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x86: unify fault_32|64.c with ifdefs
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Elimination of these ifdefs can be done in a unified file.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Harvey Harrison authored and Ingo Molnar committed Jan 30, 2008
1 parent 1156e09 commit f8c2ee2
Showing 2 changed files with 177 additions and 16 deletions.
100 changes: 95 additions & 5 deletions arch/x86/mm/fault_32.c
View file
Original file line number Diff line number Diff line change
@@ -48,7 +48,11 @@ static inline int notify_page_fault(struct pt_regs *regs)
int ret = 0;

/* kprobe_running() needs smp_processor_id() */
#ifdef CONFIG_X86_32
if (!user_mode_vm(regs)) {
#else
if (!user_mode(regs)) {
#endif
preempt_disable();
if (kprobe_running() && kprobe_fault_handler(regs, 14))
ret = 1;
@@ -430,11 +434,15 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
#endif

/*
* X86_32
* Handle a fault on the vmalloc or module mapping area
*
* X86_64
* Handle a fault on the vmalloc area
*
* This assumes no large pages in there.
*/
static inline int vmalloc_fault(unsigned long address)
static int vmalloc_fault(unsigned long address)
{
#ifdef CONFIG_X86_32
unsigned long pgd_paddr;
@@ -509,6 +517,9 @@ int show_unhandled_signals = 1;
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
#ifdef CONFIG_X86_64
asmlinkage
#endif
void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
struct task_struct *tsk;
@@ -517,6 +528,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
unsigned long address;
int write, si_code;
int fault;
#ifdef CONFIG_X86_64
unsigned long flags;
#endif

/*
* We can fault from pretty much anywhere, with unknown IRQ state.
@@ -548,6 +562,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
* (error_code & 4) == 0, and that the fault was not a
* protection error (error_code & 9) == 0.
*/
#ifdef CONFIG_X86_32
if (unlikely(address >= TASK_SIZE)) {
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
vmalloc_fault(address) >= 0)
@@ -570,7 +585,45 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
*/
if (in_atomic() || !mm)
goto bad_area_nosemaphore;
#else /* CONFIG_X86_64 */
if (unlikely(address >= TASK_SIZE64)) {
/*
* Don't check for the module range here: its PML4
* is always initialized because it's shared with the main
* kernel text. Only vmalloc may need PML4 syncups.
*/
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
((address >= VMALLOC_START && address < VMALLOC_END))) {
if (vmalloc_fault(address) >= 0)
return;
}
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
*/
goto bad_area_nosemaphore;
}
if (likely(regs->flags & X86_EFLAGS_IF))
local_irq_enable();

if (unlikely(error_code & PF_RSVD))
pgtable_bad(address, regs, error_code);

/*
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault.
*/
if (unlikely(in_atomic() || !mm))
goto bad_area_nosemaphore;

/*
* User-mode registers count as a user access even for any
* potential system fault or CPU buglet.
*/
if (user_mode_vm(regs))
error_code |= PF_USER;
again:
#endif
/* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
* kernel and should generate an OOPS. Unfortunately, in the case of an
@@ -596,7 +649,11 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
#ifdef CONFIG_X86_32
if (vma->vm_start <= address)
#else
if (likely(vma->vm_start <= address))
#endif
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
@@ -634,7 +691,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
goto bad_area;
}

survive:
#ifdef CONFIG_X86_32
survive:
#endif
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
@@ -705,6 +764,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
print_vma_addr(" in ", regs->ip);
printk("\n");
}

tsk->thread.cr2 = address;
/* Kernel addresses are always protection faults */
tsk->thread.error_code = error_code | (address >= TASK_SIZE);
@@ -722,9 +782,13 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
return;

/*
* X86_32
* Valid to do another page fault here, because if this fault
* had been triggered by is_prefetch fixup_exception would have
* handled it.
*
* X86_64
* Hall of shame of CPU/BIOS bugs.
*/
if (is_prefetch(regs, address, error_code))
return;
@@ -736,7 +800,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/

#ifdef CONFIG_X86_32
bust_spinlocks(1);

show_fault_oops(regs, error_code, address);
@@ -747,18 +811,39 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
die("Oops", regs, error_code);
bust_spinlocks(0);
do_exit(SIGKILL);
#else /* CONFIG_X86_64 */
flags = oops_begin();

show_fault_oops(regs, error_code, address);

tsk->thread.cr2 = address;
tsk->thread.trap_no = 14;
tsk->thread.error_code = error_code;
if (__die("Oops", regs, error_code))
regs = NULL;
/* Executive summary in case the body of the oops scrolled away */
printk(KERN_EMERG "CR2: %016lx\n", address);
oops_end(flags, regs, SIGKILL);
#endif

/*
* 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);
#ifdef CONFIG_X86_32
if (is_global_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
}
#else
if (is_global_init(current)) {
yield();
goto again;
}
#endif
printk("VM: killing process %s\n", tsk->comm);
if (error_code & PF_USER)
do_group_exit(SIGKILL);
@@ -770,17 +855,22 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
/* Kernel mode? Handle exceptions or die */
if (!(error_code & PF_USER))
goto no_context;

