static void force_signal_inject(int signal, int code, struct pt_regs *regs,
unsigned long address)
{
siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);
const char *desc;
switch (signal) {
case SIGILL:
desc = "undefined instruction";
break;
case SIGSEGV:
desc = "illegal memory access";
break;
default:
desc = "bad mode";
break;
}
if (unhandled_signal(current, signal) &&
show_unhandled_signals_ratelimited()) {
pr_info("%s[%d]: %s: pc=%p\n",
current->comm, task_pid_nr(current), desc, pc);
dump_instr(KERN_INFO, regs);
}
info.si_signo = signal;
info.si_errno = 0;
info.si_code = code;
info.si_addr = pc;
arm64_notify_die(desc, regs, &info, 0);
}
/*
* 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);
}
asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);
/* check for AArch32 breakpoint instructions */
if (!aarch32_break_handler(regs))
return;
if (call_undef_hook(regs) == 0)
return;
if (unhandled_signal(current, SIGILL) && show_unhandled_signals_ratelimited()) {
#ifdef CONFIG_HUAWEI_PRINTK_CTRL
printk_level_setup(LOGLEVEL_DEBUG);
#endif
pr_info("%s[%d]: undefined instruction: pc=%p\n",
current->comm, task_pid_nr(current), pc);
dump_instr(KERN_INFO, regs);
#ifdef CONFIG_HUAWEI_PRINTK_CTRL
printk_level_setup(sysctl_printk_level);
#endif
}
info.si_signo = SIGILL;
info.si_errno = 0;
info.si_code = ILL_ILLOPC;
info.si_addr = pc;
arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
}
asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
long error_code)
{
conditional_sti(regs);
if (user_mode(regs)) {
struct task_struct *tsk = current;
if (exception_trace && unhandled_signal(tsk, SIGSEGV))
printk(KERN_INFO
"%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
tsk->comm, tsk->pid,
regs->rip,regs->rsp,error_code);
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
force_sig(SIGSEGV, tsk);
return;
}
/* kernel gp */
{
const struct exception_table_entry *fixup;
fixup = search_exception_tables(regs->rip);
if (fixup) {
regs->rip = fixup->fixup;
return;
}
if (notify_die(DIE_GPF, "general protection fault", regs,
error_code, 13, SIGSEGV) == NOTIFY_STOP)
return;
die("general protection fault", regs, error_code);
}
}
asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);
/* check for AArch32 breakpoint instructions */
if (!aarch32_break_handler(regs))
return;
if (call_undef_hook(regs) == 0)
return;
if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
printk_ratelimit()) {
pr_info("%s[%d]: undefined instruction: pc=%p\n",
current->comm, task_pid_nr(current), pc);
dump_instr(KERN_INFO, regs);
}
info.si_signo = SIGILL;
info.si_errno = 0;
info.si_code = ILL_ILLOPC;
info.si_addr = pc;
arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
}
dotraplinkage void __kprobes
do_general_protection(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk;
conditional_sti(regs);
#ifdef CONFIG_X86_32
if (lazy_iobitmap_copy()) {
/* restart the faulting instruction */
return;
}
if (regs->flags & X86_VM_MASK)
goto gp_in_vm86;
#endif
tsk = current;
if (!user_mode(regs))
goto gp_in_kernel;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
printk_ratelimit()) {
printk(KERN_INFO
"%s[%d] general protection ip:%lx sp:%lx error:%lx",
tsk->comm, task_pid_nr(tsk),
regs->ip, regs->sp, error_code);
print_vma_addr(" in ", regs->ip);
printk("\n");
}
force_sig(SIGSEGV, tsk);
return;
#ifdef CONFIG_X86_32
gp_in_vm86:
local_irq_enable();
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
return;
#endif
gp_in_kernel:
if (fixup_exception(regs))
return;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (notify_die(DIE_GPF, "general protection fault", regs,
error_code, 13, SIGSEGV) == NOTIFY_STOP)
return;
die("general protection fault", regs, error_code);
}
static inline void report_user_fault(struct pt_regs *regs, int signr)
{
if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
return;
if (!unhandled_signal(current, signr))
return;
