| 1 |
3 |
xianfeng |
/* $Id: fault.c,v 1.5 2000/01/26 16:20:29 jsm Exp $
|
| 2 |
|
|
*
|
| 3 |
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
| 4 |
|
|
* License. See the file "COPYING" in the main directory of this archive
|
| 5 |
|
|
* for more details.
|
| 6 |
|
|
*
|
| 7 |
|
|
*
|
| 8 |
|
|
* Copyright (C) 1995, 1996, 1997, 1998 by Ralf Baechle
|
| 9 |
|
|
* Copyright 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
|
| 10 |
|
|
* Copyright 1999 Hewlett Packard Co.
|
| 11 |
|
|
*
|
| 12 |
|
|
*/
|
| 13 |
|
|
|
| 14 |
|
|
#include <linux/mm.h>
|
| 15 |
|
|
#include <linux/ptrace.h>
|
| 16 |
|
|
#include <linux/sched.h>
|
| 17 |
|
|
#include <linux/interrupt.h>
|
| 18 |
|
|
#include <linux/module.h>
|
| 19 |
|
|
|
| 20 |
|
|
#include <asm/uaccess.h>
|
| 21 |
|
|
#include <asm/traps.h>
|
| 22 |
|
|
|
| 23 |
|
|
#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
|
| 24 |
|
|
/* dumped to the console via printk) */
|
| 25 |
|
|
|
| 26 |
|
|
|
| 27 |
|
|
/* Various important other fields */
|
| 28 |
|
|
#define bit22set(x) (x & 0x00000200)
|
| 29 |
|
|
#define bits23_25set(x) (x & 0x000001c0)
|
| 30 |
|
|
#define isGraphicsFlushRead(x) ((x & 0xfc003fdf) == 0x04001a80)
|
| 31 |
|
|
/* extended opcode is 0x6a */
|
| 32 |
|
|
|
| 33 |
|
|
#define BITSSET 0x1c0 /* for identifying LDCW */
|
| 34 |
|
|
|
| 35 |
|
|
|
| 36 |
|
|
DEFINE_PER_CPU(struct exception_data, exception_data);
|
| 37 |
|
|
|
| 38 |
|
|
/*
|
| 39 |
|
|
* parisc_acctyp(unsigned int inst) --
|
| 40 |
|
|
* Given a PA-RISC memory access instruction, determine if the
|
| 41 |
|
|
* the instruction would perform a memory read or memory write
|
| 42 |
|
|
* operation.
|
| 43 |
|
|
*
|
| 44 |
|
|
* This function assumes that the given instruction is a memory access
|
| 45 |
|
|
* instruction (i.e. you should really only call it if you know that
|
| 46 |
|
|
* the instruction has generated some sort of a memory access fault).
|
| 47 |
|
|
*
|
| 48 |
|
|
* Returns:
|
| 49 |
|
|
* VM_READ if read operation
|
| 50 |
|
|
* VM_WRITE if write operation
|
| 51 |
|
|
* VM_EXEC if execute operation
|
| 52 |
|
|
*/
|
| 53 |
|
|
static unsigned long
|
| 54 |
|
|
parisc_acctyp(unsigned long code, unsigned int inst)
|
| 55 |
|
|
{
|
| 56 |
|
|
if (code == 6 || code == 16)
|
| 57 |
|
|
return VM_EXEC;
|
| 58 |
|
|
|
| 59 |
|
|
switch (inst & 0xf0000000) {
|
| 60 |
|
|
case 0x40000000: /* load */
|
| 61 |
|
|
case 0x50000000: /* new load */
|
| 62 |
|
|
return VM_READ;
|
| 63 |
|
|
|
| 64 |
|
|
case 0x60000000: /* store */
|
| 65 |
|
|
case 0x70000000: /* new store */
|
| 66 |
|
|
return VM_WRITE;
|
| 67 |
|
|
|
| 68 |
|
|
case 0x20000000: /* coproc */
|
| 69 |
|
|
case 0x30000000: /* coproc2 */
|
| 70 |
|
|
if (bit22set(inst))
|
| 71 |
|
|
return VM_WRITE;
|
| 72 |
|
|
|
| 73 |
|
|
case 0x0: /* indexed/memory management */
|
| 74 |
|
|
if (bit22set(inst)) {
|
| 75 |
|
|
/*
|
| 76 |
|
|
* Check for the 'Graphics Flush Read' instruction.
