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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/ia64/mm/fault.c
19261a99e6234cee94a8bb23a26b0b5241783938
2 * MMU fault handling support.
4 * Copyright (C) 1998-2002 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
7 #include <linux/sched.h>
8 #include <linux/kernel.h>
10 #include <linux/interrupt.h>
11 #include <linux/kprobes.h>
12 #include <linux/kdebug.h>
14 #include <asm/pgtable.h>
15 #include <asm/processor.h>
16 #include <asm/system.h>
17 #include <asm/uaccess.h>
19 extern int die(char *, struct pt_regs
*, long);
22 static inline int notify_page_fault(struct pt_regs
*regs
, int trap
)
26 if (!user_mode(regs
)) {
27 /* kprobe_running() needs smp_processor_id() */
29 if (kprobe_running() && kprobe_fault_handler(regs
, trap
))
37 static inline int notify_page_fault(struct pt_regs
*regs
, int trap
)
44 * Return TRUE if ADDRESS points at a page in the kernel's mapped segment
45 * (inside region 5, on ia64) and that page is present.
48 mapped_kernel_page_is_present (unsigned long address
)
55 pgd
= pgd_offset_k(address
);
56 if (pgd_none(*pgd
) || pgd_bad(*pgd
))
59 pud
= pud_offset(pgd
, address
);
60 if (pud_none(*pud
) || pud_bad(*pud
))
63 pmd
= pmd_offset(pud
, address
);
64 if (pmd_none(*pmd
) || pmd_bad(*pmd
))
67 ptep
= pte_offset_kernel(pmd
, address
);
72 return pte_present(pte
);
76 ia64_do_page_fault (unsigned long address
, unsigned long isr
, struct pt_regs
*regs
)
78 int signal
= SIGSEGV
, code
= SEGV_MAPERR
;
79 struct vm_area_struct
*vma
, *prev_vma
;
80 struct mm_struct
*mm
= current
->mm
;
85 /* mmap_sem is performance critical.... */
86 prefetchw(&mm
->mmap_sem
);
89 * If we're in an interrupt or have no user context, we must not take the fault..
91 if (in_atomic() || !mm
)
94 #ifdef CONFIG_VIRTUAL_MEM_MAP
96 * If fault is in region 5 and we are in the kernel, we may already
97 * have the mmap_sem (pfn_valid macro is called during mmap). There
98 * is no vma for region 5 addr's anyway, so skip getting the semaphore
99 * and go directly to the exception handling code.
102 if ((REGION_NUMBER(address
) == 5) && !user_mode(regs
))
107 * This is to handle the kprobes on user space access instructions
109 if (notify_page_fault(regs
, TRAP_BRKPT
))
112 down_read(&mm
->mmap_sem
);
114 vma
= find_vma_prev(mm
, address
, &prev_vma
);
115 if (!vma
&& !prev_vma
)
119 * find_vma_prev() returns vma such that address < vma->vm_end or NULL
121 * May find no vma, but could be that the last vm area is the
122 * register backing store that needs to expand upwards, in
123 * this case vma will be null, but prev_vma will ne non-null
125 if (( !vma
&& prev_vma
) || (address
< vma
->vm_start
) )
126 goto check_expansion
;
131 /* OK, we've got a good vm_area for this memory area. Check the access permissions: */
133 # define VM_READ_BIT 0
134 # define VM_WRITE_BIT 1
135 # define VM_EXEC_BIT 2
137 # if (((1 << VM_READ_BIT) != VM_READ || (1 << VM_WRITE_BIT) != VM_WRITE) \
138 || (1 << VM_EXEC_BIT) != VM_EXEC)
139 # error File is out of sync with <linux/mm.h>. Please update.