#ifdef CONFIG_X86_32
/* User space => ok to do another page fault */
if (is_prefetch(regs, address, error_code))
return;

#endif
tsk->thread.cr2 = address;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 14;
force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
}

#ifdef CONFIG_X86_64
DEFINE_SPINLOCK(pgd_lock);
LIST_HEAD(pgd_list);
#endif

void vmalloc_sync_all(void)
{
#ifdef CONFIG_X86_32
93 changes: 82 additions & 11 deletions arch/x86/mm/fault_64.c
View file
Original file line number Diff line number Diff line change
@@ -51,7 +51,11 @@ static inline int notify_page_fault(struct pt_regs *regs)
int ret = 0;

/* kprobe_running() needs smp_processor_id() */
#ifdef CONFIG_X86_32
if (!user_mode_vm(regs)) {
#else
if (!user_mode(regs)) {
#endif
preempt_disable();
if (kprobe_running() && kprobe_fault_handler(regs, 14))
ret = 1;
@@ -433,6 +437,10 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
#endif

/*
* X86_32
* Handle a fault on the vmalloc or module mapping area
*
* X86_64
* Handle a fault on the vmalloc area
*
* This assumes no large pages in there.
@@ -512,16 +520,20 @@ int show_unhandled_signals = 1;
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
unsigned long error_code)
#ifdef CONFIG_X86_64
asmlinkage
#endif
void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct *vma;
unsigned long address;
int write, fault;
int write, si_code;
int fault;
#ifdef CONFIG_X86_64
unsigned long flags;
int si_code;
#endif

/*
* We can fault from pretty much anywhere, with unknown IRQ state.
@@ -553,6 +565,30 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
* (error_code & 4) == 0, and that the fault was not a
* protection error (error_code & 9) == 0.
*/
#ifdef CONFIG_X86_32
if (unlikely(address >= TASK_SIZE)) {
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
vmalloc_fault(address) >= 0)
return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
*/
goto bad_area_nosemaphore;
}

/* It's safe to allow irq's after cr2 has been saved and the vmalloc
fault has been handled. */
if (regs->flags & (X86_EFLAGS_IF|VM_MASK))
local_irq_enable();

/*
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault.
*/
if (in_atomic() || !mm)
goto bad_area_nosemaphore;
#else /* CONFIG_X86_64 */
if (unlikely(address >= TASK_SIZE64)) {
/*
* Don't check for the module range here: its PML4
@@ -570,7 +606,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
*/
goto bad_area_nosemaphore;
}

if (likely(regs->flags & X86_EFLAGS_IF))
local_irq_enable();

@@ -590,8 +625,8 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
*/
if (user_mode_vm(regs))
error_code |= PF_USER;

again:
again:
#endif
/* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
* kernel and should generate an OOPS. Unfortunately, in the case of an
@@ -617,7 +652,11 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
#ifdef CONFIG_X86_32
if (vma->vm_start <= address)
#else
if (likely(vma->vm_start <= address))
#endif
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
@@ -655,6 +694,9 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
goto bad_area;
}

#ifdef CONFIG_X86_32
survive:
#endif
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
@@ -730,7 +772,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
/* Kernel addresses are always protection faults */
tsk->thread.error_code = error_code | (address >= TASK_SIZE);
tsk->thread.trap_no = 14;

force_sig_info_fault(SIGSEGV, si_code, address, tsk);
return;
}
@@ -744,9 +785,14 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
return;

/*
* X86_32
* Valid to do another page fault here, because if this fault
* had been triggered by is_prefetch fixup_exception would have
* handled it.
*
* X86_64
* Hall of shame of CPU/BIOS bugs.
*/

if (is_prefetch(regs, address, error_code))
return;

@@ -757,7 +803,18 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
#ifdef CONFIG_X86_32
bust_spinlocks(1);

show_fault_oops(regs, error_code, address);

tsk->thread.cr2 = address;
tsk->thread.trap_no = 14;
tsk->thread.error_code = error_code;
die("Oops", regs, error_code);
bust_spinlocks(0);
do_exit(SIGKILL);
#else /* CONFIG_X86_64 */
flags = oops_begin();

show_fault_oops(regs, error_code, address);
@@ -770,17 +827,26 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
/* Executive summary in case the body of the oops scrolled away */
printk(KERN_EMERG "CR2: %016lx\n", address);
oops_end(flags, regs, SIGKILL);
#endif

/*
* 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);
#ifdef CONFIG_X86_32
if (is_global_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
}
#else
if (is_global_init(current)) {
yield();
goto again;
}
#endif
printk("VM: killing process %s\n", tsk->comm);
if (error_code & PF_USER)
do_group_exit(SIGKILL);
@@ -792,16 +858,21 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
/* Kernel mode? Handle exceptions or die */
if (!(error_code & PF_USER))
goto no_context;

#ifdef CONFIG_X86_32
/* User space => ok to do another page fault */
if (is_prefetch(regs, address, error_code))
return;
#endif
tsk->thread.cr2 = address;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 14;
force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
return;
}

#ifdef CONFIG_X86_64
DEFINE_SPINLOCK(pgd_lock);
LIST_HEAD(pgd_list);
#endif

void vmalloc_sync_all(void)
{

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