|
| 77 |
|
|
* It resembles an FDC instruction, except for bits
|
| 78 |
|
|
* 20 and 21. Any combination other than zero will
|
| 79 |
|
|
* utilize the block mover functionality on some
|
| 80 |
|
|
* older PA-RISC platforms. The case where a block
|
| 81 |
|
|
* move is performed from VM to graphics IO space
|
| 82 |
|
|
* should be treated as a READ.
|
| 83 |
|
|
*
|
| 84 |
|
|
* The significance of bits 20,21 in the FDC
|
| 85 |
|
|
* instruction is:
|
| 86 |
|
|
*
|
| 87 |
|
|
* 00 Flush data cache (normal instruction behavior)
|
| 88 |
|
|
* 01 Graphics flush write (IO space -> VM)
|
| 89 |
|
|
* 10 Graphics flush read (VM -> IO space)
|
| 90 |
|
|
* 11 Graphics flush read/write (VM <-> IO space)
|
| 91 |
|
|
*/
|
| 92 |
|
|
if (isGraphicsFlushRead(inst))
|
| 93 |
|
|
return VM_READ;
|
| 94 |
|
|
return VM_WRITE;
|
| 95 |
|
|
} else {
|
| 96 |
|
|
/*
|
| 97 |
|
|
* Check for LDCWX and LDCWS (semaphore instructions).
|
| 98 |
|
|
* If bits 23 through 25 are all 1's it is one of
|
| 99 |
|
|
* the above two instructions and is a write.
|
| 100 |
|
|
*
|
| 101 |
|
|
* Note: With the limited bits we are looking at,
|
| 102 |
|
|
* this will also catch PROBEW and PROBEWI. However,
|
| 103 |
|
|
* these should never get in here because they don't
|
| 104 |
|
|
* generate exceptions of the type:
|
| 105 |
|
|
* Data TLB miss fault/data page fault
|
| 106 |
|
|
* Data memory protection trap
|
| 107 |
|
|
*/
|
| 108 |
|
|
if (bits23_25set(inst) == BITSSET)
|
| 109 |
|
|
return VM_WRITE;
|
| 110 |
|
|
}
|
| 111 |
|
|
return VM_READ; /* Default */
|
| 112 |
|
|
}
|
| 113 |
|
|
return VM_READ; /* Default */
|
| 114 |
|
|
}
|
| 115 |
|
|
|
| 116 |
|
|
#undef bit22set
|
| 117 |
|
|
#undef bits23_25set
|
| 118 |
|
|
#undef isGraphicsFlushRead
|
| 119 |
|
|
#undef BITSSET
|
| 120 |
|
|
|
| 121 |
|
|
|
| 122 |
|
|
#if 0
|
| 123 |
|
|
/* This is the treewalk to find a vma which is the highest that has
|
| 124 |
|
|
* a start < addr. We're using find_vma_prev instead right now, but
|
| 125 |
|
|
* we might want to use this at some point in the future. Probably
|
| 126 |
|
|
* not, but I want it committed to CVS so I don't lose it :-)
|
| 127 |
|
|
*/
|
| 128 |
|
|
while (tree != vm_avl_empty) {
|
| 129 |
|
|
if (tree->vm_start > addr) {
|
| 130 |
|
|
tree = tree->vm_avl_left;
|
| 131 |
|
|
} else {
|
| 132 |
|
|
prev = tree;
|
| 133 |
|
|
if (prev->vm_next == NULL)
|
| 134 |
|
|
break;
|
| 135 |
|
|