if (!printk_ratelimit())
return;
printk("User process fault: interruption code %04x ilc:%d ",
regs->int_code & 0xffff, regs->int_code >> 17);
print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
printk("\n");
show_regs(regs);
}
static inline void report_user_fault(struct pt_regs *regs, long int_code,
int signr, unsigned long address)
{
if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
return;
if (!unhandled_signal(current, signr))
return;
if (!printk_ratelimit())
return;
printk("User process fault: interruption code 0x%lX ", int_code);
print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN);
printk("\n");
printk("failing address: %lX\n", address);
show_regs(regs);
}
static inline void report_user_fault(struct pt_regs *regs, long signr)
{
if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
return;
if (!unhandled_signal(current, signr))
return;
if (!printk_ratelimit())
return;
printk(KERN_ALERT "User process fault: interruption code 0x%X ",
regs->int_code);
print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN);
printk(KERN_CONT "\n");
printk(KERN_ALERT "failing address: %lX\n",
regs->int_parm_long & __FAIL_ADDR_MASK);
show_regs(regs);
}
void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault)
{
if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
return;
if (!unhandled_signal(current, signr))
return;
if (!printk_ratelimit())
return;
printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ",
regs->int_code & 0xffff, regs->int_code >> 17);
print_vma_addr(KERN_CONT "in ", regs->psw.addr);
printk(KERN_CONT "\n");
if (is_mm_fault)
dump_fault_info(regs);
show_regs(regs);
}
asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
u32 instr;
siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);
struct thread_info *thread = current_thread_info();
/* check for AArch32 breakpoint instructions */
if (!aarch32_break_handler(regs))
return;
if (user_mode(regs)) {
if (compat_thumb_mode(regs)) {
if (get_user(instr, (u16 __user *)pc))
goto die_sig;
if (is_wide_instruction(instr)) {
u32 instr2;
if (get_user(instr2, (u16 __user *)pc+1))
goto die_sig;
instr <<= 16;
instr |= instr2;
}
} else if (get_user(instr, (u32 __user *)pc)) {
goto die_sig;
}
} else {
/* kernel mode */
instr = *((u32 *)pc);
}
if (call_undef_hook(regs, instr) == 0)
return;
die_sig:
if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
printk_ratelimit()) {
pr_info("%s[%d]: undefined instruction: pc=%p\n",
current->comm, task_pid_nr(current), pc);
dump_instr(KERN_INFO, regs);
}
info.si_signo = SIGILL;
info.si_errno = 0;
info.si_code = ILL_ILLOPC;
info.si_addr = pc;
arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
}
/*
* Handle stack alignment exceptions.
*/
asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
unsigned int esr,
struct pt_regs *regs)
{
struct siginfo info;
struct task_struct *tsk = current;
if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS))
pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n",
tsk->comm, task_pid_nr(tsk),
esr_get_class_string(esr), (void *)regs->pc,
(void *)regs->sp);
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRALN;
info.si_addr = (void __user *)addr;
arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr);
}
static void show_segv_info(struct uml_pt_regs *regs)
{
struct task_struct *tsk = current;
struct faultinfo *fi = UPT_FAULTINFO(regs);
if (!unhandled_signal(tsk, SIGSEGV))
return;
if (!printk_ratelimit())
return;
printk("%s%s[%d]: segfault at %lx ip %p sp %p error %x",
task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, task_pid_nr(tsk), FAULT_ADDRESS(*fi),
(void *)UPT_IP(regs), (void *)UPT_SP(regs),
fi->error_code);
print_vma_addr(KERN_CONT " in ", UPT_IP(regs));
printk(KERN_CONT "\n");
}
static void arm64_show_signal(int signo, const char *str)
{
static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
struct task_struct *tsk = current;
