_MAPERR;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_atomic() || !mm)
goto no_context;
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
if (vma->vm_start <= address)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (user_mode(regs)) {
/*
* accessing the stack below usp is always a bug.
* we get page-aligned addresses so we can only check
* if we're within a page from usp, but that might be
* enough to catch brutal errors at least.
*/
if (address + PAGE_SIZE < rdusp())
goto bad_area;
}
if (expand_stack(vma, address))
goto bad_area;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
good_area:
info.si_code = SEGV_ACCERR;
/* first do some preliminary protection checks */
if (writeaccess == 2){
if (!(vma->vm_flags & VM_EXEC))
goto bad_area;
} else if (writeaccess == 1) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto bad_area;
}
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
switch (handle_mm_fault(mm, vma, address, writeaccess & 1)) {
case VM_FAULT_MINOR:
tsk->min_flt++;
break;
case VM_FAULT_MAJOR:
tsk->maj_flt++;
break;
case VM_FAULT_SIGBUS:
goto do_sigbus;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
bad_area:
up_read(&mm->mmap_sem);
bad_area_nosemaphore:
DPG(show_registers(regs));
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
info.si_signo = SIGSEGV;
info.si_errno = 0;
/* info.si_code has been set above */
info.si_addr = (void *)address;
force_sig_info(SIGSEGV, &info, tsk);
return;
}
no_context:
/* Are we prepared to handle this kernel fault?
*
* (The kernel has valid exception-points in the source
* when it acesses user-memory. When it fails in one
* of those points, we find it in a table and do a jump
* to some fixup code that loads an appropriate error
* code)
*/
if (find_fixup_code(regs))
return;
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
if ((unsigned long) (address) < PAGE_SIZE)
raw_printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
else
raw_printk(KERN_ALERT "Unable to handle kernel access");
raw_printk(" at virtual address %08lx\n",address);
die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
do_exit(SIGKILL);
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
out_of_memory:
up_read(&mm->mmap_sem);
printk("VM: killing process %s\n", tsk->comm);
if (user_mode(regs))
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void *)address;
force_sig_info(SIGBUS, &info, tsk);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
return;
vmalloc_fault:
{
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Use current_pgd instead of tsk->active_mm->pgd
* since the latter might be unavailable if this
* code is executed in a misfortunately run irq
* (like inside schedule() between switch_mm and
* switch_to...).
*/
int offset = pgd_index(address);
pgd_t *pgd, *pgd_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
pgd = (pgd_t *)per_cpu(current_pgd, smp_processor_id()) + offset;
pgd_k = init_mm.pgd + offset;
/* Since we're two-level, we don't need to do both
* set_pgd and set_pmd (they do the same thing). If
* we go three-level at some point, do the right thing
* with pgd_present and set_pgd here.
*
* Also, since the vmalloc area is global, we don't
* need to copy individual PTE's, it is enough to
* copy the pgd pointer into the pte page of the
* root task. If that is there, we'll find our pte if
* it exists.
*/
pud = pud_offset(pgd, address);
pud_k = pud_offset(pgd_k, address);
if (!pud_present(*pud_k))
goto no_context;
pmd = pmd_offset(pud, address);
pmd_k = pmd_offset(pud_k, address);
if (!pmd_present(*pmd_k))
goto bad_area_nosemaphore;
set_pmd(pmd, *pmd_k);
/* Make sure the actual PTE exists as well to
* catch kernel vmalloc-area accesses to non-mapped
* addresses. If we don't do this, this will just
* silently loop forever.
*/
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
return;
}
}
void
show_registers(struct pt_regs * regs)
{
/* We either use rdusp() - the USP register, which might not
correspond to the current process for all cases we're called,
or we use the current->thread.usp, which is not up to date for
the current process. Experience shows we want the USP
register. */
unsigned long usp = rdusp();
raw_printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
regs->irp, regs->srp, regs->dccr, usp, regs->mof );
raw_printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
regs->r0, regs->r1, regs->r2, regs->r3);
raw_printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
regs->r4, regs->r5, regs->r6, regs->r7);
raw_printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
regs->r8, regs->r9, regs->r10, regs->r11);
raw_printk("r12: %08lx r13: %08lx oR10: %08lx sp: %08lx\n",
regs->r12, regs->r13, regs->orig_r10, regs);
raw_printk("R_MMU_CAUSE: %08lx\n", (unsigned long)*R_MMU_CAUSE);
raw_printk("Process %s (pid: %d, stackpage=%08lx)\n",
current->comm, current->pid, (unsigned long)current);
/*
* When in-kernel, we also print out the stack and code at the
* time of the fault..
*/
if (! user_mode(regs)) {
int i;
show_stack(NULL, (unsigned long*)usp);
/* Dump kernel stack if the previous dump wasn't one. */
if (usp != 0)
show_stack (NULL, NULL);
raw_printk("\nCode: ");
if(regs->irp < PAGE_OFFSET)
goto bad;
/* Often enough the value at regs->irp does not point to
the interesting instruction, which is most often the
_previous_ instruction. So we dump at an offset large
enough that instruction decoding should be in sync at
the interesting point, but small enough to fit on a row
(sort of). We point out the regs->irp location in a
ksymoops-friendly way by wrapping the byte for that
address in parentheses. */
for(i = -12; i < 12; i++)
{
unsigned char c;
if(__get_user(c, &((unsigned char*)regs->irp)[i])) {
bad:
raw_printk(" Bad IP value.");
break;
}
if (i == 0)
raw_printk("(%02x) ", c);
else
raw_printk("%02x ", c);
}
raw_printk("\n");
}
}