if (prev->vm_next->vm_start > addr)
|
| 136 |
|
|
break;
|
| 137 |
|
|
tree = tree->vm_avl_right;
|
| 138 |
|
|
}
|
| 139 |
|
|
}
|
| 140 |
|
|
#endif
|
| 141 |
|
|
|
| 142 |
|
|
void do_page_fault(struct pt_regs *regs, unsigned long code,
|
| 143 |
|
|
unsigned long address)
|
| 144 |
|
|
{
|
| 145 |
|
|
struct vm_area_struct *vma, *prev_vma;
|
| 146 |
|
|
struct task_struct *tsk = current;
|
| 147 |
|
|
struct mm_struct *mm = tsk->mm;
|
| 148 |
|
|
const struct exception_table_entry *fix;
|
| 149 |
|
|
unsigned long acc_type;
|
| 150 |
|
|
int fault;
|
| 151 |
|
|
|
| 152 |
|
|
if (in_atomic() || !mm)
|
| 153 |
|
|
goto no_context;
|
| 154 |
|
|
|
| 155 |
|
|
down_read(&mm->mmap_sem);
|
| 156 |
|
|
vma = find_vma_prev(mm, address, &prev_vma);
|
| 157 |
|
|
if (!vma || address < vma->vm_start)
|
| 158 |
|
|
goto check_expansion;
|
| 159 |
|
|
/*
|
| 160 |
|
|
* Ok, we have a good vm_area for this memory access. We still need to
|
| 161 |
|
|
* check the access permissions.
|
| 162 |
|
|
*/
|
| 163 |
|
|
|
| 164 |
|
|
good_area:
|
| 165 |
|
|
|
| 166 |
|
|
acc_type = parisc_acctyp(code,regs->iir);
|
| 167 |
|
|
|
| 168 |
|
|
if ((vma->vm_flags & acc_type) != acc_type)
|
| 169 |
|
|
goto bad_area;
|
| 170 |
|
|
|
| 171 |
|
|
/*
|
| 172 |
|
|
* If for any reason at all we couldn't handle the fault, make
|
| 173 |
|
|
* sure we exit gracefully rather than endlessly redo the
|
| 174 |
|
|
* fault.
|
| 175 |
|
|
*/
|
| 176 |
|
|
|
| 177 |
|
|
fault = handle_mm_fault(mm, vma, address, (acc_type & VM_WRITE) != 0);
|
| 178 |
|
|
if (unlikely(fault & VM_FAULT_ERROR)) {
|
| 179 |
|
|
/*
|
| 180 |
|
|
* We hit a shared mapping outside of the file, or some
|
| 181 |
|
|
* other thing happened to us that made us unable to
|
| 182 |
|
|
* handle the page fault gracefully.
|
| 183 |
|
|
*/
|
| 184 |
|
|
if (fault & VM_FAULT_OOM)
|
| 185 |
|
|
goto out_of_memory;
|
| 186 |
|
|
else if (fault & VM_FAULT_SIGBUS)
|
| 187 |
|
|
goto bad_area;
|
| 188 |
|
|
BUG();
|
| 189 |
|
|
}
|
| 190 |
|
|
if (fault & VM_FAULT_MAJOR)
|
| 191 |
|
|
current->maj_flt++;
|
| 192 |
|
|
else
|
| 193 |
|
|
current->min_flt++;
|
| 194 |
|
|
up_read(&mm->mmap_sem);
|
| 195 |
|
|
return;
|
| 196 |
|
|
|
| 197 |
|
|
check_expansion:
|
| 198 |
|
|
vma = prev_vma;
|
| 199 |
|
|
if (vma && (expand_stack(vma, address) == 0))
|
| 200 |
|
|
goto good_area;
|
| 201 |
|
|
|
| 202 |
|
|
/*
|
| 203 |
|
|
* Something tried to access memory that isn't in our memory map..