142 if (((isr
>> IA64_ISR_R_BIT
) & 1UL) && (!(vma
->vm_flags
& (VM_READ
| VM_WRITE
))))
145 mask
= ( (((isr
>> IA64_ISR_X_BIT
) & 1UL) << VM_EXEC_BIT
)
146 | (((isr
>> IA64_ISR_W_BIT
) & 1UL) << VM_WRITE_BIT
));
148 if ((vma
->vm_flags
& mask
) != mask
)
153 * If for any reason at all we couldn't handle the fault, make
154 * sure we exit gracefully rather than endlessly redo the
157 fault
= handle_mm_fault(mm
, vma
, address
, (mask
& VM_WRITE
) ? FAULT_FLAG_WRITE
: 0);
158 if (unlikely(fault
& VM_FAULT_ERROR
)) {
160 * We ran out of memory, or some other thing happened
161 * to us that made us unable to handle the page fault
164 if (fault
& VM_FAULT_OOM
) {
166 } else if (fault
& VM_FAULT_SIGBUS
) {
172 if (fault
& VM_FAULT_MAJOR
)
176 up_read(&mm
->mmap_sem
);
180 if (!(prev_vma
&& (prev_vma
->vm_flags
& VM_GROWSUP
) && (address
== prev_vma
->vm_end
))) {
183 if (!(vma
->vm_flags
& VM_GROWSDOWN
))
185 if (REGION_NUMBER(address
) != REGION_NUMBER(vma
->vm_start
)
186 || REGION_OFFSET(address
) >= RGN_MAP_LIMIT
)
188 if (expand_stack(vma
, address
))
192 if (REGION_NUMBER(address
) != REGION_NUMBER(vma
->vm_start
)
193 || REGION_OFFSET(address
) >= RGN_MAP_LIMIT
)
196 * Since the register backing store is accessed sequentially,
197 * we disallow growing it by more than a page at a time.
199 if (address
> vma
->vm_end
+ PAGE_SIZE
- sizeof(long))
201 if (expand_upwards(vma
, address
))
207 up_read(&mm
->mmap_sem
);
208 #ifdef CONFIG_VIRTUAL_MEM_MAP
211 if ((isr
& IA64_ISR_SP
)
212 || ((isr
& IA64_ISR_NA
) && (isr
& IA64_ISR_CODE_MASK
) == IA64_ISR_CODE_LFETCH
))
215 * This fault was due to a speculative load or lfetch.fault, set the "ed"
216 * bit in the psr to ensure forward progress. (Target register will get a
217 * NaT for ld.s, lfetch will be canceled.)
219 ia64_psr(regs
)->ed
= 1;
222 if (user_mode(regs
)) {
223 si
.si_signo
= signal
;
226 si
.si_addr
= (void __user
*) address
;
228 si
.si_flags
= __ISR_VALID
;
229 force_sig_info(signal
, &si
, current
);
234 if ((isr
& IA64_ISR_SP
)
235 || ((isr
& IA64_ISR_NA
) && (isr
& IA64_ISR_CODE_MASK
) == IA64_ISR_CODE_LFETCH
))
238 * This fault was due to a speculative load or lfetch.fault, set the "ed"
239 * bit in the psr to ensure forward progress. (Target register will get a
240 * NaT for ld.s, lfetch will be canceled.)
242 ia64_psr(regs
)->ed
= 1;
247 * Since we have no vma's for region 5, we might get here even if the address is
248 * valid, due to the VHPT walker inserting a non present translation that becomes
249 * stale. If that happens, the non present fault handler already purged the stale
250 * translation, which fixed the problem. So, we check to see if the translation is
251 * valid, and return if it is.
253 if (REGION_NUMBER(address
) == 5 && mapped_kernel_page_is_present(address
))
256 if (ia64_done_with_exception(regs
))
260 * Oops. The kernel tried to access some bad page. We'll have to terminate things
261 * with extreme prejudice.
265 if (address
< PAGE_SIZE
)
266 printk(KERN_ALERT
"Unable to handle kernel NULL pointer dereference (address %016lx)\n", address
);
268 printk(KERN_ALERT
"Unable to handle kernel paging request at "
269 "virtual address %016lx\n", address
);
270 if (die("Oops", regs
, isr
))
278 up_read(&mm
->mmap_sem
);
279 if (is_global_init(current
)) {
281 down_read(&mm
->mmap_sem
);
284 printk(KERN_CRIT
"VM: killing process %s\n", current
->comm
);
286 do_group_exit(SIGKILL
);