unsigned int esr = tsk->thread.fault_code;
struct pt_regs *regs = task_pt_regs(tsk);
/* Leave if the signal won't be shown */
if (!show_unhandled_signals ||
!unhandled_signal(tsk, signo) ||
!__ratelimit(&rs))
return;
pr_info("%s[%d]: unhandled exception: ", tsk->comm, task_pid_nr(tsk));
if (esr)
pr_cont("%s, ESR 0x%08x, ", esr_get_class_string(esr), esr);
pr_cont("%s", str);
print_vma_addr(KERN_CONT " in ", regs->pc);
pr_cont("\n");
__show_regs(regs);
}
static void __kprobes do_trap(int trapnr, int signr, char *str,
struct pt_regs * regs, long error_code,
siginfo_t *info)
{
conditional_sti(regs);
if (user_mode(regs)) {
struct task_struct *tsk = current;
if (exception_trace && unhandled_signal(tsk, signr))
printk(KERN_INFO
"%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
tsk->comm, tsk->pid, str,
regs->rip,regs->rsp,error_code);
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
if (info)
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
return;
}
/* kernel trap */
{
const struct exception_table_entry *fixup;
fixup = search_exception_tables(regs->rip);
if (fixup) {
regs->rip = fixup->fixup;
} else
die(str, regs, error_code);
return;
}
}
static void __kprobes
do_trap(int trapnr, int signr, const char *str, struct pt_regs *regs,
long error_code, siginfo_t *info)
{
struct task_struct *tsk = current;
#ifdef CONFIG_X86_32
if (v8086_mode(regs)) {
/*
* traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
* On nmi (interrupt 2), do_trap should not be called.
*/
if (trapnr < 6)
goto vm86_trap;
goto trap_signal;
}
#endif
if (!user_mode_novm(regs))
goto kernel_trap;
#ifdef CONFIG_X86_32
trap_signal:
#endif
/*
* We want error_code and trap_no set for userspace faults and
* kernelspace faults which result in die(), but not
* kernelspace faults which are fixed up. die() gives the
* process no chance to handle the signal and notice the
* kernel fault information, so that won't result in polluting
* the information about previously queued, but not yet
* delivered, faults. See also do_general_protection below.
*/
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
#ifdef CONFIG_X86_64
if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
printk_ratelimit()) {
printk(KERN_INFO
"%s[%d] trap %s ip:%lx sp:%lx error:%lx",
tsk->comm, task_pid_nr(tsk), str,
regs->ip, regs->sp, error_code);
print_vma_addr(" in ", regs->ip);
printk("\n");
}
#endif
if (info)
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
return;
kernel_trap:
if (!fixup_exception(regs)) {
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
#if defined(CONFIG_X86_32) && defined(CONFIG_PAX_KERNEXEC)
if (trapnr == 12 && ((regs->cs & 0xFFFF) == __KERNEL_CS || (regs->cs & 0xFFFF) == __KERNEXEC_KERNEL_CS))
str = "PAX: suspicious stack segment fault";
#endif
die(str, regs, error_code);
}
#ifdef CONFIG_PAX_REFCOUNT
if (trapnr == 4)
pax_report_refcount_overflow(regs);
#endif
return;
#ifdef CONFIG_X86_32
vm86_trap:
if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
error_code, trapnr))
goto trap_signal;
return;
#endif
}
static void __kprobes
do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
long error_code, siginfo_t *info)
{
struct task_struct *tsk = current;
#ifdef CONFIG_X86_32
if (regs->flags & X86_VM_MASK) {
/*
* traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
* On nmi (interrupt 2), do_trap should not be called.
*/
if (trapnr < 6)
goto vm86_trap;
goto trap_signal;
}
#endif
if (!user_mode(regs))
goto kernel_trap;
#ifdef CONFIG_X86_32
trap_signal:
#endif
/*
* We want error_code and trap_no set for userspace faults and
* kernelspace faults which result in die(), but not
* kernelspace faults which are fixed up. die() gives the
* process no chance to handle the signal and notice the
* kernel fault information, so that won't result in polluting
* the information about previously queued, but not yet
* delivered, faults. See also do_general_protection below.
