/*
* Something tried to access memory that isn't in our memory map. User mode
* accesses just cause a SIGSEGV
*/
static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
unsigned int esr, unsigned int sig, int code,
struct pt_regs *regs)
{
struct siginfo si;
trace_user_fault(tsk, addr, esr);
if (show_unhandled_signals && unhandled_signal(tsk, sig) &&
printk_ratelimit()) {
pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
addr, esr);
show_pte(tsk->mm, addr);
show_regs(regs);
}
tsk->thread.fault_address = addr;
tsk->thread.fault_code = esr;
si.si_signo = sig;
si.si_errno = 0;
si.si_code = code;
si.si_addr = (void __user *)addr;
force_sig_info(sig, &si, tsk);
}
/*
* The kernel tried to access some page that wasn't present.
*/
static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
unsigned int esr, struct pt_regs *regs)
{
#if defined(CONFIG_HTC_DEBUG_RTB)
static int enable_logk_die = 1;
#endif
/*
* Are we prepared to handle this kernel fault?
*/
if (fixup_exception(regs))
return;
#if defined(CONFIG_HTC_DEBUG_RTB)
if (enable_logk_die) {
uncached_logk(LOGK_DIE, (void *)regs->pc);
uncached_logk(LOGK_DIE, (void *)regs->regs[30]);
uncached_logk(LOGK_DIE, (void *)addr);
/* Disable RTB here to avoid weird recursive spinlock/printk behaviors */
msm_rtb_disable();
enable_logk_die = 0;
}
#endif
/*
* No handler, we'll have to terminate things with extreme prejudice.
*/
bust_spinlocks(1);
pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);
show_pte(mm, addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
}
/*
* Oops. The kernel tried to access some page that wasn't present.
*/
static void
__do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
unsigned long fixup;
/*
* Are we prepared to handle this kernel fault?
*/
if ((fixup = search_exception_table(instruction_pointer(regs))) != 0) {
#ifdef DEBUG
printk(KERN_DEBUG "%s: Exception at [<%lx>] addr=%lx (fixup: %lx)\n",
current->comm, regs->ARM_pc, addr, fixup);
#endif
regs->ARM_pc = fixup;
return;
}
/*
* No handler, we'll have to terminate things with extreme prejudice.
*/
printk(KERN_ALERT
"Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);
show_pte(mm, addr);
die("Oops", regs, fsr);
do_exit(SIGKILL);
}
static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
unsigned int esr, struct pt_regs *regs)
{
#if defined(CONFIG_HTC_DEBUG_RTB)
static int enable_logk_die = 1;
#endif
if (fixup_exception(regs))
return;
#if defined(CONFIG_HTC_DEBUG_RTB)
if (enable_logk_die) {
uncached_logk(LOGK_DIE, (void *)regs->pc);
uncached_logk(LOGK_DIE, (void *)regs->regs[30]);
uncached_logk(LOGK_DIE, (void *)addr);
msm_rtb_disable();
enable_logk_die = 0;
}
#endif
bust_spinlocks(1);
pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);
show_pte(mm, addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
}
/*
* Currently dropped down to debug level
*/
asmlinkage void
do_DataAbort(unsigned long addr, int error_code, struct pt_regs *regs, int fsr)
{
const struct fsr_info *inf = fsr_info + (fsr & 15);
if (!inf->fn(addr, error_code, regs))
return;
force_sig(inf->sig, current);
printk(KERN_ALERT "Unhandled fault: %s (%X) at 0x%08lx\n",
inf->name, fsr, addr);
show_pte(current->mm, addr);
die_if_kernel("Oops", regs, 0);
return;
}
/*
* The kernel tried to access some page that wasn't present.
*/
static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
unsigned int esr, struct pt_regs *regs)
{
/*
* Are we prepared to handle this kernel fault?
*/
if (fixup_exception(regs))
return;
/*
* No handler, we'll have to terminate things with extreme prejudice.
*/
bust_spinlocks(1);
pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);
show_pte(mm, addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
}
static int do_page_fault(unsigned long addr, int mode, struct pt_regs *regs)
{
struct task_struct *tsk;
struct mm_struct *mm;
unsigned long fixup;
int fault;
tsk = current;
mm = tsk->mm;
/*
* 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.
*/
if (addr >= TASK_SIZE)
goto vmalloc_fault;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_interrupt() || !mm)
goto no_context;
down(&mm->mmap_sem);
fault = __do_page_fault(mm, addr, mode, tsk);
up(&mm->mmap_sem);
ret:
/*
* Handle the "normal" case first
*/
if (fault > 0)
return 0;
/*
* We had some memory, but were unable to
* successfully fix up this page fault.
*/
if (fault == 0)
goto do_sigbus;
/*
* If we are in kernel mode at this point, we
* have no context to handle this fault with.
*/
if (!user_mode(regs))
goto no_context;
if (fault == -3) {
/*
* We ran out of memory, or some other thing happened to
* us that made us unable to handle the page fault gracefully.
*/
printk("VM: killing process %s\n", tsk->comm);
do_exit(SIGKILL);
} else {
/*
* Something tried to access memory that isn't in our memory map..
* User mode accesses just cause a SIGSEGV
*/
struct siginfo si;
#ifdef CONFIG_DEBUG_USER
printk(KERN_DEBUG "%s: unhandled page fault at pc=0x%08lx, "
"lr=0x%08lx (bad address=0x%08lx, code %d)\n",
tsk->comm, regs->ARM_pc, regs->ARM_lr, addr, mode);
#endif
tsk->thread.address = addr;
tsk->thread.error_code = mode;
tsk->thread.trap_no = 14;
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = fault == -1 ? SEGV_ACCERR : SEGV_MAPERR;
si.si_addr = (void *)addr;
force_sig_info(SIGSEGV, &si, tsk);
}
return 0;
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
do_sigbus:
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.address = addr;
tsk->thread.error_code = mode;
tsk->thread.trap_no = 14;
force_sig(SIGBUS, tsk);
/* Kernel mode? Handle exceptions or die */
if (user_mode(regs))
return 0;
no_context:
/* Are we prepared to handle this kernel fault? */
if ((fixup = search_exception_table(instruction_pointer(regs))) != 0) {
#ifdef DEBUG
printk(KERN_DEBUG "%s: Exception at [<%lx>] addr=%lx (fixup: %lx)\n",
tsk->comm, regs->ARM_pc, addr, fixup);
#endif
regs->ARM_pc = fixup;
return 0;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
printk(KERN_ALERT "Unable to handle kernel %s at virtual address %08lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" : "paging request", addr);
show_pte(mm, addr);
die("Oops", regs, mode);
do_exit(SIGKILL);
return 0;
vmalloc_fault:
fault = __do_vmalloc_fault(addr, mm);
goto ret;
}