|
| 204 |
|
|
*/
|
| 205 |
|
|
bad_area:
|
| 206 |
|
|
up_read(&mm->mmap_sem);
|
| 207 |
|
|
|
| 208 |
|
|
if (user_mode(regs)) {
|
| 209 |
|
|
struct siginfo si;
|
| 210 |
|
|
|
| 211 |
|
|
#ifdef PRINT_USER_FAULTS
|
| 212 |
|
|
printk(KERN_DEBUG "\n");
|
| 213 |
|
|
printk(KERN_DEBUG "do_page_fault() pid=%d command='%s' type=%lu address=0x%08lx\n",
|
| 214 |
|
|
task_pid_nr(tsk), tsk->comm, code, address);
|
| 215 |
|
|
if (vma) {
|
| 216 |
|
|
printk(KERN_DEBUG "vm_start = 0x%08lx, vm_end = 0x%08lx\n",
|
| 217 |
|
|
vma->vm_start, vma->vm_end);
|
| 218 |
|
|
}
|
| 219 |
|
|
show_regs(regs);
|
| 220 |
|
|
#endif
|
| 221 |
|
|
/* FIXME: actually we need to get the signo and code correct */
|
| 222 |
|
|
si.si_signo = SIGSEGV;
|
| 223 |
|
|
si.si_errno = 0;
|
| 224 |
|
|
si.si_code = SEGV_MAPERR;
|
| 225 |
|
|
si.si_addr = (void __user *) address;
|
| 226 |
|
|
force_sig_info(SIGSEGV, &si, current);
|
| 227 |
|
|
return;
|
| 228 |
|
|
}
|
| 229 |
|
|
|
| 230 |
|
|
no_context:
|
| 231 |
|
|
|
| 232 |
|
|
if (!user_mode(regs)) {
|
| 233 |
|
|
fix = search_exception_tables(regs->iaoq[0]);
|
| 234 |
|
|
|
| 235 |
|
|
if (fix) {
|
| 236 |
|
|
struct exception_data *d;
|
| 237 |
|
|
|
| 238 |
|
|
d = &__get_cpu_var(exception_data);
|
| 239 |
|
|
d->fault_ip = regs->iaoq[0];
|
| 240 |
|
|
d->fault_space = regs->isr;
|
| 241 |
|
|
d->fault_addr = regs->ior;
|
| 242 |
|
|
|
| 243 |
|
|
regs->iaoq[0] = ((fix->fixup) & ~3);
|
| 244 |
|
|
|
| 245 |
|
|
/*
|
| 246 |
|
|
* NOTE: In some cases the faulting instruction
|
| 247 |
|
|
* may be in the delay slot of a branch. We
|
| 248 |
|
|
* don't want to take the branch, so we don't
|
| 249 |
|
|
* increment iaoq[1], instead we set it to be
|
| 250 |
|
|
* iaoq[0]+4, and clear the B bit in the PSW
|
| 251 |
|
|
*/
|
| 252 |
|
|
|
| 253 |
|
|
regs->iaoq[1] = regs->iaoq[0] + 4;
|
| 254 |
|
|
regs->gr[0] &= ~PSW_B; /* IPSW in gr[0] */
|
| 255 |
|
|
|
| 256 |
|
|
return;
|
| 257 |
|
|
}
|
| 258 |
|
|
}
|
| 259 |
|
|
|
| 260 |
|
|
parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);
|
| 261 |
|
|
|
| 262 |
|
|
out_of_memory:
|
| 263 |
|
|
up_read(&mm->mmap_sem);
|
| 264 |
|
|
printk(KERN_CRIT "VM: killing process %s\n", current->comm);
|
| 265 |
|
|
if (user_mode(regs))
|
| 266 |
|
|
do_group_exit(SIGKILL);
|
| 267 |
|
|
goto no_context;
|
| 268 |
|
|
}
|