*/
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
#ifdef CONFIG_X86_64
if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
printk_ratelimit()) {
printk(KERN_INFO
"%s[%d] trap %s ip:%lx sp:%lx error:%lx",
tsk->comm, tsk->pid, str,
regs->ip, regs->sp, error_code);
print_vma_addr(" in ", regs->ip);
printk("\n");
}
#endif
if (info)
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
return;
kernel_trap:
if (!fixup_exception(regs)) {
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
die(str, regs, error_code);
}
return;
#ifdef CONFIG_X86_32
vm86_trap:
if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
error_code, trapnr))
goto trap_signal;
return;
#endif
}
dotraplinkage void __kprobes
do_general_protection(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk;
conditional_sti(regs);
#ifdef CONFIG_X86_32
if (v8086_mode(regs))
goto gp_in_vm86;
#endif
tsk = current;
if (!user_mode_novm(regs))
goto gp_in_kernel;
#if defined(CONFIG_X86_32) && defined(CONFIG_PAX_PAGEEXEC)
if (!nx_enabled && tsk->mm && (tsk->mm->pax_flags & MF_PAX_PAGEEXEC)) {
struct mm_struct *mm = tsk->mm;
unsigned long limit;
down_write(&mm->mmap_sem);
limit = mm->context.user_cs_limit;
if (limit < TASK_SIZE) {
track_exec_limit(mm, limit, TASK_SIZE, VM_EXEC);
up_write(&mm->mmap_sem);
return;
}
up_write(&mm->mmap_sem);
}
#endif
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
printk_ratelimit()) {
printk(KERN_INFO
"%s[%d] general protection ip:%lx sp:%lx error:%lx",
tsk->comm, task_pid_nr(tsk),
regs->ip, regs->sp, error_code);
print_vma_addr(" in ", regs->ip);
printk("\n");
}
force_sig(SIGSEGV, tsk);
return;
#ifdef CONFIG_X86_32
gp_in_vm86:
local_irq_enable();
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
return;
#endif
gp_in_kernel:
if (fixup_exception(regs))
return;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (notify_die(DIE_GPF, "general protection fault", regs,
error_code, 13, SIGSEGV) == NOTIFY_STOP)
return;
#if defined(CONFIG_X86_32) && defined(CONFIG_PAX_KERNEXEC)
if ((regs->cs & 0xFFFF) == __KERNEL_CS)
die("PAX: suspicious general protection fault", regs, error_code);
else
#endif
die("general protection fault", regs, error_code);
}
dotraplinkage void __kprobes
do_general_protection(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk;
conditional_sti(regs);
#ifdef CONFIG_X86_32
if (regs->flags & X86_VM_MASK)
goto gp_in_vm86;
#endif
tsk = current;
if (!user_mode(regs))
goto gp_in_kernel;
#ifdef CONFIG_X86_32
{
int cpu;
int ok;
cpu = get_cpu();
ok = check_lazy_exec_limit(cpu, regs, error_code);
put_cpu();
if (ok)
return;
if (print_fatal_signals) {
printk(KERN_ERR "#GPF(%ld[seg:%lx]) at %08lx, CPU#%d.\n",
error_code, error_code/8, regs->ip, smp_processor_id());
printk(KERN_ERR "exec_limit: %08lx, user_cs: %08x/%08x.\n",
current->mm->context.exec_limit,
current->mm->context.user_cs.a,
current->mm->context.user_cs.b);
}
}
#endif /*CONFIG_X86_32*/
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
printk_ratelimit()) {
printk(KERN_INFO
"%s[%d] general protection ip:%lx sp:%lx error:%lx",
tsk->comm, task_pid_nr(tsk),
regs->ip, regs->sp, error_code);
print_vma_addr(" in ", regs->ip);
printk("\n");
}
force_sig(SIGSEGV, tsk);
return;
#ifdef CONFIG_X86_32
gp_in_vm86:
local_irq_enable();
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
return;
#endif
gp_in_kernel:
if (fixup_exception(regs))
return;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (notify_die(DIE_GPF, "general protection fault", regs,
error_code, 13, SIGSEGV) == NOTIFY_STOP)
return;
die("general protection fault", regs, error_code);
}
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
unsigned long address)
{
