2 * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
6 #include "linux/kernel.h"
8 #include "linux/sched.h"
10 #include "linux/spinlock.h"
11 #include "linux/config.h"
12 #include "linux/init.h"
13 #include "linux/ptrace.h"
14 #include "asm/semaphore.h"
15 #include "asm/pgtable.h"
16 #include "asm/pgalloc.h"
17 #include "asm/tlbflush.h"
18 #include "asm/a.out.h"
19 #include "asm/current.h"
21 #include "user_util.h"
22 #include "kern_util.h"
24 #include "chan_kern.h"
25 #include "mconsole_kern.h"
26 #include "2_5compat.h"
30 int handle_page_fault(unsigned long address
, unsigned long ip
,
31 int is_write
, int is_user
, int *code_out
)
33 struct mm_struct
*mm
= current
->mm
;
34 struct vm_area_struct
*vma
;
42 *code_out
= SEGV_MAPERR
;
43 down_read(&mm
->mmap_sem
);
44 vma
= find_vma(mm
, address
);
47 else if(vma
->vm_start
<= address
)
49 else if(!(vma
->vm_flags
& VM_GROWSDOWN
))
51 else if(!ARCH_IS_STACKGROW(address
))
53 else if(expand_stack(vma
, address
))
57 *code_out
= SEGV_ACCERR
;
58 if(is_write
&& !(vma
->vm_flags
& VM_WRITE
))
60 page
= address
& PAGE_MASK
;
61 pgd
= pgd_offset(mm
, page
);
62 pud
= pud_offset(pgd
, page
);
63 pmd
= pmd_offset(pud
, page
);
66 switch (handle_mm_fault(mm
, vma
, address
, is_write
)){
82 pgd
= pgd_offset(mm
, page
);
83 pud
= pud_offset(pgd
, page
);
84 pmd
= pmd_offset(pud
, page
);
85 pte
= pte_offset_kernel(pmd
, page
);
86 } while(!pte_present(*pte
));
88 *pte
= pte_mkyoung(*pte
);
89 if(pte_write(*pte
)) *pte
= pte_mkdirty(*pte
);
90 flush_tlb_page(vma
, page
);
92 up_read(&mm
->mmap_sem
);
96 * We ran out of memory, or some other thing happened to us that made
97 * us unable to handle the page fault gracefully.
100 if (current
->pid
== 1) {
101 up_read(&mm
->mmap_sem
);
103 down_read(&mm
->mmap_sem
);
109 LIST_HEAD(physmem_remappers
);
111 void register_remapper(struct remapper
*info
)
113 list_add(&info
->list
, &physmem_remappers
);
116 static int check_remapped_addr(unsigned long address
, int is_write
)
118 struct remapper
*remapper
;
119 struct list_head
*ele
;
123 fd
= phys_mapping(__pa(address
), &offset
);
127 list_for_each(ele
, &physmem_remappers
){
128 remapper
= list_entry(ele
, struct remapper
, list
);
129 if((*remapper
->proc
)(fd
, address
, is_write
, offset
))
136 unsigned long segv(unsigned long address
, unsigned long ip
, int is_write
,
137 int is_user
, void *sc
)
143 if(!is_user
&& (address
>= start_vm
) && (address
< end_vm
)){
144 flush_tlb_kernel_vm();
147 else if(check_remapped_addr(address
& PAGE_MASK
, is_write
))
149 else if(current
->mm
== NULL
)
150 panic("Segfault with no mm");
151 err
= handle_page_fault(address
, ip
, is_write
, is_user
, &si
.si_code
);
153 catcher
= current
->thread
.fault_catcher
;
156 else if(catcher
!= NULL
){
157 current
->thread
.fault_addr
= (void *) address
;
158 do_longjmp(catcher
, 1);
160 else if(current
->thread
.fault_addr
!= NULL
)
161 panic("fault_addr set but no fault catcher");
162 else if(arch_fixup(ip
, sc
))
166 panic("Kernel mode fault at addr 0x%lx, ip 0x%lx",
170 si
.si_signo
= SIGBUS
;
172 si
.si_code
= BUS_ADRERR
;
173 si
.si_addr
= (void *)address
;
174 force_sig_info(SIGBUS
, &si
, current
);
176 else if(err
== -ENOMEM
){
177 printk("VM: killing process %s\n", current
->comm
);
181 si
.si_signo
= SIGSEGV
;
182 si
.si_addr
= (void *) address
;
183 current
->thread
.cr2
= address
;
184 current
->thread
.err
= is_write
;
185 force_sig_info(SIGSEGV
, &si
, current
);
190 void bad_segv(unsigned long address
, unsigned long ip
, int is_write
)
194 si
.si_signo
= SIGSEGV
;
195 si
.si_code
= SEGV_ACCERR
;
196 si
.si_addr
= (void *) address
;
197 current
->thread
.cr2
= address
;
198 current
->thread
.err
= is_write
;
199 force_sig_info(SIGSEGV
, &si
, current
);
202 void relay_signal(int sig
, union uml_pt_regs
*regs
)
204 if(arch_handle_signal(sig
, regs
)) return;
205 if(!UPT_IS_USER(regs
))
206 panic("Kernel mode signal %d", sig
);
207 force_sig(sig
, current
);
210 void bus_handler(int sig
, union uml_pt_regs
*regs
)
212 if(current
->thread
.fault_catcher
!= NULL
)
213 do_longjmp(current
->thread
.fault_catcher
, 1);
214 else relay_signal(sig
, regs
);
217 void winch(int sig
, union uml_pt_regs
*regs
)
219 do_IRQ(WINCH_IRQ
, regs
);
226 DEFINE_SPINLOCK(trap_lock
);
228 static int trap_index
= 0;
230 int next_trap_index(int limit
)
234 spin_lock(&trap_lock
);
236 if(++trap_index
== limit
)
238 spin_unlock(&trap_lock
);
243 * Overrides for Emacs so that we follow Linus's tabbing style.
244 * Emacs will notice this stuff at the end of the file and automatically
245 * adjust the settings for this buffer only. This must remain at the end
247 * ---------------------------------------------------------------------------
249 * c-file-style: "linux"