struct vm_area_struct *vma = NULL;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
int code = SEGV_MAPERR;
int fault;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
cause >>= 2;
/* Restart the instruction */
regs->ea -= 4;
/*
* 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 (unlikely(address >= VMALLOC_START && address <= VMALLOC_END)) {
if (user_mode(regs))
goto bad_area_nosemaphore;
else
goto vmalloc_fault;
}
if (unlikely(address >= TASK_SIZE))
goto bad_area_nosemaphore;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (faulthandler_disabled() || !mm)
goto bad_area_nosemaphore;
if (user_mode(regs))
flags |= FAULT_FLAG_USER;
if (!down_read_trylock(&mm->mmap_sem)) {
if (!user_mode(regs) && !search_exception_tables(regs->ea))
goto bad_area_nosemaphore;
retry:
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 (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:
code = SEGV_ACCERR;
switch (cause) {
case EXC_SUPERV_INSN_ACCESS:
goto bad_area;
case EXC_SUPERV_DATA_ACCESS:
goto bad_area;
case EXC_X_PROTECTION_FAULT:
if (!(vma->vm_flags & VM_EXEC))
goto bad_area;
break;
case EXC_R_PROTECTION_FAULT:
if (!(vma->vm_flags & VM_READ))
goto bad_area;
break;
case EXC_W_PROTECTION_FAULT:
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
flags = FAULT_FLAG_WRITE;
break;
}
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
fault = handle_mm_fault(mm, vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM)
goto out_of_memory;
else if (fault & VM_FAULT_SIGSEGV)
goto bad_area;
else if (fault & VM_FAULT_SIGBUS)
goto do_sigbus;
BUG();
}
/*
* Major/minor page fault accounting is only done on the
* initial attempt. If we go through a retry, it is extremely
* likely that the page will be found in page cache at that point.
*/
if (flags & FAULT_FLAG_ALLOW_RETRY) {
if (fault & VM_FAULT_MAJOR)
current->maj_flt++;
else
current->min_flt++;
if (fault & VM_FAULT_RETRY) {
/* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
* of starvation. */
flags &= ~FAULT_FLAG_ALLOW_RETRY;
flags |= FAULT_FLAG_TRIED;
/*
* No need to up_read(&mm->mmap_sem) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
goto retry;
}
}
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:
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
if (unhandled_signal(current, SIGSEGV) && printk_ratelimit()) {
pr_info("%s: unhandled page fault (%d) at 0x%08lx, "
"cause %ld\n", current->comm, SIGSEGV, address, cause);
show_regs(regs);
}
_exception(SIGSEGV, regs, code, address);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs))
return;
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
bust_spinlocks(1);
pr_alert("Unable to handle kernel %s at virtual address %08lx",
address < PAGE_SIZE ? "NULL pointer dereference" :
"paging request", address);
pr_alert("ea = %08lx, ra = %08lx, cause = %ld\n", regs->ea, regs->ra,
cause);
panic("Oops");
return;
/*
* 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);
if (!user_mode(regs))
goto no_context;
pagefault_out_of_memory();
return;
do_sigbus:
up_read(&mm->mmap_sem);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
_exception(SIGBUS, regs, BUS_ADRERR, address);
return;
vmalloc_fault:
{
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Do _not_ use "tsk" here. We might be inside
* an interrupt in the middle of a task switch..
*/
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_current + offset;
pgd_k = init_mm.pgd + offset;
if (!pgd_present(*pgd_k))
goto no_context;
set_pgd(pgd, *pgd_k);
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 no_context;
set_pmd(pmd, *pmd_k);
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
flush_tlb_one(address);
return;
}
}